[Serum insulin levels affect body constitution, blood pressure, serum lipids and cardiac dimensions. Observations in clinically healthy offspring from hypertensive families].

BACKGROUND

According to some work hypertension is in a pathogenetic relationship with hyperinsulinaemia or is considered to be the consequence of insulin resistance. It is, however, also known that there exists a familial predisposition for hypertension; according to genetic investigations half the family relatives can suffer from hypertension. In conjunction with these views on the pathogenesis of hypertension and its familial character the authors outlined the following objectives of their investigation: to test clinically and metabolically the condition of the offspring of probands with essential hypertension requiring systematic treatment. The authors investigated in particular indicators of body composition, insulin concentration and its relationship to serum levels and some indicators of lean body mass. METHODS AND RESULTS. There were 48 offspring (25 men and 23 women) from families of 30 probands suffering from hypertension. The mean age of the offspring was 38.4 +/- 7.8 years. They were compared with a group of 72 controls, mean age 35.8 +/- 8.2 years (36 men and 36 women) without a family history of hypertension and diabetes (t-test). The basal insulin concentration (IRI O' = 20.5 +/- 12.8 microU/ml, and 14.3 +/- 7.3 microU/ml resp., p < 0.01) and basal C peptide (O' = 0.59 +/- 0.31 pmol/ml and 0.50 +/- 0.20 pmol/ml resp., p < 0.05) were elevated. The offspring of probands with hypertension had a higher body weight (BMI = 25.3 +/- 3.5 kg/m2 and 23.3 +/- 2.5 kg/m2 resp., p < 0.001) a higher ratio of waist hip circumferences (0.94 +/- 0.1 and 0.87 +/- 0.1 resp., p < 0.001) similarly as blood pressure (131.5 mmHg +/- 11.8 mmHg and 116 mmHg +/- 13.3 mmHg resp., p < 0.001) and blood sugar level (5.29 +/- 0.61 mmol/l and 4.93 +/- 0.39 mmol/resp., p < 0.01). The authors also found differences in the serum cholesterol levels (5.9 +/- 1.3 mmol/l and 5.1 +/- 0.6 mmol/l resp., p < 0.01), HDL cholesterol (1.45 +/- 0.50 mmol/l and 1.65 +/- 0.60 mmol/l resp., p < 0.01) and triacylglycerol trends (1.66 +/- 1.54 mmol/l and 1.37 +/- 0.96 mmol/l resp., p < 0.1). On echocardiographic examination the cardiac dimensions were not enlarged, however, significant relations (linear regression) were proved in offspring in particular as regards the dimensions of the left ventricle and insulin (IRI O-left atrium p < 0.05, IRI 30-left atrium, p < 0.01. C peptide O-left atrium, p < 0.05). Between the body mass index, cholesterol, uric acid HDL-cholesterol the waist/hip ratio on the one side, the dimensions of the left atrium, thickness of septum and posterior wall (p < 0.01-0.001), between insulin and C peptide (p < 0.001) on the other side even closer relations were found.

CONCLUSIONS

Elevated insulin concentrations may participate in the development of body composition, they influence the lipid transport and blood pressure in clinically healthy offspring of probands suffering from hypertension. The relationship between the insulin concentration and disposition towards enlargement of the left heart needs more detailed investigation.