Leptin levels rise after cardiopulmonary bypass in diabetes patients
MedWire News: The acute stress response in leptin appears to be higher in patients with diabetes compared with those without, show study findings.
However, the present study demonstrated that stress response is different in diabetics for only leptin, say Murat Guvener (Başkent University Adana Hospital, Turkey) and colleagues.
"Two main factors which have been reported to correlate with elevated blood concentrations of leptin are BMI [body mass index] and female gender," they write in Diabetes Research and Clinical Practice. "Other investigators have found that increases in leptin and ghrelin are accompanied by an increased release of acute phase inflammatory mediators such as interleukin 6 (IL)-6 and C-reactive protein (CRP), cortisol, and insulin," they add.
The team says that a greater acute phase response is therefore expected in diabetes but that patients with and without diabetes in the acute phase have not been compared until now.
The researchers therefore examined and compared stress response in leptin, ghrelin, IL-6, high-sensitivity (hs)CRP, cortisol, and insulin in 40 patients (20 with diabetes and 20 without) who underwent cardiopulmonary bypass (CPB).
Blood sampling was performed preoperatively, 1 hour after CPB, and on postoperative days 1 and 5.
The researchers report that the mean leptin level had decreased by 50% 1 hour after CPB in both the diabetes and nondiabetes groups. Leptin then increased gradually in both groups but rose significantly higher in patients with diabetes compared with those without.
Plasma ghrelin levels also decreased immediately after surgery and then increased to a peak on postoperative day 1 in both groups. The increase from baseline ghrelin did not differ significantly between the groups.
In addition, both the diabetes and nondiabetes groups showed significantly elevated mean serum concentrations of IL-6, hsCRP, cortisol, and insulin, but again the differences between the two groups were not significant.
Further analysis revealed that that leptin level was independently predicted by hsCRP, female gender, and BMI, whereas ghrelin was not associated with any variables in the study population.
"BMI, female gender, inflammatory markers, cortisol, and insulin levels did not differ between diabetics and nondiabetics but diabetics had significantly higher leptin levels," say Guvener et al.
"Therefore we concluded that another variable in diabetics may affect leptin resistance in acute phase," they say.
"The implications of increased leptin levels should be further elucidated," concludes the team.
MedWire (http://www.medwire-news.md/) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
By Sally Robertson