Association between glycated hemoglobin (HbA1c) and kidney stones: a cross-sectional study of NHANES from 2007 to 2018

In recent years, the incidence of kidney stones has increased alongside changes in lifestyle and the rising prevalence of metabolic diseases. The relationship between glycated hemoglobin (HbA1c), a marker of average blood glucose levels, and kidney stone risk remains unclear. This study, based on the National Health and Nutrition Examination Survey (NHANES) database, investigates the association between HbA1c and kidney stone risk to provide insights for clinical prevention and intervention. Using a cross-sectional design from the 2007–2018 NHANES data, we employed multivariable logistic regression models to analyze the relationship between higher HbA1c levels and kidney stone risk. Potential confounding factors, including body mass index (BMI), hypertension, and coronary heart disease, were adjusted for. Subgroup analyses were conducted across different clinical characteristics. A total of 21,881 participants were included, with 13,475 (61.58%) having HbA1c ≤ 5.6% and 8406 (38.42%) having HbA1c > 5.6%. The prevalence of kidney stones significantly differed between the two groups (7.83% vs. 12.67% P < 0.05). After adjusting for confounders, univariate and multivariate stratified logistic regression models with kidney stones as the dependent variable revealed that in non-diabetic male participants aged < 60 years higher HbA1c (> 5.6%) was associated with an increased risk of kidney stones (Model 2: OR = 1.671 95% CI: 1.288–2.710 P = 0.000187; Model 3: OR = 1.562 95% CI: 1.168–2.088 P = 0.000308). Further subgroup analyses indicated that this association persisted across different BMI levels, hypertension status, and coronary heart disease subgroups, with BMI potentially modifying the relationship between HbA1c and kidney stones. Based on NHANES data from 2007 to 2018, significant differences in kidney stone incidence were observed according to glycemic control (HbA1c). Moreover, an elevated HbA1c level (> 5.6%) is associated with a history of kidney stones among non-diabetic males under 60 years of age. This association underscores the potential importance of early glycemic management, even before the onset of diabetes, as a strategy for nephrolithiasis prevention in susceptible populations.