Prevalence of diagnosed and undiagnosed diabetes and prediabetes in New Zealand: findings from the 2008/09 Adult Nutrition Survey

Abstract

Aim: To describe the prevalence of diagnosed and undiagnosed diabetes and prediabetes for New Zealand adults.

Methods: The 2008/09 New Zealand Adult Nutrition Survey was a nationally representative, cross-sectional survey of 4,721 New Zealanders aged 15 years and above. Self-reported diabetes and the 2010 American Diabetes Association cutoffs for HbA1c were used to define diagnosed diabetes, undiagnosed diabetes and prediabetes. Prevalence rates were calculated and age-specific diagnosed diabetes rates were compared with those from the Virtual Diabetes Register.

Results: Overall, prevalence of diabetes was 7.0%, and prevalence of prediabetes 18.6%. Prevalence of diabetes was higher in men (8.3%, 95% CI: 6.4, 10.1) than in women (5.8%, 95% CI: 4.7, 7.0), and was higher among the obese (14.2%, 95% CI: 11.6, 16.9) compared with the normal weight group (2.4%, 95% CI: 1.4, 3.6). Prevalence of undiagnosed diabetes was highest among Pacific people (6.4%, 95% CI: 3.8, 9.1) compared with Maori (2.2%, 95% CI: 1.2, 3.1) and New Zealand European and Others (1.5%, 95% CI: 0.9, 2.1).

Conclusion: The high prevalence of prediabetes indicates the prevalence of diabetes will continue to increase in New Zealand. Implementation of effective evidence-based prevention strategies is required to reduce the increasing costs of the diabetes epidemic.