Body Mass Index Modifies The Protective Association of Physical Activity With Incident Chronic Kidney Disease: A Prospective Cohort Study

Summary

This prospective cohort study of over 11,000 adults shows that higher physical activity is associated with lower CKD risk, with stronger effects at higher BMI. Each 1000 MET-min/week increase was linked to greater risk reduction in obesity (HR = 0.72) than in overweight individuals (HR = 0.84).

Abstract

The interaction between physical activity (PA) and body mass index (BMI) on chronic kidney disease (CKD) risk is not well defined. This study aimed to investigate the independent and joint effects of PA and BMI on CKD incidence within the context of public health. This prospective cohort analysis included 11,597 adults with normal renal function from the Shanghai Suburban Adult Cohort and Biobank (SSACB). PA (MET-min/week) and BMI (kg/m²) were assessed at baseline and not updated during follow-up. Incident CKD was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² and/or a urine albumin-to-creatinine ratio (ACR) ≥30 mg/g at follow-up, consistent with KDIGO criteria. Cox regression models were used to assess main effects and the PA×BMI interaction. Over a median follow-up of 3.0 years, 485 incident CKD cases occurred. Higher PA was associated with lower CKD risk (per 1000 MET-min/week: HR = 0.91, 95% CI: 0.84–0.98). A significant interaction was observed (P = 0.031), indicating that the protective effect of PA was more pronounced at higher BMI levels. Specifically, each 1000 MET-min/week increase in PA was associated with a greater reduction in CKD risk in individuals with obesity (HR = 0.72) compared with those with overweight (HR ≈ 0.84). The protective effect of PA on CKD risk is modified by BMI, with greater benefits observed in individuals with overweight or obesity. These findings support prioritizing combined PA and weight management strategies for high-risk populations.

Introduction

Chronic kidney disease (CKD) is a major and growing global public health concern, characterized by high prevalence and strong associations with cardiovascular morbidity, mortality, and reduced quality of life¹. The burden is particularly substantial in China², where rapid population aging and increasing prevalence of metabolic disorders, especially obesity and physical inactivity, have contributed to a large CKD population. This trend places considerable pressure on healthcare systems and highlights the need for effective, scalable prevention strategies targeting modifiable risk factors. Such priorities are reflected in ....

Protocol

Informed consent was obtained from all subjects involved in the study. Written informed consent has been obtained from the patient(s) to publish this paper.

Study Design and Population

This prospective cohort study was based on the Shanghai Suburban Adult Cohort and Biobank (SSACB)⁹, an ongoing community-based study detailed in previous publications. In brief, the SSACB used a multi-stage, stratified, cluster sampling method to recruit adults aged 20–74 years from suburban communities in Shanghai using a multi-stage, stratified, cluster sampling design. The baseline ....

Results

Baseline Characteristics of the Study Population

This study ultimately included 11,597 participants with normal baseline renal function, with a median follow-up time of 3.0 years. The participant selection process is illustrated in Figure 1.

Discussion

This prospective cohort study demonstrates a statistical interaction between PA and BMI in the prevention of CKD. Higher PA was associated with a lower risk of CKD, and a significant interaction indicated that this protective association was stronger at higher BMI levels. The apparent attenuation of the association in normal-weight individuals should be interpreted cautiously, as it likely reflects lower baseline risk rather than a true absence of benefit. Translating this interaction into a risk-stratification framework.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Item	Manufacturer / Source	Identifier
Biochemical analyzer	Roche Diagnostics	Cobas C702
Biochemical analyzer	Roche Diagnostics	Cobas C501
Physical activity questionnaire	nternational Physical Activity Questionnaire (IPAQ)	https://sites.google.com/site/theipaq/
Statistical software	R Foundation for Statistical Computing	RRID:SCR_001905