Prevalence of diabetes mellitus and impaired glucose tolerance in a New Zealand multiracial workforce.

A cross sectional survey was carried out among a multiracial workforce of 5677 staff aged 40 to 64 years at worksites in Auckland and Tokoroa to determine the prevalence of diabetes mellitus and impaired glucose tolerance (IGT). The prevalences of diabetes mellitus and IGT were both similar for men and women, but increased with age. The relative risks for diabetes mellitus and for IGT were both inversely associated with gross annual household income, independent of age and ethnicity, being 1.61 (95% Cl = 1.10, 2.37) and 1.80 (95% Cl = 1.21, 2.67) respectively, in the lowest income group (less than $30,000) compared with the highest (greater than $40,000). Compared with Europeans, the relative risk of diabetes mellitus was significantly increased among Maori (3.63; 95% Cl = 2.48, 5.32), Pacific Islanders (2.34; 95% Cl = 1.50, 3.66) and Asians (5.97; 95% Cl = 2.61, 13.65), after controlling for age, income and body mass index. The increased prevalence of diabetes mellitus among Maori and Pacific Islanders, but not in Asians, could be partly attributed to their increased levels of obesity compared with Europeans. However, other factors, in addition to obesity, explain the increased diabetes prevalence in nonEuropean groups.