title: Appropriate cut-off values of waist circumference to predict cardiovascular outcomes: 7-year follow-up in an Iranian population.
abstract: OBJECTIVE
  Due to the lack of compelling evidence for waist circumference (WC) as a cardiovascular disease (CVD) risk factor in many ethnic groups, the need for local research has been expressed by international authorities. This study was undertaken to determine the optimal cut-off points of WC for predicting incident CVD and metabolic syndrome in an Iranian population.
  
  
  METHODS
  A total of 6,504 participants from three areas in central Iran were followed over 7 years. Receiver operating characteristics (ROC) and area under the curve (AUC) were used to identify the maximum value of sensitivity and specificity combinations corresponding to the appropriate cut-off points of WC for the detection of the metabolic syndrome and CVD events. The optimal cut-off values were defined as the point at which the value of "sensitivity+specificity-1" reached the maximum value. Finally, Cox proportional hazard modeling was used to determine which cut-off point was better fit in the CVD risk prediction model.
  
  
  RESULTS
  After 394,418 person-years of follow-up, 427 incident primary CVD events (233 men) were identified. Considering CVD, the optimum cut-off points were 99/103.5 cm (men/women) but these had a low sensitivity (AUC: 0.59, 95%CI 0.55-0.63 in both men and women). The second highest values for discriminating CVD were 93/97 cm that resulted in acceptable sensitivity. Regarding the metabolic syndrome, 92.6/97.8 cm were identified as optimum (AUC: 0.67, 95%CI 0.65-0.69 in men and 0.65, 95%CI 0.63-0.67 in women). The best cut-off values that fit in the Cox regression model were 90/97 cm.
  
  
  CONCLUSIONS
  International recommended WC cut-off values for the Middle East are not appropriate compared to the locally defined cut-off values in Iran.
authors.affiliation: Public Health, Epidemiology & Biostatistics, University of Birmingham, UK. talaei@crc.mui.ac.ir
authors.forename: Mohammad
authors.initials: M
authors.lastname: Talaei
authors.forename: G Neil
authors.initials: GN
authors.lastname: Thomas
authors.forename: Tom
authors.initials: T
authors.lastname: Marshall
authors.forename: Masoumeh
authors.initials: M
authors.lastname: Sadeghi
authors.forename: Rokhsareh
authors.initials: R
authors.lastname: Iranipour
authors.forename: Shahram
authors.initials: S
authors.lastname: Oveisgharan
authors.forename: Nizal
authors.initials: N
authors.lastname: Sarrafzadegan
mesh_terms: D000328:Adult; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000503:physiopathology; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006306:Health Surveys / Q000379:methods; D006801:Humans; D007492:Iran; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications / Q000503:physiopathology; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000503:physiopathology; D011237:Predictive Value of Tests; D012016:Reference Values; D016896:Treatment Outcome; D055105:Waist Circumference; D049629:Waist-Hip Ratio / Q000592:standards*