Campoverde Reyes Karen J, Stanford Fatima Cody, Singhal Vibha, Animashaun Abisayo O, Bose Amita, Gleeson Elizabeth L, Bredella Miriam A, Misra Madhusmita
Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America; Liver Research Center, Beth Israel Deaconess Medical Center, Boston, MA, United States of America.
Neuroendocrine Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America; Division of Pediatric Endocrinology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America; MGH Weight Center, Massachusetts General Hospital, Boston, MA, United States of America.
Bone. 2020 Sep;138:115514. doi: 10.1016/j.bone.2020.115514. Epub 2020 Jul 1.
African Americans (AA) have more favorable bone density and microarchitecture compared to Whites (W), which may explain their observed lower fracture rates. Obesity has deleterious effects on bone microarchitecture and strength estimates and is associated with an increase in fracture risk. Adolescence and young adulthood are periods of active bone accrual and also periods characterized by an increasing prevalence of obesity. The effect of obesity on the relationship between race and bone parameters remains unclear, particularly in youth.
To assess differences in BMD, bone microarchitecture and strength estimates in AA and W adolescents and young adults with moderate to severe obesity. We hypothesized that racial differences in bone endpoints in lean youth would also be noted in youth with moderate to severe obesity.
We evaluated 24 AA and 48 W adolescent and young adults with a mean age of 18.2 ± 2.4 years and a median body mass index (BMI) of 44.8 (40.5-49.4) kg/m who underwent dual energy X-ray absorptiometry (DXA), high resolution peripheral quantitative computed tomography (HRpQCT), extended cortical analysis (ECA) and micro-finite element analysis (FEA) to obtain measures of volumetric bone mineral density (vBMD), bone geometry, microarchitecture, and strength estimates at the distal radius and tibia.
We found no differences between AA and W for total fat and lean mass, and areal BMD Z-scores (p > 0.05 for all). At the distal radius, no significant differences were detected in vBMD, bone geometry or microarchitecture (p > 0.05 for all); however, stiffness and failure load were higher in the AA group (p = 0.031 and 0.047 respectively). At the distal tibia, cortical vBMD was higher in AA vs. W (p = 0.012), while trabecular number was higher and trabecular separation lower in W vs. AA (p ≤ 0.028). Stiffness and failure load trended higher in AA vs. W (p = 0.052 and p = 0.048, respectively). Groups did not differ for any other bone parameter (p > 0.05).
Racial differences in bone endpoints appear to be less marked in those with moderate to severe obesity, suggesting that effects of obesity may blunt the effect of race on bone endpoints.
与白人（W）相比，非裔美国人（AA）具有更有利的骨密度和骨微结构，这可能解释了他们观察到的较低骨折率。肥胖对骨微结构和强度评估有有害影响，并与骨折风险增加相关。青春期和青年期是骨量快速积累的时期，也是肥胖患病率不断上升的时期。肥胖对种族与骨参数之间关系的影响仍不清楚，尤其是在年轻人中。
评估中度至重度肥胖的非裔美国人和白人青少年及青年在骨密度、骨微结构和强度评估方面的差异。我们假设，在瘦体重的年轻人中观察到的骨指标的种族差异，在中度至重度肥胖的年轻人中也会存在。
我们评估了24名非裔美国人和48名白人青少年及青年，平均年龄为18.2±2.4岁，中位体重指数（BMI）为44.8（40.5 - 49.4）kg/m²，他们接受了双能X线吸收法（DXA）、高分辨率外周定量计算机断层扫描（HRpQCT）、扩展皮质分析（ECA）和微有限元分析（FEA），以获取桡骨远端和胫骨的骨体积密度（vBMD）、骨几何形状、微结构和强度评估指标。
我们发现非裔美国人和白人在总脂肪量和瘦体重以及面积骨密度Z评分方面没有差异（所有p>0.05）。在桡骨远端，vBMD、骨几何形状或微结构方面未检测到显著差异（所有p>0.05）；然而，非裔美国人组的刚度和破坏载荷更高（分别为p = 0.031和0.047）。在胫骨远端，非裔美国人的皮质vBMD高于白人（p = 0.012），而白人的骨小梁数量更高，骨小梁间距低于非裔美国人（p≤0.028）。非裔美国人的刚度和破坏载荷趋势高于白人（分别为p = 0.052和p = 0.048）。两组在任何其他骨参数上均无差异（p>0.05）。
在中度至重度肥胖人群中，骨指标的种族差异似乎不太明显，这表明肥胖的影响可能会减弱种族对骨指标的影响。
