Relationship between the dietary inflammatory index and kidney stone prevalence

This study aimed to investigate the association between the dietary inflammatory index and lifetime kidney stone prevalence.

We performed a cross-sectional study utilizing the 2013-2014 National Health and Nutrition Examination Survey data. Data were available on 2192 participants aged > 20 years with a complete kidney stone history and 24 h dietary intake interview. Weighted multivariable linear regression, subgroup analyses, and interaction terms were employed. Covariates including age, race, sex, energy and protein intake, total serum calcium, serum iron, PIR, phosphorus, serum/urine creatinine, HDL, glucose, diastolic and systolic pressure, education level, eGFR, BMI, albuminuria, diabetes, smoking status, and marital status were hierarchically adjusted in three different models.

The average dietary inflammatory index for 2192 participants was - 0.11 ± 1.73, ranging from - 4.52 to 4.28. In the fully adjusted model, participants in the highest dietary inflammatory index tertile (the most proinflammatory) had 72% higher odds of the lifetime prevalence of kidney stones than those in tertile 1 (OR = 1.72, 95% CI: 1.03, 2.88, P = 0.0367). Subgroup analysis showed that the association between the dietary inflammatory index and kidney stone history was only statistically significant in the younger age (age ≥ 60), female, Mexican American groups, married people or people without diabetes, hypertension, low eGFR, and albuminuria.

There is a positive association between the dietary inflammatory index and self-reported kidney stones in US adults, which indicates that dietary patterns could greatly impact kidney stone prevalence.