title: Menstrual irregularity and cardiovascular mortality.
abstract: BACKGROUND
  Polycystic ovary syndrome, the most common cause of irregular menstrual cycles, is associated with an adverse cardiovascular risk profile. However, there are limited prospective studies confirming the link between polycystic ovary syndrome and cardiovascular mortality.
  
  
  METHODS
  We studied 15,005 pregnant women recruited from the Kaiser Foundation Health Plan in California between 1959 and 1966. The menstrual cycle pattern was assessed at baseline according to self-report, physician report, and medical record abstraction. Participants were matched to California Vital Status files annually until 2007 to identify deaths due to overall cardiovascular disease (CVD) and subsets of coronary heart disease (CHD) and cerebrovascular disease based on International Classification of Diseases codes. Cox proportional hazards models were used to estimate the association between irregular cycles and cardiovascular mortality. Missing covariate data were multiply imputated using standard methods.
  
  
  RESULTS
  During 456,298.5 person-years of follow-up, there were 666 CVD deaths, including 301 CHD deaths and 149 cerebrovascular deaths. Compared with women with regular cycles, women with irregular cycles had an increased risk for CHD mortality [age adjusted hazards ratio (HR) 1.42, 95% confidence interval (CI) 1.03-1.94]; however, the association was not statistically significant after adjustment for body mass index (adjusted HR 1.35, 95% CI 0.98-1.85). There was a nonsignificant increase in CVD mortality (age adjusted HR 1.21, 95% CI 0.97-1.52) but not cerebrovascular mortality (age adjusted HR 0.85, 95% CI 0.49-1.47).
  
  
  CONCLUSIONS
  In this large prospective cohort of pregnant women, we found an increase in age-adjusted risk for CHD mortality in women with irregular menstrual cycles. This risk was attenuated after adjustment for body mass index.
authors.affiliation: Center for Research on Women's and Children's Health, Public Health Institute, University of California San Francisco, San Francisco, California 94115, USA.
authors.forename: Erica T
authors.initials: ET
authors.lastname: Wang
authors.forename: Piera M
authors.initials: PM
authors.lastname: Cirillo
authors.forename: Eric
authors.initials: E
authors.lastname: Vittinghoff
authors.forename: Kirsten
authors.initials: K
authors.lastname: Bibbins-Domingo
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Cohn
authors.forename: Marcelle I
authors.initials: MI
authors.lastname: Cedars
mesh_terms: D000367:Age Factors; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000150:complications* / Q000401:mortality*; D005260:Female; D006801:Humans; D008597:Menstrual Cycle; D008599:Menstruation Disturbances / Q000150:complications*; D011247:Pregnancy; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors