Intervention fidelity assessment: A sub-study of the Norfolk Diabetes Prevention Study (NDPS).

BACKGROUND: Previous research has shown that lifestyle modification can delay or prevent the onset of type 2 diabetes in high-risk individuals. The Norfolk Diabetes Prevention Study (NDPS) was a parallel, three-arm, randomized controlled trial with up to 46 months follow-up that tested a group-delivered, theory-based lifestyle intervention to reduce the incidence of type 2 diabetes in high-risk groups. The current study aimed to evaluate if the NDPS intervention was delivered to an acceptable standard and if any part(s) of the delivery required improvement. METHODS: A sub-sample of 30, 25 for inter-rater reliability and audio-recordings of the NDPS intervention education sessions were assessed independently by two reviewers (CT, TW) using a 12-item checklist. Each item was scored on a 0-5 scale, with a score of 3 being defined as 'adequate delivery'. Inter-rater reliability was assessed. Analysis of covariance (ANCOVA) was used to assess changes in intervention fidelity as the facilitators gained experience. RESULTS: Inter-rater agreement was acceptable (86%). A mean score of 3.47 (SD = .38) was achieved across all items of the fidelity checklist and across all intervention facilitators (n = 6). There was an apparent trend for intervention fidelity scores to decrease with experience; however, this trend was non-significant (p > .05) across all domains in this small sample. CONCLUSION: The NDPS was delivered to an acceptable standard by all Diabetes Prevention Facilitators. Further research is needed to better understand how the intervention's delivery characteristics can be optimized and how they might vary over time.

Quantity and specificity of action-plans as predictors of weight loss: analysis of data from the Norfolk Diabetes Prevention Study (NDPS).

OBJECTIVE: Investigate associations between quantity, content and specificity of action-plans and weight loss in a diabetes prevention study. DESIGN: Prospective cohort study nested within a randomised controlled trial. Participants completed action-planning worksheets during intervention sessions. MAIN OUTCOME MEASURES: Action-plans were coded in terms of: number of plans set, their content, and specificity. Multivariate regression analyses assessed associations with weight loss at four-months. RESULTS: 890 planning-worksheets from 106 participants were analysed. Participants wrote a mean of 2.12 (SD = 1.20) action-plans per worksheet, using a mean of 2.20 (SD = 0.68) specificity components per action-plan. Quantity of action-plans per worksheet decreased over time (r = -0.137, p < 0.001) and increased quantity was associated with reduced specificity [r = -.215, p < 0.001]. Walking (34.9% of action-plans) and reducing high fat/sugar snacks (26.1%) were the most commonly planned lifestyle actions. In multivariate modelling, increased quantity of action-plans was associated with greater weight loss (R2 = 0.135, Unstandardised Beta = 0.144, p = 0.002). Specificity was not significantly associated with weight-loss (p = 0.096). CONCLUSION: Producing more action-plans was associated with greater weight loss. Further research should directly compare more versus less specific action-plans and explore ways to sustain engagement in action-planning. Our findings imply that participants should freely set numerous action-plans, rather than being encouraged to focus on specificity.Supplemental data for this article is available online at https://doi.org/10.1080/08870446.2022.2055026 .

Trained Volunteers With Type 2 Diabetes Experience Significant Health Benefits When Providing Peer Support.

Trained lay volunteers may have value in supporting lifestyle change programs in the prevention of type 2 diabetes, but the potential health benefits (or harms) experienced by these lay volunteers have not been well described. This is important, as this is an appealing model in terms of workforce planning. The aim of the prespecified quantitative study reported here, was to examine the possible health benefits or harms experienced by these trained lay volunteers with type 2 diabetes. In a large type 2 diabetes prevention program, we recruited and trained 104 lay volunteers with type 2 diabetes themselves, to act as diabetes prevention mentors and codeliver the lifestyle intervention. Mentors made motivational telephone calls to 461 participants randomized to one of the trial arms to encourage lifestyle changes. Weight, diet, physical activity, well-being, quality of life, diabetes-specific self-efficacy, and glycaemic control were measured at baseline, 12 and 24 months. Average mentor age was 62.0 years, 57 (54.8%) were male, 92 (88.5%) were overweight or obese (BMI>30 kg/m2). At 12 months, mentor dietary behaviors (fat and fiber intake) improved significantly, sedentary time spent fell significantly, and diabetes specific self-efficacy scores significantly increased. These significant improvements, with no evidence of harms, suggest lay volunteers with type 2 diabetes codelivering a lifestyle intervention, may themselves experience health benefits from volunteering.

Discordance in glycemic categories and regression to normality at baseline in 10,000 people in a Type 2 diabetes prevention trial.

The world diabetes population quadrupled between 1980 and 2014 to 422 million and the enormous impact of Type 2 diabetes is recognised by the recent creation of national Type 2 diabetes prevention programmes. There is uncertainty about how to correctly risk stratify people for entry into prevention programmes, how combinations of multiple 'at high risk' glycemic categories predict outcome, and how the large recently defined 'at risk' population based on an elevated glycosylated haemoglobin (HbA1c) should be managed. We identified all 141,973 people at highest risk of diabetes in our population, and screened 10,000 of these with paired fasting plasma glucose and HbA1c for randomisation into a very large Type 2 diabetes prevention trial. Baseline discordance rate between highest risk categories was 45.6%, and 21.3-37.0% of highest risk glycaemic categories regressed to normality between paired baseline measurements (median 40 days apart). Accurate risk stratification using both fasting plasma glucose and HbA1c data, the use of paired baseline data, and awareness of diagnostic imprecision at diagnostic thresholds would avoid substantial overestimation of the true risk of Type 2 diabetes and the potential benefits (or otherwise) of intervention, in high risk subjects entering prevention trials and programmes.

Metformin in non-diabetic hyperglycaemia: the GLINT feasibility RCT.

BACKGROUND: The treatment of people with diabetes with metformin can reduce cardiovascular disease (CVD) and may reduce the risk of cancer. However, it is unknown whether or not metformin can reduce the risk of these outcomes in people with elevated blood glucose levels below the threshold for diabetes [i.e. non-diabetic hyperglycaemia (NDH)]. OBJECTIVE: To assess the feasibility of the Glucose Lowering In Non-diabetic hyperglycaemia Trial (GLINT) and to estimate the key parameters to inform the design of the full trial. These parameters include the recruitment strategy, randomisation, electronic data capture, postal drug distribution, retention, study medication adherence, safety monitoring and remote collection of outcome data. DESIGN: A multicentre, individually randomised, double-blind, parallel-group, pragmatic, primary prevention trial. Participants were individually randomised on a 1 : 1 basis, blocked within each site. SETTING: General practices and clinical research facilities in Cambridgeshire, Norfolk and Leicestershire. PARTICIPANTS: Males and females aged ≥ 40 years with NDH who had a high risk of CVD. INTERVENTIONS: Prolonged-release metformin (500 mg) (Glucophage® SR, Merck KGaA, Bedfont Cross, Middlesex, UK) or the matched placebo, up to three tablets per day, distributed by post. MAIN OUTCOME MEASURES: Recruitment rates; adherence to study medication; laboratory results at baseline and 3 and 6 months; reliability and acceptability of study drug delivery; questionnaire return rates; and quality of life. RESULTS: We sent 5251 invitations, with 511 individuals consenting to participate. Of these, 249 were eligible and were randomised between March and November 2015 (125 to the metformin group and 124 to the placebo group). Participants were followed up for 0.99 years [standard deviation (SD) 0.30 years]. The use of electronic medical records to identify potentially eligible individuals in individual practices was resource intensive. Participants were generally elderly [mean age 70 years (SD 6.7 years)], overweight [mean body mass index 30.1 kg/m2 (SD 4.5 kg/m2)] and male (88%), and the mean modelled 10-year CVD risk was 28.8% (SD 8.5%). Randomisation, postal delivery of the study drug and outcome assessment using registers/medical records were feasible and acceptable to participants. Most participants were able to take three tablets per day, but premature discontinuation of the study drug was common (≈30% of participants by 6 months), although there were no differences between the groups. All randomised participants returned questionnaires at baseline and 67% of participants returned questionnaires by the end of the study. There was no between-group difference in Short Form questionnaire-8 items or EuroQol-5 Dimensions scores. Compared with placebo, metformin was associated with small improvements in the mean glycated haemoglobin level [-0.82 mmol/mol, 95% confidence interval (CI) -1.39 to -0.24 mmol/mol], mean estimated glomerular filtration rate (2.31 ml/minute/1.73 m2, 95% CI -0.2 to 4.81 ml/minute/1.73 m2) and mean low-density lipoprotein cholesterol level (-0.11 mmol/l, 95% CI -0.25 to 0.02 mmol/l) and a reduction in mean plasma vitamin B12 level (-16.4 ng/l, 95% CI -32.9 to -0.01 ng/l). There were 35 serious adverse events (13 in the placebo group, 22 in the metformin group), with none deemed to be treatment related. LIMITATIONS: Changes to sponsorship reduced the study duration, the limited availability of information in medical records reduced recruitment efficiency and discontinuation of study medication exceeded forecasts. CONCLUSIONS: A large, pragmatic trial comparing the effects of prolonged-release metformin and placebo on the risk of CVD events is potentially feasible. However, changes to the study design and conduct are recommended to enable an efficient scaling up of the trial. Recommendations include changing the inclusion criteria to recruit people with pre-existing CVD to increase the recruitment and event rates, using large primary/secondary care databases to increase recruitment rates, conducting follow-up remotely to improve efficiency and including a run-in period prior to randomisation to optimise trial adherence. TRIAL REGISTRATION: Current Controlled Trials ISRCTN34875079. FUNDING: The project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 18. See the NIHR Journals Library website for further project information. Merck KGaA provided metformin and matching placebo.

Study Protocol: The Norfolk Diabetes Prevention Study [NDPS]: a 46 month multi - centre, randomised, controlled parallel group trial of a lifestyle intervention [with or without additional support from lay lifestyle mentors with Type 2 diabetes] to prevent transition to Type 2 diabetes in high risk groups with non - diabetic hyperglycaemia, or impaired fasting glucose.

BACKGROUND: This 7 year NIHR programme [2011-2018] tests the primary hypothesis that the NDPS diet and physical activity intervention will reduce the risk of transition to type 2 diabetes (T2DM) in groups at high risk of Type 2 diabetes. The NDPS programme recognizes the need to reduce intervention costs through group delivery and the use of lay mentors with T2DM, the realities of normal primary care, and the complexity of the current glycaemic categorisation of T2DM risk. METHODS: NDPS identifies people at highest risk of T2DM on the databases of 135 general practices in the East of England for further screening with ab fasting plasma glucose and glycosylated haemoglobin [HbA1c]. Those with an elevated fasting plasma glucose [impaired fasting glucose or IFG] with or without an elevated HbA1c [non -diabetic hyperglycaemia; NDH] are randomised into three treatment arms: a control arm receiving no trial intervention, an arm receiving an intensive bespoke group-based diet and physical activity intervention, and an arm receiving the same intervention with enhanced support from people with T2DM trained as diabetes prevention mentors [DPM]. The primary end point is cumulative transition rates to T2DM between the two intervention groups, and between each intervention group and the control group at 46 months. Participants with screen detected T2DM are randomized into an equivalent prospective controlled trial with the same intervention and control arms with glycaemic control [HbA1c] at 46 months as the primary end point. Participants with NDH and a normal fasting plasma glucose are randomised into an equivalent prospective controlled intervention trial with follow up for 40 months. The intervention comprises six education sessions for the first 12 weeks and then up to 15 maintenance sessions until intervention end, all delivered in groups, with additional support from a DPM in one treatment arm. DISCUSSION: The NDPS programme reports in 2018 and will provide trial outcome data for a group delivered diabetes prevention intervention, supported by lay mentors with T2DM, with intervention in multiple at risk glycaemic categories, and that takes into account the realities of normal clinical practice. TRIAL REGISTRATION: ISRCTN34805606 (Retrospectively registered 16.3.16).

Vascular function and atherosclerosis progression after 1 y of flavonoid intake in statin-treated postmenopausal women with type 2 diabetes: a double-blind randomized controlled trial.

BACKGROUND: In healthy participants, short-term flavan-3-ol and isoflavone intakes improve vascular function; however, the potential combined benefit of these compounds on atherosclerosis progression remains unclear for those at elevated risk of cardiovascular disease. OBJECTIVE: The objective was to examine whether combined isoflavone and flavan-3-ol intake alters vascular function in postmenopausal women with type 2 diabetes mellitus (T2DM). DESIGN: A double-blind, parallel-design, placebo-controlled 1-y trial was conducted in postmenopausal T2DM patients randomly assigned to a split dose of 27 g flavonoid-enriched chocolate/d [850 mg flavan-3-ols (90 mg epicatechin) + 100 mg isoflavones (aglycone equivalents)/d] or matched placebo. Intima-media thickness of the common carotid artery (CCA-IMT), pulse wave velocity (PWV), augmentation index, blood pressure (BP), and vascular biomarkers were assessed. RESULTS: A total of 93 patients completed the trial. Overall, the flavonoid intervention did not significantly change CCA-IMT, augmentation index, or BP, but pulse pressure variability improved (flavonoid: -0.11 ± 0.07 mm Hg/min; placebo: 0.10 ± 0.11 mm Hg/min; P = 0.04). In a subgroup with PWV data, net improvements were observed [flavonoid (n = 18): -0.07 ± 0.38 m/s; placebo (n = 17): 0.68 ± 0.25 m/s; P = 0.01], which equated to a 10% CV risk reduction. Equol producers (n = 17) had larger reductions in diastolic BP, mean arterial pressure, and PWV (-2.24 ± 1.31 mm Hg, -1.24 ± 1.30 mm Hg, and -0.68 ± 0.40 m/s, respectively; P < 0.01) compared with non-equol producers (n = 30). CONCLUSIONS: Although the 1-y intervention did not change CCA-IMT or BP, clinically relevant improvements in arterial stiffness were observed; equol producers were particularly responsive. Flavonoids may augment existing therapeutic strategies to reduce cardiovascular disease risk in postmenopausal T2DM patients, and longer studies are needed to examine the effects on atherosclerosis progression. This trial was registered at clinicaltrials.gov as NCT00677599.

A motivational peer support program for type 2 diabetes prevention delivered by people with type 2 diabetes: the UEA-IFG feasibility study.

PURPOSE: The purpose of this study was to develop a peer support program for individuals at high risk of type 2 diabetes as part of a novel Diabetes Prevention Programme (The UEA-IFG Study). Lay members of the public with existing type 2 diabetes volunteered as peer supporters (termed type 2 trainers) for participants at high risk of developing type 2 diabetes. The feasibility of type 2 trainer recruitment, training, and retention was tested. METHODS: Between January and September 2009, 1500 potential type 2 trainers with existing type 2 diabetes were contacted and 168 (11%) expressed an interest. From this group, 26 type 2 trainers were appointed to begin training. All completed 7 training seminars, covering diabetes prevention, nutrition, physical activity, listening skills, motivation, and goal planning. Motivational calls were made every 12 weeks to each study participant by each type 2 trainer in addition to health care professional-delivered education sessions. RESULTS: Twenty-six type 2 trainers were recruited to enter the program. One type 2 trainer withdrew before beginning their role. The retention rate was high, with 22 (89%) of the type 2 trainers continuing until study end (July 2010; 20 months), with a total of 240 phone calls made. CONCLUSION: The recruiting and training of lay volunteers with existing type 2 diabetes as type 2 trainers to support study participants at risk of developing the same condition was a cost-effective strategy in comparison to employing salaried health care professionals and warrants further investigation on health outcomes.

Chronic ingestion of flavan-3-ols and isoflavones improves insulin sensitivity and lipoprotein status and attenuates estimated 10-year CVD risk in medicated postmenopausal women with type 2 diabetes: a 1-year, double-blind, randomized, controlled trial.

OBJECTIVE: To assess the effect of dietary flavonoids on cardiovascular disease (CVD) risk in postmenopausal women with type 2 diabetes on established statin and hypoglycemic therapy. RESEARCH DESIGN AND METHODS: Despite being medicated, patients with type 2 diabetes have elevated CVD risk, particularly postmenopausal women. Although dietary flavonoids have been shown to reduce CVD risk factors in healthy participants, no long-term trials have examined the additional benefits of flavonoids to CVD risk in medicated postmenopausal women with type 2 diabetes. We conducted a parallel-design, placebo-controlled trial with type 2 diabetic patients randomized to consume 27 g/day (split dose) flavonoid-enriched chocolate (containing 850 mg flavan-3-ols [90 mg epicatechin] and 100 mg isoflavones [aglycone equivalents)]/day) or matched placebo for 1 year. RESULTS: Ninety-three patients completed the trial, and adherence was high (flavonoid 91.3%; placebo 91.6%). Compared with the placebo group, the combined flavonoid intervention resulted in a significant reduction in estimated peripheral insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR] -0.3 ± 0.2; P = 0.004) and improvement in insulin sensitivity (quantitative insulin sensitivity index [QUICKI] 0.003 ± 0.00; P = 0.04) as a result of a significant decrease in insulin levels (-0.8 ± 0.5 mU/L; P = 0.02). Significant reductions in total cholesterol:HDL-cholesterol (HDL-C) ratio (-0.2 ± 0.1; P = 0.01) and LDL-cholesterol (LDL-C) (-0.1 ± 0.1 mmol/L; P = 0.04) were also observed. Estimated 10-year total coronary heart disease risk (derived from UK Prospective Diabetes Study algorithm) was attenuated after flavonoid intervention (flavonoid +0.1 ± 0.3 vs. placebo 1.1 ± 0.3; P = 0.02). No effect on blood pressure, HbA(1c), or glucose was observed. CONCLUSIONS: One-year intervention with flavan-3-ols and isoflavones improved biomarkers of CVD risk, highlighting the additional benefit of flavonoids to standard drug therapy in managing CVD risk in postmenopausal type 2 diabetic patients.

Cost-effectiveness of a lifestyle intervention in preventing Type 2 diabetes.

OBJECTIVES: Previous research has suggested people with impaired fasting glucose (IFG) are less likely to develop Type 2 diabetes (T2DM) if they receive prolonged structured diet and exercise advice. This study examined the within-trial cost-effectiveness of such lifestyle interventions. METHODS: Screen-detected participants with either newly diagnosed T2DM or IFG were randomized 2:1 to intervention versus control (usual care) between February and December 2009, in Norfolk (UK). The intervention consisted of group based education, physiotherapy and peer support sessions, plus telephone contacts from T2DM volunteers. We monitored healthcare resource use, intervention costs, and quality of life (EQ-5D). The incremental cost per quality-adjusted life-year (QALY) gain (incremental cost effectiveness ratio [ICER]), and cost effectiveness acceptability curves (CEAC) were estimated. RESULTS: In total, 177 participants were recruited (118 intervention, 59 controls), with a mean follow-up of 7 months. Excluding screening and recruitment costs, the mean cost was estimated to be £551 per participant in the intervention arm, compared with £325 in the control arm. The QALY gains were -0.001 and -0.004, respectively. The intervention was estimated to have an ICER of £67,184 per QALY (16 percent probability of being cost-effective at the £20,000/QALY threshold). Cost-effectiveness estimates were more favorable for IFG participants and those with longer follow-up (≥ 4 months) (ICERs of £20,620 and £17,075 per QALY, respectively). CONCLUSIONS: Group sessions to prevent T2DM were not estimated to be within current limits of cost-effectiveness. However, there was a large degree of uncertainty surrounding these estimates, suggesting the need for further research.

Genetic evidence that raised sex hormone binding globulin (SHBG) levels reduce the risk of type 2 diabetes.

Epidemiological studies consistently show that circulating sex hormone binding globulin (SHBG) levels are lower in type 2 diabetes patients than non-diabetic individuals, but the causal nature of this association is controversial. Genetic studies can help dissect causal directions of epidemiological associations because genotypes are much less likely to be confounded, biased or influenced by disease processes. Using this Mendelian randomization principle, we selected a common single nucleotide polymorphism (SNP) near the SHBG gene, rs1799941, that is strongly associated with SHBG levels. We used data from this SNP, or closely correlated SNPs, in 27 657 type 2 diabetes patients and 58 481 controls from 15 studies. We then used data from additional studies to estimate the difference in SHBG levels between type 2 diabetes patients and controls. The SHBG SNP rs1799941 was associated with type 2 diabetes [odds ratio (OR) 0.94, 95% CI: 0.91, 0.97; P = 2 x 10(-5)], with the SHBG raising allele associated with reduced risk of type 2 diabetes. This effect was very similar to that expected (OR 0.92, 95% CI: 0.88, 0.96), given the SHBG-SNP versus SHBG levels association (SHBG levels are 0.2 standard deviations higher per copy of the A allele) and the SHBG levels versus type 2 diabetes association (SHBG levels are 0.23 standard deviations lower in type 2 diabetic patients compared to controls). Results were very similar in men and women. There was no evidence that this variant is associated with diabetes-related intermediate traits, including several measures of insulin secretion and resistance. Our results, together with those from another recent genetic study, strengthen evidence that SHBG and sex hormones are involved in the aetiology of type 2 diabetes.

Lack of association of colonic epithelium telomere length and oxidative DNA damage in Type 2 diabetes under good metabolic control.

BACKGROUND: Telomeres are DNA repeat sequences necessary for DNA replication which shorten at cell division at a rate directly related to levels of oxidative stress. Critical telomere shortening predisposes to cell senescence and to epithelial malignancies. Type 2 diabetes is characterised by increased oxidative DNA damage, telomere attrition, and an increased risk of colonic malignancy. We hypothesised that the colonic mucosa in Type 2 diabetes would be characterised by increased DNA damage and telomere shortening. METHODS: We examined telomere length (by flow fluorescent in situ hybridization) and oxidative DNA damage (flow cytometry of 8 - oxoguanosine) in the colonic mucosal cells of subjects with type 2 diabetes (n = 10; mean age 62.2 years, mean HbA1c 6.9%) and 22 matched control subjects. No colonic pathology was apparent in these subjects at routine gastrointestinal investigations. RESULTS: Mean colonic epithelial telomere length in the diabetes group was not significantly different from controls (10.6 [3.6] vs. 12.1 [3.4] Molecular Equivalent of Soluble Fluorochrome Units [MESF]; P = 0.5). Levels of oxidative DNA damage were similar in both T2DM and control groups (2.6 [0.6] vs. 2.5 [0.6] Mean Fluorescent Intensity [MFI]; P = 0.7). There was no significant relationship between oxidative DNA damage and telomere length in either group (both p > 0.1). CONCLUSION: Colonic epithelium in Type 2 diabetes does not differ significantly from control colonic epithelium in oxidative DNA damage or telomere length. There is no evidence in this study for increased oxidative DNA damage or significant telomere attrition in colonic mucosa as a carcinogenic mechanism.

Low density lipoprotein from patients with Type 2 diabetes increases expression of monocyte matrix metalloproteinase and ADAM metalloproteinase genes.

AIMS: Type 2 diabetes is characterised by increased plasma concentrations of pro-inflammatory cytokines [such as tumour necrosis factor - alpha; TNF-alpha] and soluble forms of adhesion molecules involved in leukocyte - endothelial interactions. These molecules are synthesised as transmembrane proteins and the plasma soluble forms are generated by ectodomain cleavage from the cell surface by members of the ADAM [adisintegrin and metalloproteinase] proteinase family. We hypothesised that plasma low density lipoprotein [LDL] from subjects with Type 2 diabetes would influence in vitro monocytic ADAM and matrix metalloproteinase [MMP] gene expression differently compared to control LDL. METHODS: We examined relative mRNA expression by real time PCR in a monocytic cell line [THP-1] cultured for 4, 8 and 24 hrs with human plasma LDL derived from subjects with [n = 5] or without [n = 4] Type 2 diabetes. Gene expression for MMP-1 and 9, and ADAM - 8, 15, 17 and 28 was studied. RESULTS: Type 2 diabetes LDL significantly increased gene expression of MMP - 1 [p < 0.01] MMP - 9 [p < 0.001], and ADAM 17 [p < 0.05], - 28 [p < 0.01] and - 15 [p < 0.01] compared to control LDL. Type 2 diabetes LDL had disparate effects on inhibitors of MMP. CONCLUSION: These data suggest that Type 2 diabetes LDL could lead to increased adhesion molecule and TNF alpha cell surface shedding, and vascular plaque instability, by promoting increased expression of ADAM and MMP genes.

Pro-oxidant effect of alpha-tocopherol in patients with type 2 diabetes after an oral glucose tolerance test--a randomised controlled trial.

BACKGROUND: As a part of a larger study investigating the effects of alpha-tocopherol on gene expression in type 2 diabetics we observed a pro-oxidant effect of alpha-tocopherol which we believe may be useful in interpreting outcomes of large intervention trials of alpha-tocopherol. METHODS: 19 type 2 diabetes subjects were randomised into two groups taking either 1200 IU/day of alpha-tocopherol or a matched placebo for 4 weeks. On day 0 and 29 of this study oxidative DNA damage was assessed in mononuclear cells from fasted blood samples and following a 2 h glucose tolerance test (GTT). RESULTS: On day 0 there was no significant difference in oxidative DNA damage between the two groups or following a GTT. On day 29 there was no significant difference in oxidative DNA damage in fasted blood samples, however following a GTT there was a significant increase in oxidative DNA damage in the alpha-tocopherol treatment group. CONCLUSION: High dose supplementation with alpha-tocopherol primes mononuclear cells from patients with type 2 diabetes for a potentially damaging response to acute hyperglycaemia.

Total and excess bed occupancy by age, specialty and insulin use for nearly one million diabetes patients discharged from all English Acute Hospitals.

To investigate total diabetes bed occupancy and prolonged inpatient length of stay (LOS) in all English Acute Hospitals, we analysed hospital episode statistics (HES) discharge data for all English Acute Hospitals over 4 years for ICD10 discharge codes of E10 ('insulin-dependent diabetes') or E11 ('non-insulin dependent diabetes') by age-band (18-60, 61-75 and >75 years) and specialties. We matched these data to control discharges without these codes. There were 943,613 diabetes discharges (6,508,668 bed days) and 10,724,414 matched controls. Mean diabetes LOS increased with age for each specialty and both E10 and E11 codes, but excess diabetes LOS decreased with age. Excess diabetes LOS was <1.0 days in most groups and highest (1.2 days) in insulin-dependent surgical patients under 60 years old, where 19.7% of bed days were excess. A similar pattern was seen for 76,570 diabetes inpatients with key cardiac or surgical conditions. Excess bed occupancy due to prolonged mean LOS accounted for 325,033 bed days under general medical and surgical codes. There were 25,525 discharges with diabetic ketoacidosis (126,495 bed days) in these 4 years. Excess diabetes LOS is concentrated in younger age groups. Excess bed occupancy due to prolonged LOS in medical and surgical inpatients is three times greater than bed occupancy due to diabetic ketoacidosis. Strategies to reduce excess diabetes bed occupancy should emphasize reducing inpatient LOS in younger inpatients.

Monocyte telomere shortening and oxidative DNA damage in type 2 diabetes.

OBJECTIVE: Telomeres are DNA sequences necessary for DNA replication, which shorten at cell division at a rate related to levels of oxidative stress. Once shortened to a critical length, cells are triggered into replicative senescence. Type 2 diabetes is associated with oxidative DNA damage, and we hypothesized that telomere shortening would characterize type 2 diabetes. RESEARCH DESIGN AND METHODS: We studied 21 male type 2 diabetic subjects (mean age 61.2 years, mean HbA(1c) 7.9%) selected to limit confounding effects on telomere length and 29 matched control subjects. Telomere length was measured in peripheral venous monocyte and T-cells (naïve and memory) by fluorescent in situ hybridization and oxidative DNA damage by flow cytometry of oxidized DNA bases. Peripheral insulin resistance (homeostasis model assessment) and high-sensitivity C-reactive protein (hsCRP) were measured. RESULTS: Mean monocyte telomere length in the diabetic group was highly significantly lower than in control subjects (4.0 [1.1] vs. 5.5 [1.1]; P < 0.0001), without significant differences in lymphocyte telomere length. There was a trend toward increased oxidative DNA damage in all diabetes cell types examined and a significant inverse relationship between oxidative DNA damage and telomere length (r = -0.55; P = 0.018) in the diabetic group. Telomere length was unrelated to plasma CRP concentration or insulin resistance. CONCLUSIONS: Monocyte telomere shortening in type 2 diabetes could be due to increased oxidative DNA damage to monocyte precursors during cell division. This data suggests that monocytes adhering to vascular endothelium and entering the vessel wall in type 2 diabetes are from a population with shorter telomeres and at increased risk of replicative senescence within vascular plaque.

Monocyte matrix and ADAM metalloproteinase expression in type 2 diabetes after aspirin therapy.

The matrix metalloproteinase system (MMP and the TIMP inhibitors), and the ADAM metalloproteinases, have roles in maintaining vascular plaque stability and the shedding of cell surface molecules, such as TNF-alpha and adhesion molecules; aspirin suppresses MMP expression and ADAM activity from some cell lines in vitro. In a randomised prospective controlled study, we examined peripheral venous monocyte MMP-9, TIMP-1 and ADAM mRNA levels, and protein expression, in subjects with type 2 diabetes (n=10) and controls (n=14) before and after oral aspirin therapy (150mg daily for 14 days) or no active intervention. Baseline monocyte TIMP-1 mRNA levels were significantly lower in the diabetes group (p=0.0014), although monocyte MMP-9 mRNA, and MMP-9 and TIMP-1 protein expression after culture did not differ significantly between groups. Plasma MMP-9 (p=0.027) and TIMP-1 (p=0.016) concentrations were significantly greater, and the ratio of plasma TIMP-1:MMP-9 concentrations significantly lower, in the diabetes group (p=0.023). ADAM mRNA levels did not differ significantly between groups and oral aspirin therapy had no significant effect on any variable. Type 2 diabetes is characterised by reduced monocyte TIMP-1 mRNA levels, and a lower plasma MMP-9 to TIMP-1 protein ratio compared to controls, a pattern that would promote coronary plaque instability if reproduced within vascular plaque. Monocyte ADAM mRNA levels do not differ between group and oral aspirin has no significant effect on these variables.

Paraoxonase-1 (PON-1) genotype and activity and in vivo oxidized plasma low-density lipoprotein in Type II diabetes.

The HDL (high-density lipoprotein)-associated enzyme PON (paraoxonase)-1 protects LDL (low-density lipoprotein) from oxidative modification in vitro, although it is unknown if this anti-atherogenic action occurs in vivo. In a cross-sectional study of 58 Type II diabetic subjects and 50 controls, we examined the fasting plasma LDL basal conjugated diene concentration [a direct measurement of circulating oxLDL (oxidatively modified LDL)], lipoprotein particle size by NMR spectroscopy, PON-1 polymorphisms (coding region polymorphisms Q192R and L55M, and gene promoter polymorphisms -108C/T and -162G/A), PON activity (with paraoxon or phenyl acetate as the substrates) and dietary antioxidant intake. Plasma oxLDL concentrations were higher in Type II diabetic patients (males, P = 0.048; females, P = 0.009) and unrelated to NMR lipoprotein size, PON-1 polymorphisms or PON activity (with paraoxon as the substrate) in any group. In men with Type II diabetes, however, there was a direct relationship between oxLDL concentrations and PON activity (with phenyl acetate as the substrate; r = 0.611, P = 0.0001) and an atherogenic NMR lipid profile in those who were PON-1 55LL homozygotes. Circulating oxLDL concentrations in vivo were unrelated to PON-1 genotypes or activity, except in male Type II diabetics where there was a direct association between PON activity (with phenyl acetate as the substrate) and oxLDL levels. These in vivo data contrast with in vitro data, and may be due to confounding by dietary fat intake. Male Type II diabetic subjects with PON-1 55LL homozygosity have an atherogenic NMR lipid profile independent of LDL oxidation. These data do not support an in vivo action of PON on LDL oxidation.

Association studies of insulin receptor substrate 1 gene (IRS1) variants in type 2 diabetes samples enriched for family history and early age of onset.

The gene encoding insulin receptor substrate-1 (IRS1) represents a strong biological candidate for a contributory role in type 2 diabetes susceptibility. Indeed, functional studies have implicated the G971R variant, and a recent meta-analysis of 27 association studies suggested that carriage of 971R was associated with a 25% increase in disease risk. However, this association has not been evaluated in large samples. The present study genotyped the P512A and G971R IRS1 variants in 971 U.K. type 2 diabetic subjects ascertained for strong family history and/or early onset, as well as 1,257 control subjects matched by ethnicity. There was no evidence for association with type 2 diabetes for either variant. (For example, the odds ratio [OR] for carriage of 971R was 1.11 [95% CI 0.86-1.44, P = 0.44]) An updated meta-analysis (31 studies: 5,104 case and 7,418 control subjects) remained significant for the G971R association (P = 0.025), albeit with a diminished OR (1.15 [95% CI 1.02-1.31]). Additional studies of IRS1 variation will be required to obtain a robust estimate of the overall contribution of IRS1 variation to type 2 diabetes susceptibility, but the current study suggests that previous studies have overestimated the magnitude of this effect.