Dietary Magnesium Intake and Kidney Stone: The National Health and Nutrition Examination Survey 2011-2018.

ABSTRACT

BACKGROUND: The association between dietary magnesium intake (DMI) and kidney stone (KS) disease is not clear. AIM: To determine the association between DMI and prevalent KS disease defined as self-report of any previous episode of KS. METHODS: We examined The National Health and Nutrition Examination Survey (NHANES) 2011-2018 and used logistic regression analyses adjusting for demographics, BMI, histories of hypertension, diabetes, thiazide use, cigarette smoking, alcohol drinking, relevant dietary and supplemental intakes to determine the independent association between DMI and prevalent KS disease. RESULTS: A total of 19,271 participants were eligible for the final analysis, including 1878 prevalent KS formers. Mean DMI among stone formers was 295.4 mg/day, as compared to 309.6 mg/day among non-stone formers (p=0.02). Higher DMI was strongly associated with lower odds of prevalent KS disease in univariate analysis regardless of when DMI was analyzed as a continuous variable (OR=0.94, 95% CI 0.89-0.99, p=0.02) or when the extreme quartiles of DMI were compared (OR=0.74, 95% CI 0.60-0.92, p=0.007). In the multivariable-adjusted regression analysis, those in the highest quartile of DMI compared to the lowest quartile (≥379 mg vs. <205 mg) had significantly reduced odds of prevalent KS (OR=0.70, 95% CI 0.52-0.93, p=0.01). When DMI was analyzed as a continuous variable, there was a trend toward reduced odds of prevalent KS disease with higher DMI (OR=0.92 per 100 mg, 95% CI 0.84-1.01, p=0.07). CONCLUSIONS: Our study suggests that higher DMI is associated with a reduced risk of KS disease. Future prospective studies are needed to clarify the causal relationship between DMI and KS disease.