RELATION BETWEEN GEOGRAPHIC VARIABILITY IN KIDNEY-STONES PREVALENCE AND RISK-FACTORS FOR STONES

To determine whether geographic variability in rates of kidney stones in the United States was attributable to differences in personal and e nvironmental exposures, the authors examined cross-sectional data that included information on self-reported, physician-diagnosed kidney sto nes collected from 1,167,009 men and women, aged greater than or equal to 30 years, recruited nationally in 1982, Information on risk factor s for stones including age, race, education, body mass, hypertension, and diuretic and vitamin C supplement use was obtained by self-adminis tered questionnaire, Consumption of milk, coffee, tea, soft drinks, an d alcohol was based on food frequency data. Indices of ambient tempera ture and sunlight level were assigned to subjects based on state of re sidence. Stones were nearly twice as prevalent in the Southeast as in the Northwest among men and women, Ambient temperature and sunlight in dices were independently associated with stones prevalence after contr olling for other risk factors for stones, Regional variation was elimi nated for men and greatly reduced for women after adjustment for tempe rature, sunlight, and beverage consumption, Other factors appeared to not contribute to regional variation, These results provide evidence t hat ambient temperature and sunlight levels are important risk factors for stones and that differences in exposure to temperature and sunlig ht and beverages may contribute to geographic variability.