Clinicopathological Study of Renal Function in Type 2 Diabetics in Ile-Ife, Southwest Nigeria

Aims: To determine the prevalence and clinico-pathological correlates of diabetic nephropathy among type 2 diabetics in Southwest Nigeria.

Study Design: Descriptive, cross-sectional.

Place and Duration of Study: Renal Unit, Medicine Department, Obafemi Awolowo University Teaching Hospital, Ile-Ife, Southwest Nigeria.

Methodology: Percutaneous ultrasound-guided renal biopsy was carried out in 40 consenting type 2 diabetic adults out of 88 patients in stages 3 and 4 chronic kidney disease using the Kidney Disease Improving Global Outcomes classification.

Results: Eighty eight (48.1%) of the one hundred and eighty three subjects with mean age of 58.05(±6.10) years had clinical Diabetic Nephropathy. The duration of diabetes was 9.55(±4.1) years. Median protein excretion was 0.55 g/day. Mean estimated Glomerular Filtration Rate was 45.1(±12) ml/min. Thirty nine renal (97.5%) tissues showed glomerular basement membrane thickening.

There was a positive correlation between the systolic blood pressure and severity of glomerular lesions (r=0.480, p=0.002), interstitial changes (p=0.602, r<0.001) and vascular lesions (0.429, 0.006). The diastolic blood pressure correlated with glomerular lesions (r=0.500, p=0.001), interstitial changes (0.479, 0.002), vascular lesions (p=0.431, r=0.006), nodular glomerulosclerosis (r=0.333, p=0.036) and diffuse glomerulosclerosis (r=0.372, p=0.018). Urinary protein excretion correlated with severity of glomerular lesions (r=0.457, p=0.003), vascular changes (r=0.483, p=0.002) and diffuse glomerulosclerosis (r=0.407, p=0.009). Diabetic retinopathy correlated positively with severity of glomerular lesion (r=0.406, p=0.009) and diffuse glomerulosclerosis (r=0.547, p<0.001).

Conclusion: The prevalence of diabetic nephropathy among type 2 diabetics in Ile-Ife is high. Glomerular basement membrane thickening was the most prevalent renal pathology. There was a positive correlation between blood pressure, protein excretion, retinopathy and renal histology.