B Lapauw, Department of Endocrinology, Ghent University Hospital, Ghent, Belgium.
Objective: To assess and compare effects of short-term aromatase inhibition on glucose metabolism, lipid profile and adipocytokine levels in young and elderly men. Design and methods: Ten elderly and nine young healthy men were randomized to receive letrozole 2.5 mg daily or placebo for 28 days in a crossover design. Results: Both in young and elderly men, active treatment significantly increased serum testosterone (+128 and +99%, resp.) and decreased estradiol levels (-41 and -62%, resp.). Fasting glucose and insulin levels decreased in young men after active intervention (-7 and -37%, resp.) compared to placebo. Leptin levels fell markedly in both age groups (-24 and -25%, resp.), while adiponectin levels were not affected by the intervention. Lipid profile was slightly impaired in both groups, with increasing LDL-cholesterol levels (+14%) in the younger age group and 10% lower levels of ApoA1 in the elderly. A decline in IGF-1 levels (-15%) was observed in the younger age group. No changes in weight or BMI were observed in either young or old men. Conclusions: Short-term aromatase inhibition appears to affect glucose metabolism in young men, and lipid metabolism, including leptin secretion, in young and elderly men Furthermore, the short period of exposure suggests that these changes might be mediated by direct effects of sex steroids rather than by changes in body composition.
Objective: To assess and compare effects of short-term aromatase inhibition on glucose metabolism, lipid profile and adipocytokine levels in young and elderly men. Design and methods: Ten elderly and nine young healthy men were randomized to receive letrozole 2.5 mg daily or placebo for 28 days in a crossover design. Results: Both in young and elderly men, active treatment significantly increased serum testosterone (+128 and +99%, resp.) and decreased estradiol levels (-41 and -62%, resp.). Fasting glucose and insulin levels decreased in young men after active intervention (-7 and -37%, resp.) compared to placebo. Leptin levels fell markedly in both age groups (-24 and -25%, resp.), while adiponectin levels were not affected by the intervention. Lipid profile was slightly impaired in both groups, with increasing LDL-cholesterol levels (+14%) in the younger age group and 10% lower levels of ApoA1 in the elderly. A decline in IGF-1 levels (-15%) was observed in the younger age group. No changes in weight or BMI were observed in either young or old men. Conclusions: Short-term aromatase inhibition appears to affect glucose metabolism in young men, and lipid metabolism, including leptin secretion, in young and elderly men Furthermore, the short period of exposure suggests that these changes might be mediated by direct effects of sex steroids rather than by changes in body composition.
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