Should the insulin resistance syndrome be treated in the elderly?

The insulin resistance syndrome represents the co-occurrence of hyperglycaemia, hypertension, central and overall obesity, and dyslipidaemia characterised by low high density lipoprotein-cholesterol (HDL-C) and high triglyceride levels. Epidemiologic studies have revealed an increasing prevalence of the insulin resistance syndrome in elderly populations. Indeed, recent data indicate that over 40% of US adults aged > or =60 years meet current criteria for the insulin resistance syndrome. Patients with this syndrome are at increased risk for the development of both cardiovascular disease (CVD) and type 2 diabetes mellitus, two of the most significant health problems among people >65 years of age. Identification and treatment of the insulin resistance syndrome may thus represent an important approach to reducing the overall burden of morbidity and mortality in the elderly. While development of the insulin resistance syndrome is partly determined by modifiable environmental factors, there may be a genetic basis for the syndrome, with high levels of concordance among monozygotic twins. Ongoing research focusing on the pathophysiology of this syndrome has implicated insulin resistance as the central disorder underlying both the development of diabetes as well as the pro-thrombotic endothelial dysfunction characteristic of CVD. Studies aimed at reversing insulin resistance have identified weight loss, exercise and pharmacological treatment with metformin, thiazolidinediones, HMG-CoA reductase inhibitors (statins) and ACE inhibitors as potential therapies to prevent the development of type 2 diabetes. However, although insulin sensitisation may be beneficial for preventing type 2 diabetes, there are no data yet available to show whether this strategy will reduce the incidence of CVD. Increased exercise and other healthy lifestyle changes form the cornerstone of therapy for elderly patients with the insulin resistance syndrome. In addition, active identification and aggressive management of traditional cardiovascular risk factors are the current standard of care. For elderly patients, recent studies have conclusively demonstrated the safety and efficacy of pharmacological management of elevated blood pressure and cholesterol levels.