Effects of growth hormone (GH) administration on homocyst (e) ine levels in men with GH deficiency: a randomized controlled trial

G Sesmilo, BMK Biller, J Llevadot… - The Journal of …, 2001 - academic.oup.com
G Sesmilo, BMK Biller, J Llevadot, D Hayden, G Hanson, N Rifai, A Klibanski
The Journal of Clinical Endocrinology & Metabolism, 2001academic.oup.com
GH deficiency is associated with increased cardiovascular mortality and early manifestations
of atherosclerosis. Elevated serum homocyst (e) ine levels have been found to be
associated with increased cardiovascular risk. The effect of GH replacement on homocyst (e)
ine has not been investigated to date. We evaluated the effect of GH replacement on fasting
homocyst (e) inemia in a group of men with adult-onset GH deficiency in a randomized,
single blind, placebo-controlled trial. Forty men with adult-onset GH deficiency were …
GH deficiency is associated with increased cardiovascular mortality and early manifestations of atherosclerosis. Elevated serum homocyst(e)ine levels have been found to be associated with increased cardiovascular risk. The effect of GH replacement on homocyst(e)ine has not been investigated to date. We evaluated the effect of GH replacement on fasting homocyst(e)inemia in a group of men with adult-onset GH deficiency in a randomized, single blind, placebo-controlled trial.
Forty men with adult-onset GH deficiency were randomized to GH or placebo for 18 months, with dose adjustments made according to serum insulin-like growth factor I (IGF-I) levels. Fasting serum homocyst(e)ine, folate, vitamin B12, and total T3 levels were determined at baseline and 6 and 18 months. Anthropometry, IGF-I levels, insulin, and glucose were measured at 1, 3, 6, 12, and 18 months. Nutritional assessment, body composition, total T4, thyroid hormone binding index, and free T4 index were assessed every 6 months.
Homocyst(e)ine decreased in the GH-treated group compared with that in the placebo group (net difference, −1.2 ± 0.6 μmol/L; confidence interval, −2.4, −0.02 μmol/L; P = 0.047). Homocyst(e)ine at baseline was negatively correlated with plasma levels of folate (r = −0.41; P = 0.0087). Total T3 increased in the GH-treated group vs. that in the placebo group (net difference, 0.17± 0.046 ng/dL; confidence interval, 0.071, 0.26 nmol/L; P = 0.0012). Folate and vitamin B12 levels did not significantly change between groups. Changes in homocyst(e)ine were negatively correlated with changes in IGF-I. For each 1 nmol/L increase in IGF-I, homocyst(e)ine decreased by 0.04 ± 0.02 μmol/L (P = 0.029). In contrast, changes in homocyst(e)ine did not correlate with changes in folate, vitamin B12, total T3, C-reactive protein, interleukin-6, or insulin levels. This study shows that GH replacement decreases fasting homocyst(e)ine levels compared with placebo. This may be one of the mechanisms involved in the putative modulation of atherosclerosis and cardiovascular risk by GH replacement.
Oxford University Press