膝骨关节炎患者血清瘦素水平变化及其临床意义

Changes and clinical significance of serum leptin in knee osteoarthritis

目的探讨膝骨关节炎(OA)患者血清瘦素(LPT)水平与骨密度(BMD)、膝X线分期的关系。方法采用酶联免疫吸附法检测87例膝OA患者血清LPT水平;应用双能X线骨密度扫描仪测定患者全身、骨盆、腰椎、股骨的BMD及全身脂肪肌肉质量;用X线评估膝关节骨赘(OP)分级及关节间隙狭窄(JSN)分级;根据国际测量学会(ISCD)及临床实践将受试者分为骨量正常组、骨量减少组及骨质疏松组;根据国际肥胖协作组(ISAO)诊断标准将受试者分为正常体重组、超重组及肥胖组。分析LPT水平与BMD、膝X线Kellgren-Lawrence(K-L)分级、JSN分级、OP分级及体质指数(BMI)等临床指标的关系。结果①87例受试者中女性LPT水平明显高于男性(P<0.01);②血清LPT水平与腰围、臀围、腰臀比、BMI、体脂百分率、总胆固醇(TC)、低密度脂蛋白、全身脂肪重量、躯干脂肪重量呈正相关(P<0.05),与全身BMD呈负相关(P<0.05);腰围、TC和年龄是LPT水平的影响因素。③骨量正常组、骨量减少组和骨质疏松组的LPT水平呈逐渐增加的趋势,骨质疏松组较骨量减少组血清LPT明显升高(P<0.05),且均高于骨量正常组(P<0.05)。④血清LPT水平与左、右膝股骨内OP呈正相关(P<0.05)。LPT是影响左、右膝股胫骨外JSN的主要危险因素(P<0.05)。左、右膝胫骨内OP是影响膝关节疼痛的主要因素(P<0.05)。结论肥胖是膝OA的危险因素,血清LPT可能介导肥胖对膝OA关节软骨的破坏作用。OP分级、JSN分级较传统的膝K-L分级更敏感、可靠,OP的放射学分级对患者疼痛评估有指导意义。

Objective To determine the serum levels of leptin （LPT）in knee radiographic osteoarthritis（KOA） and the association of serum leptin with bone mineral density in knee radiographic osteoarthritis. According to the ISCD and clinical practice, 87 subjests were divided into normal bone group, osteopenia group and osteoporosis group. Based on the international obesity group （ISAO） diagnostic criteria, subjects were divided into normal weight group, overweight group and obesity group. Methods Serum leptin levels were detected by enzyme-linked immunosorbent assay （ELISA） in 87 Cases with OA. BMD （ bone mineral density） was measured by dual enery X-ray absorptiometry （DXA） at the whole body, pelvic, lumbar spine and femora. Body compositions including lean tissue mass and body fat mass were measured by DXA. Joint osteophytes and joint-space narrowing were assessed by Xray,and their relationship was analyzed. Results （1） women LPT levels obviously were higher than male （P 〈 0. 01 ） ; （2） positive correlation was detected between serum leptin levels and the following ： waist circumference, hip circumference, waist hip ratio, BMI, body fat percentage, total cholesterol （TC）, low density lipoprotein （LDL）, the whole body fat weight, trunk fat weight of the patients with OA（ both P 〈0.05 ） ; and negative correlation was found between serum leptin levels and the whole body bone mineral density （ P 〈 0. 0 5 ） . Waist circumference, TC and age were influencing factors of serum leptin levels. （3） the LPT levels of normal BMD group, osteopenia group and osteoporosis group were gradually increased. Serum leptin levels in osteoporosis group were obviously higher than that in osteopenia group （P 〈 0.05 ）, and both groups were higher than normal group （P 〈 0.05 ） ;（4） serum leptin levels were found to have positive correlation in the medial femoral OP of the knees （ P 〈 0.05, respectively）. Leptin was the main risk factor of both lateral tibiofemoral joint-space narrowing of the knees （P 〈 0. 05, respectively）. The medial tibial OP of both knees were the main influencing factors of pain （ P 〈 0. 05 ）. Conclusion Obesity is the risk factor in knee OA. Leptin may be mediated in obesity in knee OA articular cartilage damage effect. Osteophytes and joint-space narrowing grades are more sensitive, reliable than the traditional X-ray K-L grades. Osteophytes are closely related to the patients pain.