Menzies Research Institute, University of Tasmania, Hobart, Tasmania, Australia.
Int J Obes (Lond). 2013 Jun;37(6):822-7. doi: 10.1038/ijo.2012.136. Epub 2012 Aug 21.
To determine the associations between body composition at baseline and knee cartilage loss over 2.9 years in older adults.
A total of 395 randomly selected subjects (mean 62 years, range 51-81, 50% female) were studied at baseline and 2.9 years later. T1-weighted fat-suppressed magnetic resonance imaging of the right knee was performed to determine knee cartilage volume and tibial bone area at baseline and follow-up. Height, weight and radiographic osteoarthritis were measured by standard protocols at baseline. Fat mass and lean mass were measured by dual-energy X-ray absorptiometry at baseline.
Tibial cartilage volume decreased by 2.0-2.7% per annum. In multivariable analysis, annual change in medial cartilage volume was negatively and significantly associated with body mass index (β: -0.14% per kg m(-2), 95% confidence interval (CI): -0.25%, -0.02%), percentage total body fat (β: -0.19% per %, 95% CI: -0.30%, -0.07%) and percentage trunk fat (β: -0.10% per %, 95% CI: -0.19%, -0.02%), and positively associated with percentage lean mass (β: 0.20% per %, 95% CI: 0.08%, 0.32%). Change in lateral tibial cartilage volume was also significantly associated with percentage total body fat (β: -0.11% per %, 95% CI: -0.21%, -0.001%) and total lean mass (β: 0.13% per kg, 95% CI: 0.04%, 0.22%). These were independent of sex and age even though both were also significant predictors.
Body fat adversely affects tibial cartilage loss over time, whereas lean mass is protective. Strategies aimed at reducing body fat but increasing lean mass may reduce knee cartilage loss in older people.
确定基线时的身体成分与老年人 2.9 年内膝关节软骨丢失的相关性。
共纳入 395 名随机选择的受试者（平均年龄 62 岁，范围 51-81 岁，50%为女性），分别在基线和 2.9 年后进行研究。使用右膝 T1 加权脂肪抑制磁共振成像来确定基线和随访时的膝关节软骨体积和胫骨骨面积。在基线时通过标准协议测量身高、体重和放射学骨关节炎。在基线时通过双能 X 射线吸收法测量脂肪量和瘦体重。
胫骨软骨体积每年减少 2.0-2.7%。多变量分析显示，内侧软骨体积的年变化与体重指数（β：-0.14%/kg·m(-2)，95%置信区间（CI）：-0.25%，-0.02%）、全身脂肪百分比（β：-0.19%/%，95%CI：-0.30%，-0.07%）和躯干脂肪百分比（β：-0.10%/%，95%CI：-0.19%，-0.02%）呈负相关，与瘦体重百分比（β：0.20%/%，95%CI：0.08%，0.32%）呈正相关。外侧胫骨软骨体积的变化也与全身脂肪百分比（β：-0.11%/%，95%CI：-0.21%，-0.001%）和总瘦体重（β：0.13/kg，95%CI：0.04%，0.22%）显著相关。这些结果独立于性别和年龄，尽管它们也是重要的预测因素。
体脂随时间推移对胫骨软骨丢失有不利影响，而瘦体重则有保护作用。旨在减少体脂但增加瘦体重的策略可能会减少老年人的膝关节软骨丢失。
