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1.
Pan Afr Med J ; 48: 10, 2024.
Article in English | MEDLINE | ID: mdl-38946743

ABSTRACT

Introduction: the utility of glycated haemoglobin (HbA1c) for the diagnosis and monitoring of diabetes in sub-Saharan Africa is uncertain due to limited data on the performance of the available HbA1c assay methods in this population, which has a high prevalence of haemoglobin variants. We aimed to compare the diagnostic accuracy of the major HbA1c methodologies (Boronate Affinity, Capillary Electrophoresis, High Performance Liquid Chromatography, Immunoassay) in an African population, and assess the impact of the common haemoglobin variant HbAS (sickle cell trait). Methods: whole blood samples were obtained from 182 individuals living with type 2 diabetes in Uganda. HbA1c values for each method were compared to average glucose measured over 14 days by continuous glucose monitoring (CGM). To determine concordance, the three HbA1c assay methods were compared to the capillary electrophoresis method. Results: there was a strong correlation between CGM average glucose levels and all four HbA1c methodologies (r=0.81-0.89) which did not differ in those with and without HbAS (present in 37/182 participants). The presence of HbAS did not alter the relationship between HbA1c and CGM glucose for any assay (p for interaction >0.2 for all methods). Diagnostic accuracy for CGM average glucose thresholds of 7 and 10mmol/L was similar across methods (area under the receiver operating characteristic curve 0.80-0.84 and 0.76-0.84 respectively). The maximum bias between the HbA1c assay methodologies was 2 mmol/mol (2.07%). Conclusion: all major HbA1c technologies offer accurate and comparable HbA1c measurement even in this population with high prevalence of haemoglobin variants.


Subject(s)
Blood Glucose , Diabetes Mellitus, Type 2 , Electrophoresis, Capillary , Glycated Hemoglobin , Sensitivity and Specificity , Humans , Glycated Hemoglobin/analysis , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/blood , Electrophoresis, Capillary/methods , Female , Blood Glucose/analysis , Male , Middle Aged , Chromatography, High Pressure Liquid/methods , Uganda , Adult , Immunoassay/methods , Immunoassay/standards , Blood Glucose Self-Monitoring/methods , Aged , Hemoglobins, Abnormal/analysis
2.
PLOS Glob Public Health ; 3(9): e0001263, 2023.
Article in English | MEDLINE | ID: mdl-37756263

ABSTRACT

Sub-Saharan Africa is projected to have the highest increase in the number of people with diabetes worldwide. However, the drivers of diabetes in this region have not been clearly elucidated. The aim of this study was to evaluate the incidence of diabetes and the predictors of progression in a population-based cohort with impaired fasting glucose (IFG) in Malawi. We used data from an extensive rural and urban non-communicable disease survey. One hundred seventy-five, of 389 individuals with impaired fasting glucose (IFG) at baseline, age 48 ±15 years and body mass index 27.5 ±5.9 kg/m2 were followed up for a median of 4.2 years (714 person-years). Incidence rates were calculated, and predictors of progression to diabetes were analysed using multivariable logistic regression models, with overall performance determined using receiver operator characteristics (ROC) curves. The median follow-up was 4.2 (IQR 3.4-4.7) years. Forty-five out of 175 (26%) progressed to diabetes. Incidence rates of diabetes were 62.9 per 1000 person-years 95% CI, 47.0-84.3. The predictors of progression were higher; age (odds ratio [OR] 1.48, P = 0.046), BMI (OR 1.98, P = 0.001), waist circumference (OR 2.50,P<0.001), waist-hip ratio (OR 1.40, P = 0.03), systolic blood pressure (OR 1.56, P = 0.01), fasting plasma glucose (OR 1.53, P = 0.01), cholesterol (OR 1.44, P = 0.05) and low-density lipoprotein cholesterol (OR 1.80, P = 0.002). A simple model combining fasting plasma glucose and waist circumference was predictive of progression to diabetes (ROC area under the curve = 0.79). The incidence of diabetes in people with IFG is high in Malawi and predictors of progression are like those seen in other populations. Our data also suggests that a simple chart with probabilities of progression to diabetes based on waist circumference and fasting plasma glucose could be used to identify those at risk of progression in clinical settings in sub-Saharan Africa.

3.
PLoS One ; 17(10): e0275642, 2022.
Article in English | MEDLINE | ID: mdl-36227889

ABSTRACT

BACKGROUND: The 23-valent pneumococcal polysaccharide vaccine (PPV23) is recommended for UK older adults, but how age moderates effectiveness is unclear. METHODS: Three annual cohorts of primary-care patients aged≥65y from the Clinical Practice Research Datalink selected from 2003-5 created a natural experiment (n = 324,804), reflecting the staged introduction of the vaccine. The outcome was symptoms consistent with community-acquired pneumococcal pneumonia (CAP) requiring antibiotics or hospitalisation. We used the prior event rate ratio (PERR) approach to address bias from unmeasured confounders. RESULTS: Vaccinated patients had higher rates of CAP in the year before vaccination than their controls, indicating the potential for confounding bias. After adjustment for confounding using the prior event rate ratio (PERR) method, PPV23 was estimated to be effective against CAP for two years after vaccination in all age sub-groups with hazard ratios (95% confidence intervals) of 0.86 (0.80 to 0.93), 0.74 (0.65 to 0.85) and 0.65 (0.57 to 0.74) in patients aged 65-74, 75-79 and 80+ respectively in the 2005 cohort. Age moderated the effect of vaccination with predicted risk reductions of 8% at 65y and 29% at 80y. CONCLUSIONS: PPV23 is moderately effective at reducing CAP among UK patients aged≥65y, in the two years after vaccination. Vaccine effectiveness is maintained, and may increase, in the oldest age groups in step with increasing susceptibility to CAP.


Subject(s)
Community-Acquired Infections , Pneumococcal Infections , Pneumonia, Pneumococcal , Pneumonia , Aged , Anti-Bacterial Agents , Cohort Studies , Community-Acquired Infections/prevention & control , Humans , Pneumococcal Infections/prevention & control , Pneumococcal Vaccines/therapeutic use , Pneumonia, Pneumococcal/prevention & control , Streptococcus pneumoniae , United Kingdom/epidemiology , Vaccination/methods
4.
J Clin Epidemiol ; 151: 122-131, 2022 11.
Article in English | MEDLINE | ID: mdl-35817230

ABSTRACT

OBJECTIVES: We aimed to estimate the real-world effectiveness of the influenza vaccine against myocardial infarction (MI) and influenza in the decade since adults aged ≥ 65 years were first recommended the vaccine. STUDY DESIGN AND SETTING: We identified annual cohorts, 1997 to 2011, of adults aged ≥ 65 years, without previous influenza vaccination, from UK general practices, registered with the Clinical Practice Research Datalink. Using a quasi-experimental study design to control for confounding bias, we estimated influenza vaccine effectiveness on hospitalization for MI, influenza, and antibiotic prescriptions for lower respiratory tract infections. RESULTS: Vaccination was moderately effective against influenza, the prior event rate ratio-adjusted hazard ratios ranging from 0.70 in 1999 to 0.99 in 2001. Prior event rate ratio-adjusted hazard ratios demonstrated a protective effect against MIs, varying between 0.40 in 2010 and 0.89 in 2001. Aggregated across the cohorts, influenza vaccination reduced the risk of MIs by 39% (95% confidence interval: 34%, 44%). CONCLUSION: Effectiveness of the flu vaccine in preventing MIs in older UK adults is consistent with the limited evidence from clinical trials. Similar trends in effectiveness against influenza and against MIs suggest the risk of influenza mediates the effectiveness against MIs, although divergence in some years implies the mechanism may be complex.


Subject(s)
Influenza Vaccines , Influenza, Human , Myocardial Infarction , Humans , Aged , Influenza, Human/epidemiology , Influenza, Human/prevention & control , Influenza, Human/drug therapy , Influenza Vaccines/therapeutic use , Vaccination , Hospitalization , Myocardial Infarction/epidemiology , Myocardial Infarction/prevention & control , United Kingdom/epidemiology , Seasons
5.
Article in English | MEDLINE | ID: mdl-35450869

ABSTRACT

INTRODUCTION: People living with diabetes in low-resource settings may be at increased hypoglycemia risk due to food insecurity and limited access to glucose monitoring. We aimed to assess hypoglycemia risk associated with sulphonylurea (SU) and insulin therapy in people living with type 2 diabetes in a low-resource sub-Saharan African setting. RESEARCH DESIGN AND METHODS: This study was conducted in the outpatients' diabetes clinics of two hospitals (one rural and one urban) in Uganda. We used blinded continuous glucose monitoring (CGM) and self-report to compare hypoglycemia rates and duration in 179 type 2 diabetes patients treated with sulphonylureas (n=100) and insulin (n=51) in comparison with those treated with metformin only (n=28). CGM-assessed hypoglycemia was defined as minutes per week below 3mmol/L (54mg/dL) and number of hypoglycemic events below 3.0 mmol/L (54 mg/dL) for at least 15 minutes. RESULTS: CGM recorded hypoglycemia was infrequent in SU-treated participants and did not differ from metformin: median minutes/week of glucose <3 mmol/L were 39.2, 17.0 and 127.5 for metformin, sulphonylurea and insulin, respectively (metformin vs sulphonylurea, p=0.6). Hypoglycemia risk was strongly related to glycated haemoglobin (HbA1c) and fasting glucose, with most episodes occurring in those with tight glycemic control. After adjusting for HbA1c, time <3 mmol/L was 2.1 (95% CI 0.9 to 4.7) and 5.5 (95% CI 2.4 to 12.6) times greater with sulphonylurea and insulin, respectively, than metformin alone. CONCLUSIONS: In a low-resource sub-Saharan African setting, hypoglycemia is infrequent among people with type 2 diabetes receiving sulphonylurea treatment, and the modest excess occurs predominantly in those with tight glycemic control.


Subject(s)
Diabetes Mellitus, Type 2 , Hypoglycemia , Metformin , Blood Glucose , Blood Glucose Self-Monitoring/methods , Diabetes Mellitus, Type 2/drug therapy , Glycated Hemoglobin/analysis , Humans , Hypoglycemia/chemically induced , Hypoglycemia/epidemiology , Insulin/adverse effects , Insulin, Regular, Human , Metformin/adverse effects , Sulfonylurea Compounds/adverse effects
6.
Sci Total Environ ; 821: 153375, 2022 May 15.
Article in English | MEDLINE | ID: mdl-35093377

ABSTRACT

There is concern about the buildup of plastic waste in soil, their degradation into microplastics, and their potential to interfere with the natural processing of soil organic carbon and other nutrient cycling processes. Here we used scanning electron microscopy (SEM) and 13C isotope ratio mass spectrometry to determine if precut consumer plastics comprised of either high density polyethylene (HDPE), a blend of linear low density polyethylene and low density polyethylene (L/LDPE), or polyethylene terephthalate (PETE) would degrade or transform during a short-term, 32 day, exposure to soil or sludge in laboratory microcosms. SEM confirmed morphological changes occurred to all plastics, but the attachment of biofilm and presence of microorganisms mostly favored PETE and HDPE surfaces. These observations support the idea that abiotic and/or biotic processes may degrade plastics in soil; however distinguishable and significant changes in mean stable isotopic values (Δδ13C) of ~0.2-0.7‰ were only observed for exposed PETE and HDPE. This indicates that each plastic's degradation in soil may be dependent on their physical and chemical properties, with L/LDPE being more resistant and less prone to degradation compared to the others, and less dependent on the environmental conditions or properties of the soil or sludge. Our experiments were short-term and while the mechanisms of degradation are not clear, the results provide strong motivation for further studies of plastic fate and processing in soil systems. Direct mechanistic studies using stable isotopic approaches in combination with other characterizations and techniques are clearly warranted and may lead to a significant enhancement in our present understanding of the interactions and dynamics of plastics in the soil environment.


Subject(s)
Plastics , Soil , Carbon , Isotopes , Polyethylene , Sewage
7.
Article in English | MEDLINE | ID: mdl-34535465

ABSTRACT

INTRODUCTION: The utility of HbA1c (glycosylated hemoglobin) to estimate glycemic control in populations of African and other low-resource countries has been questioned because of high prevalence of other medical conditions that may affect its reliability. Using continuous glucose monitoring (CGM), we aimed to determine the comparative performance of HbA1c, fasting plasma glucose (FPG) (within 5 hours of a meal) and random non-fasting glucose (RPG) in assessing glycemic burden. RESEARCH DESIGN AND METHODS: We assessed the performance of HbA1c, FPG and RPG in comparison to CGM mean glucose in 192 Ugandan participants with type 2 diabetes. Analysis was undertaken in all participants, and in subgroups with and without medical conditions reported to affect HbA1c reliability. We then assessed the performance of FPG and RPG, and optimal thresholds, in comparison to HbA1c in participants without medical conditions thought to alter HbA1c reliability. RESULTS: 32.8% (63/192) of participants had medical conditions that may affect HbA1c reliability: anemia 9.4% (18/192), sickle cell trait and/or hemoglobin C (HbC) 22.4% (43/192), or renal impairment 6.3% (12/192). Despite high prevalence of medical conditions thought to affect HbA1c reliability, HbA1c had the strongest correlation with CGM measured glucose in day-to-day living (0.88, 95% CI 0.84 to 0.91), followed by FPG (0.82, 95% CI 0.76 to 0.86) and RPG (0.76, 95% CI 0.69 to 0.81). Among participants without conditions thought to affect HbA1c reliability, FPG and RPG had a similar diagnostic performance in identifying poor glycemic control defined by a range of HbA1c thresholds. FPG of ≥7.1 mmol/L and RPG of ≥10.5 mmol/L correctly identified 78.2% and 78.8%, respectively, of patients with an HbA1c of ≥7.0%. CONCLUSIONS: HbA1c is the optimal test for monitoring glucose control even in low-income and middle-income countries where medical conditions that may alter its reliability are prevalent; FPG and RPG are valuable alternatives where HbA1c is not available.


Subject(s)
Blood Glucose , Diabetes Mellitus, Type 2 , Blood Glucose Self-Monitoring , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/epidemiology , Glycated Hemoglobin/analysis , Humans , Prevalence , Reproducibility of Results
8.
BMC Med ; 19(1): 184, 2021 08 20.
Article in English | MEDLINE | ID: mdl-34412655

ABSTRACT

BACKGROUND: Type 2 diabetes (T2D) is common and increasing in prevalence. It is possible to prevent or delay T2D using lifestyle intervention programmes. Entry to these programmes is usually determined by a measure of glycaemia in the 'intermediate' range. This paper investigated the relationship between HbA1c and future diabetes risk and determined the impact of varying thresholds to identify those at high risk of developing T2D. METHODS: We studied 4227 participants without diabetes aged ≥ 40 years recruited to the Exeter 10,000 population cohort in South West England. HbA1c was measured at study recruitment with repeat HbA1c available as part of usual care. Absolute risk of developing diabetes within 5 years, defined by HbA1c ≥ 48 mmol/mol (6.5%), according to baseline HbA1c, was assessed by a flexible parametric survival model. RESULTS: The overall absolute 5-year risk (95% CI) of developing T2D in the cohort was 4.2% (3.6, 4.8%). This rose to 7.1% (6.1, 8.2%) in the 56% (n = 2358/4224) of participants classified 'high-risk' with HbA1c ≥ 39 mmol/mol (5.7%; ADA criteria). Under IEC criteria, HbA1c ≥ 42 mmol/mol (6.0%), 22% (n = 929/4277) of the cohort was classified high-risk with 5-year risk 14.9% (12.6, 17.2%). Those with the highest HbA1c values (44-47 mmol/mol [6.2-6.4%]) had much higher 5-year risk, 26.4% (22.0, 30.5%) compared with 2.1% (1.5, 2.6%) for 39-41 mmol/mol (5.7-5.9%) and 7.0% (5.4, 8.6%) for 42-43 mmol/mol (6.0-6.1%). Changing the entry criterion to prevention programmes from 39 to 42 mmol/mol (5.7-6.0%) reduced the proportion classified high-risk by 61%, and increased the positive predictive value (PPV) from 5.8 to 12.4% with negligible impact on the negative predictive value (NPV), 99.6% to 99.1%. Increasing the threshold further, to 44 mmol/mol (6.2%), reduced those classified high-risk by 59%, and markedly increased the PPV from 12.4 to 23.2% and had little impact on the NPV (99.1% to 98.5%). CONCLUSIONS: A large proportion of people are identified as high-risk using current thresholds. Increasing the risk threshold markedly reduces the number of people that would be classified as high-risk and entered into prevention programmes, although this must be balanced against cases missed. Raising the entry threshold would allow limited intervention opportunities to be focused on those most likely to develop T2D.


Subject(s)
Diabetes Mellitus, Type 2 , Blood Glucose , Cohort Studies , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/prevention & control , England/epidemiology , Glycated Hemoglobin , Humans
9.
BMJ Glob Health ; 6(5)2021 05.
Article in English | MEDLINE | ID: mdl-34016577

ABSTRACT

INTRODUCTION: Low high-density lipoprotein (HDL) is widely used as a marker of cardiovascular disease risk, although this relationship is not causal and is likely mediated through associations with other risk factors. Low HDL is extremely common in sub-Saharan African populations, and this has often been interpreted to indicate that these populations will have increased cardiovascular risk. We aimed to determine whether the association between HDL and other cardiovascular risk factors differed between populations in sub-Saharan Africa and the UK. METHODS: We compared data from adults living in Uganda and Malawi (n=26 216) and in the UK (n=8747). We examined unadjusted and adjusted levels of HDL and applied the WHO recommended cut-offs for prevalence estimates. We used spline and linear regression to assess the relationship between HDL and other cardiovascular risk factors. RESULTS: HDL was substantially lower in the African than in the European studies (geometric mean 0.9-1.2 mmol/L vs 1.3-1.8 mmol/L), with African prevalence of low HDL as high as 77%. Total cholesterol was also substantially lower (geometric mean 3.3-3.9 mmol/L vs 4.6-5.4 mmol/L). In comparison with European studies the relationship between HDL and adiposity (body mass index, waist to hip ratio) was greatly attenuated in African studies and the relationship with non-HDL cholesterol reversed: in African studies low HDL was associated with lower non-HDL cholesterol. The association between sex and HDL was also different; using the WHO sex-specific definitions, low HDL was substantially more common among women (69%-77%) than men (41%-59%) in Uganda/Malawi. CONCLUSION: The relationship between HDL and sex, adiposity and non-HDL cholesterol in sub-Saharan Africa is different from European populations. In sub-Saharan Africans low HDL is a marker of low overall cholesterol and sex differences are markedly attenuated. Therefore low HDL in isolation is unlikely to indicate raised cardiovascular risk and the WHO sex-based cut-offs are inappropriate.


Subject(s)
Cardiovascular Diseases , Heart Disease Risk Factors , Lipoproteins, HDL/blood , Sex Factors , Adult , Africa South of the Sahara/epidemiology , Cardiovascular Diseases/epidemiology , Cholesterol, HDL , Female , Humans , Lipoproteins, LDL , Male , Risk Factors , United Kingdom
10.
Article in English | MEDLINE | ID: mdl-33922547

ABSTRACT

Information received by women regarding physical activity during and after pregnancy often lacks clarity and may be conflicting and confusing. Without clear, engaging, accessible guidance centred on the experiences of pregnancy and parenting, the benefits of physical activity can be lost. We describe a collaborative process to inform the design of evidence-based, user-centred physical activity resources which reflect diverse experiences of pregnancy and early parenthood. Two iterative, collaborative phases involving patient and public involvement (PPI) workshops, a scoping survey (n = 553) and stakeholder events engaged women and maternity, policy and physical activity stakeholders to inform pilot resource development. These activities shaped understanding of challenges experienced by maternity and physical activity service providers, pregnant women and new mothers in relation to supporting physical activity. Working collaboratively with women and stakeholders, we co-designed pilot resources and identified important considerations for future resource development. Outcomes and lessons learned from this process will inform further work to support physical activity during pregnancy and beyond, but also wider health research where such collaborative approaches are important. We hope that drawing on our experiences and sharing outcomes from this work provide useful information for researchers, healthcare professionals, policy makers and those involved in supporting physical activity behaviour.


Subject(s)
Exercise , Patient Participation , Female , Health Personnel , Humans , Mothers , Pregnancy , Pregnant Women
11.
PLoS One ; 16(1): e0246156, 2021.
Article in English | MEDLINE | ID: mdl-33513169

ABSTRACT

BACKGROUND: Bacterial infections of the upper and lower respiratory tract are a frequent complication of influenza and contribute to the widespread use of antibiotics. Influenza vaccination may help reduce both appropriate and inappropriate prescribing of antibiotics. Electronic health records provide a rich source of information for assessing secondary effects of influenza vaccination. METHODS: We conducted a retrospective study to estimate effects of influenza vaccine on antibiotic (amoxicillin) prescription in the elderly based on data from the Clinical Practice Research Datalink. The introduction of UK policy to recommend the influenza vaccine to older adults in 2000 led to a substantial increase in uptake, creating a natural experiment. Of 259,753 eligible patients that were unvaccinated in 1999 and aged≥65y by January 2000, 88,519 patients received influenza vaccination in 2000. These were propensity score matched 1:1 to unvaccinated patients. Time-to-amoxicillin was analysed using the Prior Event Rate Ratio (PERR) Pairwise method to address bias from time-invariant measured and unmeasured confounders. A simulation study and negative control outcome were used to help strengthen the validity of results. RESULTS: Compared to unvaccinated patients, those from the vaccinated group were more likely to be prescribed amoxicillin in the year prior to vaccination: hazard ratio (HR) 1.90 (95% confidence interval 1.83, 1.98). Following vaccination, the vaccinated group were again more likely to be prescribed amoxicillin, HR 1.64 (1.58,1.71). After adjusting for prior differences between the two groups using PERR Pairwise, overall vaccine effectiveness was 0.86 (0.81, 0.92). Additional analyses suggested that provided data meet the PERR assumptions, these estimates were robust. CONCLUSIONS: Once differences between groups were taken into account, influenza vaccine had a beneficial effect, lowering the frequency of amoxicillin prescribing in the vaccinated group. Ensuring successful implementation of national programmes of vaccinating older adults against influenza may help contribute to reducing antibiotic resistance.


Subject(s)
Amoxicillin/administration & dosage , Bacterial Infections , Drug Prescriptions , Influenza Vaccines/administration & dosage , Influenza, Human , Primary Health Care , Vaccination , Aged , Aged, 80 and over , Bacterial Infections/epidemiology , Bacterial Infections/prevention & control , Female , Humans , Influenza, Human/epidemiology , Influenza, Human/prevention & control , Male , Retrospective Studies , United Kingdom/epidemiology
12.
J Clin Epidemiol ; 122: 78-86, 2020 06.
Article in English | MEDLINE | ID: mdl-32194148

ABSTRACT

OBJECTIVES: Electronic health records (EHR) provide a valuable resource for assessing drug side-effects, but treatments are not randomly allocated in routine care creating the potential for bias. We conduct a case study using the Prior Event Rate Ratio (PERR) Pairwise method to reduce unmeasured confounding bias in side-effect estimates for two second-line therapies for type 2 diabetes, thiazolidinediones, and sulfonylureas. STUDY DESIGN AND SETTINGS: Primary care data were extracted from the Clinical Practice Research Datalink (n = 41,871). We utilized outcomes from the period when patients took first-line metformin to adjust for unmeasured confounding. Estimates for known side-effects and a negative control outcome were compared with the A Diabetes Outcome Progression Trial (ADOPT) trial (n = 2,545). RESULTS: When on metformin, patients later prescribed thiazolidinediones had greater risks of edema, HR 95% CI 1.38 (1.13, 1.68) and gastrointestinal side-effects (GI) 1.47 (1.28, 1.68), suggesting the presence of unmeasured confounding. Conventional Cox regression overestimated the risk of edema on thiazolidinediones and identified a false association with GI. The PERR Pairwise estimates were consistent with ADOPT: 1.43 (1.10, 1.83) vs. 1.39 (1.04, 1.86), respectively, for edema, and 0.91 (0.79, 1.05) vs. 0.94 (0.80, 1.10) for GI. CONCLUSION: The PERR Pairwise approach offers potential for enhancing postmarketing surveillance of side-effects from EHRs but requires careful consideration of assumptions.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/therapeutic use , Metformin/therapeutic use , Randomized Controlled Trials as Topic/statistics & numerical data , Research Design/statistics & numerical data , Sulfonylurea Compounds/therapeutic use , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Treatment Outcome
13.
Small ; 14(44): e1802563, 2018 11.
Article in English | MEDLINE | ID: mdl-30286280

ABSTRACT

Drug delivery to a specific site in the body typically relies on the use of targeting agents that recognize a unique biomarker. Unfortunately, it is often difficult to identify unique molecular signatures that exist only at the site of interest. An alternative strategy is to deliver energy (e.g., light) to locally trigger release from a drug carrier; however, the use of this approach is limited because energy delivery to deep tissues is often impractical or invasive. In this work, radiofrequency-responsive superparamagnetic iron oxide nanoparticles (SPIONs) are used to trigger drug release from nanoscale vesicles. Because the body is inherently nonmagnetic, this approach allows for deep tissue targeting. To overcome the unfavorable meter-scale diffraction limit of SPION-compatible radiofrequency (RF) fields, a strong static gating field containing a sharp zero point is superimposed on the RF field. Only drug carriers that are at or near the zero point are susceptible to RF-triggered drug release, thereby localizing drug delivery with millimeter-scale resolution. This approach induces >40% drug release from thermally responsive doxorubicin-loaded liposomes within a 3.2 mm radius of the zero point with <10% release in the surrounding area, leading to a >2.5 therapeutic index in Huh 7 hepatocellular carcinoma cells.


Subject(s)
Drug Carriers/chemistry , Drug Delivery Systems/methods , Nanoparticles/chemistry , Doxorubicin/analogs & derivatives , Doxorubicin/chemistry , Drug Liberation , Ferric Compounds/chemistry , Polyethylene Glycols/chemistry
14.
Diabetes Care ; 41(9): 1844-1853, 2018 09.
Article in English | MEDLINE | ID: mdl-30072404

ABSTRACT

OBJECTIVE: The choice of therapy for type 2 diabetes after metformin is guided by overall estimates of glycemic response and side effects seen in large cohorts. A stratified approach to therapy would aim to improve on this by identifying subgroups of patients whose glycemic response or risk of side effects differs markedly. We assessed whether simple clinical characteristics could identify patients with differing glycemic response and side effects with sulfonylureas and thiazolidinediones. RESEARCH DESIGN AND METHODS: We studied 22,379 patients starting sulfonylurea or thiazolidinedione therapy in the U.K. Clinical Practice Research Datalink (CPRD) to identify features associated with increased 1-year HbA1c fall with one therapy class and reduced fall with the second. We then assessed whether prespecified patient subgroups defined by the differential clinical factors showed differing 5-year glycemic response and side effects with sulfonylureas and thiazolidinediones using individual randomized trial data from ADOPT (A Diabetes Outcome Progression Trial) (first-line therapy, n = 2,725) and RECORD (Rosiglitazone Evaluated for Cardiovascular Outcomes and Regulation of Glycemia in Diabetes) (second-line therapy, n = 2,222). Further replication was conducted using routine clinical data from GoDARTS (Genetics of Diabetes Audit and Research in Tayside Scotland) (n = 1,977). RESULTS: In CPRD, male sex and lower BMI were associated with greater glycemic response with sulfonylureas and a lesser response with thiazolidinediones (both P < 0.001). In ADOPT and RECORD, nonobese males had a greater overall HbA1c reduction with sulfonylureas than with thiazolidinediones (P < 0.001); in contrast, obese females had a greater HbA1c reduction with thiazolidinediones than with sulfonylureas (P < 0.001). Weight gain and edema risk with thiazolidinediones were greatest in obese females; however, hypoglycemia risk with sulfonylureas was similar across all subgroups. CONCLUSIONS: Patient subgroups defined by sex and BMI have different patterns of benefits and risks on thiazolidinedione and sulfonylurea therapy. Subgroup-specific estimates can inform discussion about the choice of therapy after metformin for an individual patient. Our approach using routine and shared trial data provides a framework for future stratification research in type 2 diabetes.


Subject(s)
Body Mass Index , Datasets as Topic , Diabetes Mellitus, Type 2/drug therapy , Sulfonylurea Compounds/therapeutic use , Thiazolidinediones/therapeutic use , Adult , Aged , Aged, 80 and over , Blood Glucose/drug effects , Blood Glucose/metabolism , Cost-Benefit Analysis , Datasets as Topic/statistics & numerical data , Diabetes Mellitus, Type 2/economics , Diabetes Mellitus, Type 2/epidemiology , Female , Humans , Hypoglycemia/chemically induced , Hypoglycemia/economics , Hypoglycemia/epidemiology , Hypoglycemic Agents/economics , Hypoglycemic Agents/therapeutic use , Male , Metformin/economics , Metformin/therapeutic use , Middle Aged , Primary Health Care/statistics & numerical data , Randomized Controlled Trials as Topic/statistics & numerical data , Risk Assessment , Sex Factors , Sulfonylurea Compounds/economics , Thiazolidinediones/economics , United Kingdom/epidemiology
15.
Diabetes Care ; 41(4): 705-712, 2018 04.
Article in English | MEDLINE | ID: mdl-29386249

ABSTRACT

OBJECTIVE: A precision approach to type 2 diabetes therapy would aim to target treatment according to patient characteristics. We examined if measures of insulin resistance and secretion were associated with glycemic response to dipeptidyl peptidase 4 (DPP-4) inhibitor therapy. RESEARCH DESIGN AND METHODS: We evaluated whether markers of insulin resistance and insulin secretion were associated with 6-month glycemic response in a prospective study of noninsulin-treated participants starting DPP-4 inhibitor therapy (Predicting Response to Incretin Based Agents [PRIBA] study; n = 254), with replication for routinely available markers in U.K. electronic health care records (Clinical Practice Research Datalink [CPRD]; n = 23,001). In CPRD, we evaluated associations between baseline markers and 3-year durability of response. To test the specificity of findings, we repeated analyses for glucagon-like peptide 1 (GLP-1) receptor agonists (PRIBA, n = 339; CPRD, n = 4,464). RESULTS: In PRIBA, markers of higher insulin resistance (higher fasting C-peptide [P = 0.03], HOMA2 insulin resistance [P = 0.01], and triglycerides [P < 0.01]) were associated with reduced 6-month HbA1c response to DPP-4 inhibitors. In CPRD, higher triglycerides and BMI were associated with reduced HbA1c response (both P < 0.01). A subgroup defined by obesity (BMI ≥30 kg/m2) and high triglycerides (≥2.3 mmol/L) had reduced 6-month response in both data sets (PRIBA HbA1c reduction 5.3 [95% CI 1.8, 8.6] mmol/mol [0.5%] [obese and high triglycerides] vs. 11.3 [8.4, 14.1] mmol/mol [1.0%] [nonobese and normal triglycerides]; P = 0.01). In CPRD, the obese, high- triglycerides subgroup also had less durable response (hazard ratio 1.28 [1.16, 1.41]; P < 0.001). There was no association between markers of insulin resistance and response to GLP-1 receptor agonists. CONCLUSIONS: Markers of higher insulin resistance are consistently associated with reduced glycemic response to DPP-4 inhibitors. This finding provides a starting point for the application of a precision diabetes approach to DPP-4 inhibitor therapy.


Subject(s)
Biomarkers , Blood Glucose/drug effects , Diabetes Mellitus, Type 2/diagnosis , Diabetes Mellitus, Type 2/drug therapy , Dipeptidyl-Peptidase IV Inhibitors/therapeutic use , Insulin Resistance , Precision Medicine/methods , Aged , Biomarkers/metabolism , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/metabolism , Female , Humans , Hypoglycemic Agents/therapeutic use , Male , Middle Aged , Predictive Value of Tests , Primary Health Care , Prognosis , Retrospective Studies , Treatment Outcome , United Kingdom
16.
Am J Emerg Med ; 36(5): 739-740, 2018 May.
Article in English | MEDLINE | ID: mdl-29079377

ABSTRACT

BACKGROUND: Poiseuille's law states flow rates are directly proportional to the radius to the 4th power and indirectly proportional to the length of a tube. Because of this property, large bore catheters are commonly used in the resuscitation of the critically ill patient. However, there are no studies comparing simultaneous use of all three lumens of a triple lumen (TL) central venous catheter (CVC) with other catheter types. Our objective was to compare the flow rates of normal saline (NS) through various resuscitation catheters against a TL CVC using all 3 ports. METHODS: We performed a blinded prospective observational study of flow rates utilizing multiple resuscitation catheters. Each catheter type was attached to a 1l bag of NS using standard saline tubing and mean time to infuse 1l of normal saline was determined. Three trials each were completed with and without pressure bags. RESULTS: Simultaneous infusion of NS through all ports of a TL CVC demonstrated no statistically significant difference compared to the following catheters: 16ga peripheral venous catheter (PVC) and 6 Fr CVC with pressure bag. The 14 g PVC and 8.5Fr CVC had statistically significant faster flow rates than the TL CVC both with and without a pressure bag. The 6Fr CVC showed significantly faster flow rates than the TL CVC without a pressure bag. CONCLUSIONS: Simultaneous use of all 3 ports of a TL CVC generates flow rates comparable to many other commonly used resuscitation catheters.


Subject(s)
Catheterization, Central Venous/instrumentation , Catheters, Indwelling , Central Venous Catheters , Resuscitation/standards , Critical Illness , Equipment Design , Humans , Infusion Pumps , Materials Testing , Prospective Studies , Single-Blind Method
17.
Clin Child Psychol Psychiatry ; 23(1): 25-41, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28135832

ABSTRACT

There is a growing focus on child wellbeing and happiness in schools, but we lack self-report measures for very young children. Three samples ( N = 2345) were combined to assess the psychometric properties of the How I Feel About My School (HIFAMS) questionnaire, which was designed for children aged 4-8 years. Test-retest reliability was moderate (intraclass correlation coefficient = .62). HIFAMS assessed a single concept and had moderate internal consistency (Cronbach's alpha values from .62 to .67). There were low correlations between scores on the child-reported HIFAMS and parent and teacher reports. Children at risk of exclusion had significantly lower HIFAMS scores than the community sample (mean difference = 2.4; 95% confidence interval (CI) = [1.6, 3.2]; p < .001). Schools contributed only 4.5% of the variability in HIFAMS score, the remaining 95.5% reflecting pupil differences within schools. Girls' scores were 0.37 units (95% CI = [0.16, 0.57]; p < .001) higher than boys, while year group and deprivation did not predict HIFAMS score. HIFAMS is a promising measure that demonstrates moderate reliability and discriminates between groups even among very young children.


Subject(s)
Child Welfare , Emotions , Quality of Life/psychology , Schools , Students/psychology , Child , Child, Preschool , Female , Happiness , Humans , Male , Psychometrics , Reproducibility of Results , Surveys and Questionnaires
18.
BMJ Open ; 7(10): e017989, 2017 Oct 12.
Article in English | MEDLINE | ID: mdl-29025846

ABSTRACT

PURPOSE: This is a retrospective cohort study using observational data from anonymised primary care records. We identify and extract all patients with type 2 diabetes and associated clinical data from the Clinical Practice Research Datalink (CPRD) to inform models of disease progression and stratification of treatment. PARTICIPANTS: Data were extracted from CPRD on 8 August 2016. The initial data set contained all patients (n=313 485) in the database who had received a type 2 diabetes medication. Criteria were applied to identify and exclude those with type 1 diabetes, polycystic ovarian syndrome or other forms of diabetes (n=40 204), and for data quality control (n=12). We identified 251 338 patients for inclusion in future analyses of diabetes progression and treatment response. FINDINGS TO DATE: For 6-month response to treatment, measured by change in glycated haemoglobin (HbA1c), we have 91 765 patients with 119 785 treatment response episodes. The greatest impact on reduction of HbA1c occurs with first-line and second-line treatments, metformin and sulfonylurea. Patients moving to third-line treatments tend to have greater weights and higher body mass index. We have investigated the impact of non-adherence to commonly used glucose-lowering medications on HbA1c. For baseline-adjusted HbA1c change over 1 year, non-adherent patients had lower HbA1c reductions than adherent patients, with mean and 95% CI of -4.4 (-4.7 to -4.0) mmol/mol (-0.40 (-0.43 to -0.37) %). FUTURE PLANS: Findings from studies using these data will help inform future treatment plans and guidelines. Additional data are added with updates from CPRD. This will increase the numbers of patients on newer medications and add more data on those already receiving treatment. There are several ongoing studies investigating different hypotheses regarding differential response to treatment and progression of diabetes. For side effects, links to Hospital Episode Statistics data, where severe events such as hypoglycaemia will be recorded, will also be explored.


Subject(s)
Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/drug therapy , Electronic Health Records , Hypoglycemic Agents/therapeutic use , Adult , Aged , Body Mass Index , Body Weight , Databases as Topic , Diabetes Mellitus, Type 2/diagnosis , Disease Progression , Female , Glycated Hemoglobin/metabolism , Humans , Male , Medication Adherence , Metformin/therapeutic use , Middle Aged , Retrospective Studies , Sulfonylurea Compounds/therapeutic use , Treatment Outcome
19.
Alzheimers Dement ; 12(3): 334-69, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26868060

ABSTRACT

INTRODUCTION: Under the U.S. national Alzheimer's plan, the National Institutes of Health identified milestones required to meet the plan's biomedical research goal (Goal 1). However, similar milestones have not been created for the goals on care (Goal 2) and support (Goal 3). METHODS: The Alzheimer's Association convened a workgroup with expertise in clinical care, long-term services and supports, dementia care and support research, and public policy. The workgroup reviewed the literature on Alzheimer's care and support; reviewed how other countries are addressing the issue; and identified public policies needed over the next 10 years to achieve a more ideal care and support system. RESULTS: The workgroup developed and recommended 73 milestones for Goal 2 and 56 milestones for Goal 3. DISCUSSION: To advance the implementation of the U.S. national Alzheimer's plan, the U.S. government should adopt these recommended milestones, or develop similar milestones, to be incorporated into the national plan.


Subject(s)
Alzheimer Disease/epidemiology , Alzheimer Disease/therapy , Long-Term Care/methods , Biomedical Research , Humans , National Institutes of Health (U.S.)/standards , National Institutes of Health (U.S.)/trends , Public Policy , United States/epidemiology
20.
Diabetes Care ; 39(2): 258-263, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26681714

ABSTRACT

OBJECTIVE: The impact of taking oral glucose-lowering medicines intermittently, rather than as recommended, is unclear. We conducted a retrospective cohort study using community-acquired U.K. clinical data (Clinical Practice Research Database [CPRD] and GoDARTS database) to examine the prevalence of nonadherence to treatment for type 2 diabetes and investigate its potential impact on HbA1c reduction stratified by type of glucose-lowering medication. RESEARCH DESIGN AND METHODS: Data were extracted for patients treated between 2004 and 2014 who were newly prescribed metformin, sulfonylurea, thiazolidinedione, or dipeptidyl peptidase 4 inhibitors and who continued to obtain prescriptions over 1 year. Cohorts were defined by prescribed medication type, and good adherence was defined as a medication possession ratio ≥0.8. Linear regression was used to determine potential associations between adherence and 1-year baseline-adjusted HbA1c reduction. RESULTS: In CPRD and GoDARTS, 13% and 15% of patients, respectively, were nonadherent. Proportions of nonadherent patients varied by the oral glucose-lowering treatment prescribed (range 8.6% [thiazolidinedione] to 18.8% [metformin]). Nonadherent, compared with adherent, patients had a smaller HbA1c reduction (0.4% [4.4 mmol/mol] and 0.46% [5.0 mmol/mol] for CPRD and GoDARTs, respectively). Difference in HbA1c response for adherent compared with nonadherent patients varied by drug (range 0.38% [4.1 mmol/mol] to 0.75% [8.2 mmol/mol] lower in adherent group). Decreasing levels of adherence were consistently associated with a smaller reduction in HbA1c. CONCLUSIONS: Reduced medication adherence for commonly used glucose-lowering therapies among patients persisting with treatment is associated with smaller HbA1c reductions compared with those taking treatment as recommended. Differences observed in HbA1c responses to glucose-lowering treatments may be explained in part by their intermittent use.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Glycated Hemoglobin/analysis , Hypoglycemic Agents/therapeutic use , Medication Adherence , Aged , Blood Glucose/drug effects , Cohort Studies , Databases, Factual , Diabetes Mellitus, Type 2/blood , Dipeptidyl-Peptidase IV Inhibitors/therapeutic use , Female , Humans , Male , Metformin/therapeutic use , Middle Aged , Primary Health Care/statistics & numerical data , Retrospective Studies , Sulfonylurea Compounds/therapeutic use , Thiazolidinediones/therapeutic use
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