High impact of nephropathy on ®ve-year mortality rates among patients with Type 2 diabetes mellitus from a multi-ethnic population in New Zealand D. Simmons*, J. Schaumkel², A. Cecil², D. J. Scott² and T. Kenealy² Abstract Aims Type 2 diabetes mellitus and its complications are common among Polynesians in New Zealand. This study investigated the mortality from diabetes among indigenous Maori and recent migrants from the South Paci®c. Methods Death certi®cates and other reports were collected to enumerate those who had died in an across-community cohort study of 765 diabetic patients aged 40±79 years in 1991. Five year mortality status was ascertained in 99.7% and death certi®cates were obtained from 129 (88%) of the 146 who had died. Diabetes was missed from 36% of death certi®cates. Results Compared to Europeans with Type 2 diabetes, Maori with Type 2 diabetes were 2.66 (1.63±4.35) fold as likely to die from diabetes-related conditions, including a 13.1 (3.7±46.4) fold greater risk of death from nephropathy. Paci®c Islands Polynesians with Type 2 diabetes had a similar mortality to Europeans with Type 2 diabetes (hazards ratio 1.06 (0.68±1.65)). After 6 years, 10.7 (2.2±19.3)% more Maori had died than Paci®c Islands Polynesians. Conclusions Maori with Type 2 diabetes are dying from diabetic compli- cations, particularly nephropathy, at an alarming rate. The magnitude of the difference between Maori and Paci®c Islands Polynesians suggests environmental rather than inherited factors are involved and these need further investigation. Diabet. Med. 16, 926±931 (1999) Keywords diabetes complications, diabetic nephropathy, mortality, polynesians, Type 2 diabetes mellitus Abbreviations ESRF, end stage renal failure; NZHIS, New Zealand Health In- formation Service; SMR, standardized mortality ratio Introduction Type 2 diabetes mellitus is associated with increased mortality [1,2]. The major cause of death is cardiovascular disease, although diabetic nephropathy was the major cause among Pimas between 1975 and 1984 [3]. The New Zealand Government is currently monitoring the impact of diabetes using of®cial mortality statistics [4] and in view of the known under-ascertainment of diabetes in mortality ®gures elsewhere [1], validation by cohort studies is clearly required. To date, the only cohort data available from New Zealand have been from predominantly New Zealand European patients (`Europeans') attending the Christchurch Hospital Diabetes Centre [5]. Over one-third of the population of South Auckland (total population in 1991: 303 000), New Zealand are either Maori or Paci®c Islands people-ethnic groups at a L *Department of Rural Health, University of Melbourne, Goulburn Valley Base Hospital, Shepparton, Victoria, Australia ²South Auckland Diabetes Project, South Auckland Academic Division, Middlemore Hospital, University of Auckland, Auckland, New Zealand Received 8 April 1999; revised 17 July 1999; accepted 2 August 1999 Correspondence to: Prof. David Simmons, Dept of Rural Health, University of Melbourne, C/o Goulburn Valley, Base Hospital, Grahame St, Shepparton, Victoria 3630, Australia. E-mail: d.simmons@medicine.unimelb.edu.au 926 ã 1999 British Diabetic Association. Diabetic Medicine, 16, 926±931