title: Associations between conventional cardiovascular risk factors and risk of peripheral artery disease in men.
abstract: BACKGROUND
  Previous studies have examined the associations of individual clinical risk factors with risk of peripheral artery disease (PAD), but the combined effects of these risk factors are largely unknown.
  
  
  OBJECTIVE
  To estimate the degree to which the 4 conventional cardiovascular risk factors of smoking, hypertension, hypercholesterolemia, and type 2 diabetes are associated with the risk of PAD among men.
  
  
  METHODS
  Prospective study of 44,985 men in the United States without a history of cardiovascular disease at baseline in 1986; participants in the Health Professionals Follow-up Study were followed up for 25 years until January 2011. The presence of risk factors was updated biennially during follow-up.
  
  
  METHODS
  Clinically significant PAD defined as limb amputation or revascularization, angiogram reporting vascular obstruction of 50% or greater, ankle-brachial index of less than 0.90, or physician-diagnosed PAD.
  
  
  RESULTS
  During a median follow-up of 24.2 years (interquartile range, 20.8-24.7 years), there were 537 cases of incident PAD. Each risk factor was significantly and independently associated with a higher risk of PAD after adjustment for the other 3 risk factors and confounders. The age-adjusted incidence rates were 9 (95% CI, 6-14) cases/100,000 person-years (n = 19 incident cases) for 0 risk factors, 23 (95% CI, 18-28) cases/100,000 person-years (n = 99 incident cases) for 1 risk factor, 47 (95% CI, 39-56) cases/100,000 person-years (n = 176 incident cases) for 2 risk factors, 92 (95% CI, 76-111) cases/100,000 person-years (n = 180 incident cases) for 3 risk factors, and 186 (95% CI, 141-246) cases/100,000 person-years (n = 63 incident cases) for 4 risk factors. The multivariable-adjusted hazard ratio for each additional risk factor was 2.06 (95% CI, 1.88-2.26). Men without any of the 4 risk factors had a hazard ratio of PAD of 0.23 (95% CI, 0.14-0.36) compared with all other men in the cohort. In 96% of PAD cases (95% CI, 94%-98%), at least 1 of the 4 risk factors was present at the time of PAD diagnosis. The population-attributable risk associated with these 4 risk factors was 75% (95% CI, 64%-87%). The absolute incidence of PAD among men with all 4 risk factors was 3.5/1000 person-years.
  
  
  CONCLUSIONS
  Among men in this cohort, smoking, hypertension, hypercholesterolemia, and type 2 diabetes account for the majority of risk associated with development of clinically significant PAD.
authors.affiliation: Division of General Medicine and Primary Care, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA. hpmmj@channing.harvard.edu
authors.forename: Michel M
authors.initials: MM
authors.lastname: Joosten
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Pai
authors.forename: Monica L
authors.initials: ML
authors.lastname: Bertoia
authors.forename: Eric B
authors.initials: EB
authors.lastname: Rimm
authors.forename: Donna
authors.initials: D
authors.lastname: Spiegelman
authors.forename: Murray A
authors.initials: MA
authors.lastname: Mittleman
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Mukamal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D006801:Humans; D006937:Hypercholesterolemia / Q000453:epidemiology*; D006973:Hypertension / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000453:epidemiology*; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*; D014481:United States / Q000453:epidemiology