High YKL-40 level predicts mortality in diabetes
MedWire News: High levels of the inflammatory marker YKL-40 predict all-cause mortality in Type 2 diabetes patients, report researchers.
"To our knowledge, this is the first time serum YKL-40 level has been investigated prospectively in relation to mortality in a population with Type 2 diabetes," write Frederik Persson (Steno Diabetes Center, Gentofte, Denmark) and colleagues in the journal Diabetes Research and Clinical Practice.
The team assessed baseline YKL-40 levels in a total of 290 diabetes patients, 177 of whom had normoalbuminuria (urinary albumin excretion rate [UAER] <30 mg/24h), 71 microalbuminuria (UAER 30-299 mg/24h), and 42 macroalbuminuria (UAER >300 mg/24h).
The researchers report that the median baseline YKL-40 levels were 46.0 ng/mL, 61.0 ng/mL, and 81.5 ng/mL, in patients with normoalbuminuria, microalbuminuria, and macroalbuminuria, respectively.
Patients were divided according to YKL-40 level into three tertiles (16-42 ng/mL, 43-72 ng/mL, and 73-2902 ng/mL).
The team followed-up the patients for a median of 17.2 years using central registers in the Danish National Board of Health and cause-of-death information from death certificates.
The authors found that 189 patients had died by the end of follow-up, with the cause of death being cardiovascular disease (CVD) in 119 (41%) individuals.
Analysis revealed that all-cause mortality was significantly elevated in patients with YKL-40 levels in the second and third tertile compared with the first tertile, at hazard ratios (HRs) of 1.50 and 2.88, respectively.
In addition, CV mortality was significantly increased in those with YKL-40 levels in the third versus first tertile, at an HR of 2.70.
These associations both remained after adjustment for conventional CV risk factors (age, gender, systolic blood pressure, cholesterol, and smoking status), but were no longer significant after additional adjustment for UAER and estimated glomerular filtration rate.
"The association between YKL-40 and albuminuria could reflect common determinants (such as inflammation) or a causal link (inflammation leading to increase in YKL-40), and subsequent generalized vascular damage reflected by albuminuria," suggest the authors.
"YKL-40 is cleared by the kidney and this may also affect the predictive ability of the biomarker in patients with impaired kidney function, but this requires further studies," they add.
The team says more research is needed to establish the impact of different treatments on levels of YKL-40 and to investigate whether treatments that lower YKL-40 levels also translate into beneficial clinical outcome.
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By Sally Robertson