Positive association between serum calcium-phosphorus ratio and kidney stone prevalence: Analysis of NHANES data (2007–2020)

Kidney stones are a common urological disease with a complex pathogenesis influenced by multiple factors. Calcium and phosphorus, as essential minerals in the body, may be closely related to the prevalence of kidney stones. However, studies on the association between the serum calcium-phosphorus ratio and the prevalence of kidney stones remain limited, and systematic analyses are lacking. This study utilized data from the 2007 to 2020 National Health and Nutrition Examination Survey (NHANES), including a total of 34,122 participants. Multivariable logistic regression models were employed, progressively adjusting for demographic characteristics, health status, and dietary factors to assess the association between the serum calcium-phosphorus ratio and kidney stone prevalence. Restricted cubic spline (RCS) analysis was used to explore any potential nonlinear associations between the serum calcium-phosphorus ratio and kidney stone prevalence. Subgroup and interaction analyses were conducted to further investigate the influence of covariates on this association. Among the 34,122 participants, 3207 were diagnosed with kidney stones. The model adjusted for multiple covariates showed a significant positive association between the serum calcium-phosphorus ratio and the prevalence of kidney stones (OR: 1.29, 95% CI: 1.14-1.45, P < .001). RCS analysis indicated no significant nonlinear association between the serum calcium-phosphorus ratio and the prevalence of kidney stones (P for nonlinearity = 0.558). Subgroup analysis revealed that this positive association remained consistent across multiple subgroups, with no significant interactions observed. Sensitivity analysis further confirmed the robustness of these findings. This study demonstrates a significant positive association between the serum calcium-phosphorus ratio and the prevalence of kidney stones, and this association is linear. Further research is needed to explore the potential role of the serum calcium-phosphorus ratio as a risk marker for kidney stones and to identify possible intervention strategies.