C-reactive protein as a predictor of total arteriosclerotic outcomes in type 2 diabetic nephropathy.
BACKGROUND
The inflammatory marker C-reactive protein (CRP) has been found in most, but not all, prospective studies to be associated with future cardiovascular outcomes. However, CRP has not been tested in the high-cardiovascular risk population of type 2 diabetic nephropathy.


METHODS
We studied the independent relationship between CRP and the subsequent development of incident or recurrent arteriosclerotic outcomes (primary) and congestive heart failure events (secondary) in 1560 individuals with diabetic nephropathy, overt proteinuria, and hypertension enrolled in the prospective Irbesartan Diabetic Nephropathy Trial.


RESULTS
Traditional cardiac risk factors were highly prevalent, CRP levels were high overall [quintiles (mg/L) 1st, 0 to 1.2; 2nd, 1.3 to 2.5; 3rd, 2.6 to 5.0; 4th, 5.1 to 10.0; and 5th, >10), and subsequent cardiovascular events were very common. A univariate relationship existed between CRP and total arteriosclerotic outcomes (P < 0.0001). However, after adjusting for study intervention and traditional risk factors, the relationship no longer remained. In fact, controlling for previous cardiovascular disease alone caused the association to become nonsignificant. The secondary analysis found a significant univariate relationship between CRP and congestive heart failure events (P= 0.007) that persisted in multivariate analyses (P= 0.006). However, this relationship was confined to the highest CRP quintile [RR (95% CI) 2.0 (1.27, 3.16)].


CONCLUSIONS
In diabetic patients with nephropathy, CRP does not add predictive information above and beyond that provided by traditional established risk factors. Whether this holds true for other populations with similar risk burdens is an important public health question that should be addressed. A secondary finding of a link between CRP and congestive heart failure requires further confirmation.
Friedman
Allon N
AN
Division of Nephrology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA. allfried@iupui.edu
Hunsicker
Lawrence G
LG
Selhub
Jacob
J
Bostom
Andrew G
AG
D000368:Aged; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use; D001161:Arteriosclerosis / Q000097:blood* / Q000188:drug therapy / Q000453:epidemiology*; D015415:Biomarkers / Q000097:blood; D001713:Biphenyl Compounds / Q000627:therapeutic use; D002097:C-Reactive Protein / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications / Q000453:epidemiology*; D003928:Diabetic Nephropathies / Q000097:blood / Q000188:drug therapy / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D000077405:Irbesartan; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012307:Risk Factors; D013777:Tetrazoles / Q000627:therapeutic use
D047228:Angiotensin II Type 1 Receptor Blockers; D015415:Biomarkers; D001713:Biphenyl Compounds; D013777:Tetrazoles; D002097:C-Reactive Protein; D000077405:Irbesartan