Bone mineral density in healthy Kuwaiti women

OBJECTIVE: This study aimed to measure bone mineral density (BMD) of the lumber spine and femur regions in healthy adult Kuwaiti women, and to evaluate the influence of body size on BMD results. METHODS: Bone mass measurement was performed by dual-energy X-ray absorptiometry at the lumbar spine (L2-L4) and femur (four regions) of healthy ambulatory Kuwaiti females aged between 20 and 80 years. Body size measurements and a detailed questionnaire on past medical and gynecologic history, as well as lifestyle factors, were administered to all subjects. After excluding those with apparent or suggested abnormalities affecting bone mass, only 805 women from 4,887 were included and served as the target subjects. RESULTS: The spine BMD values for Kuwaiti women up to 69 years old were lower than their US counterparts; the peak value was established in the fifth decade. Femur neck BMD was relatively stable up to menopause. Spine osteoporosis was prevalent among 10% of the subjects, compared with 4% in the femoral neck. Regression analysis revealed that each kilogram of body weight has a change of 0.3% in premenopausal women and 0.5–0.6% in the older group. In multiple regressions that included the three factors (height, weight and age), the effect of age superseded that of weight in the older group of women, where there was a detrimental annual effect on spine and femur (neck and total hip) BMD by 0.9%, while each kilogram of body weight had a constructive effect by 0.4 and 0.3%. In the premenopausal women, the positive effect of 1 kg of body weight was equivalent to about 1 year of aging in the trochanter region and half a year in the total hip region. CONCLUSION: The BMD value of healthy Kuwaiti women tend to be lower than the US reference at the lumber spine in all age groups but showed higher values for femur neck only in the age group of late 30s through 60 years. Weight has a stronger effect on BMD than does the height. The prevalence of osteoporosis in the lumber spine was more than double that in the femur neck in postmenopausal women.