title: Nephrolithiasis and increased blood pressure among females with high body mass index.
abstract: BACKGROUND
  We hypothesized that one reason for the heterogeneity in previously reported links between kidney stones and blood pressure (BP) was the differential effects of nephrolithiasis among subgroups of individuals. In particular, we hypothesized that the association between stone history and BP may vary with respect to sex and body size.
  
  
  METHODS
  Data from the Third National Health and Nutrition Examination Survey were used to estimate the association between history of stone disease and odds of prior diagnosis of hypertension and mean difference in systolic BP, diastolic BP, and pulse pressure. Nine hundred nineteen persons with a history of stones and 19,120 persons without stones were available for analysis.
  
  
  RESULTS
  In women, it was estimated that stone formers (SFs) experienced a 69% increase in odds of self-reported hypertension (95% confidence interval [CI], 1.33 to 2.17; P < 0.001). No significant difference was found in men. The estimated difference in mean systolic and diastolic BP comparing SFs with non-SFs increased with body mass index in both sexes, but was more pronounced in women. Mean systolic BPs in women SFs in quintiles 4 and 5 of body mass index were 7.62 mm Hg (95% CI, 1.04 to 14.2; P = 0.024) and 4.36 mm Hg (95% CI, 0.30 to 8.42; P = 0.036) greater than those in similar women non-SFs, respectively.
  
  
  CONCLUSIONS
  Our findings not only support the link between kidney stone disease and BP, but also suggest that overweight women SFs may be at significantly increased risk for hypertension.
authors.affiliation: Department of Statistics, University of California, Irvine, CA 92697-1250, USA. dgillen@uci.edu
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Gillen
authors.forename: Fredric L
authors.initials: FL
authors.lastname: Coe
authors.forename: Elaine M
authors.initials: EM
authors.lastname: Worcester
mesh_terms: D000293:Adolescent; D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D015992:Body Mass Index; D015897:Comorbidity; D003971:Diastole; D004032:Diet / Q000706:statistics & numerical data; D005260:Female; D006306:Health Surveys; D006801:Humans; D006973:Hypertension / Q000453:epidemiology*; D007669:Kidney Calculi / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000453:epidemiology*; D012306:Risk; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology; D013599:Systole; D044465:White People / Q000706:statistics & numerical data