Biochemical and nutritional determinants of bone loss in elderly women.

摘要

In elderly women, risk of osteoporotic fracture is a function of a woman's peak bone mass, attained sometime during the fourth decade of life, and subsequent rates of bone loss. It is therefore important to understand risk factors which predispose elderly women to more rapid rates of bone loss and focus preventive strategies on such factors. Presented herein are results concerning selected biochemical and nutritional determinants of rates of bone loss in elderly women, based upon data from the Study of Osteoporotic Fractures, a prospective study of 9,704 community-dwelling white women aged 65 and above.;To test hypotheses that baseline concentrations of biochemical factors such as sex steroids, sex hormone binding globulin (SHBG), calciotropic hormones and vitamin B-12 predict rates of bone loss in elderly women, baseline sera were assayed for concentrations of sex and calciotropic hormones, SHBG and vitamin B-12 in subcohorts of women who had initial and repeat measurements of calcaneal and hip bone mineral density (BMD). After controlling for age, weight and concentrations of other hormones, lower levels of endogenous estrogens and higher SHBG concentrations were associated with more rapid subsequent bone loss from both the calcaneus and hip. Lower 25(OH)D levels were associated with increased hip, but not calcaneal bone loss. Women with serum vitamin B-12 levels at or below 280 pg/ml experienced more rapid rates of bone loss from the hip, but not from the calcaneus.;In a separate subcohort of elderly women, a 63-item Block food-frequency questionnaire was administered and BMD of the hip was measured at the second clinic visit in 1988-89. Repeat measurements of hip BMD were taken in 1993-94. Prospective ascertainment of hip and non-spine/non-trauma fractures was also performed. Frequent consumption of foods high in lutein such as broccoli, spinach and kale, was associated with slower rates of femoral neck bone loss, and reduced risk of hip fracture, in elderly women. Diets high in vegetable relative to animal protein were associated with slower rates of femoral neck bone loss and reduced risk of hip fracture in elderly women.