RELATIVE FASTING HYPOINSULINEMIA AND ULTRASONICALLY MEASURED EARLY ARTERIAL-DISEASE IN TYPE-2 DIABETES

Macrovascular disease is the most important cause of morbidity and mor tality in Type 2 (non-insulin-dependent) diabetes. Dyslipidaemia and h yperinsulinaemia have been proposed as aetiological factors. This pape r describes the interrelationships between fasting serum insulin, seru m lipids, and the extent of ultrasonically measured early arterial dis ease in Type 2 diabetic subjects screened for entry into a prospective study set up to ascertain whether improving serum lipids can alter th e progress of arterial disease in Type 2 diabetes. Measurements were m ade of the initima media thickness (IMT) in the carotid artery, and an arterial ultrasound score (AUS) based on appearances of both carotid and femoral arteries was calculated for 192 established Type 2 diabeti c subjects, males and females, mean age 51 (range 35-66) years, median duration of diabetes 3.5 years, with no known cardiovascular disease. Multiple regression analysis showed that carotid IMT increased with a ge and was inversely related to serum insulin (variance accounted for, R(2), = 8.8 %, p = 0.0002). AUS increased with age and was related in versely to serum insulin, or to C-peptide when this was substituted in the model. In addition to age and serum insulin, AUS was positively a ssociated with non-HDL cholesterol and negatively with HDL 3 cholester ol (R(2) = 26 %, p = 0.0001). Early thickening and damage to the arter ial wall in Type 2 diabetes may be related to relative fasting hypoins ulinaemia.