Anthropometry at birth as a strong determinant factor of young women bone status: influence of high-level physical activity.

OBJECTIVE

To analyze the influence of anthropometry at birth on bone status and physical activity aptitudes of adult women.

METHODS

Our population was composed of 70 women (17-29 years): 40 athletes and 30 controls. Athletes participated in various long-lasting and high-level weight-bearing sports (10.2 ± 2.2h ours/week). Birth weight and height were collected. Bone Mineral Density (BMD) was measured by DXA, at whole body, lumbar spine, non dominant femur (total hip (TH), femoral neck (FN)) and tibia. The Hip Structural Analysis software was applied to assess cross-sectional area (CSA), cross-sectional moment of inertia (CSMI), section modulus (Z) and cortical thickness of three regions of the proximal femur: intertrochanter, narrow neck and femoral shaft.

RESULTS

BMD and HSA measurements at all sites were significantly higher in athletes versus controls, as well as birth height (P = 0.009) and weight (P = 0.02). For the whole population, we found significant positive correlations between birth weight and BMDs (0.30 < r< 0.46; 0.02 < P < 0.04); between birth height and TH (r = 0.32; P = 0.04), FN (r = 0.38; P = 0.04) and tibia BMD (r = 0.46, P = 0.0006); between birth weight and all HSA parameters (0.40 < r < 0.54; 10(-5) < P < 0.002); between birth height and all HSA parameters (0.28 < r < 0.34; 0.01 < P < 0.05) except intertrochanter CSMI and Z. Correlations were still significant in athlete group but it was just a trend in controls.

DISCUSSION/CONCLUSIONS: Adult bone status is conditioned by birth anthropometry, which can be used to predict fracture risk in later life. Predisposition to practice a weight-bearing sport could be related to the greater birth anthropometry described in athletes. The benefits of birth anthropometry on adult bone status appear to be maintained by sports.