Lappe Joan M, Watson Patrice, Gilsanz Vicente, Hangartner Thomas, Kalkwarf Heidi J, Oberfield Sharon, Shepherd John, Winer Karen K, Zemel Babette
Creighton University, Omaha, NE, USA.
J Bone Miner Res. 2015 Jan;30(1):156-64. doi: 10.1002/jbmr.2319.
Childhood and adolescence are critical periods of bone mineral content (BMC) accrual that may have long-term consequences for osteoporosis in adulthood. Adequate dietary calcium intake and weight-bearing physical activity are important for maximizing BMC accrual. However, the relative effects of physical activity and dietary calcium on BMC accrual throughout the continuum of pubertal development in childhood remains unclear. The purpose of this study was to determine the effects of self-reported dietary calcium intake and weight-bearing physical activity on bone mass accrual across the five stages of pubertal development in a large, diverse cohort of US children and adolescents. The Bone Mineral Density in Childhood study was a mixed longitudinal study with 7393 observations on 1743 subjects. Annually, we measured BMC by dual-energy X-ray absorptiometry (DXA), physical activity and calcium intake by questionnaire, and pubertal development (Tanner stage) by examination for up to 7 years. Mixed-effects regression models were used to assess physical activity and calcium intake effects on BMC accrual at each Tanner stage. We found that self-reported weight-bearing physical activity contributed to significantly greater BMC accrual in both sexes and racial subgroups (black and nonblack). In nonblack males, the magnitude of the activity effect on total body BMC accrual varied among Tanner stages after adjustment for calcium intake; the greatest difference between high- and low-activity boys was in Tanner stage 3. Calcium intake had a significant effect on bone accrual only in nonblack girls. This effect was not significantly different among Tanner stages. Our findings do not support differential effects of physical activity or calcium intake on bone mass accrual according to maturational stage. The study demonstrated significant longitudinal effects of weight-bearing physical activity on bone mass accrual through all stages of pubertal development.
儿童期和青春期是骨矿物质含量（BMC）积累的关键时期，这可能对成年后的骨质疏松症产生长期影响。充足的膳食钙摄入量和负重体育活动对于使BMC积累最大化很重要。然而，体育活动和膳食钙对儿童期青春期发育连续过程中BMC积累的相对影响仍不清楚。本研究的目的是确定自我报告的膳食钙摄入量和负重体育活动对美国大量不同儿童和青少年队列青春期发育五个阶段骨量积累的影响。儿童期骨密度研究是一项混合纵向研究，对1743名受试者进行了7393次观察。我们每年通过双能X线吸收法（DXA）测量BMC，通过问卷测量体育活动和钙摄入量，并通过检查评估青春期发育（坦纳分期），最长达7年。使用混合效应回归模型评估每个坦纳阶段体育活动和钙摄入量对BMC积累的影响。我们发现，自我报告的负重体育活动对男女两性以及种族亚组（黑人与非黑人）的BMC积累均有显著更大的贡献。在非黑人男性中，调整钙摄入量后，活动对全身BMC积累的影响程度在坦纳各阶段有所不同；高活动量和低活动量男孩之间的最大差异出现在坦纳3期。钙摄入量仅对非黑人女孩的骨积累有显著影响。这种影响在坦纳各阶段之间没有显著差异。我们的研究结果不支持体育活动或钙摄入量根据成熟阶段对骨量积累产生不同影响的观点。该研究表明，负重体育活动在青春期发育的所有阶段对骨量积累都有显著的纵向影响。
