INSULIN-LIKE GROWTH FACTOR-I AND SODIUM-LITHIUM COUNTERTRANSPORT IN ESSENTIAL-HYPERTENSION AND IN HYPERTENSIVE LEFT-VENTRICULAR HYPERTROPHY

Objective: The aim of this work was to study the insulin-like growth factor 1 (IGF1), a substance able to promote cell proliferation in vascular smooth muscle, in patients with mild-to-moderate hypertension and to analyse its relationship to sodium-lithium countertransport, a genetic marker of hypertension that is related to cardiovascular complications. Method: We studied 32 hypertensive subjects, some with left ventricular hypertrophy, and 14 healthy subjects. Fasting plasma IGF1 was measured by means of a radioimmunoassay after octadecylsilica chromatography and Na+-Li+ countertransport was determined by the method of Canessa. Results: Hypertensive patients had higher values of both IGF1 and Na+-Li+ countertransport. We found a positive correlation, irrespective of age, between IGF1 and Na+-Li+ countertransport. The patients with left ventricular hypertrophy had significantly higher plasma IGF1 levels than those without left ventricular hypertrophy. Conclusion: Our results confirm a possible role for IGF1 in the cardiovascular complications of hypertension and emphasize its relationship to genetically determined factors.