The insulin resistance is common in the patients with essential hypertension, even in the absence of non-insulin-dependent diabetes mellitus(NIDDM) or hyperlipidemia. It is well known that the offspring of patients with NIDDM have shown less insulin sensitivity compared with that of normal parents. But it is not yet known whether the insulin resistance is common in the offspring of patients with essential hypertension in Korea, who have no hypertension, NIDDM and hyperlipidemia. The aims of this study were to find out whether the insulin resistance exist in the middle aged normal offspring of the patients with essential hypertension and whether the insulin resistance is dependent on the metabolic abnormalities such as the body mass index(BMI), obesity and hyperlipidemia.

The serum lipid profiles and oral glucose tolerance test were performed. The anthropometrical measurement was done. The abdominal CT scan at umbilicus level and thigh CT was performed in the 11 offspring of parents with essential hypertension(group I;male : 7, female : 4)and 24 offspring of parents without essential hypertension, NIDDM, ischemic heart disease and hyperlipidemia(group II; male : 9, female : 15).

The average age of group I was 44.1±6.9 years, and that of the group II was 47.5±9.5 years. There were no significant differences in the blood pressure, weight, BMI, waist to hip ratio, waist to thigh ratio. And there were no significant differences in the serum cholesterol, triglyceride, HDL-cholesterol, serum Na, and plasma renin activities between both groups. Fasting plasma insulin and 2 hour insulin after 75gm glucose ingestion were significantly higher in group I than in group II(8.5±3.0mU/mL versus 5.0±1.8mU/mL, 61.6±31.7mU/mL versus 33.3±16.8mU/mL, p<0.05). The insulin sensitivity index was significantly lower in group I than in group II(355.1±92.6 versus 451.8±88.1, p<0.05). The visceral fat area was wider in group I than in group II(102.0±30.7cm² versus 64.5±28.5cm², p<0.05). The multiple regression analysis with the fasting plasma insulin and insulin sensitivity index as the dependent variables and family history of essential hypertension, visceral fat area and BMI as the predictor variables revealed that only the family history was associated with the fasting plasma insulin and insulin sensitivity index.

The offspring of the parents with essential hypertension showed the insulin resistance with increased visceral fat area in comparison with the offspring of the parents without essential hypertension.