title: Appropriate body mass index and waist circumference cutoffs for middle and older age group in Thailand: data of 19,621 participants from Thai epidemiologic stroke (TES) study.
abstract: OBJECTIVE
  To determine the appropriate body mass index (BMI) and waist circumference (WC) cutoff point for identification of at least one cardiovascular risk factor (hypertension, dyslipidemia, and type 2 diabetes) in Thailand, and to compare the discrimination ability of BMI with that of WC for discrimination of at least one cardiovascular risk factor.
  
  
  METHODS
  Baseline health survey data of participants of Thai Epidemiologic Stroke (TES) Study, who were free from stroke, enrolled from five geographic regions around the country, were studied as cross-sectional analysis. Receiver operating characteristics curve (ROC) analysis was performed to determine the appropriate cutoff points of BMI and WC in identifying those with presence of at least one cardiovascular risk factors. The BMI or WC value with the shortest distance on the ROC curve was considered to be appropriate cutoffs. Comparing the ability of BMI in discrimination of at least one cardiovascular risk factor with that of WC was performed by comparing ROC area under curve (AUC).
  
  
  RESULTS
  Among 19,621 (6,608 men and 13,013 women) participants with age range of 45 to 80 years, the average age was 59.8 years for men and 58.5 years for women. The appropriate cutoff point of BMI was 23 kg/m2 in men and 24 kg/m2 in women. The cutoffs of WC were 80 cm and 78 cm in men and women, respectively. In both gender, waist circumference (WC) (AUC in men = 0.684; 95% CI, 0.672-0.695, AUC in women = 0.673; 95% CI, 0.665-0.681) was significantly (p < 0.001) better than BMI (AUC in men = 0.667; 95% CI, 0.656-0.679, AUC in women = 0.636; 95% CI, 0.628-0.644) in discrimination of at least one cardiovascular risk factor.
  
  
  CONCLUSIONS
  In Thai adults aged 45 to 80 years, the cutoff points of BMI should be 23 kg/m2 in men and 24 kg/m2 in women. For WC, 80 cm and 78 cm should be considered to be appropriate cutoffs for men and women, respectively. Waist circumference (WC) as a simple obesity index should be advocated for public health screening.
authors.affiliation: Prasat Neurological Institute, Department of Medical Services, Ministry of Public Health, Bangkok, Thailand. maiyadhajs@yahoo.com
authors.forename: Maiyadhaj
authors.initials: M
authors.lastname: Samsen
authors.forename: Suchat
authors.initials: S
authors.lastname: Hanchaiphiboolkul
authors.forename: Pimchanok
authors.initials: P
authors.lastname: Puthkhao
authors.forename: Tasanee
authors.initials: T
authors.lastname: Tantirittisak
authors.forename: Somchai
authors.initials: S
authors.lastname: Towanabut
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012307:Risk Factors; D012680:Sensitivity and Specificity; D020521:Stroke / Q000175:diagnosis; D013785:Thailand; D055105:Waist Circumference