High impact of nephropathy on five-year mortality rates among patients with Type 2 diabetes mellitus from a multi-ethnic population in New Zealand

Aims Type 2 diabetes mellitus and its complications are common among Polyne sians in New Zealand. This study investigated the mortality from diabetes a mong indigenous Maori and recent migrants from the South Pacific. Methods Death certificates and other reports were collected to enumerate th ose who had died in an across-community cohort study of 765 diabetic patien ts aged 40-79 years in 1991. Five year mortality status was ascertained in 99.7% and death certificates were obtained from 129 (88%) of the 146 who ha d died. Diabetes was missed from 36% of death certificates. Results Compared to Europeans with Type 2 diabetes, Maori with Type 2 diabe tes were 2.66 (1.63-4.35) fold as likely to die from diabetes-related condi tions, including a 13.1 (3.7-16.4) fold greater risk of death from nephropa thy. Pacific Islands Polynesians with Type 2 diabetes had a similar mortali ty to Europeans with Type 2 diabetes (hazards ratio 1.06 (0.68-1.65)). Afte r 6 years, 10.7 (2.2-19.3)% more Maori had died than Pacific Islands Polyne sians. Conclusions Maori with Type 2 diabetes are dying from diabetic complication s, particularly nephropathy, at an alarming rate. The magnitude of the diff erence between Maori and Pacific Islands Polynesians suggests environmental rather than inherited factors are involved and these need further investig ation.