Higher blood lipid index linked to kidney stones in large Chinese case-control study

Adults with higher levels of a blood lipid marker known as the atherogenic index of plasma (AIP) show higher odds of having kidney stones, according to a large case-control study of Chinese adults published in BMC Urology.

The study, led by Feng Shi, Dingguo Zhang, Hui Wang and Dawei Wang, set out to evaluate the association between AIP levels and kidney stone prevalence among Chinese adults. AIP is a calculated marker of dyslipidemia, defined as an imbalance of lipids in the blood. It is derived from the logarithm of the ratio of triglycerides to high-density lipoprotein cholesterol (HDL-C), and it has previously been used as a predictor of metabolic and cardiovascular diseases. Because both metabolic disturbances and cardiovascular problems have been linked to kidney stones, the researchers considered it a useful lens through which to examine the condition.

The analysis included 11,645 people with kidney stones and 106,112 control participants without the condition. The kidney stone cases had a mean age of 53.25 years and were 61.83 percent male, while the controls had a mean age of 55.46 years and were 50.66 percent male. Kidney stone status was determined by ultrasound examinations performed by trained clinicians, and the association between AIP and stone prevalence was examined using multivariable logistic regression, with a restricted cubic spline analysis used to assess the dose-response relationship.

The results showed a clear difference in average AIP between the two groups. The mean AIP was 0.86 (standard deviation 0.70) in the control group and 0.95 (standard deviation 0.73) in the kidney stone group, and participants with stones had significantly higher AIP values than those without, a difference that reached statistical significance at P < 0.001.

When participants were grouped by AIP quartiles, the association became more apparent. Compared with people in the lowest AIP quartile, the adjusted odds ratios for kidney stones were 1.03 (95 percent confidence interval 0.97 to 1.09) in the second quartile, 1.08 (95 percent confidence interval 1.02 to 1.15) in the third, and 1.15 (95 percent confidence interval 1.08 to 1.22) in the highest. The elevated odds in the top two quartiles suggest that the relationship is concentrated among those with the highest lipid ratios, while the second quartile showed no statistically clear difference from the lowest.

The researchers also examined the relationship on a continuous scale. In the fully adjusted model, each standard deviation increase in AIP was associated with higher odds of kidney stones, with an odds ratio of 1.07 (95 percent confidence interval 1.04 to 1.09). The restricted cubic spline analysis confirmed a significant and linear dose-response relationship between AIP levels and kidney stone prevalence, with an overall P value below 0.001 and a P value for nonlinearity of 0.326, indicating that the association did not depart meaningfully from a straight-line pattern.

Sensitivity analyses further supported the robustness of these findings, according to the study authors. The consistency of the results across the analytic approaches they employed strengthens the observation that the association is not an artifact of a single modeling choice.

The authors conclude that elevated AIP values were positively associated with higher odds of kidney stones in the Chinese population, suggesting that dyslipidemia, as reflected by AIP, may play a role in stone formation. As a case-control study, the design captures participants at a single point in relation to their stone status and cannot establish that higher AIP causes stones to develop; the odds ratios describe the likelihood of having kidney stones among people with different lipid profiles rather than the risk of developing them over time. The findings were reported in a version of the article shared early to provide faster access to peer-reviewed, accepted research, which is subject to further edits before the final version of record appears.

Subject of Research: The association between the atherogenic index of plasma and kidney stones in Chinese adults

Article Title: Association between atherogenic index of plasma and kidney stones: a case-control study in Chinese adults

Article References: Shi, F., Zhang, D., Wang, H., & Wang, D. (2026). Association between atherogenic index of plasma and kidney stones: a case-control study in Chinese adults. BMC Urology. https://doi.org/10.1186/s12894-026-02413-w

Image Credits: AI Generated

DOI: 10.1186/s12894-026-02413-w

Keywords: atherogenic index of plasma, kidney stones, dyslipidemia, triglycerides, HDL cholesterol, case-control study, Chinese adults, logistic regression, dose-response, BMC Urology, Association, between