Pattern and predictors of urine protein excretion among patients with type 2 diabetes attending a single tertiary hospital in Lagos, Nigeria

Testing for proteinuria is used to screen for diabetic nephropathy. However, significant proportion of diabetics has normal urine protein excretion despite impaired renal function. We aimed to determine the factors predicting increased urine protein excretion in patients with type 2 diabetes. This was a cross-sectional study of 358 type 2 diabetics attending the diabetes clinic of a teaching hospital in Lagos. Data regarding patients' demographic characteristics, and disease history were retrieved. Clinical measurement and samples for determination of plasma creatinine, and urine protein/creatinine ratio were obtained. Comparison of means was by student's t-test, while for percentages, Chi-square test was used. Relationship between glomerular filtration rate (GFR) and urine protein excretion was assessed using linear regression while factors associated with increased urine protein was determined excretion logistic regression analysis. Level of statistical significance was set at P <0.05. Mean age was 57.84 + 11.12 years and mean duration of diabetes was 8.63 + 7.53 years. Urine protein excretion was increased in 191 (53.4%) of the patients. Patients with increased urine protein excretion were more likely to be hypertensive, to be on an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker had a higher mean systolic blood pressure, and a lower mean GFR. Patients with a GFR <60 mL/min/1.73 m2 had a six-fold increased odds of having increased urine protein excretion, while patients on an inhibitor of the renin-angiotensin-aldosterone system had a 50% reduced odds of having increased urine protein excretion. Proteinuria and reduced GFR are common among sub-Saharan African patients with type 2 diabetes. GFR below 60 mL/min/1.73 m2 and not receiving an inhibitor of the renin-angiotensin-aldosterone system predict increased urine protein excretion in them.