While extreme heat represents an established risk factor for mortality in patients with diabetes mellitus (DM), its synergistic effects with air pollution

Background: Maintenance hemodialysis patients exhibit low physical activity, which is associated with sarcopenia, increased risk of cardiovascular events, and elevated all-cause mortality. Social support is an important resource for promoting healthy behaviors. But the mechanisms of influencing these patients’ intrinsic psychological processes to raise physical activity levels are unclear. Methods: This study was a cross-sectional observational study from September 2021 to February 2022, enrolling 460 hemodialysis patients from four tertiary hospitals in Xi’an City. We assessed social support, exercise self-efficacy, and exercise benefits and barriers perceptions with the Social Support Rating Scale (SSRS), the Self-Efficacy for Exercise Scale (SEE), and the Dialysis Patient-perceived Exercise Benefits and Barriers Scale (DPEBBS) respectively. Daily total step count was measured using an Omron electronic pedometer (model HJ-321) worn continuously for seven days. Descriptive statistics, Pearson correlation analysis, and chain mediation analysis using the PROCESS macro developed by Hayes (Model 6) were performed; the significance of mediation effects was tested via bootstrapping. Results: Pearson correlation analysis revealed significant positive correlations among social support, exercise self-efficacy, perceived exercise benefits and barriers, and total daily steps ( r = 0.289–0.507; all P < 0.01). Chain mediation model analysis indicated social support’s total effect on daily steps was 0.289. Specific mediation pathways included: (1) social support → exercise self-efficacy → total daily steps; (2) social support → perceived barriers to exercise benefits → total daily steps; (3) social support → exercise self-efficacy → perceived barriers to exercise benefits → total daily steps. Significant positive correlations were observed among social support, exercise self-efficacy, perceived exercise benefits and barriers, and total daily steps (all P < 0.01). Chain mediation analysis revealed that social support’s total effect on daily steps was 0.289 (95% CI: 0.201–0.377). Three significant mediation pathways were identified: social support → exercise self-efficacy → daily steps; social support → perceived barriers to exercise benefits → daily steps; and the chain mediation pathway social support → exercise self-efficacy → perceived barriers to exercise benefits → daily steps. Conclusion: Social support not only directly and positively influences physical activity levels among patients undergoing hemodialysis but also indirectly promotes physical activity by enhancing exercise self-efficacy and improving perceptions of barriers to exercise benefits. A chain mediation pathway "social support → exercise self-efficacy → perception of barriers to exercise benefits → physical activity "was identified. Trial registration: The study protocol was approved by the Ethics Committee of Xi’an Jiaotong University (approval number: 20211575).