Plant-based diets, insulin sensitivity and inflammation in elderly men with chronic kidney disease

Tommy Cederholm,Bengt Lindholm,Hong Xu,Johan Ärnlöv,Angeles Espinosa-Cuevas,Ulf Risérus,Carla M Avesani,Ailema González-Ortiz,Juan Jesús Carrero

doi:10.1007/s40620-020-00765-6

Abstract

BackgroundIn persons with CKD, adherence to plant-based diets is associated with lower risk of CKD progression and death, but underlying mechanisms are poorly characterized. We here explore associations between adherence to plant-based diets and measures of insulin sensitivity and inflammation in men with CKD stages 3–5.MethodsCross-sectional study including 418 men free from diabetes, aged 70–71 years and with cystatin-C estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m2 and not receiving kidney-specific dietetic advice. Information from 7-day food records was used to evaluate the adherence to a plant-based diet index (PBDi), which scores positively the intake of plant-foods and negatively animal-foods. Insulin sensitivity and glucose disposal rate were assessed with the gold-standard hyperinsulinemic euglycemic glucose clamp technique. Inflammation was evaluated by serum concentrations of C-reactive protein (CRP) and interleukin (IL)-6. Associations were explored through linear regression and restricted cubic splines.ResultsThe majority of men had CKD stage 3a. Hypertension and cardiovascular disease were the most common comorbidities. The median PBDi was 38 (range 14–55). Across higher quintiles of PBDi (i.e. higher adherence), participants were less often smokers, consumed less alcohol, had lower BMI and higher eGFR (P for trend <0.05 for all). Across higher PBDi quintiles, patients exhibited higher insulin sensitivity and lower inflammation (P for trend <0.05). After adjustment for eGFR, lifestyle factors, BMI, comorbidities and energy intake, a higher PBDi score remained associated with higher glucose disposal rate and insulin sensitivity as well as with lower levels of IL-6 and CRP.ConclusionIn elderly men with non-dialysis CKD stages 3–5, adherence to a plant-based diet was associated with higher insulin sensitivity and lower inflammation, supporting a possible role of plant-based diets in the prevention of metabolic complications of CKD.Graphic abstract

Highlights

Dietary recommendations to treat chronic kidney disease (CKD) are focused on restricting dietary protein intake to avoid kidney overload and limiting the amount of nutrients that can accumulate into toxic levels while ensuring sufficient energy intake [1, 2]
In elderly men with non-dialysis CKD stages 3–5, adherence to a plant-based diet was associated with higher insulin sensitivity and lower inflammation, supporting a possible role of plant-based diets in the prevention of metabolic complications of CKD
One established mechanism by which increased intake of plant-foods may benefit CKD patients involves an overall reduction of dietary acid load [8], which in randomized trials lead to a better control of metabolic acidosis, reduction in urine excretion of angiotensinogen and estimated glomerular filtration rate preservation compared to usual care [9]

Summary

Introduction

Dietary recommendations to treat chronic kidney disease (CKD) are focused on restricting dietary protein intake to avoid kidney overload and limiting the amount of nutrients that can accumulate into toxic levels (sodium, potassium, phosphorus) while ensuring sufficient energy intake [1, 2]. A number of recent observational studies suggest, that a more liberal consumption of plant-based foods in persons with CKD is associated with a lower risk of death and progression to end-stage kidney disease (ESKD) [5,6,7]. Mechanisms underlying these associations have, been poorly investigated. After adjustment for eGFR, lifestyle factors, BMI, comorbidities and energy intake, a higher PBDi score remained associated with higher glucose disposal rate and insulin sensitivity as well as with lower levels of IL-6 and CRP

Objectives

Methods

Results

Conclusion