Changes in Omentin Levels and Its mRNA Expression in Epicardial Adipose Tissue in Patients Undergoing Elective Cardiac Surgery: the Influence of Type 2 Diabetes and Coronary Heart Disease

Abstract

Omentin is a protein produced by numerous tissues including adipose tissue. Its concentrations are decreased in patients with obesity, type 2 diabetes mellitus (DM) and coronary artery disease (CAD). Experimental studies suggest that omentin may have anti-inflammatory and insulin-sensitizing properties. In the present study, we measured circulating omentin levels and its mRNA expression in epicardial and subcutaneous fat, intercostal and heart muscle before and after elective cardiac surgery in patients with CAD (CAD+, DM-, n=18), combination of CAD and DM (CAD+, DM+, n=9) or with none of these conditions (CAD-, DM-, n=11). The groups did not differ in baseline anthropometric and biochemical characteristics with the exception of higher blood glucose and HBA1c in CAD+, DM+ group. Baseline circulating omentin levels tended to be lower in CAD+, DM- and CAD+, DM+ groups as compared to CAD-, DM- group and cardiac surgery increased its concentration only in CAD-, DM- group. The change in serum omentin levels during surgery inversely correlated with epicardial fat thickness. While baseline omentin mRNA expression did not differ among the groups in any of the studied tissues, its increase after surgery was present only in subcutaneous fat in CAD-, DM- and CAD+, DM- groups, but not in CAD+, DM+ group. Intercostal muscle omentin mRNA expression increased after surgery only in CAD-, DM- group. In conclusion, cardiac surgery differentially affects omentin levels and subcutaneous fat and skeletal muscle mRNA expression in patients without coronary artery disease and diabetes as compared to patients with these conditions.

<p>The association between omentin and diabetes: a systematic review and meta-analysis of observational studies</p>

“…The analysis proved lower levels of omentin in these populations which is consistent with previous reports, 19,20,33,45 but was not confirmed by some other evidence. 35,39 The quality of included studies was high 23,27,35,37,41,43,44,47,[50][51][52] or moderate. 12,19,20,25,26,33,34,36,38,39,45,46,48,53,54 The last sub-group consisted of patients diagnosed with IGT.…”

“…Twenty-one studies recruited both gender, 17,19,[22][23][24]27,[32][33][34][35][36][37][38][39][40][41][42][43][44][45][46] four were conducted only in men, 18,21,25,47 and three used female subjects. 20,26,48 Included studies were conducted in participants with T1DM, 17,32,40 T2DM 22,23,26,27,38,39,41,[43][44][45][46][47] , and patients with IGT. 18,21,24,42 Seven studies enrolled normal weight (BMI<24.9) subjects, 23,32,33,36,44-46 13 recruited overweight participants (24.9≤BMI≤29.9) 17,…”

“…20,26,48 Included studies were conducted in participants with T1DM, 17,32,40 T2DM 22,23,26,27,38,39,41,[43][44][45][46][47] , and patients with IGT. 18,21,24,42 Seven studies enrolled normal weight (BMI<24.9) subjects, 23,32,33,36,44-46 13 recruited overweight participants (24.9≤BMI≤29.9) 17,18,21,22,25,27,34,38,39,41,43,47,48 and 6 were conducted on obese subjects 20,24,26,35,37,42 but 2 studies did not mention baseline BMI. 19,40 Two studies were cross sectional 35,37 and the others were casecontrol.…”

“…19,40 Two studies were cross sectional 35,37 and the others were casecontrol. [17][18][19][20][21][22][23][24][25][26][27][32][33][34]36,[38][39][40][41][42][43][44][45][46][47][48] Based on the NOS, 10 studies ranked as high-quality 23,27,32,35,37,40,41,43,44,47 and the others as were classified as moderate in quality assessment.…”

“…Twenty-eight studies with 2941 participants examined serum omentin level among patients with diabetes (T1DM, T2DM, and IGT) and healthy subjects. [17][18][19][20][21][22][23][24][25][26][27][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48] There was a significant association between serum omentin and diabetes (WMD−1.68; 95% CI, −2.17 to −1.19; P<0.001). There was evidence of heterogeneity between the effect sizes of the included studies (I 2 =96.9% p<0.001).…”