Association of accelerometer-derived rest–activity rhythm with incident kidney stones: a prospective cohort study

Objective: To investigate the prospective association between accelerometer-derived rest–activity rhythm parameters and the risk of incident kidney stones in a large general population. Methods: This prospective cohort study included 93 598 participants from the UK Biobank who provided valid 7-day wrist accelerometry data. Incident kidney stones were identified through linkage to hospital inpatient and primary care records. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for non-parametric and parametric rhythm metrics, adjusting for sociodemographic, lifestyle, and clinical confounders, including sleep duration and moderate-to-vigorous physical activity. Restricted cubic splines were employed to assess dose-response relationships. Results: During a median follow-up of 7.8 years, 615 incident kidney stone cases were documented. Dampened circadian rhythms were independently associated with an increased risk of kidney stones. In fully adjusted analyses, comparing the lowest versus highest quartiles, lower relative amplitude (HR: 1.50, 95% CI: 1.11–2.02), lower daytime activity (M10) (HR: 1.59, 95% CI: 1.12–2.26), and higher nocturnal activity (L5) (HR: 1.40, 95% CI: 1.07–1.85) were significant predictors. Spline analyses revealed a non-linear association for relative amplitude, with risk rising sharply as rhythm robustness decreased, whereas M10 and L5 exhibited linear dose-response relationships. Conclusion: Dampened rest–activity rhythms, characterized by reduced amplitude and increased nocturnal restlessness, are robust risk factors for kidney stones, independent of sleep quantity and physical activity intensity. Targeting circadian health may offer a novel, modifiable avenue for the primary prevention of urolithiasis.