John McKnight

The prevention of progression of arterial disease and diabetes (POPADAD) trial: factorial randomised placebo controlled trial of aspirin and antioxidants in patients with diabetes and asymptomatic peripheral arterial disease

Objective To determine whether aspirin and antioxidant therapy, combined or alone, are more effective than placebo in reducing the development of cardiovascular events in patients with diabetes mellitus and asymptomatic peripheral arterial disease. Design Multicentre, randomised, double blind, 2×2 factorial, placebo controlled trial. Setting 16 hospital centres in Scotland, supported by 188 primary care groups. Participants 1276 adults aged 40 or more with type 1 or type 2 diabetes and an ankle brachial pressure index of 0.99 or less but no symptomatic cardiovascular disease. Interventions Daily, 100 mg aspirin tablet plus antioxidant capsule (n=320), aspirin tablet plus placebo capsule (n=318), placebo tablet plus antioxidant capsule (n=320), or placebo tablet plus placebo capsule (n=318). Main outcome measures Two hierarchical composite primary end points of death from coronary heart disease or stroke, non-fatal myocardial infarction or stroke, or amputation above the ankle for critical limb ischaemia; and death from coronary heart disease or stroke. Results No evidence was found of any interaction between aspirin and antioxidant. Overall, 116 of 638 primary events occurred in the aspirin groups compared with 117 of 638 in the no aspirin groups (18.2% v 18.3%): hazard ratio 0.98 (95% confidence interval 0.76 to 1.26). Forty three deaths from coronary heart disease or stroke occurred in the aspirin groups compared with 35 in the no aspirin groups (6.7% v 5.5%): 1.23 (0.79 to 1.93). Among the antioxidant groups 117 of 640 (18.3%) primary events occurred compared with 116 of 636 (18.2%) in the no antioxidant groups (1.03, 0.79 to 1.33). Forty two (6.6%) deaths from coronary heart disease or stroke occurred in the antioxidant groups compared with 36 (5.7%) in the no antioxidant groups (1.21, 0.78 to 1.89). Conclusion This trial does not provide evidence to support the use of aspirin or antioxidants in primary prevention of cardiovascular events and mortality in the population with diabetes studied. Trial registration Current Controlled Trials ISRCTN53295293.

Estimated Life Expectancy in a Scottish Cohort With Type 1 Diabetes, 2008-2010

IMPORTANCE Type 1 diabetes has historically been associated with a significant reduction in life expectancy. Major advances in treatment of type 1 diabetes have occurred in the past 3 decades. Contemporary estimates of the effect of type 1 diabetes on life expectancy are needed. OBJECTIVE To examine current life expectancy in people with and without type 1 diabetes in Scotland. We also examined whether any loss of life expectancy in patients with type 1 diabetes is confined to those who develop kidney disease. DESIGN, SETTING, AND PARTICIPANTS Prospective cohort of all individuals alive in Scotland with type 1 diabetes who were aged 20 years or older from 2008 through 2010 and were in a nationwide register (n=24,691 contributing 67,712 person-years and 1043 deaths). MAIN OUTCOMES AND MEASURES Differences in life expectancy between those with and those without type 1 diabetes and the percentage of the difference due to various causes. RESULTS Life expectancy at an attained age of 20 years was an additional 46.2 years among men with type 1 diabetes and 57.3 years among men without it, an estimated loss in life expectancy with diabetes of 11.1 years (95% CI, 10.1-12.1). Life expectancy from age 20 years was an additional 48.1 years among women with type 1 diabetes and 61.0 years among women without it, an estimated loss with diabetes of 12.9 years (95% CI, 11.7-14.1). Even among those with type 1 diabetes with an estimated glomerular filtration rate of 90 mL/min/1.73 m2 or higher, life expectancy was reduced (49.0 years in men, 53.1 years in women) giving an estimated loss from age 20 years of 8.3 years (95% CI, 6.5-10.1) for men and 7.9 years (95% CI, 5.5-10.3) for women. Overall, the largest percentage of the estimated loss in life expectancy was related to ischemic heart disease (36% in men, 31% in women) but death from diabetic coma or ketoacidosis was associated with the largest percentage of the estimated loss occurring before age 50 years (29.4% in men, 21.7% in women). CONCLUSIONS AND RELEVANCE Estimated life expectancy for patients with type 1 diabetes in Scotland based on data from 2008 through 2010 indicated an estimated loss of life expectancy at age 20 years of approximately 11 years for men and 13 years for women compared with the general population without type 1 diabetes.

Risk of cardiovascular disease and total mortality in adults with type 1 diabetes: Scottish registry linkage study

Helen Colhoun and colleagues report findings from a Scottish registry linkage study regarding contemporary risks for cardiovascular events and all-cause mortality among individuals diagnosed with type 1 diabetes.

Glycaemic control of Type 1 diabetes in clinical practice early in the 21st century: an international comparison

Improving glycaemic control in people with Type 1 diabetes is known to reduce complications. Our aim was to compare glycaemic control among people with Type 1 diabetes using data gathered in regional or national registries.

Association Between BMI Measured Within a Year After Diagnosis of Type 2 Diabetes and Mortality

OBJECTIVE To describe the association of BMI with mortality in patients diagnosed with type 2 diabetes. RESEARCH DESIGN AND METHODS Using records of 106,640 patients in Scotland, we investigated the association between BMI recorded around the diagnosis of type 2 diabetes mellitus (T2DM) and mortality using Cox proportional hazards regression adjusted for age and smoking status, with BMI 25 to <30 kg/m2 as a referent group. Deaths within 2 years of BMI determination were excluded. Mean follow-up to death or the end of 2007 was 4.7 years. RESULTS A total of 9,631 deaths occurred between 2001 and 2007. Compared with the reference group, mortality risk was higher in patients with BMI 20 to <25 kg/m2 (hazard ratio 1.22 [95% CI 1.13–1.32] in men, 1.32 [1.22–1.44] in women) and patients with BMI ≥35 kg/m2 (for example, 1.70 [1.24–2.34] in men and 1.81 [1.46–2.24] in women for BMI 45 to <50 kg/m2). Vascular mortality was higher for each 5-kg/m2 increase in BMI >30 kg/m2 by 24% (15–35%) in men and 23% (14–32%) in women, but was lower below this threshold. The results were similar after further adjustment for HbA1c, year of diagnosis, lipids, blood pressure, and socioeconomic status. CONCLUSIONS Patients categorized as normal weight or obese with T2DM within a year of diagnosis of T2DM exhibit variably higher mortality outcomes compared with the overweight group, confirming a U-shaped association of BMI with mortality. Whether weight loss interventions reduce mortality in all T2DM patients requires study.

Hospitalised hip fracture risk with rosiglitazone and pioglitazone use compared with other glucose-lowering drugs

Aims/hypothesisCurrent drug labels for thiazolidinediones (TZDs) warn of increased fractures, predominantly for distal fractures in women. We examined whether exposure to TZDs affects hip fracture in women and men and compared the risk to that found with other drugs used in diabetes.MethodsUsing a nationwide database of prescriptions, hospital admissions and deaths in those with type 2 diabetes in Scotland we calculated TZD exposure among 206,672 individuals. Discrete-time failure analysis was used to model the effect of cumulative drug exposure on hip fracture during 1999–2008.ResultsThere were 176 hip fractures among 37,479 exposed individuals. Hip fracture risk increased with cumulative exposure to TZD: OR per year of exposure 1.18 (95% CI 1.09, 1.28; p = 3 × 10−5), adjusted for age, sex and calendar month. Hip fracture increased with cumulative exposure in both men (OR 1.20; 95% CI 1.03, 1.41) and women (OR 1.18; 95% CI 1.07, 1.29) and risks were similar for pioglitazone (OR 1.18) and rosiglitazone (OR 1.16). The association was similar when adjusted for exposure to other drugs for diabetes and for other potential confounders. There was no association of hip fracture with cumulative exposure to sulfonylureas, metformin or insulin in this analysis. The 90-day mortality associated with hip fractures was similar in ever-users of TZD (15%) and in never-users (13%).Conclusions/interpretationHip fracture is a severe adverse effect with TZDs, affecting both sexes; labels should be changed to warn of this. The excess mortality is at least as much as expected from the reported association of pioglitazone with bladder cancer.

Contemporary Risk of Hip Fracture in Type 1 and Type 2 Diabetes: A National Registry Study From Scotland

The purpose of this study was to compare contemporary risk of hip fracture in type 1 and type 2 diabetes with the nondiabetic population. Using a national diabetes database, we identified those with type 1 and type 2 diabetes who were aged 20 to 84 years and alive anytime from January 1, 2005 to December 31, 2007. All hospitalized events for hip fracture in 2005 to 2007 for diabetes patients were linked and compared with general population counts. Age‐ and calendar‐year‐adjusted incidence rate ratios were calculated by diabetes type and sex. One hundred five hip fractures occurred in 21,033 people (59,585 person‐years) with type 1 diabetes; 1421 in 180,841 people (462,120 person‐years) with type 2 diabetes; and 11,733 hip fractures over 10,980,599 person‐years in the nondiabetic population (3.66 million people). Those with type 1 diabetes had substantially elevated risks of hip fracture compared with the general population incidence risk ratio (IRR) of 3.28 (95% confidence interval [CI] 2.52–4.26) in men and 3.54 (CI 2.75–4.57) in women. The IRR was greater at younger ages, but absolute risk difference was greatest at older ages. In type 2 diabetes, there was no elevation in risk among men (IRR 0.97 [CI 0.92–1.02]) and the increase in risk in women was small (IRR 1.05 [CI 1.01–1.10]). There remains a substantial elevation relative risk of hip fracture in people with type 1 diabetes, but the relative risk is much lower than in earlier studies. In contrast, there is currently little elevation in overall hip fracture risk with type 2 diabetes, but this may mask elevations in risk in particular subgroups of type 2 diabetes patients with different body mass indexes, diabetes duration, or drug exposure.

Reduced Incidence of Lower-Extremity Amputations in People with Diabetes in Scotland: A nationwide study

OBJECTIVE To establish the incidence of nontraumatic lower-extremity amputation (LEA) in people with diabetes in Scotland. RESEARCH DESIGN AND METHODS This cohort study linked national morbidity records and diabetes datasets to establish the number of people with diabetes who underwent nontraumatic major and minor LEA in Scotland from 2004 to 2008. RESULTS Two thousand three hundred eighty-two individuals with diabetes underwent a nontraumatic LEA between 2004 and 2008; 57.1% (n = 1,359) underwent major LEAs. The incidence of any LEA among persons with diabetes fell over the 5-year study period by 29.8% (3.04 per 1,000 in 2004 to 2.13 per 1,000 in 2008, P < 0.001). Major LEA rates decreased by 40.7% from 1.87 per 1,000 in 2004 to 1.11 per 1,000 in 2008 (P < 0.001). CONCLUSIONS There has been a significant reduction in the incidence of LEA in persons with diabetes in Scotland between 2004 and 2008, principally explained by a reduction in major amputation.

Effect of a lifestyle intervention on weight change in south Asian individuals in the UK at high risk of type 2 diabetes: a family-cluster randomised controlled trial.

BACKGROUND The susceptibility to type 2 diabetes of people of south Asian descent is established, but there is little trial-based evidence for interventions to tackle this problem. We assessed a weight control and physical activity intervention in south Asian individuals in the UK. METHODS We did this non-blinded trial in two National Health Service (NHS) regions in Scotland (UK). Between July 1, 2007, and Oct 31, 2009, we recruited men and women of Indian and Pakistani origin, aged 35 years or older, with waist circumference 90 cm or greater in men or 80 cm or greater in women, and with impaired glucose tolerance or impaired fasting glucose determined by oral glucose tolerance test. Families were randomised (using a random number generator program, with permuted blocks of random size, stratified by location [Edinburgh or Glasgow], ethnic group [Indian or Pakistani], and number of participants in the family [one vs more than one]) to intervention or control. Participants in the same family were not randomised separately. The intervention group received 15 visits from a dietitian over 3 years and the control group received four visits in the same period. The primary outcome was weight change at 3 years. Analysis was by modified intention to treat, excluding participants who died or were lost to follow-up. We used linear regression models to provide mean differences in baseline-adjusted weight at 3 years. This trial is registered, number ISRCTN25729565. FINDINGS Of 1319 people who were screened with an oral glucose tolerance test, 196 (15%) had impaired glucose tolerance or impaired fasting glucose and 171 entered the trial. Participants were in 156 family clusters that were randomised (78 families with 85 participants were allocated to intervention; 78 families with 86 participants were allocated to control). 167 (98%) participants in 152 families completed the trial. Mean weight loss in the intervention group was 1.13 kg (SD 4.12), compared with a mean weight gain of 0.51 kg (3.65) in the control group, an adjusted mean difference of -1.64 kg (95% CI -2.83 to -0.44). INTERPRETATION Modest, medium-term changes in weight are achievable as a component of lifestyle-change strategies, which might control or prevent adiposity-related diseases. FUNDING National Prevention Research Initiative, NHS Research and Development; NHS National Services Scotland; NHS Health Scotland.

External validity of randomized controlled trials of glycaemic control and vascular disease: how representative are participants?

To describe the proportion of people with Type 2 diabetes living in Scotland who meet eligibility criteria for inclusion in several large randomized controlled trials of glycaemic control to inform physicians and guideline developers about the generalizibility of trial results.