Naturally occurring menopause in cynomolgus monkeys: changes in hormone, lipid, and carbohydrate measures with hormonal status

Naturally occurring post-menopausal (PM) female cynomolgus monkeys (Macaca fascicularis) were identified. Their sex hormone profile was characterized and compared with younger pre-menopausal females before and after ovariectomy (OVX). PM females had lower estrogens and increased follicle-stimulating hormone (FSH) concentrations. Two PM females had diabetes mellitus and elevated androgens (androstenodione and dihydroepiandrosterone sulfate). Non-diabetic PM females were given parenteral E-2 which normalized FSH, and caused improvements in body weight, plasma lipids and lipoprotein cholesterol. Androgens remained lower with E-2 treatment. OVX induced comparable increases in FSH seen with the PM monkeys, however they had lower bodyweights, and had higher estrone and androstenodione concentrations. Natural menopause occurs in cynomolgus monkeys and hormone changes with OVX are similar however, differences in sex hormones that can relate to body mass and age may be important. E-2 treatment restored estrogen levels and induced improvements in the lipid profile of PM females.