Identifying nutritional and life-style risk factors associated with the development of osteoporosis in women of Asian origin at the Aga Khan University Hospital, Nairobi, Kenya
Thesis (MNutr (Interdisciplinary Health Sciences. Human Nutrition))--University of Stellenbosch, 2006.
INTRODUCTION: Postmenopausal osteoporosis is associated with significant morbidity, mortality, reduction in quality of life, and increasing health care costs OBJECTIVE: The study objective was to identify the risk factors associated with the occurrence of osteoporosis, in Kenyan Asian women seen at the Aga Khan University Hospital, Nairobi, Kenya since there is no literature on the prevalence of all these risk factors for osteoporosis in a similar middle aged population sample of Kenyan Asian women. METHOD: The study was of a retrospective design and used recall as a basis of data collection. A socio-demographic questionnaire was completed and anthropometric measurements, of height, weight, waist and hip circumference taken. Bone mineral density (BMD) had been measured previously using Quantitative Computed Tomography (QCT) at the lumbar spine, T11 to L4. Nutrient intake was assessed using a validated food frequency questionnaire (FFQ) and physical activity was determined using the Epic Physical Activity Questionnaire 2 (EPAQ2). BMD scans had been done on all study participants from January 2004 to December 2004 and the subjects were aware of their bone status. RESULTS: Risk factors that were identified by being associated with the development of osteoporosis in Asian women were age (p<0.001), waist size (p<0.001), hip size (p<0.001) and BMI (p<0.001), low physical activity (p=0.001) and use of prescription drugs. Seventy two percent of the study sample was using prescription drugs and the effect on bone mass was most likely detrimental. Anti-hypertensive (p=0.002), non steroidal anti inflammatory drugs (p=0.003) and anti-diabetic drugs (p=0.033) had a significant negative association with bone health. Energy, protein, fat and carbohydrate intake in all the groups was above the EAR and comparatively similar. The intake of all the micronutrients in the study group was above the DRI. There were no statistical significant differences in most of the trace element intake between the two groups, apart from iodine, biotin and manganese. No dietary risk factors were identified which impacted adversely on bone health in this group. The impact of gynaecologic history (parity, oral contraceptive use, age of menarche) on BMD was uncertain. The educational level of the study sample was high as 50% of the subjects were graduates and had a relatively better diet. CONCLUSION: As Kenyan Asian women age they experience the menopausal transition and the risk of developing osteoporosis increases. No nutritional factors were identified that were adversely associated with BMD. Low level of physical activity, prescription drugs for chronic diseases like hypertension, asthma, diabetes and arthritis, age, weight and body mass index were identified and found to be adversely associated with bone mineral density. Early detection, and implementation of patient education, physical activity, and a diet rich in all nutrients, will help to slow down the progression of osteoporosis.