Division of Nephrology and Hypertension, Department of Medicine, University of California San Diego, San Diego, California.
Vanderbilt Center for Kidney Disease, Nashville, Tennessee; Division of Epidemiology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee; Jackson Heart Study Vanguard Center at Vanderbilt University Medical Center, Nashville, Tennessee.
J Ren Nutr. 2018 Jul;28(4):245-250. doi: 10.1053/j.jrn.2017.11.008. Epub 2018 Feb 13.
Dietary protein intake could have deleterious renal effects in populations at risk for chronic kidney disease. Here, we examined whether higher protein intake (≥80th percentile of energy from protein) is associated with decline in kidney function and whether this decline varies by diabetes status.
Observational cohort study.
Participants were African-Americans (n = 5,301), who enrolled in the Jackson Heart Study between 2000 and 2004.
Dietary intake was assessed using a validated food-frequency questionnaire at baseline, and serum creatinine was measured at baseline (visit 1) and 8 years later (visit 3). Estimated glomerular filtration rates (eGFRs) at baseline and follow-up were computed using the chronic kidney disease epidemiology collaboration equation.
The change in eGFR was computed by subtracting eGFR at visit 1 from that at visit 3.
Of 3,165 participants with complete data, 64% were women, 57% had hypertension, and 19% had diabetes. The median (25th, 75th percentile) percent energy intake from protein was 14.3 (12.4, 16.4), comparable to that reported for the general US population (15% of energy). During a median (25th, 75th percentile) follow-up of 8.0 (7.4, 8.3) years, eGFR declined by 10.5% from a mean (SD) of 97.4 (17.5) to 86.9 (21.3) mL/min/1.73 m. In the fully adjusted model, consumption of protein as percent of energy intake in lowest and highest quintiles was associated with decline in eGFR among diabetic subjects. The analysis of variance with a robust variance estimator was used to determine whether long-term change in eGFR significantly varies by protein intake.
Our results show that, among African-Americans with diabetes, higher protein intake as a percent of total energy intake is positively associated with greater decline in eGFR in analyses that accounted for risk factors for kidney disease.
对于有慢性肾病风险的人群，膳食蛋白质的摄入量可能会对肾脏产生有害影响。在这里，我们研究了较高的蛋白质摄入量（蛋白质提供的能量占比≥第 80 百分位）是否与肾功能下降有关，以及这种下降是否因糖尿病状况而异。
观察性队列研究。
参与者为非洲裔美国人（n=5301），他们于 2000 年至 2004 年期间参加了杰克逊心脏研究。
在基线时使用经过验证的食物频率问卷评估膳食摄入量，并在基线（第 1 次访视）和 8 年后（第 3 次访视）测量血清肌酐。使用慢性肾脏病流行病学合作方程计算基线和随访时的估计肾小球滤过率（eGFR）。
通过从第 3 次访视中减去第 1 次访视的 eGFR 来计算 eGFR 的变化。
在 3165 名具有完整数据的参与者中，64%为女性，57%患有高血压，19%患有糖尿病。蛋白质提供的能量占比中位数（25 百分位，75 百分位）为 14.3%（12.4%，16.4%），与美国一般人群报告的比例（能量的 15%）相当。在中位数（25 百分位，75 百分位）为 8.0（7.4，8.3）年的随访期间，eGFR 从平均值（SD）97.4（17.5）mL/min/1.73 m 下降了 10.5%，至 86.9（21.3）mL/min/1.73 m。在完全调整的模型中，最低和最高五分位的蛋白质摄入量作为能量摄入量的百分比与糖尿病患者的 eGFR 下降有关。使用稳健方差估计量的方差分析用于确定长期 eGFR 变化是否因蛋白质摄入量而显著不同。
我们的结果表明，在有糖尿病的非裔美国人中，较高的蛋白质摄入量占总能量摄入量的百分比与分析中 eGFR 的更大下降呈正相关，该分析考虑了肾脏病的风险因素。
