Background: Kidney stones and their risk factors aggregate in families, yet few studies have estimated the heritability of known risk factors.
Objective: Estimate the heritability of dietary risk factors for kidney stones.
Methods: Dietary intakes were assessed using the Viocare Food Frequency Questionnaire in sibships enrolled in the Rochester, MN cohort of the Genetic Epidemiology Network of Arteriopathy. Measures of urinary supersaturation were determined using 24 h urine samples. Heritabilities and genetic correlations were estimated using variance components methods.
Results: Samples were available from 620 individuals (262 men, 358 women, mean (SD) age 65 (9) years). Dietary intakes of protein, sucrose, and calcium had strong evidence for heritability (p < 0.01) after adjustment for age, sex, height and weight. Among the significantly heritable dietary intakes (p < 0.05), genetic factors explained 22-50 % of the inter-individual variation. Significant genetic correlations were observed among dietary protein, dietary sucrose, and dietary calcium intakes (p < 0.001).
Conclusions: Evidence from this relatively large cohort suggests a strong heritable component to dietary intakes of protein, sucrose and calcium that contributes to nephrolithiasis risk. Further efforts to understand the interplay of genetic and environmental risk factors in kidney stone pathogenesis are warranted.
Keywords: Diet; Heritability; Nephrolithiasis; Supersaturation.