Comparison of bone mineral density between premenopausal and postmenopausal women in Bangladesh.

ABSTRACT

This cross sectional study was conducted in the department of Obstetrics and Gynaecology at Bangabandhu Sheikh Mujib Medical University, Dhaka during July 1997 to June 1998. Two hundred and twenty (220) Bangladeshi premenopausal and post-menopausal women aged from 35 to 55 years were studied to compare the effect of age, parity, socioeconomic status and nutritional status on bone mineral density (BMD) of distal and ultra distal ends of radius and ulna. A bone densitometer (Single photon X-ray absorptiometry, DTX100, USA) was used to measure the BMD. BMD was calculated by taking the mean of the two sites and is expressed in g/cm2. Bone mineral density in post-menopausal women (0.48 +/- 0.1 g/cm2) was significantly lower than pre-menopausal women (0.61 +/- 0.06 g/cm2, p<0.001). Parity and number of family members were significantly greater in post-menopausal women compared to pre-menopausal women (6.5 +/- 2.9 vs. 4.2 +/- 2.3 and 8.1 +/- 2.5 vs. 6.2 +/- 2.3 respectively, p<0.001). Height was significantly lower in post-menopausal women (148.6 +/- 6.9 vs. 151.8 +/- 5.7 cm, p<0.001). After adjustment of various biological factors in multiple linear regression, body mass index (BMI) showed negative relationship with age (slope -0.0068, p<0.001) and positive relationship with weight (slope 0.0011, p<0.05). Peak BMD was observed upto the age of 40 years and thereafter declined and sharply after menopause. The study concluded that bone mineral density is greater in pre-menopausal women than post-menopausal women and remains high up to 35-40 years of age, and declines to older age. BMD positively correlates with weight of women. Premenopausal women have higher height than postmenopausal women though height does not have correlation with BMD in this study.