Hyperinsulinemia in Obese and Non-Obese Young Japanese Hypertensive Men

We investigated whether hyperinsulinemia and insulin resistance were associated with hypertension independent of obesity in young (mean age 20 years) Japanese men. Subjects were classified as hypertensive if their systolic or diastolic blood pressure (BP) was ≥140 or≥90 mm Hg, respectively. Subjects were classified as obese if their body mass index (BMI) was ≥26. We divided 88 subjects into four groups: 29 nonobese normotensives (NONT), 12 nonobese hypertensives (NOHT), 28 obese normotensives (ONT), and 19 obese hypertensives (OHT). We conducted a 75 g oral glucose tolerance test (OGTT) and measured plasma glucose and serum insulin at 0, 30, and 60 min. We found similar glucose levels at fasting and during OGTT in all groups. Compared with the NONT group, the insulin levels at fasting and during OGTT were significantly higher in the NOHT group. No difference was found between the NOHT and ONT groups. The glucose/insulin ratios and the ratio of glucose area to insulin area were significantly lower in the NOHT group than in the NONT group; no difference was found between the NOHT and ONT groups. The OHT group had higher fasting insulin levels and lower fasting glucose/insulin ratios than the NOHT or ONT group. The fasting glucose/insulin ratio was correlated with the mean BP when the normotensives and hypertensives were combined. In a multiple regression analysis including BMI, the mean BP was still significantly related to the fasting glucose /insulin ratio. Our data indicate that hyperinsulinemia is associated with hypertension and is independent of obesity in young Japanese men. (Hypertens Res 1994; 17: 133 136).