老年2型糖尿病患者血尿酸水平与骨代谢、骨密度及骨质疏松的关系

目的探讨老年2型糖尿病患者血尿酸水平与骨代谢标志物、骨密度及骨质疏松的相关关系。方法选取2018-2019年于北京大学国际医院内分泌科门诊就诊及住院的年龄60岁以上的老年2型糖尿病患者,共计577人,其中男性289人,女性288人(均为绝经后女性)。对所有研究对象进行一般临床资料调查、生化指标及甲状旁腺素(PTH)、25羟维生素D[25(OH)D]、骨钙素(OC)、血清I型前胶原N-末端前肽(P1NP)、I型胶原交联C-末端肽(β-CTX)测定,计算估算肾小球滤过率(eGFR),双能X线吸收法(DXA)测定股骨颈(FN)及腰椎(L1~4)骨密度(bone mineral density,BMD)。将血尿酸(SUA)四分位法分层比较分析股骨颈及腰椎总BMD变化趋势,Pearson和Spearman相关分析SUA与血钙(Ca)、PTH及OC、P1NP、CTX、25(OH)D、腰椎及股骨颈BMD的关系,多因素Logistic回归分析SUA与骨质疏松的关系。结果SUA第4分组BMI、肌酐(Cr)、股骨颈及总腰椎BMD水平明显高于第1分位组,SUA第4分组eGFR水平明显低于第1分位组,差异具有统计学意义(P<0.05);Pearson相关分析显示SUA与股骨颈BMD(r=0.082,P=0.002)、糖尿病病程(r=0.129,P=0.005)、BMI(r=0.201,P=0.000)正相关,与eGFR负相关(r=-0.434,P=0.000),Spearman相关分析显示SUA与腰椎总BMD(r=0.168,P=0.003)、Ca(r=0.147,P=0.001)正相关,与β-CTX负相关(r=-0.157,P=0.001),与PTH、25(OH)D、OC、P1NP无相关性(P>0.05)。以老年2型糖尿病合并骨质疏松为因变量,多因素Logistic回归显示,调整年龄、eGFR、BMI、HbA1c后,SUA是老年2型糖尿病患者发生骨质疏松的保护因素(P=0.039,OR=0.452,95%CI:0.212~0.962)。结论在老年2型糖尿病患者中,正常偏高的血尿酸水平可能减少骨质疏松的发生风险。

The relationship between serum uric acid level and bone metabolism, bone mineral density, and osteoporosis in elderly patients with type 2 diabetes mellitus

Objective To explore the correlation between serum uric acid level and bone metabolic markers, bone mineral density, and osteoporosis in elderly patients with type 2 diabetes mellitus. Methods From 2018 to 2019, 577 elderly patients with type 2 diabetes mellitus aged over 60 years old were selected, including 289 males and 288 females (all postmenopausal females). The general clinical data were investigated. Biochemical indexes and levels of parathyroid hormone (PTH), 25-hydroxyvitamin D (25-OH-D), osteocalcin (OC), serum procollagen type I N-terminal propeptide (P1NP), and collagen type I cross-linked C-terminal peptide (beta-CTX) were determined. Glomerular filtration rate (eGFR) and dual energy X-ray absorption were calculated and estimated. Bone mineral density (BMD) of the femoral neck (FN) and lumbar spine (L1-4) was measured with DXA. The trend of total BMD of the femoral neck and lumbar spine was analyzed with SUA quartile method. The relationship between SUA and blood calcium (Ca), PTH, OC, P1NP, CTX, 25-OH-D, and BMD of the lumbar spine and femoral neck was analyzed using Pearson and Pearman correlation analysis. The relationship between SUA and osteoporosis was analyzed with multivariate logistic regression. Results BMI, creatinine (Cr), and BMD of the femoral neck and lumbar spine in SUA group 4 were significantly higher than those in subgroup 1. eGFR levels in SUA group 4 were significantly lower than those in subgroup 1 (P<0.05). Pearson correlation analysis showed that SUA was positively correlated with BMD of the femoral neck (r=0.082, P=0.002), duration of diabetes mellitus (r=0.129, P=0.05), and BMI (r=0.201, P=0.000), but was negatively correlated with eGFR (r=-0.434, P=0.000). Spearman correlation analysis showed that SUA was positively correlated with BMD of total lumbar spine (r=0.168, P=0.003) and Ca (r=0.147, P=0.001) and negatively correlated with beta-CTX (r=-0.157, P=0.001), and there was no correlation with PTH, 25-OH-D, OC, and P1 (P>0.05). With osteoporosis as dependent variable, multivariate logistic regression showed that after adjusting age, eGFR, BMI, and HbA1c, high level of SUA was the protective factor for osteoporosis (P=0.039, OR=0.452, 95% CI: 0.212-0.962). Conclusion Normal or slight high serum level of uric acid may reduce the risk of osteoporosis in elderly patients with type 2 diabetes mellitus.