Associations of Physical Activity, Diet, and Kidney Function in Pre-diabetic Early Stage Chronic Kidney Disease

Abstract

PURPOSE: Early-stage chronic kidney disease (CKD) is prevalent in pre-diabetes. A healthy lifestyle is promoted in those at high risk of developing type 2 diabetes (T2DM) yet any relationships between physical activity and nutritional intake on kidney function in these individuals is unknown. This study aimed to quantify the independent associations that may exist between changes in physical activity, dietary fats and fibre, and estimated kidney function in individuals with pre-diabetic stage-2 CKD. METHODS: The study analysed data from a subset of adults at high risk of T2DM recruited to a lifestyle education programme (Yates et al. Diabet Med. 34:698-707, 2017). At baseline and 24 months, 126 (84 male) pre-diabetic CKD stage 2 (mean(SD) baseline estimated glomerular filtration rate (eGFR) 76.7(8.0) ml/min/1.73 m2, age 66(6) years, BMI 31.6(5.1) kg/m2) provided dietary data via the Dietary Instrument for Nutrition Education food frequency questionnaire and physical activity and steps by 7-day accelerometry. Linear regression examined the independent associations of baseline and change at 24 month in eGFR and average number of steps, moderate to vigorous physical activity (MVPA), total fat and unsaturated fat, and dietary fibre against 95% level of significance (p≤0.05). RESULTS: Between baseline and 24 months eGFR decreased by -3.04(9.4) ml/min/1.73 m2. There were no changes in MVPA, steps, fat and fibre intake but responses were highly variable between individuals. Baseline and change in eGFR at 24 months were positively associated with baseline MVPA (Pearson correlation, r=0.182, p=0.02 and r=0.160, p=0.04 for baseline eGFR and change in eGFR respectively), but not change in MVPA. There was a positive association between change in eGFR and average number of steps at baseline (r=0.140, p=0.059). However, after adjustment for known confounders (including age, sex, BMI, smoking status, ethnicity), these associations disappeared. There were no associations between eGFR and dietary fats (total and unsaturated), and fibre. CONCLUSIONS: Higher MVPA and average number of steps were associated with (but not predictive of) higher eGFR in a group of adults with pre-diabetic stage-2 CKD. Therefore, a healthy active lifestyle should be encouraged in pre-diabetes to prevent decline in kidney function.