Comment
Statins reduce cardiovascular events in patients with type 2 diabetes,1,2 and these drugs are now included in major therapeutic guidelines. However, previous clinical trials of statins were designed to assess their macrovascular effects. Thus, although statins have been shown to increase the incidence of type 2 diabetes,3,4 the effect of statins on the risk of developing microvascular disease is uncertain. Several trials have assessed the effect of statins on surrogate markers of diabetic retinopathy; however, results have been mixed and must be judged inconclusive. For example, in the Heart Protection Study,1 41 (14%) of 2978 patients receiving simvastatin needed laser treatment for retinopathy, compared with 36 (12%) of 2985 on placebo. With respect to diabetic nephropathy, the effects of statins on urine albumin excretion and progression to end-stage renal failure have not been established conclusively. Atorvastatin seems to reduce the progressive decline of estimated glomerular filtration in mixed populations, including patients with type 2 diabetes.5,6 This finding has been interpreted to indicate the renoprotective capacity of statins, but other explanations exist, such as the potential of statins to induce a change in muscle mass. In The Lancet Diabetes & Endocrinology, Sune Nielsen and Børge Nordestgaard7 report data from an observational analysis of the Danish Patient Registry, in which records for more than 60 000 patients who developed diabetes were linked electronically to microvascular outcomes. In the population studied, a quarter of patients had been treated with statins before diabetes diagnosis, and these individuals were matched with three-quarters who had not received statins before diagnosis. Over a median follow-up of 2·7 years (range 0–13), people who had used statins were less likely to be diagnosed with diabetic neuropathy (hazard ratio 0·66, 95% CI 0·57–0·75; p
Statins reduce cardiovascular events in patients with type 2 diabetes,1,2 and these drugs are now included in major therapeutic guidelines. However, previous clinical trials of statins were designed to assess their macrovascular effects. Thus, although statins have been shown to increase the incidence of type 2 diabetes,3,4 the effect of statins on the risk of developing microvascular disease is uncertain. Several trials have assessed the effect of statins on surrogate markers of diabetic retinopathy; however, results have been mixed and must be judged inconclusive. For example, in the Heart Protection Study,1 41 (14%) of 2978 patients receiving simvastatin needed laser treatment for retinopathy, compared with 36 (12%) of 2985 on placebo. With respect to diabetic nephropathy, the effects of statins on urine albumin excretion and progression to end-stage renal failure have not been established conclusively. Atorvastatin seems to reduce the progressive decline of estimated glomerular filtration in mixed populations, including patients with type 2 diabetes.5,6 This finding has been interpreted to indicate the renoprotective capacity of statins, but other explanations exist, such as the potential of statins to induce a change in muscle mass. In The Lancet Diabetes & Endocrinology, Sune Nielsen and Børge Nordestgaard7 report data from an observational analysis of the Danish Patient Registry, in which records for more than 60 000 patients who developed diabetes were linked electronically to microvascular outcomes. In the population studied, a quarter of patients had been treated with statins before diabetes diagnosis, and these individuals were matched with three-quarters who had not received statins before diagnosis. Over a median follow-up of 2·7 years (range 0–13), people who had used statins were less likely to be diagnosed with diabetic neuropathy (hazard ratio 0·66, 95% CI 0·57–0·75; p
