Chronic kidney disease (CKD) has significantly increased the global disease burden. Its prevalence and mortality are increasing year by year and are closely related to visceral fat accumulation. The cardiometabolic index (CMI) is a novel indicator for comprehensively evaluating visceral obesity. Several cross-sectional studies suggest a connection between CMI and CKD risk. However, this relationship has not been sufficiently examined through longitudinal cohort studies, especially in the general Chinese population.

The primary objective of this study was to investigate the relationship between CMI and CKD risk in the general Chinese population.

A prospective cohort study was conducted. Based on the established inclusion and exclusion criteria, a total of 78 115 employees who participated in the health examination organized by Kailuan Group during the years 2006—2007 were selected as research subjects. The participants were categorized into four groups according to the quartiles of CMI, Q1 group (CMI≤0.27, n=19 545), Q2 group (0.27<CMI ≤0.44, n=19 907), Q3 group (0.44<CMI≤0.72, n=19 227), and Q4 group (CMI>0.72, n=19 436). The follow-up period commenced upon completion of the 2006 annual physical examination, with subsequent follow-ups conducted biennially. The endpoint event was the occurrence of CKD or death during follow-up, with the date of either event marking the end of follow-up. For participants without incident CKD, the last physical examination date served as the follow-up endpoint, and the follow-up time concluded on December 31, 2021. The Kaplan-Meier method was used to calculate the cumulative incidence of CKD in different CMI groups, and Log-rank test was used for inter-group comparison. Cox proportional hazards regression models were used to assess the association between CMI and CKD incidence. Restricted cubic splines (at the 10th, 50th, and 90th percentiles) were used to evaluate the non-linear relationship between CMI and CKD. Subgroup analyses were performed using Cox proportional hazards regression models, and multiplicative interactions were assessed.

During the median follow-up period of 14.89 years, 20 639 participants occurred CKD events. The number of CKD patients in the first quartile group of CMI was 4 137, the second quartile group was 5 090, the third quartile group was 5 289, and the fourth quartile group was 6 123. The corresponding incidence densities were 16.61, 20.82, 22.70, and 26.83 per thousand person-years, respectively. As the level of CMI exposure rose, the cumulative incidence of CKD showed a progressive increase, and the overall discrepancy was statistically significant by the Log-Rank test (P<0.01). Cox proportional hazard regression analysis showed that elevated CMI levels significantly increased the risk of CKD. Compared with the first quartile of CMI (Q1 group), the HR (95%CI) of the second (Q2 group), third (Q3 group), and fourth quartile (Q4 group) were 1.12 (1.07-1.17), 1.16 (1.11-1.21), and 1.34 (1.28-1.40), respectively. Restricted cubic spline analysis showed that there was an inverted L-shaped curve relationship between baseline CMI level and CKD. The results of stratified analysis showed that there was only a multiplicative interaction between smoking, drinking, and CMI.

In the general Chinese population, elevated levels of CMI were significantly associated with CKD, and this association was especially strong in smokers and drinkers.

慢性肾脏病（CKD）是全球疾病负担显著增长的重要原因，其患病率和死亡率逐年上升，且与内脏脂肪蓄积密切关联。心脏代谢指数（CMI）是一种能够全面评估内脏型肥胖的新型指标，多项横断面研究表明，CMI和CKD风险之间存在显著关联。然而，关于CMI和CKD风险之间相关性的纵向队列研究仍然缺乏，尤其在中国普通人群中。

本研究的主要目的是调查中国普通人群中CMI与CKD发病之间的关联。

采用前瞻性队列研究，根据纳入与排除标准选取参加2006—2007年度开滦集团健康体检的78 115名职工为研究对象，将参与者按照CMI四分位数分为4组，Q1组（CMI≤0.27，n=19 545）、Q2组（0.27<CMI≤0.44，n=19 907）、Q3组（0.44<CMI≤0.72，n=19 227）、Q4组（CMI>0.72，n=19 436）。以完成2006年度体检的时间为随访起点，每2年随访1次，以随访过程中发生CKD或死亡为终点事件，CKD或死亡的时间为随访终点时间，未发生CKD者则以末次参见体检的时间作为随访终点时间，随访末次时间为2021-12-31。采用Kaplan-Meier法计算不同CMI组CKD累积发病率，并采用Log-rank检验进行组间比较。采用Cox比例风险回归模型评估CMI与CKD发生率的关联。使用限制性立方样条（第10、50、90百分位点）评估CMI与CKD之间的非线性关系。使用Cox比例风险回归模型进行不同亚组分层分析，并评估乘法交互作用。

在中位随访14.89年发现，有20 639名参与者新发CKD事件。其中Q1组、Q2组、Q3组和Q4组CKD的发病人数分别为4 137、5 090、5 289、6 123例。相应的发病密度分别为16.61、20.82、22.70、26.83/千人年。并且随着CMI暴露水平升高，CKD的累积发病率逐渐升高，经Log-rank检验，总体差异有统计学意义（P<0.01）；采用Cox比例风险回归模型分析，发现CMI水平升高可显著增加CKD风险。与CMI Q1组相比，Q2组、Q3组和Q4组的HR（95%CI）分别为1.12（1.07~1.17）、1.16（1.11~1.21）和1.34（1.28~1.40）；限制性立方样条分析发现，基线CMI水平与CKD之间存在倒"L"形曲线关系；分层分析结果表明仅吸烟、饮酒和CMI之间存在乘法交互作用。

中国普通人群中CMI水平升高与CKD发生显著相关，这种关联性在吸烟者和饮酒者中更为显著。