Inflammatory parameters are independently associated with urinary albumin in type 2 diabetes mellitus.
BACKGROUND
Data about the relationship of inflammation to nephropathy in type 2 diabetes mellitus are scarce. In the present study, we test the hypothesis that inflammatory parameters are independently related to urinary albumin excretion (UAE) at early stages of nephropathy.


METHODS
Sixty-five patients with type 2 diabetes with microalbuminuria (MAB) or mild proteinuria (protein < 1 g/d) were included. We analyzed serum concentrations of high-sensitivity C-reactive protein (hs-CRP) and tumor necrosis factor-alpha (TNF-alpha), as well as urinary level of this cytokine.


RESULTS
Inflammatory parameters were significantly greater in patients with diabetes than controls; furthermore, urinary TNF-alpha levels increased significantly as nephropathy progressed. Median urinary TNF-alpha level was 7 pg/mg in normoalbuminurics, 13 pg/mg in microalbuminurics (P < 0.001), and 18 pg/mg in proteinurics (P < 0.001 versus normoalbuminuria and P < 0.01 versus MAB). Albuminuria was related to hs-CRP (r= 0.68; P < 0.001) and serum (r = 0.45; P < 0.01) and urinary TNF-alpha levels (r = 0.71; P < 0.001), but there was no association between serum and urinary TNF-alpha levels. Partial correlation analysis showed that hs-CRP level, urinary TNF-alpha level, duration of diabetes, and glycated hemoglobin level remained significantly associated with UAE. A stepwise multiple regression analysis showed that UAE was significantly associated with hs-CRP level (P < 0.001), duration of diabetes (P < 0.001), urinary TNF-alpha level (P < 0.01), and glycated hemoglobin level (P < 0.05; adjusted R2 = 0.73; P < 0.001).


CONCLUSIONS
Inflammatory parameters in patients with type 2 diabetes at an early stage of nephropathy are independently associated with UAE. In addition to traditional metabolic and hemodynamic factors, it is possible to hypothesize on the participation of inflammation in the pathogenesis of diabetic nephropathy.
Navarro
Juan F
JF
Nephrology Service and Research Unit, Universitary Hospital Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Spain. jnavgon@gobiernodecanarias.com
Mora
Carmen
C
Maca
Manuel
M
Garca
Javier
J
D000368:Aged; D000419:Albuminuria / Q000097:blood* / Q000453:epidemiology; D002097:C-Reactive Protein / Q000032:analysis*; D015897:Comorbidity; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000453:epidemiology / Q000652:urine; D003928:Diabetic Nephropathies / Q000097:blood* / Q000453:epidemiology / Q000209:etiology; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000453:epidemiology / Q000652:urine; D011237:Predictive Value of Tests; D011507:Proteinuria / Q000097:blood / Q000453:epidemiology; D012307:Risk Factors; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis* / Q000652:urine
D002097:C-Reactive Protein; D006442:Glycated Hemoglobin; D014409:Tumor Necrosis Factor-alpha