title: Concordance rates and modifiable risk factors for lower urinary tract symptoms in twins.
abstract: BACKGROUND
  Lower urinary tract symptoms, which are common in older men, are thought to be determined genetically and by modifiable environmental risk factors. We examined the contribution of these 2 etiologic components in a cohort of U.S. twins.
  
  
  METHODS
  In 1998, a questionnaire that assessed lower urinary tract symptoms, weight, height, alcohol consumption, cigarette smoking, and physical activity was sent out to members of the National Academy of Science-National Research Council Twins Registry. We analyzed 1,723 complete twin pairs with information on lower urinary tract symptoms and zygosity and who did not have a previous diagnosis of prostate cancer. We calculated concordance rates of categories of the International Prostate Symptom Score in monozygotic (MZ) and dizygotic (DZ) twins. Generalized estimating equations were used to calculate the odds ratio of having high-moderate/severe lower urinary tract symptoms.
  
  
  RESULTS
  Concordance rates were higher in MZ than in DZ twins with concordance rate ratios of 2.2 and 6.9 depending on the specificity of definition of symptoms. Genetic factors contributed 72% to the risk of high-moderate/severe lower urinary tract symptoms. Taking into account correlated individuals, we observed high odds of lower urinary tract symptoms in obese men compared with lean men (odds ratio = 1.91; 95% confidence interval = 1.16-3.15 comparing first versus fourth quartile). Cigarette smoking was not associated with lower urinary tract symptoms, but alcohol consumption was positively associated. Men who were more physically active tended to have lower odds of lower urinary tract symptoms compared with less active men (0.62; 0.36-1.08).
  
  
  CONCLUSIONS
  The findings indicate a strong genetic component of lower urinary tract symptoms, but also support previous studies that modifiable environmental risk factors are associated with this condition.
authors.affiliation: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
authors.forename: Sabine
authors.initials: S
authors.lastname: Rohrmann
authors.forename: M Daniele
authors.initials: MD
authors.lastname: Fallin
authors.forename: William F
authors.initials: WF
authors.lastname: Page
authors.forename: Terry
authors.initials: T
authors.lastname: Reed
authors.forename: Alan W
authors.initials: AW
authors.lastname: Partin
authors.forename: Patrick C
authors.initials: PC
authors.lastname: Walsh
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Platz
mesh_terms: D000368:Aged; D004200:Diseases in Twins / Q000453:epidemiology* / Q000235:genetics; D015444:Exercise; D006801:Humans; D008019:Life Style; D008297:Male; D024821:Metabolic Syndrome / Q000209:etiology; D016017:Odds Ratio; D011470:Prostatic Hyperplasia / Q000453:epidemiology / Q000235:genetics; D012307:Risk Factors; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic; D014481:United States / Q000453:epidemiology; D014570:Urologic Diseases / Q000453:epidemiology* / Q000235:genetics