The present study demonstrated that decreased serum omentin-1 levels predicted cardiac events in patients with HF. Serum omentin-1 level appears to be a novel prognostic marker for the risk stratification of patients with HF.
Various types of adipocytokines are reported to be a predictor of unfavorable cardiac outcomes in patients with HF . In addition to their roles as predictors of cardiac outcome, a variety of adipocytokines have been associated with the development of HF through insulin resistance and chronic inflammation [14, 27–29]. Serum adiponectin levels are reported to be correlated with BNP levels, and are associated with HF severity and unfavorable outcomes in patients with HF [30, 31]. Adiponectin has been suggested to play a role in the prevention of cardiovascular diseases via its anti-inflammatory, anti-oxidant, and anti-apoptotic properties [6–9]. Recently, reports have shown several adipokines to have beneficial effects on cardiovascular diseases [32–34]. However, the precise role of these adipokines remains unclear.
Omentin-1 is a 38 kDa novel adipokine identified in 2004 from visceral adipose tissue [12, 13]. Shibata et al. reported that decreased plasma omentin-1 levels predict the prevalence of coronary artery disease . Yang et al. reported that omentin-1 enhances insulin-stimulated glucose uptake in human adipocytes and may regulate insulin sensitivity . Yamawaki et al. reported that omentin-1 modulates vascular function and attenuates cyclooxygenase-2 expression and c-jun N-terminal kinase (JNK) activation in cytokine-stimulated endothelial cells [35, 36]. These studies all suggest that omentin-1 may improve insulin resistance and suppress vascular inflammation. Interestingly, Pan et al. suggested that omentin-1 expression and production are decreased with elevated inflammatory adipokines, such as tumor necrosis factor-alpha and interleukin-6, in patients with impaired glucose intolerance and newly diagnosed type 2 diabetes mellitus .
Unlike to adiponectin, serum omentin-1 was reported to decrease with chronic inflammation and oxidative stress in patients with HF. The bioactivity of omentin-1 appears multifaceted and remains to be fully defined. The present study showed no correlation between serum omentin-1 and BNP levels unlike adiponectin , suggesting that these markers indicate different features of the pathophysiological process of HF. Serum omentin-1 levels may represent a promising biomarker for cardiac prognosis, irrespective of serum BNP levels. The inclusion of serum omentin-1 levels in the prediction model (includes age, gender, NYHA functional class, left ventricular ejection fraction, and serum BNP levels) for the prediction of cardiac events, improved the NRI and IDI values, suggesting effective reclassification and discrimination.
The present study has certain limitations. Firstly, the sample size was relatively small and it was a single center study. Nonetheless, there was a significant relationship between serum omentin-1 levels and cardiac events. In addition, the inclusion of serum omentin-1 levels in the prediction model with conventional risk factors, including serum BNP levels, for the prediction of cardiac events, improved the NRI and IDI values. Secondly, there were no data for other adipocytokines. Further study is needed to clarify the association between serum omentin-1 and other adipocytokines in a large HF population.
In conclusion, decreased serum omentin-1 levels were associated with cardiac events in patients with HF, irrespective of serum BNP levels. Serum omentin-1 level appears to represent a novel prognostic marker for the risk stratification of patients with HF.