Insulin-like growth factor I and collagen type III synthesis in patients with essential hypertension and left ventricular hypertrophy.

An excess of circulating insulin-like growth factor I (IGF-I) has been found in patients with essential hypertension and left ventricular hypertrophy (LVH). In addition, an increase in collagen type III synthesis has also been reported in hypertensive patients. Since IGF-I is a positive effector of collagen type III expression, we have investigated whether a relationship exists between circulating IGF-I and collagen type III synthesis in patients with essential hypertension. The relationship between plasma concentrations of IGF-I and an index of tissue synthesis of collagen type III (serum concentrations of procollagen type III aminoterminal peptide [PIIIP]) was investigated in 37 patients with essential hypertension before and after six months of treatment with lisinopril. The control group consisted of 30 age- and sex-matched normotensive subjects without LVH. Baseline concentrations of IGF-I were higher in hypertensive patients than in normotensive controls (285 +/- 25 vs. 240 +/- 15 ng/ml; P < 0.01). Mean IGF-I levels were higher in hypertensive patients with LVH (n = 10, 330 +/- 49 ng/ml) than in those without LVH (n = 27, 252 +/- 25 ng/ml; P < 0.05). Baseline concentrations of PIIIP were higher in hypertensive patients than in normotensive controls (10.07 +/- 0.54 vs. 8.47 +/- 0.77 ng/ml; P < 0.01). Mean PIIIP levels were higher in hypertensives with LVH than in those without LVH (12.20 +/- 0.78 vs. 7.97 +/- 0.55 ng/ml; P < 0.05). There was no correlation between IGF-I and PIIIP at baseline.(ABSTRACT TRUNCATED AT 250 WORDS)