Objective: To investigate blood apelin concentrations in patients with newly diagnosed and untreated type 2 diabetes mellitus (T2DM) who had no additional disorder and to investigate the association of apelin with adiponectin, body mass indexes (BMI) and insulin sensitivity. Methods: Forty patients with T2DM and 40 healthy controls were enrolled. Apelin levels were measured along with BMI, lipids, glucose, insulin and adiponectin levels, and HOMA-IR indexes. Age, sex and BMI were similar in the two groups. Results: Plasma apelin and adiponectin levels were significantly lower in the diabetic group compared to controls (p<0.001, for both). Insulin levels and HOMA indexes were significantly higher in patients with T2DM (p<0.001 and p=0.001, respectively). Apelin levels were negatively correlated with age (r=-0.315, p=0.006), fasting blood glucose (r=-0.556, p<0.001) and HOMA indexes (r=-0.411, p=0.001), and positively correlated with plasma adiponectin levels (r=0.593, p<0.001). Plasma adiponectin was negatively correlated to plasma insulin (r=-0.379, p=0.001), fasting glucose (r=-0.604, p<0.001), HOMA-IR (r=-0.559, p<0.001) and BMI (=-0.229, p=0.04). Conclusions: Plasma apelin is reduced in newly diagnosed and untreated patients with T2DM having no confounders. Regulation of circulating apelin and adiponectin seems to be in the same manner in patients with T2DM. Dysregulation of apelin might be involved in the mechanism of establishment of overt diabetes mellitus as well as associated atherosclerotic complications.

Both apelin and asymetric dymethyl arginine (ADMA) regulate blood pressures. Low apelin and high ADMA levels have been reported in several cardiometabolic disorders. However, there is no data about ADMA and apelin levels in essential hypertension and any relationship between them. We investigated a group of newly diagnosed and untreated 30 young hypertensive men and 30 healthy controls. Apelin levels were significantly lower and the ADMA levels were significantly higher in the patients (p = 0.04 for both). Both ADMA and apelin were related to the systolic blood pressures (SBP) (beta = −0.393, p = 0.003; beta = 0.285, p = 0.03, respectively). Future studies are necessary in order to clearly define the role of ADMA and apelin in the pathogenesis of essential hypertension.

Hypercholesterolemia is a major risk factor for atherosclerosis. Dysregulation of adipokines contribute to atherosclerotic diseases. Apelin has recently been shown to be secreted by the adipose tissue in association with hyperinsulinemia and inflammation. We searched plasma apelin levels in patients with elevated low density lipoprotein (LDL)-cholesterol having no additional disorder. Thirty-three patients with hypercholesterolemia and 50 age-, sex-, and body mass index-matched healthy controls were evaluated for their apelin, adiponectin and high sensitivity C-reactive protein (hsCRP) levels, and homeostasis model assessment (HOMA) indexes. Plasma apelin-12 and adiponectin were determined by ELISA and RIA, respectively. Plasma apelin levels were lower in patients with elevated LDL-cholesterol compared to healthy controls (p<0.001). Plasma adiponectin concentration was also lower in the dyslipidemic patients (p<0.001). hsCRP levels were similar in the two groups. Fasting plasma glucose was normal in both groups. HOMA indexes in the dyslipidemic group were higher than the controls (p=0.005). A mild to moderate negative correlation with HOMA and positive correlation with high density lipoprotein cholesterol of apelin was found in the dyslipidemic group. Plasma apelin is decreased in non-obese, non-diabetic and normotensive patients with elevated LDL-cholesterol. Low apelin levels in hypercholesterolemia seem associated with insulin resistance, which needs to be investigated in larger populations as well as in other atherosclerotic conditions.

Introduction: Acute pancreatitis is a local inflammatory process that leads to a systemic inflammatory response in the majority of cases. Bacterial contamination has been estimated to occur in 30–40% of patients with necrotizing pancreatitis. Development of pancreatic necrosis depends mainly on the degree of inflammation and on the microvascular circulation of the pancreatic tissue. Activated protein C (APC) is known to inhibit coagulation and inflammation, and to promote fibrinolysis in patients with severe sepsis. We investigated the effects of APC on histopathology, bacterial translocation, and systemic inflammation in experimental acute necrotizing pancreatitis. Materials and method: Forty-five male Sprague-Dawley rats were studied. Rats were randomly allocated to three groups. Acute pancreatitis was induced in group II (positive control; n = 15) and group III (treatment; n = 15) rats by retrograde injection of taurocholate into the common biliopancreatic duct. Group I rats (sham; n = 15) received an injection of normal saline into the common biliopancreatic duct to mimic a pressure effect. Group III rats were treated with intravenous APC 6 hours after induction of pancreatitis. Pancreatic tissue and blood samples were obtained from all animals for histopathological examination and assessment of amylase, tumor necrosis factor-α, and IL-6 levels in serum. Bacterial translocation to pancreas and mesenteric lymph nodes was measured. Results: Acute pancreatitis developed in all groups apart from group I (sham), as indicated by microscopic parenchymal necrosis, fat necrosis and abundant turbid peritoneal fluid. Histopathological pancreatitis scores in the APC-treated group were lower than in positive controls (10.31 ± 0.47 versus 14.00 ± 0.52; P < 0.001). Bacterial translocation to mesenteric lymph nodes and to pancreas in the APC-treated group was significantly decreased compared with controls (P < 0.02 and P < 0.007, respectively). Serum amylase, tumor necrosis factor--α, and IL-6 levels were also significantly decreased in comparison with positive controls (P < 0.001, P < 0.04 and P < 0.001, respectively). Conclusion: APC improved the severity of pancreatic tissue histology, superinfection rates and serum markers of inflammation during the course of acute necrotizing pancreatitis.

Apelin, a relatively newer adipokine with various actions in cardiovascular system, was recently reported to decrease in dyslipidemia. The present study addresses whether plasma apelin increases after hypolipidemic intervention either through therapeutic life style change (TLC) or statin treatment. A total of 134 patients were subjected to treatment with a TLC intervention for 12 weeks. Of these, 116 successfully completed the period, and LDL-cholesterol level decreased to target level (<160 mg/dL) in 54 (46.5%) individuals. The remaining 62 patients were treated with rosuvastatin for 12 weeks, and 56 of them finished the study. Circulating apelin, adiponectin, leptin, TNF-alpha, hsCRP and insulin levels were determined both at baseline and after TLC intervention and statin treatment. There was no significant change in plasma apelin concentration in patients unresponsive to TLC (p=0.110). LDL-cholesterol lowering either through TLC or statin treatment was accompanied by an increase in plasma apelin (p=0.000, p=0.020) and adiponectin (p=0.001, p=0.011). Serum leptin decreased after successful TLC (p=0.042/male, p=0.023/female) but not after statin treatment (p=0.959/male, p=0.134/female). Serum TNF-alpha (p=0.902) and plasma hsCRP (p=0.135) levels remained unchanged after TLC intervention but decreased after statin treatment (p=0.000, p=0.023, respectively). Plasma insulin and homeostasis model assessment scores decreased after TLC (p=0.000 for both) but not rosuvastatin treatment (p=0.865, p=0.722, respectively). In conclusion, independent of the type of treatment, reduction in LDL-cholesterol levels in otherwise healthy people with isolated dyslipidemia results in an increase in plasma apelin concentration. More experiments may show a substantial role for this peptide in the mechanism of atherosclerosis.