Bone Mineral Density among Egyptian Adolescents

Abstract Background Adolescent bone mineral density is affected by several endogenous and exogenous factors. Failure to maintain optimal bone health during adolescence carries a great risk for low bone mass later on with increase liability for fractures. Aim of the Study To determine the level of bone mineral density (BMD)in Egyptian adolescents and to evaluate the impact of, weight, height, body mass index (BMI), physical activity, sun exposure, pubertal stage and socio-economic status on bone mass. Methods Forty healthy Egyptian adolescents aged 12-13years were subjected to comprehensive medical history, dietary history to assess daily calcium intake, sunlight exposure, physical activity and socio-economic status. Complete physical examination was done including anthropometric measurements and identification of Tanner stage. Serum levels of calcium, phosphorus, and alkaline phosphatase were measured. Assessment of BMD of whole body, lumbar spine (LS), femoral neck (FN) and body composition was done using Hologic dual energy X-ray absorptiometry (DEXA) scanner. Results The mean values of total, subtotal, lumbar and, femoral BMD of our subjects were 0.86± 0.08,80± 0.080, 0.65±0.10, 0.77±0.1 respectively. Males had significant higher values regarding each of total, subtotal and femoral BMD (p value = 0.003, 0.004,< 0.001respectively) while females had significant higher values regarding lumbar spine BMD, total body fat and fat %(p value = 0.023,< 0.001,< 0.001respectively). No difference of significance was found in lean mass or total bone mineral content. Most of DEXA parameters correlated positively with each of exercise, sun exposure as well as anthropometric measurements. (p value < 0.05). No relation of significance was found with each of social status, Tanner stage and biochemical bone markers. Conclusion Peak bone mass in our patients has many influencing factors, for example gender, weight, height, exercise and sun exposure. Further interventions should be done to modify the exogenous factors aiming to decrease risk of fracture later on throughout adulthood.