Prevalence of undiagnosed diabetes, impaired glucose tolerance, and impaired fasting glucose among Maori in Te Wai o Rona: Diabetes Prevention Strategy.

Objective: To describe the prevalence of undiagnosed diabetes, impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) ("dysglycaemia") among Maori.

Methods: Te Wai o Rona: Diabetes Prevention Strategy was a trial of lifestyle change among Maori families in the Waikato/Lakes areas of New Zealand. All Maori family household members aged > or = 28 years, without known diabetes, were invited to participate through primary care, community, and media approaches. Participants were invited to have an oral glucose tolerance test (OGTT).

Results: Of the 3817 eligible Maori, mean BMI was 32.9+/-7.8 kg/m2 (women) and 33.1+/-6.7 kg/m2 (men). The age standardised prevalence of undiagnosed diabetes was higher among men than women (6.5[5.8-7.4]% vs 4.2[3.6-4.8]%), as was that for IFG (5.4[4.7-6.1]% vs 3.0[2.3-3.5]%), but not IGT (8.5[7.6-9.4]% vs 9.7[8.7-10.6]%) with no rural-urban differences. The prevalence of dysglycaemia increased with increasing BMI with no clear inflection point and was 1.33(1.11-1.60) greater among those with a community services card after adjusting for age, sex and BMI.

Conclusions: Undiagnosed diabetes, IGT, and IFG remain common among Maori, particularly men, the very obese, and those with greater socioeconomic disadvantage. There remains significant opportunity to reduce Maori morbidity and premature mortality through diabetes case-finding and intervention.