Aims: Comparing waist circumference (WC) role in diabetes risk prediction and diagnosis of
metabolic syndrome (MS) in different populations.
Methods: Population-based samples from Australia (n = 9026) and Iran (n = 8259) were studied
in 2000 and followed for 4 years. Follow-up attendance was 58% and mean age was 51
vs. 47. Pearson correlations calculated between WC and other MS components. ROC for the
role of WC in the prediction of incident diabetes was used.
Results: Prevalences ofMS (48% vs. 28%), an increasedWC (58.5% vs. 54.5%), low HDL-C (35% vs.
11.2%), high triglyceride (52.2% vs. 29.6%) were significantly higher in Iran. Fasting glucose
5.6 mmol/L was higher in Australia (26% vs. 23%). Hypertension was no different (38%).
Pearson correlations betweenWC and otherMS componentswere stronger in Australians: FPG
(0.32 vs. 0.2), HDL (0.47 vs. 0.16), TG (0.38 vs. 0.30) and SBP (0.38 vs. 0.36). Among women, area
under ROC curve for WC as a predictor for diabetes was significantly higher for Australians
(0.76 vs. 0.68, p < 0.001) with no difference among men (0.69 vs. 0.71, p = 0.4).
Conclusion: WC was more strongly related to other components of MS in Australia. Association
between WC and MS or incident diabetes varies between ethnicities.