Jeddi Marjan, Dabbaghmanesh Mohammad Hossein, Ranjbar Omrani Gholamhossein, Ayatollahi Sayed Mohammad Taghi, Bagheri Zahra, Bakhshayeshkaram Marzieh
Endocrine and Metabolism Research Center, Department of Internal Medicine, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, IR Iran.
Department of Biostatistics, Shiraz University of Medical Sciences, Shiraz, IR Iran.
Int J Endocrinol Metab. 2015 Jul 1;13(3):e25542. doi: 10.5812/ijem.25542v2. eCollection 2015 Jul.
Body weight is made up of lean and fat mass and both are involved in growth and development. Impression of these two components in bone density accrual has been controversial.
The aim of this study was to evaluate the relationship between fat and lean mass and bone density in Iranian children and adolescents.
A cross-sectional study was performed on 472 subjects (235 girls, 237 boys) aged 9-18 years old in Fars Province. The participants' weight, height, waist circumference, stage of puberty, and level of physical activity were recorded. Bone Mineral Content (BMC), Bone Mineral Density (BMD), total body fat and lean mass were measured using dual-energy X-ray absorptiometry.
Results showed that 12.2% of boys and 12.3% of girls were overweight and 5.5% of boys and 4.7% of girls were obese. Obese individuals had greater total body BMD (0.96 ± 0.11) than normal-weight ones (0.86 ± 0.11) (P < 0.001). We found the greatest correlation between total body BMD and total body lean mass (R = 0.78. P < 0.001) and the least correlation with total body fat percentage (R = 0.03, P = 0.44). Total lean mass in more active boys was 38.1 ± 10.9 and in less active boys was 32.3 ± 11.0 (P < 0.001). The results of multiple regression analysis showed that age and total body lean mass were independent factors of BMD in growing children and adolescents.
These findings suggest that lean mass was the most important predictor of BMD in both genders. Physical activity appears to positively impact on lean mass and needs to be considered in physical education and health-enhancing programs in Iranian school children.
体重由瘦体重和脂肪量组成，二者均与生长发育有关。这两个组成部分对骨密度积累的影响一直存在争议。
本研究旨在评估伊朗儿童和青少年的脂肪量、瘦体重与骨密度之间的关系。
对法尔斯省472名9至18岁的受试者（235名女孩，237名男孩）进行了一项横断面研究。记录了参与者的体重、身高、腰围、青春期阶段和身体活动水平。使用双能X线吸收法测量骨矿物质含量（BMC）、骨矿物质密度（BMD）、全身脂肪和瘦体重。
结果显示，12.2%的男孩和12.3%的女孩超重，5.5%的男孩和4.7%的女孩肥胖。肥胖个体的全身骨密度（0.96±0.11）高于正常体重个体（0.86±0.11）（P<0.001）。我们发现全身骨密度与全身瘦体重之间的相关性最强（R=0.78，P<0.001），与全身脂肪百分比的相关性最弱（R=0.03，P=0.44）。活动较多的男孩的总瘦体重为38.1±10.9，活动较少的男孩为32.3±11.0（P<0.001）。多元回归分析结果表明，年龄和全身瘦体重是成长中儿童和青少年骨密度的独立影响因素。
这些发现表明，瘦体重是两性骨密度最重要的预测指标。身体活动似乎对瘦体重有积极影响，在伊朗学童的体育教育和健康促进计划中需要加以考虑。
