HYPERTRIGLYCERIDEMIA IN SUBJECTS WITH NORMAL AND ABNORMAL GLUCOSE-TOLERANCE - RELATIVE CONTRIBUTIONS OF INSULIN-SECRETION, INSULIN-RESISTANCE AND SUPPRESSION OF PLASMA NONESTERIFIED FATTY-ACIDS

Although plasma insulin and triglyceride concentrations are positively correlated in many studies, the relationships between insulin resista nce, insulin secretion and hypertriglyceridaemia remain unclear. To st udy these associations, subjects between the ages of 40 and 64 were ra ndomly selected from a general practice register and invited to attend for a standard oral glucose tolerance test for measurement of insulin , triglyceride and non-esterified fatty acid concentrations. The study comprised 1122 subjects who were not previously known to have diabete s and who completed the test. Using the World Health Organisation crit eria, 51 subjects were classified to have non-insulin-dependent diabet es mellitus, 188 had impaired glucose tolerance and 883 subjects had n ormal glucose tolerance. Triglyceride concentrations in subjects with glucose intolerance were elevated compared to those in control subject s, even after adjustment for age, obesity and gender (p < 0.001 for su bjects with diabetes and p < 0.01 for those with impaired glucose tole rance compared to normal subjects). In separate multiple regression an alyses for mates and females, the most important determinants of the p lasma triglyceride concentration were the area under the non-esterifie d fatty acid suppression curve (p < 0.001 in both genders) and the wai st-hip ratio (p < 0.001 for men and < 0.01 for women). The fasting ins ulin concentration was independently associated with triglyceride conc entration in women only (p < 0.01). The most important determinant of the area under the non-esterified fatty acid suppression curve in men was the 30-min insulin increment, a measure of insulin secretion, (p < 0.001) whereas for women age (p < 0.001) and the body mass index (p < 0.01) were the most important.