Feresin Rafaela G, Johnson Sarah A, Elam Marcus L, Jo Edward, Arjmandi Bahram H, Hakkak Reza
Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL 32306, USA ; The Center for Advancing Exercise and Nutrition Research on Aging (CAENRA), Florida State University, Tallahassee, FL 32306, USA.
The Center for Advancing Exercise and Nutrition Research on Aging (CAENRA), Florida State University, Tallahassee, FL 32306, USA ; Department of Kinesiology and Health Promotion, California State Polytechnic University, Pomona, CA 91768, USA.
J Obes. 2014;2014:690123. doi: 10.1155/2014/690123. Epub 2014 Sep 18.
Obesity and osteoporosis are two chronic conditions that have been increasing in prevalence. Despite prior data supporting the positive relationship between body weight and bone mineral density (BMD), recent findings show excess body weight to be detrimental to bone mass, strength, and quality. To evaluate whether obesity would further exacerbate the effects of ovariectomy on bone, we examined the tibiae and fourth lumbar (L4) vertebrae from leptin receptor-deficient female (Lepr(fa/fa)) Zucker rats and their heterozygous lean controls (Lepr(fa/+)) that were either sham-operated or ovariectomized (Ovx). BMD of L4 vertebra was measured using dual-energy X-ray absorptiometry, and microcomputed tomography was used to assess the microstructural properties of the tibiae. Ovariectomy significantly (P < 0.001) decreased the BMD of L4 vertebrae in lean and obese Zucker rats. Lower trabecular number and greater trabecular separation (P < 0.001) were also observed in the tibiae of lean- and obese-Ovx rats when compared to sham rats. However, only the obese-Ovx rats had lower trabecular thickness (Tb.Th) (P < 0.005) than the other groups. These findings demonstrated that ovarian hormone deficiency adversely affected bone mass and quality in lean and obese rats while obesity only affected Tb.Th in Ovx-female Zucker rats.
肥胖和骨质疏松是两种患病率不断上升的慢性疾病。尽管先前的数据支持体重与骨矿物质密度（BMD）之间存在正相关关系，但最近的研究结果表明，超重对骨量、骨强度和骨质量有害。为了评估肥胖是否会进一步加剧卵巢切除对骨骼的影响，我们检查了瘦素受体缺陷型雌性（Lepr(fa/fa)） Zucker大鼠及其杂合子瘦型对照（Lepr(fa/+)）的胫骨和第四腰椎（L4）椎体，这些大鼠要么接受假手术，要么接受卵巢切除术（Ovx）。使用双能X线吸收法测量L4椎体的骨密度，并用微型计算机断层扫描评估胫骨的微观结构特性。卵巢切除术显著（P < 0.001）降低了瘦型和肥胖型Zucker大鼠L4椎体的骨密度。与假手术大鼠相比，瘦型和肥胖型卵巢切除大鼠的胫骨小梁数量减少，小梁间距增大（P < 0.001）。然而，只有肥胖型卵巢切除大鼠的小梁厚度（Tb.Th）低于其他组（P < 0.005）。这些研究结果表明，卵巢激素缺乏对瘦型和肥胖型大鼠的骨量和骨质量有不利影响，而肥胖仅影响卵巢切除雌性Zucker大鼠的Tb.Th。
