Determination of optimal cut-off values for waist circumferences used for the diagnosis of the metabolic syndrome among Batswana adults (ELS 32).

BACKGROUND

To date, no definitive waist circumference (WC) cut-off values for abdominal obesity (AO) have been established for sub-Saharan Africa, including Botswana. Therefore, the classification of AO among these populations is based on European values. For accurate diagnosis of the metabolic syndrome (MetS), cut-off values reflective of the population investigated must be used.

OBJECTIVE

The study was an attempt to determine optimal cut-off values for AO among Batswana adults.

METHODS

The receiver operating characteristic curve was used to determine the optimal cut-off values for predicting at least two other risk factors of the MetS. Data were used from a descriptive cross-sectional study employing a complex multi-stage cluster sampling. Demographic and anthropometric measurements (weight and height, waist and hip circumferences), blood pressure, and blood glucose, triglycerides, high-density lipoprotein cholesterol and total cholesterol levels were collected from 384 men and 416 women in Gaborone and the surrounding villages.

RESULTS

The ability of waist circumference to predict at least two other risk factors of the MetS gave cut-off values of ≥ 91.0 cm (sensitivity 69.1% and specificity of 90.8%, area under the curve 0.85) for men and ≥ 82.3 cm (sensitivity of 88.6% and specificity of 58.9%, area under the curve of 0.76) for women.

CONCLUSIONS

There is a difference between the cut-off values for Europeans with those determined for Batswana adults. Inconsistencies in cut-off values used have the potential for undesirable consequences for cardiovascular risk stratification and prioritisation of preventative strategies for AO and the MetS. The need to determine population-, ethnic- and gender-based cut-off values for AO for Batswana adults has never been more paramount.