Inflammatory marker signals diabetic nephropathy development

By Sara Freeman, medwireNews Reporter

Measuring serum levels of high-sensitivity C-reactive protein (hs-CRP) could help to predict which patients with Type 2 diabetes will develop renal disease, research suggests.

Results of a prospective cohort study conducted in Japan show that patients with the highest hs-CRP levels were more likely to develop microalbuminuria than those with the lowest levels.

Over a median follow-up of 0.94 years, 197 patients developed diabetic nephropathy, with an incidence ratio of 155.4 per 1000 person–years. Adjusted hazard ratios (HR) for the risk of developing nephropathy associated with the second, third and fourth hs-CRP quartiles versus the first quartile were 1.31, 1.55 and 1.57, respectively.

However, hs-CRP levels did not appear to be associated with the progression from microalbuminuria to macroalbuminuria. During the same follow-up period, 109 patients experienced diabetic nephropathy progression, with an incidence ratio of 92.4 per 1000 patient–years. Adjusted HRs were 0.59, 1.14 and 1.03, respectively, for the lowest versus the second, third and fourth highest quartiles of hs-CRP, respectively.

“Our study identifies new information regarding CRP and disease outcomes”, observe Yasuaki Hayashino, from Tenri Hospital in Nara, Japan, and co-authors.

“There is a temporal association between elevated levels of hs-CRP and the subsequent risk of developing, not progressing, diabetic nephropathy”, they write in Diabetes Care, adding that this association is seen “even after adjusting for possible confounders, including medication use which may influence the natural course of renal function.”

Longitudinal data on 2518 patients with Type 2 diabetes were obtained from the Diabetes Distress and Care Registry at Tenri study to look at the association between baseline hs-CRP and subsequent risk of development or progression of diabetic nephropathy at 1 year.

Development of diabetic nephropathy was defined as the transition from normoalbuminuria (urinary albumin-to-creatinine ratio [UACR] <3.4 mg/mmol) to microalbuminuria (UACR 3.4–33.9 mg/mmol), and progression as the transition from microalbuminuria to macroalbuminuria (UACR ≥33.9 mg/mmol).

Hayashino et al note that their results were obtained from studying patients seen at a single diabetes centre in Japan, and so it remains to be seen if they apply to multi-ethnic populations in North American and Europe.

“More research is needed to examine if there is an effective strategy to reduce the risk of diabetic nephropathy in a group of patients with diabetes and elevated levels of hs-CRP”, they conclude.

Licensed from medwireNews with permission from Springer Healthcare Ltd. ©Springer Healthcare Ltd. All rights reserved. Neither of these parties endorse or recommend any commercial products, services, or equipment.