Body mass index, waist circumference and waist-to-hip ratio cut-off points for categorisation of obesity among Omani Arabs.
BACKGROUND
There are no data on optimal cut-off points to classify obesity among Omani Arabs. The existing cut-off points were obtained from studies of European populations.


OBJECTIVE
To determine gender-specific optimal cut-off points for body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) associated with elevated prevalent cardiovascular disease (CVD) risk among Omani Arabs.


METHODS
A community-based cross-sectional study.


METHODS
The survey was conducted in the city of Nizwa in Oman in 2001.


METHODS
The study contained a probabilistic random sample of 1421 adults aged > or =20 years. Prevalent CVD risk was defined as the presence of at least two of the following three risk factors: hyperglycaemia, hypertension and dyslipidaemia. Logistic regression and receiver-operating characteristic (ROC) curve analyses were used to determine optimal cut-off points for BMI, WC and WHR in relation to the area under the curve (AUC), sensitivity and specificity.


RESULTS
Over 87% of Omanis had at least one CVD risk factor (38% had hyperglycaemia, 19% hypertension and 34.5% had high total cholesterol). All three indices including BMI (AUC = 0.766), WC (AUC = 0.772) and WHR (AUC = 0.767) predicted prevalent CVD risk factors equally well. The optimal cut-off points for men and women respectively were 23.2 and 26.8 kg m-2 for BMI, 80.0 and 84.5 cm for WC, and 0.91 and 0.91 for WHR.


CONCLUSIONS
To identify Omani subjects of Arab ethnicity at high risk of CVD, cut-off points lower than currently recommended for BMI, WC and WHR are needed for men while higher cut-off points are suggested for women.
Al-Lawati
Jawad A
JA
Department of Non-communicable Diseases Surveillance & Control, Muscat 113, Ministry of Health, Oman. jallawat@yahoo.com
Jousilahti
Pekka
P
D000328:Adult; D000368:Aged; D018912:Arabs / Q000706:statistics & numerical data; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000150:complications / Q000453:epidemiology; D006973:Hypertension / Q000150:complications / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D024821:Metabolic Syndrome / Q000453:epidemiology; D008875:Middle Aged; D009765:Obesity / Q000145:classification* / Q000150:complications* / Q000208:ethnology; D009850:Oman / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D012737:Sex Factors; D049629:Waist-Hip Ratio