Increased prevalence of albuminuria among non-European peoples with type 2 diabetes

BACKGROUND: A high incidence of albuminuria, varying by ethnicity, has been found in a number of populations worldwide. There have been few opportunities to explore the prevalence of albuminuria as a marker of chronic kidney disease while adjusting for other risk factors in the different ethnic groups in New Zealand. METHODS: We examined the association between albuminuria and ethnicity using cross-sectional data from a large cohort study of type 2 diabetes conducted in New Zealand. RESULTS: The study population was 65 171 adults in primary care with type 2 diabetes, not on renal replacement therapy; median age was 64.7 years, median diabetes duration 5.1 years and 48.5% were non-European. Microalbuminuria or greater was present in 50% of Maori, 49% of Pacific people, 31% of Indo- and East-Asians and 28% of Europeans. Regression analyses were used to examine the association between ethnicity and albuminuria-measured as albumin:creatinine ratio-after controlling for study site and other known risk variables: age, sex, duration of diabetes, smoking status, socioeconomic status, body mass index, systolic and diastolic blood pressure, triglyceride levels, HbA(1C) and being on an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker. After controlling for these risk factors and compared with Europeans, odds ratios for 'advanced' albuminuria (≥100 mg/mmol) were 3.9 (95% confidence interval: 3.2-4.6) in Maori, 4.7 (3.6-6.3) in Pacific people, 2.0 (1.5-2.7) in Indo-Asians and 4.1 (3.2-5.1) in East-Asians. CONCLUSION: Non-European ethnicities appear to carry significantly higher risks of albuminuria in type 2 diabetes.