Abstract
OBJECTIVE: We evaluate the association between the Dietary Inflammatory Index (DII) and kidney stones. DESIGN: We performed a cross-sectional analysis using data from National Health and Nutrition Examination Survey (NHANES). Dietary intake information was assessed using first 24-h dietary recall interviews, and the Kidney Conditions were presented by a questionnaire. The primary outcome was to investigate the association between DII and incidence of kidney stones, and the secondary outcome was to assess the association between DII and nephrolithiasis recurrence. SETTING: The NHANES, 2007-2016. PARTICIPANTS: The study included 25 984 NHANES participants, whose data on DII and kidney stones were available, of whom 2439 reported a history of kidney stones. RESULTS: For the primary outcome, after fully multivariate adjustment, DII score is positively associated with the risk of kidney stones (OR = 1·07; 95 % CI 1·04, 1·10). Then, compared Q4 with Q1, a significant 38 % increased likelihood of nephrolithiasis was observed. (OR = 1·38; 95 % CI 1·19, 1·60). For the secondary outcome, the multivariate regression analysis showed that DII score is positively correlated with nephrolithiasis recurrence (OR = 1·07; 95 % CI 1·00, 1·15). The results noted that higher DII scores (Q3 and Q4) are positively associated with a significant 48 % and 61 % increased risk of nephrolithiasis recurrence compared with the reference after fully multivariate adjustment (OR = 1·48; 95 % CI 1·07, 2·05; OR = 1·61; 95 % CI 1·12, 2·31). CONCLUSIONS: Our findings revealed that increased intake of pro-inflammatory diet, as a higher DII score, is correlated with increased odds of kidney stones incidence and recurrence.