We evaluated the role of insulin in regulating and predicting blood pressure among 3596 to 2799 Finnish children and adolescents aged 3 to 18 years who were followed from 1980 to 1986. Blood pressure, weight, and height were measured in three surveys 3 years apart. Fasting blood samples were drawn and serum insulin was analyzed. The effect of insulin on blood pressure was evaluated in each of the 3 study years, together with the effect of fasting insulin on future blood pressure and the effect of insulin on the change in blood pressure. We also analyzed the correlation between insulin and blood pressure in different age groups and the correlation between change in insulin and change in blood pressure.
A constant positive correlation was found between insulin and both systolic and diastolic (Korotkoff's fifth phase) blood pressures measured in the respective years (correlation coefficients 0.10 to 0.41 and partial correlation coefficients 0.02 to 0.15), except between insulin and diastolic blood pressure in the first two surveys in terms of partial correlation and multiple regression analysis. Similarly insulin and blood pressure correlated positively in every age group. Insulin measured in 1980 or 1983 predicted systolic blood pressure as measured 3 and 6 years later (correlation coefficients 0.30 to 0.47 and partial correlation coefficients 0.06 to 0.13), and likewise diastolic blood pressure as measured 3 and 6 years later (correlation coefficients 0.17 to 0.35 and partial correlation coefficients 0.05 to 0.08), except among the males in 1983. Correlation between insulin and the change in blood pressure was not significant or remained marginal. Similarly, the correlation between change in insulin and change in blood pressure was not significant or remained marginal.
We suggest that insulin seems to regulate actual blood pressure within the normal range and to predict future blood pressure among children and adolescents, independently of age and weight. However, insulin does not enhance the rise in blood pressure.
