The effects of alcohol consumption after menopause on bone regulating hormones

Abstract

The goal of this project was to determine if the alcohol-associated increase in osteopenia as observed in ovariectomized rats, which simulated human females after menopause, was due to the elect of alcohol on hormones that regulate bone metabolism. The study was a 2x3 factorial design with 2 types of hormone groups (ovariectomized and non-ovariectomized) and 3 types of diet groups (alcohol, pair-fed liquid control diet, and chow control diet). The alcohol groups were given ad libitum access to a modified Lieber-DeCarli liquid diet which contained 35% ethanol-derived calories, while the pair-fed control groups were given an equivalent volume of the same diet as the alcohol animals had consumed the previous day except the alcohol was replaced with isocaloric amounts of maltose-dextrin. The chow control groups were furnished standard lab pellets ad libitum. Terminal serum was analyzed for PTH, calcitonin, 25-OH-D, estradiol, testosterone, IGF-1, and osteocalcin. The results indicated increased PTH levels in the alcohol and pair-fed groups, while 25-OH-D levels were decreased and osteocalcin levels were increased in the pair-fed groups. There were no differences in estradiol and E/T ratio among diet groups. Testosterone values in the significantly lower than the chow group, but similar to each other. IGF-1 levels were decreased in the alcohol groups. Calcitonin, IGF-1, and osteocalcin levels were increased due to orchectomy, while estradiol and testosterone were decreased. The only significant interaction between diet and hormone was observed in the 25-OH-D levels in the normal and ovariectomized chow groups. Although the mechanism for the alcohol-associated osteopenia observed in ovariectomized rats is unclear, this study concludes that alcohol does not directly affect bone regulating hormones. Rather it appears to act directly on bone cells by possibly inhibiting the production and/or release of local factors such as IGF-1.