Diabetic nephropathy in New Zealand Maori and Pacific Islands people

In 1983, a study at Middlemore Hospital demonstrated that a high proportion of Maori and Pacific Islands (Polynesian) diabetic inpatients had chronic renal failure when compared with Europeans (8%, 28% vs 1%, respectively). Since this time renal replacement therapy (RRT) has grown by 10%, p.a., and this is mainly due to increasing numbers of Polynesians with non-insulin-dependent diabetes (NIDDM). Among 286 new patients requiring RRT in 19995, 9% Europeans, 67% Maori and 43%, of Pacific Islanders had NIDDM. There are now quantitatively more Maori than Europeans receiving transplants for diabetic nephropathy. The reasons for the increasing importance of diabetic nephropathy among Polynesians rest with their excess of NIDDM. All age-adjusted prevalences of known diabetes are 1.9% (1.7-2.0%) among Europeans but 5.2% (4.9-5.5%) among Maori and 4.0 (3.8-4.2%) among Pacific Islanders and their greater risk of diabetic nephropathy once NIDDM has developed (cross-sectional results showed that 0.3% Europeans, 4.7% Maori and 3.3% Pacific Islanders with NIDDM have end-stage renal failure, 22% of whom were untreated). The characteristics of the diabetic nephropathy in NIDDM are also different, Proteinuria is more common among Polynesians (5.4% Europeans us 30.2% Maori cr 13.0% Pacific Islanders). Differences in rates of proteinuria and microalbuminuria and degree of glomerular hyperfiltration are seen within 5 years of diagnosis. The cause(s) for differences in predisposition remain unclear, although they are partly due to differences in glycaemia and blood pressure control. Family studies and prospective studies are currently underway to help unravel the underlying mechanisms.