Regional Variation in Nephrolithiasis Incidence and Prevalence among United States Men

Abstract

The southeastern region of the United States has long been considered to have higher rates of nephrolithiasis than other regions. Previous reports examined hospital discharge rates for nephrolithiasis rather than stone incidence rates and did not evaluate potential confounding variables. We studied prospectively the regional rates of incident stone formation within the United States in a cohort of 45,289 men 40 to 75 years old in 1986 who had no history of kidney stones. Dietary intake was measured by a semiquantitative food frequency questionnaire. During 6 years of followup 753 incident cases of kidney stones were documented. We also examined regional prevalence among 4,082 men who had a history of nephrolithiasis at the start of the study.