Ding C, Parameswaran V, Cicuttini F, Burgess J, Zhai G, Quinn S, Jones G
Menzies Research Institute, Private Bag 23, Hobart, Tasmania 7000, Australia.
Ann Rheum Dis. 2008 Sep;67(9):1256-61. doi: 10.1136/ard.2007.082651. Epub 2008 Jan 3.
To describe the associations between leptin, body composition, sex and knee cartilage volume/defects in older adults.
A cross-sectional sample of 190 randomly selected subjects (mean 63 years, range 52-78, 48% female) were studied. Knee cartilage volume and defects were determined using T1-weighted fat saturation MRI. Serum leptin levels were measured by radioimmunoassay. Fat and lean mass were measured by dual energy x ray absorptiometry (DXA). Body mass index (BMI) was calculated.
In multivariable analysis, serum levels of leptin were negatively associated with total cartilage volume (beta: -541 mm3/log transformed unit, 95% CI -861 to -221) but not with prevalent knee cartilage defects. BMI was negatively associated with cartilage volume after adjustment for total lean mass and positively with prevalent knee cartilage defects. However, the association between BMI and cartilage volume disappeared after adjustment for leptin while the association between BMI and cartilage defects remained unchanged. Lastly, sex differences in total cartilage volume decreased substantially after adjustment for leptin (R2 from 51% to 30%).
This cross-sectional study suggests cartilage volume loss with obesity and female sex is related to leptin and, thus, is hormonally mediated in older adults. By contrast, obesity related knee focal cartilage defects may be more related to non-hormonal factors.
描述老年人中瘦素、身体成分、性别与膝关节软骨体积/缺损之间的关联。
对190名随机选取的受试者（平均年龄63岁，范围52 - 78岁，48%为女性）进行横断面研究。使用T1加权脂肪饱和磁共振成像（MRI）测定膝关节软骨体积和缺损情况。通过放射免疫测定法测量血清瘦素水平。采用双能X线吸收法（DXA）测量脂肪和瘦体重。计算体重指数（BMI）。
在多变量分析中，血清瘦素水平与总软骨体积呈负相关（β：-541立方毫米/对数转换单位，95%置信区间-861至-221），但与膝关节软骨缺损患病率无关。调整总瘦体重后，BMI与软骨体积呈负相关，与膝关节软骨缺损患病率呈正相关。然而，调整瘦素后，BMI与软骨体积之间的关联消失，而BMI与软骨缺损之间的关联保持不变。最后，调整瘦素后，总软骨体积的性别差异大幅降低（决定系数R2从51%降至30%）。
这项横断面研究表明，在老年人中，肥胖和女性的软骨体积减少与瘦素有关，因此是由激素介导的。相比之下，肥胖相关的膝关节局灶性软骨缺损可能更多与非激素因素有关。
