John H. Fuller

Primary prevention of cardiovascular disease with atorvastatin in type 2 diabetes in the Collaborative Atorvastatin Diabetes Study (CARDS): multicentre randomised placebo-controlled trial

BACKGROUND Type 2 diabetes is associated with a substantially increased risk of cardiovascular disease, but the role of lipid-lowering therapy with statins for the primary prevention of cardiovascular disease in diabetes is inadequately defined. We aimed to assess the effectiveness of atorvastatin 10 mg daily for primary prevention of major cardiovascular events in patients with type 2 diabetes without high concentrations of LDL-cholesterol. METHODS 2838 patients aged 40-75 years in 132 centres in the UK and Ireland were randomised to placebo (n=1410) or atorvastatin 10 mg daily (n=1428). Study entrants had no documented previous history of cardiovascular disease, an LDL-cholesterol concentration of 4.14 mmol/L or lower, a fasting triglyceride amount of 6.78 mmol/L or less, and at least one of the following: retinopathy, albuminuria, current smoking, or hypertension. The primary endpoint was time to first occurrence of the following: acute coronary heart disease events, coronary revascularisation, or stroke. Analysis was by intention to treat. FINDINGS The trial was terminated 2 years earlier than expected because the prespecified early stopping rule for efficacy had been met. Median duration of follow-up was 3.9 years (IQR 3.0-4.7). 127 patients allocated placebo (2.46 per 100 person-years at risk) and 83 allocated atorvastatin (1.54 per 100 person-years at risk) had at least one major cardiovascular event (rate reduction 37% [95% CI -52 to -17], p=0.001). Treatment would be expected to prevent at least 37 major vascular events per 1000 such people treated for 4 years. Assessed separately, acute coronary heart disease events were reduced by 36% (-55 to -9), coronary revascularisations by 31% (-59 to 16), and rate of stroke by 48% (-69 to -11). Atorvastatin reduced the death rate by 27% (-48 to 1, p=0.059). No excess of adverse events was noted in the atorvastatin group. INTERPRETATION Atorvastatin 10 mg daily is safe and efficacious in reducing the risk of first cardiovascular disease events, including stroke, in patients with type 2 diabetes without high LDL-cholesterol. No justification is available for having a particular threshold level of LDL-cholesterol as the sole arbiter of which patients with type 2 diabetes should receive statins. The debate about whether all people with this disorder warrant statin treatment should now focus on whether any patients are at sufficiently low risk for this treatment to be withheld.

Effect of lisinopril on progression of retinopathy in normotensive people with type 1 diabetes

BACKGROUND Retinopathy commonly occurs in people with type 1 diabetes. Strict glycaemic control can decrease development and progression of retinopathy only partially. Blood pressure is also a risk factor for microvascular complications. Antihypertensive therapy, especially with inhibitors of angiotensin-converting enzyme (ACE), can slow progression of nephropathy, but the effects on retinopathy have not been established. We investigated the effect of lisinopril on retinopathy in type 1 diabetes. METHODS As part of a 2-year randomised double-blind placebo-controlled trial, we took retinal photographs at baseline and follow-up (24 months) in patients aged 20-59 in 15 European centres. Patients were not hypertensive, and were normoalbuminuric (85%) or microalbuminuric. Retinopathy was classified from photographs on a five-level scale (none to proliferative). FINDINGS The proportion of patients with retinopathy at baseline was 65% (117) in the placebo group and 59% (103) in the lisinopril group (p = 0.2). Patients on lisinopril had significantly lower HbA1c at baseline than those on placebo (6.9% vs 7.3 p = 0.05). Retinopathy progressed by at least one level in 21 (13.2%) of 159 patients on lisinopril and 39 (23.4%) of 166 patients on placebo (odds ratio 0.50 [95% CI 0.28-0.89], p = 0.02). This 50% reduction was the same when adjusted for centre and glycaemic control (0.55 [0.30-1.03], p = 0.06). Lisinopril also decreased progression by two or more grades (0.27 [0.07-1.00], p = 0.05), and progression to proliferative retinopathy (0.18 [0.04-0.82], p = 0.03). Progression was not associated with albuminuric status at baseline. Treatment reduced retinopathy incidence (0.69 [0.30-1.59], p = 0.4). INTERPRETATION Lisinopril may decrease retinopathy progression in non-hypertensive patients who have type 1 diabetes with little or no nephropathy. These findings need to be confirmed before changes to clinical practice can be advocated.

The Role of Circulating Glucose and Triglyceride Concentrations and Their Interactions with Other “Risk Factors” as Determinants of Arterial Disease in Nine Diabetic Population Samples from the WHO Multinational Study

In 9 of the 14 national samples of diabetic patients assembled for the WHO Multinational Study of Vascular Disease in Diabetes additional laboratory data made it possible to relate manifestations of macrovascular disease to blood glucose concentrations as well as to diabetes duration and to other potential determinants. In five of the samples, serum triglyceride concentrations were also measured and were included in simple and multivariate analyses. Ischemic heart disease defined from Minnesota-coded EKGs and standardized WHO questionnaires was more strongly associated with serum triglyceride concentrations than with serum cholesterol concentrations, an association less notable in non-insulin-dependent diabetic patients. Ischemic heart disease was not related to the single fasting plasma glucose estimated for this study. Stroke and amputation were much more strongly related to the known duration of diabetes than was ischemic heart disease, and they were both related to blood glucose concentration measured at the time of study. Despite major variation in arterial disease prevalence rates between collaborating centers, risk for diabetic women appeared to equal that for diabetic men. The major variation in arterial disease prevalence between national groups could be accounted for only in part by the risk factors studied. Other factors, genetic or more likely environmental, are likely to contribute to the variation in arterial disease susceptibility and, if definable, may be potentially preventable.

Effect of candesartan on prevention (DIRECT-Prevent 1) and progression (DIRECT-Protect 1) of retinopathy in type 1 diabetes: randomised, placebo-controlled trials

BACKGROUND Results of previous studies suggest that renin-angiotensin system blockers might reduce the burden of diabetic retinopathy. We therefore designed the DIabetic REtinopathy Candesartan Trials (DIRECT) Programme to assess whether candesartan could reduce the incidence and progression of retinopathy in type 1 diabetes. METHODS Two randomised, double-blind, parallel-design, placebo-controlled trials were done in 309 centres worldwide. Participants with normotensive, normoalbuminuric type 1 diabetes without retinopathy were recruited to the DIRECT-Prevent 1 trial and those with existing retinopathy were recruited to DIRECT-Protect 1, and were assigned to candesartan 16 mg once a day or matching placebo. After 1 month, the dose was doubled to 32 mg. Investigators and participants were unaware of the treatment allocation status. The primary endpoints were incidence and progression of retinopathy and were defined as at least a two-step and at least a three-step increase on the Early Treatment Diabetic Retinopathy Study (ETDRS) scale, respectively. These trials are registered with ClinicalTrials.gov, numbers NCT00252733 for DIRECT-Prevent 1 and NCT00252720 for DIRECT-Protect 1. FINDINGS 1421 participants (aged 18-50 years) were randomly assigned to candesartan (n=711) or to placebo (n=710) in DIRECT-Prevent 1, and 1905 (aged 18-55 years) to candesartan (n=951) or to placebo (n=954) in DIRECT-Protect 1. Incidence of retinopathy was seen in 178 (25%) participants in the candesartan group versus 217 (31%) in the placebo group. Progression of retinopathy occurred in 127 (13%) participants in the candesartan group versus 124 (13%) in the placebo group. Hazard ratio (HR for candesartan vs placebo) was 0.82 (95% CI 0.67-1.00, p=0.0508) for incidence of retinopathy and 1.02 (0.80-1.31, p=0.85) for progression of retinopathy. The post-hoc outcome of at least a three-step increase for incidence yielded an HR of 0.65 (0.48-0.87, p=0.0034), which was attenuated but still significant after adjustment for baseline characteristics (0.71, 0.53-0.95, p=0.046). Final ETDRS level was more likely to have improved with candesartan treatment in both DIRECT-Prevent 1 (odds 1.16, 95% CI 1.05-1.30, p=0.0048) and DIRECT-Protect 1 (1.12, 95% CI 1.01-1.25, p=0.0264). Adverse events did not differ between the treatment groups. INTERPRETATION Although candesartan reduces the incidence of retinopathy, we did not see a beneficial effect on retinopathy progression.

Effect of candesartan on progression and regression of retinopathy in type 2 diabetes (DIRECT-Protect 2): a randomised placebo-controlled trial

BACKGROUND Diabetic retinopathy remains a leading cause of visual loss in people of working age. We examined whether candesartan treatment could slow the progression and, secondly, induce regression of retinopathy in people with type 2 diabetes. METHODS We did a randomised, double-blind, parallel-group, placebo-controlled trial in 309 centres worldwide. We recruited normoalbuminuric, normotensive, or treated hypertensive people with type 2 diabetes with mild to moderately severe retinopathy and assigned them to candesartan 16 mg once a day or placebo. After a month, the dose was doubled to 32 mg once per day. Investigators and patients were unaware of the treatment allocation status. Progression of retinopathy was the primary endpoint, and regression was a secondary endpoint. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00252694. FINDINGS 1905 participants (aged 37-75 years) were randomised to candesartan (n=951) or placebo (n=954). 161 (17%) patients in the candesartan group and 182 (19%) in the placebo group had progression of retinopathy by three steps or more on the Early Treatment Diabetic Retinopathy Study scale. The risk of progression of retinopathy was non-significantly reduced by 13% in patients on candesartan compared with those on placebo (hazard ratio [HR] 0.87, 95% CI 0.70-1.08, p=0.20). Regression on active treatment was increased by 34% (1.34, 1.08-1.68, p=0.009). HRs were not attenuated by adjustment for baseline risk factors or changes in blood pressure during the trial. An overall change towards less severe retinopathy by the end of the trial was observed in the candesartan group (odds 1.17, 95% CI 1.05-1.30, p=0.003). Adverse events did not differ between the treatment groups. INTERPRETATION Treatment with candesartan in type 2 diabetic patients with mild to moderate retinopathy might induce improvement of retinopathy.

High Risk of Cardiovascular Disease in Patients With Type 1 Diabetes in the U.K. A cohort study using the General Practice Research Database

OBJECTIVE To estimate the absolute and relative risk of cardiovascular disease (CVD) in patients with type 1 diabetes in the U.K. RESEARCH DESIGN AND METHODS Subjects with type 1 diabetes (n = 7,479) and five age- and sex-matched subjects without diabetes (n = 38,116) and free of CVD at baseline were selected from the General Practice Research Database (GPRD), a large primary care database representative of the U.K. population. Incident major CVD events, comprising myocardial infarction, acute coronary heart disease death, coronary revascularizations, or stroke, were captured for the period 1992-1999. RESULTS The hazard ratio (HR) for major CVD was 3.6 (95% CI 2.9-4.5) in type 1 diabetic men compared with those without diabetes and 7.7 (5.5-10.7) in women. Increased HRs were found for acute coronary events (3.0 and 7.6 in type 1 diabetic men and women, respectively, versus nondiabetic subjects), coronary revascularizations (5.0 in men, 16.8 in women), and for stroke (3.7 in men, 4.8 in women). Type 1 diabetic men aged 45-55 years had an absolute CVD risk similar to that of men in the general population 10-15 years older, with an even greater difference in women. CONCLUSIONS Despite advances in care, these data show that absolute and relative risks of CVD remain extremely high in patients with type 1 diabetes. Women with type 1 diabetes continue to experience greater relative risks of CVD than men compared with those without diabetes.

Effect of Candesartan on Microalbuminuria and Albumin Excretion Rate in Diabetes: Three Randomized Trials

BACKGROUND Microalbuminuria in diabetes is strongly predictive of nephropathy, end-stage renal disease, and premature cardiovascular morbidity and mortality. Effective preventive therapies are therefore a clinical priority. OBJECTIVE To determine whether the angiotensin-receptor blocker candesartan compared with placebo affects microalbuminuria incidence or rate of change in albuminuria in type 1 and type 2 diabetes. DESIGN 3 randomized trials of the DIRECT (Diabetic Retinopathy Candesartan Trials) Program. SETTING 309 secondary care centers. PATIENTS 3326 and 1905 patients with type 1 and type 2 diabetes, respectively. Most were normotensive, and all had normoalbuminuria (median urinary albumin excretion rate, 5.0 microg/min). INTERVENTION Candesartan, 16 mg/d increasing to 32 mg/d, versus placebo. Assignment was done centrally using an interactive voice-response system. Patients, caregivers, and researchers were blinded to treatment assignment. During a median follow-up of 4.7 years, 793 patients discontinued therapy and 63 were lost to follow-up. MEASUREMENTS Urinary albumin excretion rate, assessed annually by 2 overnight collections; if it was 20 microg/min or greater, then 2 further collections were done. The primary end point was new microalbuminuria (3 or 4 collections of urinary albumin excretion rate >or=20 microg/min). The secondary end point was rate of change in albuminuria. RESULTS Individual and pooled results of the 3 trials showed that candesartan had little effect on risk for microalbuminuria (pooled hazard ratio, 0.95 [95% CI, 0.78 to 1.16]; P = 0.60). Pooled results showed that the annual rate of change in albuminuria was 5.53% lower (CI, 0.73% to 10.14%; P = 0.024) with candesartan than with placebo. LIMITATIONS Investigators recruited mainly normotensive patients or patients with well-controlled hypertension who were at low overall vascular risk, which resulted in a low rate of microalbuminuria. Studies were powered for retinal and not renal end points. CONCLUSION Candesartan, 32 mg/d, for 4.7 years did not prevent microalbuminuria in mainly normotensive patients with type 1 or type 2 diabetes.

Socioeconomic gradient in morbidity and mortality in people with diabetes: cohort study findings from the Whitehall study and the WHO multinational study of vascular disease in diabetes

Objectives: To assess whether the inverse socioeconomic mortality gradient observed in the general population persists in diabetic people. Design: The Whitehall cohort study and the London cohort of the WHO multinational study of vascular disease in diabetes. Setting: London. Subjects: 17 264 male civil servants (17 046 without diabetes, 218 with diabetes) aged 40–64 examined in 1967-9, and 300 people with diabetes aged 35–55 from London clinics examined in 1975-7. Both cohorts were followed up until January 1995. Main outcome measures: Mortality from all causes, cardiovascular disease, and ischaemic heart disease. Results: In both cohorts people in the lower social groups were older, had higher blood pressure, and were more likely to smoke. In the Whitehall study, the prevalence of heart disease was higher in the lowest social group compared with the highest group, by 6% among non-diabetic people (P=0.0001) and by 14% among diabetic subjects (P=0.02). In the WHO study proteinuria was more common in the lowest social group compared with the highest (27% v 15%, P=0.01), as was retinopathy (54% v 48%, P=0.5). There was a clear socioeconomic gradient in all cause mortality in both cohorts, with death rates being about twice as high in the lowest compared with the highest social groups. In the Whitehall study this gradient was similar in both diabetic and non-diabetic subjects, and it persisted for mortality from cardiovascular disease and from ischaemic heart disease. About half of the increased risk of death in the lowest social group was accounted for by blood pressure and smoking. Conclusions: We confirm the existence of an inverse socioeconomic mortality gradient in diabetic people and suggest that this is largely due to conventional cardiovascular risk factors. Key messages People in lower social classes tend to have higher mortality than those in higher classes, but a Finnish study found no such socioeconomic gradient in mortality among diabetic people In response to this research we examined mortality in two large studies with 20 year follow up of 17 264 Whitehall civil servants (218 with diabetes) and 300 patients attending diabetes clinics in London Mortality was twice as high in diabetic people in the lowest socioeconomic groups as in those in the highest groups This difference was largely due to higher rates of smoking and high blood pressure in the lowest social groups, while blood glucose concentration had little impact on the relation These results emphasise the importance of improving conventional cardiovascular risk factors and reducing social inequality for reducing mortality in diabetic people

Relationship between risk factors and mortality in type 1 diabetic patients in Europe : the EURODIAB Prospective Complications Study (PCS)

OBJECTIVE—The purpose of this study was to examine risk factors for mortality in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS—Baseline risk factors were measured in the EURODIAB Prospective Cohort Study with 2,787 type 1 diabetic patients (51% men and 49% women) recruited from 16 European countries. Mortality data were collected during a 7-year follow-up. RESULTS—There was an annual mortality rate of 5 per 1,000 person-years in patients with type 1 diabetes (mean age at baseline 33 years, range 15–61 years); of the total 2,787 subjects, 102 died. The final multivariable model contained age at baseline (standardized hazard ratio 1.78 [95% CI 1.44–2.20]), A1C (1.18 [0.95–1.46]), waist-to-hip ratio (WHR) (1.32 [1.14–1.52]), pulse pressure (1.33 [1.13–1.58]), and non-HDL cholesterol (1.33 [1.12–1.60]) as risk factors for all-cause mortality. Macroalbuminuria (2.39 [1.19–4.78]) and peripheral (1.88 [1.06–3.35]) and autonomic neuropathy (2.40 [1.32–4.36]) were the most important risk markers for mortality. Similar risk factors were found for all-cause, non-cardiovascular disease (CVD), unknown-cause, and CVD mortality. CONCLUSIONS—Important risk factors for the increased total and non-CVD mortality in type 1 diabetic patients are age, WHR, pulse pressure, and non-HDL cholesterol. Microvascular complications from macroalbuminuria and peripheral and autonomic neuropathy are strong risk markers for future mortality exceeding the effect of the traditional risk factors.

The Effect of Type 1 Diabetes Mellitus on the Gender Difference in Coronary Artery Calcification

OBJECTIVES To examine whether the gender difference in coronary artery calcification, a measure of atherosclerotic plaque burden, is lost in type 1 diabetic patients, and whether abnormalities in established coronary heart disease risk factors explain this. BACKGROUND Type 1 diabetes abolishes the gender difference in coronary heart disease mortality because it is associated with a greater elevation of coronary disease risk in women than men. The pathophysiological basis of this is not understood. METHODS Coronary artery calcification and coronary risk factors were compared in 199 type 1 diabetic patients and 201 nondiabetic participants of similar age (30 to 55 years) and gender (50% female) distribution. Only one subject had a history of coronary disease. Calcification was measured with electron beam computed tomography. RESULTS In nondiabetic participants there was a large gender difference in calcification prevalence (men 54%, women 21%, odds ratio 4.5, p < 0.001), half of which was explained by established risk factors (odds ratio after adjustment = 2.2). Diabetes was associated with a greatly increased prevalence of calcification in women (47%), but not men (52%), so that the gender difference in calcification was lost (p = 0.002 for the greater effect of diabetes on calcification in women than men). On adjustment for risk factors, diabetes remained associated with a threefold higher odds ratio of calcification in women than men (p = 0.02). CONCLUSIONS In type 1 diabetes coronary artery calcification is greatly increased in women and the gender difference in calcification is lost. Little of this is explained by known coronary risk factors.