Interleukin-6 and C-reactive protein in pathogenesis of diabetic nephropathy: new evidence linking inflammation, glycemic control, and microalbuminuria.
BACKGROUND
Recent studies have shown that subclinical inflammation is a part of type 2 diabetes mellitus. This study was designed to explore the relationships between low-grade inflammation and renal microangiopathy in patients with type 2 diabetes mellitus.


METHODS
Sixty patients with type 2 diabetes mellitus were included in the study and further divided into normoalbuminurics, microalbuminurics, and macroalbuminurics, of 20 patients each. We analyzed serum concentrations of high-sensitivity C-reactive protein (HS-CRP) and interleukin-6 (IL-6) and studied their correlation with proteinuria. The patients and a control group of 20 healthy individuals were followed-up for a period of 6 months and the markers measured again.


RESULTS
A positive correlation was found between urinary albumin excretion and levels of HS-CRP (r = 0.781, P < .001) and IL-6 (r = 0.708, P < .001). The level of glcosylated hemoglobin (HbA1c) showed a significant positive correlation with urinary albumin excretion (r = 0.630, P < .001), CRP (r = 0.750, P < .001), and IL-6 (r = 0.680, P < .001). Levels of HbA1c, HS-CRP, and IL-6 significantly decreased in all three diabetic groups after 6 months of treatment. Also, the percentage of HbA1c decrement correlated well with the decrease percentage in HS-CRP (r = .277, P = .01).


CONCLUSIONS
Inflammatory markers in early type 2 diabetic nephropathy are elevated and are independently associated with urinary albumin excretion. It is possible to hypothesize on the participation of locally released cytokines in the development of kidney damage.
Choudhary
Nikhil
N
Maulana Azad Medical College, New Delhi, India. drnikhilchoudhary@gmail.com
Ahlawat
Ravinder S
RS
D000419:Albuminuria; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002097:C-Reactive Protein / Q000378:metabolism*; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000503:physiopathology*; D003928:Diabetic Nephropathies / Q000209:etiology* / Q000378:metabolism; D003927:Diet, Diabetic; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007249:Inflammation / Q000503:physiopathology; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged
D015415:Biomarkers; D002097:C-Reactive Protein; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D015850:Interleukin-6; C508600:IL6 protein, human