Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden.
School of Nutrition and Dietetics, Faculty of Health and Social Services, Kanagawa University of Human Services, Yokosuka, Kanagawa, Japan.
J Nutr. 2022 Jan 11;152(1):269-275. doi: 10.1093/jn/nxab348.
Observational studies have suggested that better protein nutritional status may contribute to prevention of frailty.
We sought to examine this hypothesis using a Mendelian randomization (MR) analysis.
We conducted a two-sample MR study using GWAS summary statistics data of the UK Biobank. We applied genetically predicted serum albumin as a primary exposure measure and serum total protein as a secondary exposure measure. The outcome measure was the Rockwood frailty index (FI) based on 49 deficits from 356,432 individuals (53.3% of them were women, with a mean ± SD age of 56.7 ± 8.0 y. The association between serum protein measures and FI was mainly analyzed by use of the inverse variance weighted method.
A genetically predicted serum albumin concentration was not statistically significantly associated with FI in the full sample. However, in women, we observed a preventive association between genetically predicted serum albumin and FI (β = -0.172 per g/L; 95% CI: -0.336, -0.007; P = 0.041). In the full sample, genetically predicted serum total protein was inversely associated with FI (β: -0.153 per g/L; 95% CI: -0.251, -0.056; P = 0.002). In both women and men, higher serum total protein was significantly inversely associated with FI; regression coefficients were -0.148 per g/L (95% CI: -0.287, -0.009; P = 0.037) for women, -0.154 per g/L (95% CI: -0.290, -0.018; P = 0.027) for men.
The present MR study implies that better protein nutritional status modestly contributes to reducing the risk of frailty.
观察性研究表明，更好的蛋白质营养状态可能有助于预防虚弱。
我们试图通过孟德尔随机化（MR）分析来检验这一假设。
我们使用英国生物库的 GWAS 汇总统计数据进行了两样本 MR 研究。我们应用遗传预测的血清白蛋白作为主要暴露测量指标，血清总蛋白作为次要暴露测量指标。结局测量指标是基于 356432 个人（其中 53.3%为女性）的 49 项缺陷的 Rockwood 虚弱指数（FI）（平均年龄为 56.7 ± 8.0 岁）。主要采用逆方差加权法分析血清蛋白测量值与 FI 之间的关系。
在全样本中，遗传预测的血清白蛋白浓度与 FI 无统计学显著相关性。然而，在女性中，我们观察到遗传预测的血清白蛋白与 FI 之间存在预防关联（每克/升增加 0.172；95%CI：-0.336，-0.007；P = 0.041）。在全样本中，遗传预测的血清总蛋白与 FI 呈负相关（每克/升减少 0.153；95%CI：-0.251，-0.056；P = 0.002）。在女性和男性中，较高的血清总蛋白与 FI 显著负相关；回归系数分别为女性每克/升减少 0.148（95%CI：-0.287，-0.009；P = 0.037），男性每克/升减少 0.154（95%CI：-0.290，-0.018；P = 0.027）。
本 MR 研究表明，更好的蛋白质营养状态适度有助于降低虚弱的风险。
