The association between the incidence of urolithiasis and nutrition based on Japanese National Health and Nutrition Surveys

To clarify the association between regional variations in urolithiasis incidence and nutrition intake, we evaluated associated data from Japanese national surveys. The incidence of urolithiasis in 12 regions of Japan was calculated from 2005 patient data obtained from 430 hospitals (n = 92,797). Nutrition intake data were obtained from the National Health and Nutrition Survey. We examined the association between urolithiasis incidence and average intake of various types of food or nutrients by region. Continuing surveys in Japan reveal fixed variations in urolithiasis incidence among geographic regions. The national average of patients with urolithiasis was estimated as 203.1 per 100,000 citizens. Regarding food, intake of fruit correlated negatively with the incidence of urolithiasis (r = −0.721, p = 0.008), while intake of eggs (r = 0.537, p = 0.072) and sugar (r = 0.475, p = 0.119) tended to positively correlate with incidence. Regarding nutrients, intake of potassium (r = −0.500, p = 0.098), vitamin K (r = −0.562, p = 0.057), and pantothenic acid (r = −0.560, p = 0.058) tended to negatively correlate with incidence. The incidence of urolithiasis is higher in geographic areas with populations having low fruit and high sugar intake.