Department of Nephrology & Kidney Transplantation, Area 5, Level 7, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Edgbaston, Birmingham, United Kingdom; Department of Nutrition & Dietetics, Therapy Services South Suite, 1st Floor, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Edgbaston, Birmingham, United Kingdom; School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.
Department of Cardiovascular Sciences, Clinical Sciences Wing, University of Leicester, Glenfield Hospital, Leicester, United Kingdom.
J Ren Nutr. 2019 Nov;29(6):536-547. doi: 10.1053/j.jrn.2019.06.009. Epub 2019 Aug 12.
Sarcopenia, defined as loss of both muscle strength and mass, is associated with inferior clinical outcomes and quality of life (QoL) in chronic kidney disease, but its effects are unknown in kidney transplantation. Obesity confers increased mortality risk and compromises QoL in kidney transplant recipients (KTRs), but the impacts of sarcopenic obesity remain unexplored. This study aimed to evaluate the associations of muscle strength and mass, sarcopenia, and sarcopenic obesity with clinical outcomes and QoL in KTRs.
This prospective longitudinal study enrolled 128 KTRs ≥1-year posttransplantation. Low muscle strength (by handgrip strength) and mass (by bioimpedance analysis), and a combination of both (sarcopenia) were defined as < reference cutoffs for corresponding indices. Sarcopenic obesity was defined as sarcopenia combined with fulfillment of ≥2 out of 3 criteria from (1) body mass index ≥30 kg/m, (2) bioimpedance analysis-derived fat mass > reference cutoffs, and (3) waist circumference > World Health Organization cutoffs. Prospective follow-up data on mortality and hospitalization were collected. QoL was evaluated using Medical Outcomes Study Short Form-36 questionnaire.
Median follow-up duration was 64 (60-72) months. Low muscle strength was independently associated with the composite endpoint of mortality and hospitalization (hazard ratio = 2.45; P = .006), and QoL (physical-related: β = -12.2; P = .04; mental-related: β = -9.9; P = .04). Low muscle mass (β = -8.8; P = .04) and sarcopenia (β = -14.7; P = .03) were associated with physical-related QoL only. No independent associations were found between muscle mass, sarcopenia, and sarcopenic obesity with the composite outcome of mortality and hospitalization.
Low muscle strength is common among KTRs, conferring poor prognosis in the medium term. Future research on strength training may prove valuable in improving kidney transplantation outcomes.
肌肉减少症定义为肌肉力量和质量的双重损失，与慢性肾脏病患者的临床结局和生活质量（QoL）较差相关，但在肾移植患者中其影响尚不清楚。肥胖会增加肾移植受者（KTR）的死亡风险并影响其生活质量，但关于肌少症合并肥胖的影响仍有待探索。本研究旨在评估肌肉力量和质量、肌少症和肌少症合并肥胖与 KTR 临床结局和生活质量的关系。
这是一项前瞻性纵向研究，纳入了 128 例移植后≥1 年的 KTR。通过握力（肌肉力量）和生物电阻抗分析（肌肉质量）定义低肌肉力量和低肌肉质量，以及两者的结合（肌少症），并定义为<对应指标的参考截止值。肌少症合并肥胖定义为肌少症合并满足以下 3 项标准中的 2 项：（1）体重指数≥30kg/m2；（2）生物电阻抗分析得出的脂肪量>参考截止值；（3）腰围>世界卫生组织截止值。前瞻性收集死亡率和住院的随访数据。使用医疗结局研究短表 36 问卷评估生活质量。
中位随访时间为 64（60-72）个月。低肌肉力量与死亡率和住院率的复合终点独立相关（风险比=2.45；P=0.006），也与生活质量（身体相关：β=-12.2；P=0.04；精神相关：β=-9.9；P=0.04）相关。低肌肉质量（β=-8.8；P=0.04）和肌少症（β=-14.7；P=0.03）仅与身体相关的生活质量相关。肌肉质量、肌少症和肌少症合并肥胖与死亡率和住院率的复合结局之间无独立关联。
KTR 中低肌肉力量很常见，会导致中期预后不良。未来的力量训练研究可能会证明对改善肾移植结局具有价值。
