Doing research in non-specialist mental health services for children and young people: lessons learnt from a process evaluation of the ICALM (Interpersonal Counselling for Adolescent Low Mood) feasibility randomised controlled trial.

BACKGROUND: The rising prevalence of adolescent mild depression in the UK and the paucity of evidence-based interventions in non-specialist sectors where most cases present, creates an urgent need for early psychological interventions. Randomised controlled trials (RCTs) are considered the gold standard for obtaining unbiased estimates of intervention effectiveness. However, the complexity of mental health settings poses great challenges for effectiveness evaluations. This paper reports learning from an embedded process evaluation of the ICALM RCT which tested the feasibility of delivering Interpersonal Counselling for Adolescents (IPC-A) plus Treatment as Usual (TAU) versus TAU only for adolescent (age 12-18) mild depression by non-qualified mental health professionals in non-specialist sectors. METHODS: A qualitative mixed methods process evaluation, drawing on Bronfenbrenner's socioecological model to investigate key influences on trial delivery across macro-(e.g. policy), meso-(e.g. service characteristics) and micro-(e.g. on-site trial processes) contextual levels. Data collection methods included 9 site questionnaires, 4 observations of team meetings, policy documents, and 18 interviews with stakeholders including therapists, heads of service and managers. Thematic analysis focused on understanding how contextual features shaped trial implementation. RESULTS: The ICALM trial concluded in 2022 having only randomised 14 out of the target 60 young people. At a macro-level, trial delivery was impacted by the COVID-19 pandemic, with services reporting a sharp increase in cases of (social) anxiety over low mood, and backlogs at central referral points which prolonged waiting times for mild cases (e.g. low mood). An interaction between high demand and lack of capacity at a meso-service level led to low prioritisation of trial activities at a micro-level. Unfamiliarity with research processes (e.g. randomisation) and variation in TAU support also accentuated the complexities of conducting an RCT in this setting. CONCLUSIONS: Conducting a RCT of IPC-A in non-specialist services is not feasible in the current context. Failure to conduct effectiveness trials in this setting has clinical implications, potentially resulting in escalation of mild mental health problems. Research done in this setting should adopt pragmatic and innovative recruitment and engagement approaches (e.g. creating new referral pathways) and consider alternative trial designs, e.g. cluster, stepped-wedge or non-controlled studies using complex systems approaches to embrace contextual complexity. TRIAL REGISTRATION: ISRCTN registry, ISRCTN82180413. Registered on 31 December 2019.

Risk of bias in non-randomized observational studies assessing the relationship between proton-pump inhibitors and adverse kidney outcomes: a systematic review.

BACKGROUND: Proton-pump inhibitors (PPIs) are widely prescribed as acid-suppression therapy. Some observational studies suggest that long-term use of PPIs is potentially associated with certain adverse kidney outcomes. We conducted a systematic literature review to assess potential bias in non-randomized studies reporting on putative associations between PPIs and adverse kidney outcomes (acute kidney injury, acute interstitial nephritis, chronic interstitial nephritis, acute tubular necrosis, chronic kidney disease, and end-stage renal disease). METHODS: We searched the medical literature within 10 years of 17 December 2020. Pre-specified criteria guided identification of relevant English language articles for assessment. Risk of bias on an outcome-specific basis was evaluated using the Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool by two independent reviewers. RESULTS: Of 620 initially identified records, 26 studies met a priori eligibility criteria and underwent risk of bias assessment. Nineteen studies were judged as having a moderate risk of bias for reported adverse kidney outcomes, while six studies were judged as having a serious risk of bias (mainly due to inadequate control of confounders and selection bias). We were unable to determine the overall risk of bias in two studies (one of which was assessed as having a moderate risk of bias for a different adverse kidney outcome) due to insufficient information presented. Effect estimates for PPIs in relation to adverse kidney outcomes varied widely (0.24-7.34) but associations mostly showed increased risk. CONCLUSION: Using ROBINS-I, we found that non-randomized observational studies suggesting kidney harm by PPIs have moderate to serious risk of bias, making it challenging to establish causality. Additional high-quality, real-world evidence among generalizable populations are needed to better understand the relation between PPI treatment and acute and chronic kidney outcomes, accounting for the effects of varying durations of PPI treatment, self-treatment with over-the-counter PPIs, and potential critical confounders.

Qualitative measures that assess functional disability and quality of life in ALS.

BACKGROUND: Selection of appropriate trial endpoints and outcome measures is particularly important in rare disease and rapidly progressing disease such as amyotrophic lateral sclerosis (ALS) where the challenges to conducting clinical trials, are substantial: patient and disease heterogeneity, limited understanding of exact disease pathophysiology, and lack of robust and available biomarkers. To address these challenges in ALS, the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised version (ALSFRS-R) was developed and has become a key primary endpoint in ALS clinical trials to assess functional disability and disease progression, often replacing survival as a primary outcome. However, increased understanding of the ALS disease journey and improvements in assistive technology for ALS patients have exposed issues with the ALSFRS-R, including non-linearity, multidimensionality and floor and ceiling effects that could challenge its continued utility as a primary outcome measure in ALS clinical trials. Recently, other qualitative scale measures of functioning disability have been developed to help address these issues. With this in mind, we conducted a literature search aimed at identifying both established and promising new measures for potential use in clinical trials. METHODS: We searched PubMed, Google, Google Scholar, and the reference sections of key studies to identify papers that discussed qualitative measures of functional status for potential use in ALS studies. We also searched clinicaltrials.gov to identify functional status and health-related quality of life (HRQoL) measures that have been used in ALS interventional studies. RESULTS: In addition to the ALSFRS-R, we identified several newer qualitative scales including ALSFRS-EX, ALS-MITOS, CNS-BFS, DALS-15, MND-DS, and ROADS. Strengths and limitations of each measure were identified and discussed, along with their potential to act as a primary or secondary outcome to assess patient functional status in ALS clinical trials. CONCLUSION: This paper serves as a reference guide for researchers deciding which qualitative measures to use as endpoints in their ALS clinical trials to assess functional status. This paper also discusses the importance of including ALS HRQoL and ALS cognitive screens in future clinical trials to assess the value of a new ALS therapy more comprehensively.

A Descriptive Review of Global Real World Evidence Efforts to Advance Drug Discovery and Clinical Development in Amyotrophic Lateral Sclerosis.

Understanding patient clinical progression is a key gateway to planning effective clinical trials and ultimately enabling bringing treatments to patients in need. In a rare disease like amyotrophic lateral sclerosis (ALS), studies of disease natural history critically depend on collaboration between clinical centers, regions, and countries to enable creation of platforms to allow patients, caregivers, clinicians, and researchers to come together and more fully understand the condition. Rare disease registries and collaborative platforms such as those developed in ALS collect real-world data (RWD) in standardized formats, including clinical and biological specimen data used to evaluate risk factors and natural history of disease, treatment patterns and clinical (ClinROs) and patient- reported outcomes (PROs) and validate novel endpoints. Importantly, these data support the development of new therapeutics by supporting the evaluation of feasibility and design of clinical trials and offer valuable information on real-world disease trajectory and outcomes outside of the clinical trial setting for comparative purposes. RWD may help to accelerate therapy development by identifying and validating outcome measures and disease subpopulations. RWD can also make potential contributions to the evaluation of the safety and effectiveness of new indications for approved products and to satisfy post-approval regulatory and market access requirements. There is a lack of amalgamated information on available registries, databases, and other sources of real-world data on ALS; thus, a global review of all available resources was warranted. This targeted review identifies and describes ALS registries, biobanks and collaborative research networks that are collecting and synthesizing RWD for the purposes of increasing patient awareness and advancing scientific knowledge with the hope of expediting future development of new therapies.

Efficacy of Vibegron and Mirabegron for Overactive Bladder: A Systematic Literature Review and Indirect Treatment Comparison.

BACKGROUND: In the absence of head-to-head trials, we performed an indirect treatment comparison of the ß3-adrenergic agonists vibegron and mirabegron in the treatment of overactive bladder (OAB). METHODS: PubMed, Embase, and Cochrane Library were searched for articles related to phase 3, double-blind, controlled trials of vibegron 75 mg and mirabegron 25/50 mg in patients with OAB. Efficacy outcomes included change from baseline at weeks 4, 12, and 52 in mean daily number of total urinary incontinence episodes and micturitions and mean volume voided/micturition. Effect size was computed as placebo-subtracted change from baseline (weeks 4, 12) or active control (tolterodine)-subtracted change from baseline (week 52) for each treatment group. Adverse events (AEs) are presented descriptively. RESULTS: After removal of duplicates, 49 records were identified, and after screening 9 met inclusion criteria for analysis. Vibegron showed significantly greater reduction in mean daily number of total incontinence episodes than mirabegron 25 mg at week 4, mirabegron 50 mg (weeks 4, 52), and tolterodine (weeks 4, 12) (P < 0.05, each) and significantly greater improvement in volume voided versus mirabegron 25 mg (week 12), mirabegron 50 mg (weeks 12, 52), and tolterodine (week 4) (P < 0.05, each). Confidence intervals of point estimates overlapped zero for all other comparisons of vibegron and mirabegron (25 or 50 mg) or tolterodine, indicating no significant differences between treatments for these time/endpoints. Urinary tract infection, hypertension, and dry mouth were the most commonly occurring AEs for vibegron, mirabegron, and tolterodine, respectively, in the short-term trials; hypertension was the most commonly occurring AE with all three treatments in the long-term trials. CONCLUSIONS: Vibegron was associated with significant improvement in total incontinence episodes versus mirabegron at 4 and 52 weeks and volume voided at 12 and 52 weeks. Improvement in micturitions was similar between vibegron and mirabegron or tolterodine. Incidence of AEs was generally comparable between vibegron and mirabegron.

Assessing Patients' Satisfaction With Hydrogen Peroxide Topical Solution, 40% for Treatment of Raised Seborrheic Keratoses.

OBJECTIVES: Assess participants’ satisfaction following treatment with a proprietary hydrogen peroxide topical solution 40%, w/w (HP40) for raised seborrheic keratoses (SKs). METHODS: In this Phase 4, open-label study, eligible participants aged 30–75 years had clinically typical raised SKs including 2 target SKs (Physician’s Lesion Assessment™ [PLA] grade of ≥2 [0 = clear; 1 = near clear; 2 = thin (≤1 mm); 3 = thick (>1 mm)]; 5–15 mm diameter) on the face and 1 target SK on the neck or décolletage. SKs received HP40 treatment on day 1. All SKs with PLA grade ≥1 were retreated on days 15 and 29. Endpoints included patients’ satisfaction with their skin’s appearance at day 113, relationships between patients’ satisfaction and lesion PLA grade (evaluated by chi-square test), and patients’ satisfaction with their treatment experience. RESULTS: Forty-one patients (mean [range] age, 62.4 [46–73] years) completed the study. 95% of patients were at least moderately satisfied with their skin’s appearance and 90.2% of target lesions were clear. A statistically significant association was observed between the number of target lesions achieving clearance and patients’ satisfaction with skin appearance level (χ2=22.03; P=0.001). 93% of patients were at least moderately satisfied with their HP40 treatment experience. Eight patients experienced treatment-emergent adverse events (TEAEs), most of which were mild or moderate; 4 experienced TEAEs considered treatment-related. CONCLUSIONS: Most patients with SKs on the face, neck, and décolletage were satisfied or very satisfied with both their skin’s appearance and their treatment experience following HP40 treatment. These results support the use of HP40 for raised SKs. J Drugs Dermatol. 2020;19(12): doi:10.36849/JDD.2020.4974.

Costs of Severe Maternal Morbidity During Pregnancy in US Commercially Insured and Medicaid Populations: An Observational Study.

OBJECTIVE: To estimate the maternity-related cost of health care services in women with and without severe maternal morbidity (SMM). METHODS: Women with a live inpatient birth in the calendar year 2013 were identified in the MarketScan® Commercial and Medicaid health insurance claims databases. Costs were defined as the amounts paid by insurers plus out-of-pocket and third-party payments. Costs were calculated as total maternity-related costs and categorized as prenatal, delivery, and postpartum costs. SMM was identified using the CDC algorithm of 25 ICD-9 diagnostic and procedural codes. Variables associated with higher delivery costs were determined by multivariable linear regression analysis. RESULTS: A total of 750 women met the criteria for SMM in the Commercial population. The total, per-patient mean costs of care for women without and with SMM were $14,840 and $20,380, respectively. Delivery hospitalization costs were 76-77% of total mean costs for women without and with SMM. A total of 99 women met the criteria for SMM in the Medicaid population. The total, per-patient mean costs of care for women without and with SMM were $6894 and $10,134, respectively. Delivery costs were 71-72% of total costs. Variables independently predictive of increased delivery costs in both Commercial and Medicaid populations were delivery by cesarean section, multifetal gestation, gestational hypertension/preeclampsia, and obstetric infection. CONCLUSIONS: The occurrence of SMM was associated with an increase in maternity-related costs of 37% in the Commercial and 47% in the Medicaid population. Some of the factors associated with increased delivery hospitalization costs may be prevented.

Clinical Course of Patients With Worsening Heart Failure With Reduced Ejection Fraction.

BACKGROUND: Epidemiology of patients with worsening heart failure and reduced ejection fraction (HFrEF) in the real-world setting is not well described. OBJECTIVES: The purpose of this study was to describe incidence, clinical characteristics, treatment, and outcomes of patients with HFrEF who develop worsening heart failure (HF) in the real-world setting. METHODS: Data on patients with incident HFrEF from the National Cardiovascular Data Registry PINNACLE were linked to pharmacy, private practitioner, and hospital claims databases. Incidence, clinical characteristics, treatment (angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, beta-blocker, and mineralocorticoid receptor antagonist) and outcomes of patients with worsening HF, defined as ≥90 days of stable HF with subsequent worsening requiring intravenous diuretic agents, were assessed. RESULTS: Of 11,064 HFrEF patients, 1,851 (17%) developed worsening HF on average 1.5 years following initial HF diagnosis. Patients who developed worsening HF were more likely to be African American, be octogenarians, and have higher comorbidity burden (p < 0.001). At the onset of worsening HF, 42.4% of patients were on monotherapy, 43.4% were on dual therapy, and 14.1% were on triple therapy. A total of 48%, 61%, and 98% of patients were on >50% target dose for angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, beta-blocker, and mineralocorticoid receptor antagonist, respectively. The 2-year mortality rate was 22.5%, and 56% of patients were rehospitalized within 30 days of the worsening HF event. CONCLUSIONS: In the real-world setting, 1 in 6 patients with HFrEF develop worsening HF within 18 months of HF diagnosis. These patients have a high risk for 2-year mortality and recurrent HF hospitalizations. The use of standard-of-care therapies both before and after the onset of worsening HF is low. With high unmet medical need, patients with worsening HF require novel treatment strategies as well as greater optimization of existing guideline-directed therapy.

Series: Pragmatic trials and real world evidence: Paper 2. Setting, sites, and investigator selection.

This second article in the series on pragmatic trials describes the challenges in selection of sites for pragmatic clinical trials and the impact on validity, precision, and generalizability of the results. The selection of sites is an important factor for the successful execution of a pragmatic trial and impacts the extent to which the results are applicable to future patients in clinical practice. The first step is to define usual care and understand the heterogeneity of sites, patient demographics, disease prevalence and country choice. Next, specific site characteristics are important to consider such as interest in the objectives of the trial, the level of research experience, availability of resources, and the expected number of eligible patients. It can be advisable to support the sites with implementing the trial-related activities and minimize the additional burden that the research imposes on routine clinical practice. Health care providers should be involved in an early phase of protocol development to generate engagement and ensure an appropriate selection of sites with patients who are representative of the future drug users.

Longitudinal changes of benign prostate-specific antigen and [-2]proprostate-specific antigen in seven years in a community-based sample of men.

OBJECTIVE: To determine the longitudinal changes of benign prostate-specific antigen (BPSA) and [-2]proPSA and how these changes relate to the outcomes. These markers have been shown to be predictive of prostate cancer (CaP) and benign prostatic hyperplasia treatment; however, little is known about longitudinal changes in these markers. METHODS: In 1990, a 25% subsample from a cohort of white men aged 40-79 years, who were randomly selected from Olmsted County, Minnesota residents, completed a detailed clinical examination. BPSA and [-2]proPSA were measured from frozen sera. The men were evaluated biennially (median follow-up 7 years; range 0-8.8). Mixed-effects regression models were used to estimate the longitudinal changes in the BPSA and [-2]proPSA levels overall and by outcomes. Spearman correlations were used to compare these changes with the baseline levels and the annualized changes in urologic measures. RESULTS: The median and 25th and 75th percentiles annualized percent change for [-2]proPSA and BPSA was 3.7%, 2.5% and 5.2% and 7.3%, 6.8%, and 7.7%, respectively. The annualized percent change for both markers correlated with the baseline and annualized changes in PSA and prostate volume. The annualized percent change increased with increasing age decade for [-2]proPSA but not for BPSA. The rate of increase in [-2]proPSA was significantly greater for men who developed enlarged prostates (median 3.5%, 25th and 75th percentile 2.6% and 4.4%, respectively) or CaP (median 8.1%, 25th and 75th percentile 6.6% and 9.8%, respectively) compared with those who did not develop enlarged prostates (median 1.9%, 25th and 75th percentile 0.9% and 3.0%, respectively) or CaP (median 3.5%, 25th and 75th percentile 2.3% and 4.8%, respectively). CONCLUSION: BPSA and [-2]proPSA levels increase over time. The annualized percent change in [-2]proPSA increases with age and might be a useful predictor of CaP development.

Distribution and associations of [-2]proenzyme-prostate specific antigen in community dwelling black and white men.

PURPOSE: We provide cross-sectional normative data on [-2]proenzyme-prostate specific antigen from the Olmsted County Study of Urinary Symptoms and Health Status among Men, and the Flint Men's Health Study. We also describe associations with clinical urological measures and the risk of prostate cancer diagnosis. MATERIALS AND METHODS: Measurements of [-2]proenzyme-prostate specific antigen were obtained from 420 white men from Olmsted County, Minnesota, and 328 black men from Genesee County, Michigan. Cross-sectional associations between [-2]proenzyme-prostate specific antigen and prostate enlargement/elevated prostate specific antigen were assessed. Cox proportional hazard models were used to assess associations between [-2]proenzyme-prostate specific antigen and the incident diagnosis of prostate cancer. RESULTS: Baseline [-2]proenzyme-prostate specific antigen was slightly higher in black men at a median of 6.3 pg/ml (25th, 75th percentiles 4.1, 8.9) than in white men at a median of 5.6 pg/ml (25th, 75th percentiles 3.9, 7.7, respectively, p = 0.01). Baseline [-2]proenzyme-prostate specific antigen was highly predictive of biopsy confirmed prostate cancer in the Olmsted County Study cohort. Relative to men in the [-2]proenzyme-prostate specific antigen lower quartile those in the upper quartile were at almost eightfold increased risk for prostate cancer (HR 7.8, 95% CI 2.2-27.8) after adjusting for age and baseline prostate specific antigen. CONCLUSIONS: In these cohorts of community dwelling black and white men [-2]proenzyme-prostate specific antigen was much lower than in previous studies. These data suggest that [-2]proenzyme-prostate specific antigen may help identify prostate cancer in men with serum prostate specific antigen in an indeterminate range, although the reference ranges for white and black men may differ slightly.

Benign prostate specific antigen distribution and associations with urological outcomes in community dwelling black and white men.

PURPOSE: We describe cross-sectional associations of benign prostate specific antigen with clinical urological measures and examined the risk of future urological outcomes in 2 population based cohorts of black and white men, respectively. MATERIALS AND METHODS: Two population based cohort studies were established to characterize the natural history of and risk factors for prostate disease progression in white and black male residents of Olmsted County, Minnesota, and Genesee County, Michigan, respectively. RESULTS: The benign prostate specific antigen distribution was similar in black men at a median of 32.9 pg/ml (25th, 75th percentiles 17.3, 68.0) and white men at a median of 32.2 pg/ml (25th, 75th percentiles 16.6, 68.9, respectively). However, it was much lower than in previous reports. For Olmsted County men in the upper quartile of benign prostate specific antigen there was a fifteenfold increased risk of prostate cancer (HR 14.6, 95% CI 3.1-68.6) and a twofold higher risk of treatment for benign prostatic hyperplasia (HR 2.2, 95% CI 1.2-4.2) after adjusting for age. After additional adjustment for baseline prostate specific antigen the association between benign prostate specific antigen and prostate cancer risk was attenuated but remained almost ninefold higher for men in the upper quartile of benign prostate specific antigen (HR 8.7, 95% CI 1.8-42.4). The twofold higher risk of treatment for benign prostatic hyperplasia also remained after adjusting for baseline prostate specific antigen for men in the upper benign prostate specific antigen quartile (HR 1.9, 95% CI 0.9-4.0). CONCLUSIONS: Results suggest that increased benign prostate specific antigen may help identify men with prostate cancer and those at risk for benign prostatic hyperplasia treatment.

Research design considerations for confirmatory chronic pain clinical trials: IMMPACT recommendations.

There has been an increase in the number of chronic pain clinical trials in which the treatments being evaluated did not differ significantly from placebo in the primary efficacy analyses despite previous research suggesting that efficacy could be expected. These findings could reflect a true lack of efficacy or methodological and other aspects of these trials that compromise the demonstration of efficacy. There is substantial variability among chronic pain clinical trials with respect to important research design considerations, and identifying and addressing any methodological weaknesses would enhance the likelihood of demonstrating the analgesic effects of new interventions. An IMMPACT consensus meeting was therefore convened to identify the critical research design considerations for confirmatory chronic pain trials and to make recommendations for their conduct. We present recommendations for the major components of confirmatory chronic pain clinical trials, including participant selection, trial phases and duration, treatment groups and dosing regimens, and types of trials. Increased attention to and research on the methodological aspects of confirmatory chronic pain clinical trials has the potential to enhance their assay sensitivity and ultimately provide more meaningful evaluations of treatments for chronic pain.

Natural history of benign prostatic enlargement: long-term longitudinal population-based study of prostate volume doubling times.

OBJECTIVES: To measure prostate volume doubling times (PVDTs) for a large sample of community men followed serially by transrectal ultrasonography (TRUS), and to determine whether specific characteristics are associated with a rapid PVDT. SUBJECTS AND METHODS: A subsample of 446 subjects from a larger cohort of American white men aged 40-79 years were evaluated biennially for a median (range) follow-up of 10 (3-14) years. Mixed-effects regression models were used to estimate prostate growth rates and PVDT for subjects with three or more or with five or more serial biennial TRUS PV measurements. RESULTS: The median (25-75th percentile) PVDT was 32.6 (24.6-44.0) years. The average annual increase in PV was 2.2%. The PVDT distribution was constant in men of all age groups studied (r < 0.001, P = 0.99). The factor most strongly associated with PVDT was baseline transition zone volume (r = -0.55, P < 0.001). Baseline total prostate-specific antigen (PSA) level, free PSA and total PV were also significantly inversely associated with PVDT (r = -0.30, -0.44 and -0.32, respectively, all P < 0.001). Age, baseline anthropomorphic measurements, hormone levels and specific lifestyle characteristics were not significantly correlated with PVDT. CONCLUSION: These data indicate that PVDT might be a useful future measure of benign prostatic growth. They provide a basis to forecast PV at 10, 20, or 30 years later, after one baseline TRUS measurement of prostate volume, and can be presented in a simple nomogram.

Software Assurance Using Structured Assurance Case Models.

Software assurance is an important part of the software development process to reduce risks and ensure that the software is dependable and trustworthy. Software defects and weaknesses can often lead to software errors and failures and to exploitation by malicious users. Testing, certification and accreditation have been traditionally used in the software assurance process to attempt to improve software trustworthiness. In this paper, we examine a methodology known as a structured assurance model, which has been widely used for assuring system safety, for its potential application to software assurance. We describe the structured assurance model and examine its application and use for software assurance. We identify strengths and weaknesses of this approach and suggest areas for further investigation and testing.

Hepatic fat is not associated with beta-cell function or postprandial free fatty acid response.

We evaluated the association of hepatic fat with beta-cell function estimated from the oral glucose tolerance test. In addition, we tested the hypothesis that postprandial free fatty acid (FFA) suppression after a meal tolerance test (MTT) is linked to hepatic fat. Individuals with normal glucose metabolism (NGM; n = 10 with low and n = 10 with high insulin secretion, matched for insulin sensitivity and sex), impaired glucose metabolism (IGM; n = 14), and type 2 diabetes mellitus (DM; n = 14) underwent a 75-g oral glucose tolerance test and MTT. beta-Cell function estimates were calculated from C-peptide using a mathematical model. Liver fat was quantified by proton magnetic resonance ((1)H-MR) spectroscopy. Area under the curve (AUC) of triglycerides (TG) and FFA responses during MTT represented postprandial lipid responses. Linear regression models were adjusted for age, sex, and additionally for insulin sensitivity for IGM/DM subjects. Liver fat content was equal for the NGM groups with low and high insulin secretion: 4.5% (2.6-6.0) (median, interquartile range) and 4.9% (2.3-7.8), respectively; liver fat percentages of IGM and diabetic subjects were significantly higher: 11.2 (6.7-21.1) and 10.0 (7.8-24.5). Liver fat showed a fairly strong, significant negative association with insulin sensitivity, but was not associated with beta-cell function. Significant associations of liver fat with fasting TG and AUC(TG) were shown in the total study population and in IGM/DM subjects separately. No relationship existed between fasting FFA or AUC(FFA) and liver fat. We conclude that fat accumulation in the liver is tightly linked to insulin sensitivity but not to beta-cell function. Furthermore, liver fat is associated with circulating TG levels, but not with FFA concentrations.

Classical and model-based estimates of beta-cell function during a mixed meal vs. an OGTT in a population-based cohort.

This study compared classical and model-based beta-cell responses during an oral glucose tolerance test (OGTT) and a meal tolerance test (MTT) in a population-based cohort. Individuals with normal glucose metabolism (NGM, n=161), impaired glucose metabolism (IGM, n=19) and type 2 diabetes mellitus (DM, n=20) underwent a 75 g-OGTT and an MTT (75 g carbohydrates, 50 g fat, 24 g proteins). Classical estimates of beta-cell function (insulinogenic index and the ratio of areas under insulin and glucose curves) were calculated. Mathematical modelling was used to determine beta-cell glucose sensitivity, rate sensitivity and potentiation. Insulin sensitivity was characterized by three surrogate estimates. Both classical and model-based estimates of beta-cell function were higher during MTT than during OGTT (P<0.05). Regarding the model-based parameters, especially beta-cell sensitivity was increased following MTT as compared with OGTT (P<0.05). Both during OGTT and MTT, across most parameters describing beta-cell function, the largest reduction in beta-cell response occurred between IGM and DM, while the largest reduction in insulin sensitivity occurred between NGM and IGM. We conclude that beta-cell response is stronger after a mixed meal than after an OGTT with equal carbohydrate quantity, both for classical and model-based parameters. The higher response was mostly explained by higher beta-cell sensitivity during the meal.

Adipokines, insulin resistance, and coronary artery calcification.

OBJECTIVES: We evaluated the hypothesis that plasma levels of adiponectin and leptin are independently but oppositely associated with coronary artery calcification (CAC), a measure of subclinical atherosclerosis. In addition, we assessed which biomarkers of adiposity and insulin resistance are the strongest predictors of CAC beyond traditional risk factors, metabolic syndrome, and plasma C-reactive protein (CRP). BACKGROUND: Adipokines are fat-secreted biomolecules with pleiotropic actions that converge in diabetes and cardiovascular disease. METHODS: We examined the association of plasma adipocytokines with CAC in 860 asymptomatic, nondiabetic participants in the SIRCA (Study of Inherited Risk of Coronary Atherosclerosis). RESULTS: Plasma adiponectin and leptin levels had opposite and distinct associations with adiposity, insulin resistance, and inflammation. Plasma leptin was positively (top vs. bottom quartile) associated with higher CAC after adjustment for age, gender, traditional risk factors, and Framingham risk scores (tobit regression ratio 2.42 (95% confidence interval [CI]: 1.48 to 3.95; p = 0.002) and further adjustment for metabolic syndrome and CRP (tobit regression ratio: 2.31; 95% CI: 1.36 to 3.94; p = 0.002). In contrast, adiponectin levels were not associated with CAC. Comparative analyses suggested that levels of leptin, interleukin-6, and soluble tumor necrosis factor receptor-2, as well as the homeostasis model assessment of insulin resistance (HOMA-IR) index, predicted CAC scores, but only leptin and HOMA-IR provided value beyond risk factors, metabolic syndrome, and CRP. CONCLUSIONS: In SIRCA, although both leptin and adiponectin levels were associated with metabolic and inflammatory markers, only leptin was a significant independent predictor of CAC. Of several metabolic markers, leptin and the HOMA-IR index had the most robust, independent associations with CAC.

Divergent sodium channel defects in familial hemiplegic migraine.

Familial hemiplegic migraine type 3 (FHM3) is a severe autosomal dominant migraine disorder caused by mutations in the voltage-gated sodium channel Na(V)1.1 encoded by SCN1A. We determined the functional consequences of three mutations linked to FHM3 (L263V, Q1489K, and L1649Q) in an effort to identify molecular defects that underlie this inherited migraine disorder. Only L263V and Q1489K generated quantifiable sodium currents when coexpressed in tsA201 cells with the human beta(1) and beta(2) accessory subunits. The third mutant, L1649Q, failed to generate measurable whole-cell current because of markedly reduced cell surface expression. Compared to WT-Na(V)1.1, Q1489K exhibited increased persistent current but also enhanced entry into slow inactivation as well as delayed recovery from fast and slow inactivation, thus resulting in a predominantly loss-of-function phenotype further demonstrated by a greater loss of channel availability during repetitive stimulation. In contrast, L263V exhibited gain-of-function features, including delayed entry into, as well as accelerated recovery from, fast inactivation; depolarizing shifts in the steady-state voltage dependence of fast and slow inactivation; increased persistent current; and delayed entry into slow inactivation. Notably, the two mutations (Q1489K and L1649Q) that exhibited partial or complete loss of function are linked to typical FHM, whereas the gain-of-function mutation L263V occurred in a family having both FHM and a high incidence of generalized epilepsy. We infer from these data that a complex spectrum of Na(V)1.1 defects can cause FHM3. Our results also emphasize the complex relationship between migraine and epilepsy and provide further evidence that both disorders may share common molecular mechanisms.