Clermont Université, Université Blaise Pascal, EA 3533, Laboratoire des Adaptations Métaboliques à l'Exercice en conditions Physiologiques et Pathologiques (AME2P), BP 80026, F-63171 Aubière Cedex, France.
Bone. 2013 Apr;53(2):382-90. doi: 10.1016/j.bone.2013.01.006. Epub 2013 Jan 11.
The association of a well-balanced diet with exercise is a key strategy to treat obesity. However, weight loss is linked to an accelerated bone loss. Furthermore, exercise is known to induce beneficial effects on bone. We investigated the impact of a well-balanced isoenergetic reducing diet (WBR) and exercise on bone tissue in obese rats. Sixty male rats had previously been fed with a high fat/high sucrose diet (HF/HS) for 4months to induce obesity. Then, 4 regimens were initiated for 2months: HF/HS diet plus exercise (treadmill: 50min/day, 5days/week), WBR diet plus exercise, HF/HS diet plus inactivity and WBR diet plus inactivity. Body composition and total BMD were assessed using DXA and visceral fat mass was weighed. Tibia densitometry was assessed by Piximus. Bone histomorphometry was performed on the proximal metaphysis of tibia and on L2 vertebrae (L2). Trabecular micro-architectural parameters were measured on tibia and L2 by 3D microtomography. Plasma concentration of osteocalcin and CTX were measured. Both WBR diet and exercise had decreased global weight, global fat and visceral fat mass (p<0.05). The WBR diet alone failed to alter total and tibia bone mass and BMD. However, Tb.Th, bone volume density and degree of anisotropy of tibia were decreased by the WBR diet (p<0.05). Moreover, the WBR diet had involved a significant lower MS/BS and BFR/BS in L2 (p<0.05). Exercise had significantly improved BMD of the tibia possibly by inhibiting the bone resorption, as evidenced by no change in plasma osteocalcin levels, a decrease of CTX levels (p<0.005) and trabecular osteoclast number (p<0.05). In the present study a diet inducing weight and fat mass losses did not affected bone mass and BMD of obese rats despite alterations of their bone micro-architecture. The moderate intensity exercise performed had improved the tibia BMD of obese rats without any trabecular and cortical adaptation.
均衡饮食与运动相结合是治疗肥胖的关键策略。然而，减肥与骨丢失加速有关。此外，运动已知对骨骼有有益的影响。我们研究了均衡的等热量减少饮食（WBR）和运动对肥胖大鼠骨组织的影响。60 只雄性大鼠此前已喂食高脂肪/高蔗糖饮食（HF/HS）4 个月以诱导肥胖。然后，启动了 4 种方案 2 个月：HF/HS 饮食加运动（跑步机：每天 50 分钟，每周 5 天）、WBR 饮食加运动、HF/HS 饮食加不活动和 WBR 饮食加不活动。使用 DXA 评估身体成分和总 BMD，称重内脏脂肪量。通过 Piximus 评估胫骨密度。在胫骨近端干骺端和 L2 椎体（L2）上进行骨组织形态计量学。通过 3D 微断层扫描测量胫骨和 L2 的小梁微结构参数。测量血浆骨钙素和 CTX 浓度。WBR 饮食和运动都降低了总体体重、总体脂肪和内脏脂肪量（p<0.05）。单独的 WBR 饮食未能改变总骨量和胫骨骨密度。然而，WBR 饮食降低了胫骨的 Tb.Th、骨体积密度和各向异性程度（p<0.05）。此外，WBR 饮食导致 L2 的 MS/BS 和 BFR/BS 显著降低（p<0.05）。运动显著改善了胫骨的 BMD，可能通过抑制骨吸收，因为血浆骨钙素水平没有变化，CTX 水平降低（p<0.005），小梁破骨细胞数量减少（p<0.05）。在本研究中，诱导体重和脂肪量减轻的饮食并未影响肥胖大鼠的骨量和 BMD，尽管其骨微结构发生了改变。进行的中等强度运动改善了肥胖大鼠的胫骨 BMD，而没有任何小梁和皮质的适应性改变。
