Endocrine Abstracts

Aims: Waist circumference is a convenient measure of abdominal adipose tissue,it correlates closely with BMI and is strongly linked to obesity- related risk factors. The sex specific waist circumference currently proposed for European male is 94 centimetres and for females is 80 cm. Thus, there is a need to develop sex specific waist circumference cut-offs points appropriate for different population (W.H.O).

The aims are to determine the appropriate waist cut-offs for identifying people with body mass index (≥25 kg/m²) and those with B.M.I (≥30 kg/m²) among Tunisian adult population (north Africa country).

Materials and methods: We used a sample of the Tunisian National Nutrition Survey a cross-sectional health survey, conducted in 1996 on a large nationally representative sample which included 2927 adults over 20 years old who had measurements of height, body weight, wait circumference, blood pressure, fasting plasma glucose, total cholesterol and triglycerides. Receiver operating characteristic (ROC) analysis was used to identify waist circumference values corresponding to BMI cut-offs for over weight (≥ 25 kg/m²) and obesity (≥ 30 kg/m²) in both men and women.

Results: Waist circumference exceeding 85 cm in men and 80 cm in women correctly identified subjects with a body mass index of ≥25 kg/m² with sensitivity of >90% and specificity of >83%. Whereas waist circumference exceeding 90 cm in men and 85 cm in women identified subjects with a body mass index of ≥30 kg/m² with a sensitivity of >95% and specificity of >78% compared with those with waist circumference below the first cut-offs points.

Conclusion: Waist circumference of 85 cm was most sensitive and specific in men whereas in women it was 80 cm to identify most subjects with a body mass index ≥ 25 kg/m². These cut-offs are derived by identifying waist circumference values corresponding to BMI cut-offs for over weight (≥ 25 kg/m²) in Tunisian adult population.