Effects of Diet on Levels of Bone Mineral Density and Serum Insulin-Like Growth Factor-1 - Original Investigation

Osteoporosis is a major public health problem and the role of diet in both its prevention and pathogenesis is currently investigating. Diet is a modifiable factor which has role on both bone mass formation and prevention of osteoporosis. Insulin-like growth factor-1 (IGF-1) is a peptide which is structurally similar to insulin and has effect on calcium homeostasis. Fourty four women (19 premenopausal and 25 postmenopausal) aged over 40 years were enrolled into the study. Bone mineral density measurements were performed with DXA and 24 hours urinary calcium excretion and serum biochemistry values were evaluated. Serum IGF-1 levels were measured with an immunoradiometric assay method. All subjects were directed to a trained dietician and kept a seven-day dietary record. The data which obtained from dietary record were evaluated to determine the daily calcium, phosphorus, protein, lipid, carbohydrate, fiber, sodium, zinc, vitamin C and total energy intakes. There was found no correlation between daily protein, calcium, phosphorus, lipid, carbohydrate, fiber, sodium, zinc, vitamin C and total energy intakes and lumbar and femoral BMD values. Serum IGF-1 levels were found independent from daily protein intake and lumbar and femoral BMD were not found in association with serum IGF-1 levels. Also there was no association between daily protein or sodium intakes and urinary calcium excretion. According to data derived from our study, it is seemed that, nutritional factors in a normal mixed diet do not affect mainly the manifestation of osteoporosis in women. There is need for more studies with larger series to evaluate the role of IGF-1 system in this relationship. (Osteoporoz Dünyasından 2006; 12 (2): 27-30