BACKGROUND: This study assessed whether glycated hemoglobin concentration, an indicator of psychogenic stress, differs between indigenous populations and non-indigenous reference groups. METHODS: Multivariate and stratified analyses were undertaken of cross-sectional data from multi-center community-based diabetes diagnostic and risk factor screening initiatives in Canada and Australia. Population groups were Australian Aborigines (n = 116), Torres Strait Islanders (n = 156), Native Canadians (n = 155), Greek migrants to Australia (n = 117), and Caucasian Australians (n = 67). Measurements included fasting glycated hemoglobin (HbA(1c)) concentration, fasting and 2-h post-load glucose concentrations, body mass index, waist-to-hip ratio, and demographic variables. RESULTS: Mean HbA(1c) concentrations were greater for indigenous groups than for Greek migrants and Caucasian Australians (P < 0. 0001). The covariate adjusted indigenous versus non-indigenous difference (95% CI) was 0.90 (0.58-1.22) percentage units, 18.2% higher for indigenous people. Stratified analyses indicated greater HbA(1c) for indigenous than for non-indigenous persons with normoglycemia (P = 0.009), impaired glucose tolerance (P = 0.097), and diabetes (P < 0.0001). CONCLUSIONS: HbA(1c) concentrations are greater for indigenous than for non-indigenous groups. Social changes, low control, and living conditions associated with westernization may be inherently stressful at the biological level for indigenous populations in westernized countries.