Slemenda C, Heilman D K, Brandt K D, Katz B P, Mazzuca S A, Braunstein E M, Byrd D
Indiana University School of Medicine, Indianapolis, USA.
Arthritis Rheum. 1998 Nov;41(11):1951-9. doi: 10.1002/1529-0131(199811)41:11<1951::AID-ART9>3.0.CO;2-9.
To determine whether baseline lower extremity muscle weakness is a risk factor for incident radiographic osteoarthritis (OA) of the knee.
This prospective study involved 342 elderly community-dwelling subjects (178 women, 164 men) from central Indiana, for whom baseline and followup (mean interval 31.3 months) knee radiographs were available. Lower extremity muscle strength was measured by isokinetic dynamometry and lean tissue (i.e., muscle) mass in the lower extremities by dual x-ray absorptiometry.
Knee OA was associated with an increase in body weight in women (P = 0.0014), but not in men. In both sexes, lower extremity muscle mass exhibited a strong positive correlation with body weight. In women, after adjustment for body weight, knee extensor strength was 18% lower at baseline among subjects who developed incident knee OA than among the controls (P = 0.053), whereas after adjustment for lower extremity muscle mass, knee extensor strength was 15% lower than in the controls (P not significant). In men, in contrast, adjusted knee extensor strength at baseline was comparable to that in the controls. Among the 13 women who developed incident OA, there was a strong, highly significant negative correlation between body weight and extensor strength (r = -0.740, P = 0.003), that is, the more obese the subject, the greater the reduction of quadriceps strength. In contrast, among the 14 men who developed incident OA, a modest positive correlation existed between weight and quadriceps strength (r = 0.455, P = 0.058). No correlation between knee flexor (hamstring) strength and knee OA was seen in either sex.
Reduced quadriceps strength relative to body weight may be a risk factor for knee OA in women.
确定基线时下肢肌肉无力是否为膝关节影像学骨关节炎（OA）发病的危险因素。
这项前瞻性研究纳入了342名来自印第安纳州中部的社区老年受试者（178名女性，164名男性），他们有基线和随访（平均间隔31.3个月）时的膝关节X线片。通过等速肌力测试法测量下肢肌肉力量，通过双能X线吸收法测量下肢瘦组织（即肌肉）质量。
膝关节OA与女性体重增加相关（P = 0.0014），但与男性无关。在两性中，下肢肌肉质量与体重均呈强正相关。在女性中，调整体重后，发生膝关节OA的受试者基线时膝关节伸肌力量比对照组低18%（P = 0.053），而调整下肢肌肉质量后，膝关节伸肌力量比对照组低15%（P无统计学意义）。相比之下，在男性中，基线时调整后的膝关节伸肌力量与对照组相当。在发生OA的13名女性中，体重与伸肌力量之间存在强且高度显著的负相关（r = -0.740，P = 0.003），即受试者越肥胖，股四头肌力量下降越大。相比之下，在发生OA的14名男性中，体重与股四头肌力量之间存在适度正相关（r = 0.455，P = 0.058）。在两性中均未发现膝关节屈肌（腘绳肌）力量与膝关节OA之间存在相关性。
相对于体重而言，股四头肌力量降低可能是女性膝关节OA的危险因素。
