Hyperuricemia (HUA) is a global health concern, with its prevalence on the rise in China. Sleep, as an important lifestyle factor, shows an inconsistent relationship with serum uric acid (SUA) levels in previous observational studies, and the causal relationship between them remains unclear. Therefore, it is necessary to employ more reliable methods to clarify their intrinsic association.

To investigate the bidirectional causal relationships between sleep duration, daytime napping frequency, and SUA levels using a bidirectional Mendelian randomization (MR) approach.

This study was based on publicly available summary data from large-scale genome-wide association studies (GWAS). Data on sleep duration (n=127 573), daytime napping frequency (n=452 633), and SUA levels (n=288 649) were derived from European populations. A bidirectional two-sample MR design was employed, screening eligible single nucleotide polymorphisms (SNPs) as instrumental variables. The inverse variance weighted (IVW) method, MR-Egger regression, weighted median method, and MR-PRESSO method were used to assess causal effects. Sensitivity analyses, including heterogeneity tests and leave-one-out analysis, were conducted to verify the robustness of the results.

The MR analysis results showed that the genetic prediction of sleep duration was a negative causal relationship with the SUA level (OR=0.81, 95%CI=0.67-0.98, P=0.03), while the frequency of daytime naps predicted by genetics has a positive causal relationship with the level of SUA (OR=1.20, 95%CI=1.05-1.37, P=0.009). Reverse MR analysis found no causal effect of SUA levels on either sleep duration or daytime napping frequency (P>0.05). Sensitivity analyses detected no significant horizontal pleiotropy, indicating robust findings.

This study provides genetic evidence that shorter sleep duration and higher daytime napping frequency are independent risk factors for elevated SUA levels. Improving sleep habits may serve as an effective non-pharmacological intervention strategy for the prevention and management of HUA.

高尿酸血症（HUA）是全球性健康问题，其患病率在中国呈上升趋势。睡眠作为重要的生活方式因素，其与血清尿酸（SUA）水平的关系在既往观察性研究中结论不一，二者间的因果关系尚不明确。因此，有必要采用更可靠的方法阐明其内在关联。

利用双向孟德尔随机化（MR）方法，探究睡眠时长、日间小睡频率与SUA水平之间的双向因果关系。

本研究基于大规模全基因组关联研究（GWAS）的公开汇总数据，睡眠时长（n=127 573）、日间小睡频率（n=452 633）及SUA水平（n=288 649）的数据均来自欧洲人群。采用双向两样本MR设计，筛选符合条件的单核苷酸多态性（SNP）作为工具变量。采用反方差加权（IVW）法、MR-Egger回归、加权中位数法及MR-PRESSO法评估因果效应，并采用异质性检验、逐一排除法检验等进行敏感性分析以验证结果的稳健性。

MR分析结果显示，遗传预测的睡眠时长与SUA水平呈负向因果关联（OR=0.81，95%CI=0.67~0.98，P=0.03）；遗传预测的日间小睡频率与SUA水平呈正向因果关联（OR=1.20，95%CI=1.05~1.37，P=0.009）。反向MR分析未发现SUA水平对睡眠时长或日间小睡频率有因果影响（P>0.05）。敏感性分析未发现明显的水平多效性，结果稳健。

本研究从遗传学层面证实，较短的睡眠时长和较高的日间小睡频率是导致SUA水平升高的独立危险因素。改善睡眠习惯可能成为预防和管理HUA的有效非药物干预策略。