Fasting insulin levels closely correlated with metabolic syndrome

Fasting insulin levels in non-diabetic adults are more closely correlated with the metabolic syndrome and markers of atherosclerosis than insulin resistance, a European study has found. The gold standard technique for assessing insulin sensitivity is the hyperinsulinaemic euglycaemic clamp – a test which the authors said was time-consuming, expensive and stressful. In contrast, they said, fasting insulin assessments were simple and practical, but the association between insulin levels and cardiovascular risks has been uncertain. A cohort of 1,326 men and women aged between 30 and 60 had both tests performed. Fasting insulin levels were associated with all elements of the metabolic syndrome: fasting glucose, waist circumference, triglycerides, HDL cholesterol and blood pressure. Those with a fasting insulin level in the highest quartile were five times as likely to have the metabolic syndrome as those in the lowest quartile. Links between insulin sensitivity and the metabolic syndrome were less robust. Similarly, carotid intima-media thickness, a validated marker of atherosclerosis, was associated with insulin levels but not insulin resistance. “Ina very large, healthy population, fasting hyperinsulinaemia was an independent and even stronger contributor to cardiometabolic risk and atherosclerosis than insulin resistance,” the study concluded. European Journal of Endocrinology 2009; 161: 223-230....