A study on the relationship between the weight-adjusted waist index and kidney stone prevalence mediated by diabetes: data from NHANES 2007–2018

This study investigated the association between the weight-adjusted waist circumference index (WWI) and the prevalence of kidney stones among U.S. adults with diabetes, addressing the knowledge gap regarding the role of central obesity in kidney stone formation. Using data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2018, we analyzed 21,177 participants. The WWI served as the exposure variable, whereas kidney stones were the outcome variable. Multiple regression and mediation effect analyses were employed to assess the mediating role of diabetes in the relationship between WWI and kidney stones. Among the 21,177 participants analyzed, each unit increase in the weight-adjusted waist circumference index (WWI) was associated with a 30% higher incidence of kidney stones (OR = 1.30, 95% CI 1.21-1.39; P < 0.0001). Participants in the highest WWI tertile exhibited a 66% increased risk of kidney stones compared to those in the lowest tertile (OR = 1.66, 95% CI 1.43-1.93; P < 0.0001). The diabetes mediating 12.60% of this association (95% CI 8.2-17.8%, P < 0.0001). The WWI is independently associated with an increased risk of kidney stones, with diabetes playing a partial mediating role. These findings highlight the importance of monitoring WWI as a potential risk factor for kidney stones, especially in populations with diabetes.