The Prevalence and Incidence of and Risk Factors For, Micro-Albuminuria among Urban Africans with Type 1 Diabetes in South Africa: an Inter-Ethnic Study

Type 1 diabetes (T1DM) in sub-Saharan Africans is rare and is associated with high mortality from nephropathy. We studied the prevalence and potential risk factors for microalbuminuria (MA) in African and in age-of-onset matched white patients with T1DM. Risk factors for MA were evaluated prospectively in an African cohort. 68 African and 134 white patients, age at diagnosis 10–40 years, duration of diabetes > 2 years, were evaluated for MA; 48 Africans were followed prospectively. Africans had shorter duration of diabetes (median, 8 years vs 11 years), higher HbA1c (10.62(SD 2.52)%, vs 9.02(2.44)%, lower cholesterol (4.45(1.04) vs 5.45(1.16)mmol/l), and fewer (23.5% vs 54.5%) had adolescent diabetes onset (p 0.0030 for each); the prevalence of MA was 39.7% and 24.6% respectively (p = 0.0155). In multiple regression analysis MA was associated with mean HbA1c (p < 0.0001), younger age at diagnosis (p = 0.0060), SBP (p = 0.0012) and African race (p = 0.0287). Prospectively, Africans developing MA (45%) had higher mean HbA1c levels (p = 0.0001), were more likely to have had adolescent onset of DM (33.3% vs 8.0%, p = 0.0310) and lower BMI (p = 0.0340); logistic regression revealed that higher HbA1c and SBP, and lower BMI predicted MA. Nine of 16 African subjects progressed to macroalbuminuria; they were characterised only by extremely poor glycaemic control (mean HbA1c, 13.49(2.00)%). Microalbuminuria, and severe hyperglycaemia, are common in diabetic Africans with short duration TIDM; MA may rapidly progress to macroalbumiuria. African race may be associated with increased susceptibility to diabetic nephropathy.