Bone mineral density in rural Thai adults living in Khon Kaen province.

Objectives: To define the bone status and pattern of bone loss in a normal adult population living in a rural area of Khon Kaen province.

Study Design: A descriptive study.

Settings: Department of Medicine, Faculty of Medicine, Khon Kaen University, Thailand. Subjects 436 subjects (181 men and 255 women), aged 20-80 years.

Main Outcome Measures: Bone parameter including total bone mineral density (BMD), the bone mineral density at different sites such as forearm, lumbar spine and hip, bone mineral content (BMC) were measured by dual energy X-ray absorptiometry (DEXA).

Results: The result revealed that women had lower bone mass at various bone sites than men. The peak bone mass in women was observed between 30-39 years of age except at the distal radius which occurred between 20-29 years of age while the peak bone mass in men was observed between 20-29 years of age. It was also shown that bone loss occurred in both men and women with advancing age. The rate of decline at all sites in women was greater than men especially when they were over 60 years old. When comparisons were made between pre and post-menopausal women, the mean of bone mineral density in pre-menopausal women was 1.18 +/- 0.08, 0.69 +/- 0.06, 0.69 +/- 0.06, 1.0 +/- 0.13, 1.15 +/- 0.13 g/cm2 at total body, mid-shaft radius, ultra distal radius, femoral neck and lumbar spine, respectively while the mean of bone mineral density in post-menopausal women was 1.02 +/- 0.12, 0.54 +/- 0.11, 0.54 +/- 0.11, 0.75 +/- 0.16, 0.88 +/- 0.2 g/cm2 at total body, mid-shaft radius, ultra distal radius, femoral neck and lumbar spine, respectively which were lower than BMD in pre-menopausal women (p<0.05). The mean bone mineral content (BMC) in pre-menopausal women was 2401+318.3 g while in post-menopausal women it was 1915.4+421.7 g (p<0.05). The rate of bone loss correlated with the duration after menopause. In this study, using World Health Organization criteria for diagnosis of osteopenia and osteoporosis and a reference value obtained from Khon Kaen young adults, the prevalence of osteopenia in Khon Kaen women subjects was 37.4 per cent at femoral neck, 30.2 per cent at lumbar spine, 44.5 per cent at ultra distal radius, 31.5 per cent at mid-shaft radius and the prevalence of was osteoporosis 19.3 per cent at femoral neck, 24.7 per cent at lumbar spine, 18.5 per cent at ultra distal radius and 26.4 per cent at mid-shaft radius.

Conclusion: The result of this study demonstrated the bone parameters in rural Thai adults living in Khon Kaen province, the pattern of bone loss, the difference between men and women and finally the prevalence of osteopenia and osteoporosis.