Hyperinsulinemia in relation to hypertension and other coronary risk factors in Japanese men.
In addition to obesity, abnormalities in glucose and lipid metabolism are common in hypertensives, indicating a possible link between hypertension and hyperinsulinemia. Since the frequency of obesity in Japanese is lower than that in Caucasians, the present study was designed to clarify the frequencies of hyperinsulinemia, glucose and lipid abnormalities, and obesity. We surveyed consecutively 470 men without a history of gastrectomy who visited a health clinic after excluding previously known hypertensives receiving hypotensive agents (4.2%) and diabetics (6.1%). Hypertensives with a blood pressure exceeding 150 and/or 90 mmHg (n = 62) had a significantly higher frequency of diabetes mellitus (6.5%) associated with hypercholesterolemia (24.2%) and mild obesity with a body mass index (BMI) of more than 25 (24.2%) than those of normotensives. When reanalyzed according to the presence or absence of hyperinsulinemia after 75 g oral glucose loading, hyperinsulinemic men demonstrated a higher blood pressure. The incidences of impaired glucose tolerance (67.1%), hypertriglyceridemia (64.4%), low HDL-cholesterol (53.4%), hypercholesterolemia (21.9%) and mild obesity (37.0%) were also significantly higher than those of normoinsulinemic subjects. Subjects with either hypertension and/or hyperinsulinemia had a significantly higher incidence of coexistence of these risk factors. Multiple regression analysis revealed that not only BMI, but also the plasma glucose and insulin response during the 75 g glucose loading test independently correlated with mean blood pressure. These results suggest that hypertensive and/or hyperinsulinemic subjects may be associated with excess cardiovascular risk and should be managed more carefully.