Regression of carotid atherosclerosis by control of postprandial hyperglycemia in type 2 diabetes mellitus

Background-Postprandial hyperglycemia may be a risk factor for cardiovascular disease. We compared the effects of two insulin secretagogues, repaglinide and glyburide, known to have different efficacy on postprandial hyperglycemia, on carotid intima-media thickness (CIMT) and markers of systemic vascular inflammation in type 2 diabetic patients. Methods and Results-We performed a randomized, single-blind trial on 175 drug-naive patients with type 2 diabetes mellitus (93 men and 82 women), 35 to 70 years of age, selected from a population of 401 patients who participated in an epidemiological analysis assessing the relation of postprandial hyperglycemia to surrogate measures of atherosclerosis. Eighty-eight patients were randomly assigned to receive repaglinide and 87 patients to glyburide, with a titration period of 6 to 8 weeks for optimization of drug dosage and a subsequent 12-month treatment period. The effects of repaglinide (1.5 to 12 mg/d) and glyburide (5 to 20 mg/d) on CIMT were compared by using blinded, serial assessments of the far wall. After 12 months, postprandial glucose peak was 148+/-28 mg/dL in the repaglinide group and 180+/-32 mg/dL in the glyburide group (P<0.01). HbA(1c) showed a similar decrease in both groups (-0.9%). CIMT regression, defined as a decrease of >0.020 mm, was observed in 52% of diabetics receiving repaglinide and in 18% of those receiving glyburide (P<0.01). Interleukin-6 (P=0.04) and C-reactive protein (P=0.02) decreased more in the repaglinide group than in the glyburide group. The reduction in CIMT was associated with changes in postprandial but not fasting hyperglycemia. Conclusions-Reduction of postprandial hyperglycemia in type 2 diabetic patients is associated with CIMT regression.