Which anthropometric measures best indicate type 2 diabetes among Russian, Somali and Kurdish origin migrants in Finland? A cross-sectional study

Objectives To compare the performance of body mass index (BMI), waist-to-height ratio (WHtR), waist circumference (WC) and waist-to-hip ratio (WHR) in detecting type 2 diabetes among Russian, Somali and Kurdish (born in Iraq/Iran) origin migrants and Finns. Design and participants Cross-sectional study comparing health examination survey data of Russian, Somali and Kurdish origin migrants (n=917) aged 30-64 years who took part in the Migrant Health and Wellbeing Survey with the general Finnish population in the Health 2011 Survey (n=887). Participants were randomly selected from the National Population Register. Setting Six cities in Finland, where a substantial majority of migrants live. Outcome measures Anthropometric measures included objectively measured BMI, WHtR, WC and WHR. Type 2 diabetes was defined based on self-report, laboratory measures of glycated haemoglobin and register data. Test performance was assessed using receiver operating characteristics curves, using area under the curve (AUC) as a measure of accuracy. Results Among Finns, test performance was highest for WC (AUC=0.81, 95% CI 0.74 to 0.87) and WHtR (AUC=0.81, 95% CI 0.75 to 0.87). Test performance was similar for BMI (AUC=0.80, 95% CI 0.67 to 0.92), WC (AUC=0.79, 95% CI 0.67 to 0.91) and WHtR (AUC=0.70, 95% CI 0.66 to 0.93) among Russians. WC and WHtR had highest test performance also among Somali (AUC=0.74, 95% CI 0.64 to 0.84 for WC and AUC=0.75, 95% CI 0.65 to 0.85 for WHtR) and Kurds (AUC=0.71, 95% CI 0.61 to 0.81 for WC and AUC=0.70, 95% CI 0.59 to 0.80 for WHtR).Among migrants, WHR had the poorest test performance. Conclusion WC and WHtR performed overall the best across all study groups, however, accuracy of detection was lower particularly among Somali and Kurds. Currently used diabetes risk assessment tools assume a strong association between anthropometrics and diabetes. These tools need to be validated among non-Western populations.