Association of plasma insulin with blood pressure and sodium sensitivity in children

To study the relationship between plasma insulin level, sodium sensitivity and blood pressure, 150 children aged from 10 to 15 years with high blood pressure and 150 children matched for age and sex but with normal blood pressure were measured for plasma insulin with radioimmunoassay and sodium sensitivity with the tests of oral saline load and furosemide sodium-volume depletion and followed for 5 years. The results showed that (1) In children with HBP and positive family history of hypertension (FH+), the plasma insulin level was significantly higher than that in the respective control group (P < 0.01); (2) In children with high plasma insulin level, the percentiles of systolic blood pressure kept high and had a rising tendency during the follow-up period; (3) In children with sodium sensitivity, the plasma insulin level was higher than that in children with sodium resistance (P < 0.01) and the plasma insulin level correlated positively with blood pressure increasing rate of post-load (P < 0.05). It is suggested that insulin resistance was associated with sodium sensitivity, and they might play a role in the development of hypertension in childhood.