Ethnic-specific correlations of visfatin with circulating markers of endothelial inflammation and function

Correlation of visfatin level with non-alcoholic fatty liver in metabolic syndrome

Background: Metabolic syndrome (MS) and non-alcoholic fatty liver disease (NAFLD) is a common public health problem. Visfatin is secreted by visceral adipose tissue and is an adipocytokine. It could be a pro-inflammatory adipocytokine and is related to the metabolic syndrome and non-alcoholic fatty liver disease. This study evaluated the association between visfatin levels in patients with the metabolic syndrome with and without non-alcoholic fatty liver disease (NAFLD). Methods: In this cross-sectional study, 120 patients with metabolic syndrome were selected. They were categorized into two groups, patients with fatty liver (n=70) and without fatty liver disease (n=50). Laboratory and anthropometric options such as age, sex, systolic blood pressure, fasting blood sugar, lipid profile, liver enzymes, uric acid, visfatin, insulin, BMI, waist circumference, and TNF-α were measured. The chi-square test, Mann-Whitney, t test, Spearman and Pearson correlations were used for the data analysis. Results: There was a significant difference between the fatty liver and non-fatty liver disease with visfatin, BMI, FBS and lipid profile (p<0.05). The mean±SD level of visfatin was 37.1±1.7 ng/dl in the non-fatty liver and was 44.4±1.5 ng/dl in fatty liver participants (p=0.02). 59% of patients with metabolic syndrome had fatty liver in ultrasonography. Conclusion: According to this study, there was a correlation between visfatin levels and fatty liver disease.

Endothelial NLRP3 inflammasome activation and enhanced neointima formation in mice by adipokine visfatin

Inflammasomes serve as an intracellular machinery to initiate inflammatory response to various danger signals. The present study tested whether an inflammasome centered on nucleotide oligomerization domain-like receptor protein 3 (NLRP3) triggers endothelial inflammatory response to adipokine visfatin, a major injurious adipokine during obesity. NLRP3 inflammasome components were abundantly expressed in cultured mouse microvascular endothelial cells, including NLRP3, apoptosis-associated speck-like protein, and caspase-1. These NLRP3 inflammasome molecules could be aggregated to form an inflammasome complex on stimulation of visfatin, as shown by fluorescence confocal microscopy and size exclusion chromatography. Correspondingly, visfatin significantly increased caspase-1 activity and IL-1β release in microvascular endothelial cells, indicating an activation of NLRP3 inflammasomes. In animal experiments, direct infusion of visfatin in mice with partially ligated left carotid artery were found to have significantly increased neointimal formation, which was correlated with increased NLRP3 inflammasome formation and IL-1β production in the intima. Further, visfatin-induced neointimal formation, endothelial inflammasome formation, and IL-1β production in mouse partially ligated left carotid artery were abolished by caspase-1 inhibition, local delivery of apoptosis-associated speck-like protein shRNA or deletion of the ASC gene. In conclusion, the formation and activation of NLRP3 inflammasomes by adipokine visfatin may be an important initiating mechanism to turn on the endothelial inflammatory response leading to arterial inflammation and endothelial dysfunction in mice during early stage obesity.

Full-length visfatin levels are associated with inflammation in women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common gynaecological endocrinopathy characterized by oligomenorrhea, amenorrhoea, clinical and/or biochemical hyperandrogenism and polycystic ovaries. Abdominal deposition of excess body fat and metabolic diseases like insulin resistance and compensatory hyperinsulinemia are commonly observed in PCOS subjects. It has been suggested that visfatin is an adipokine secreted from the abdominal fat influencing glucose metabolism and might therefore contribute to the metabolic disturbances in PCOS.

MATERIALS AND METHODS

We measured circulating full-length visfatin levels with a specific enzyme immunoassay (AdipoGen Inc, Incheon, South-Korea) in 57 women with self-reported symptoms of PCOS (hirsutism and/or oligomenorrhea) and ultrasound confirmed polycystic ovaries, and in 57 controls from the Northern Finland 1966 Birth Cohort and explored its association with metabolic and inflammatory parameters.

RESULTS

Polycystic ovary syndrome cases had higher body mass index (BMI) (25·7 vs. 24·1 kg/m(2)) and waist circumference (83·2 vs. 78·8 cm) compared to controls, yet there was no difference in plasma visfatin levels between them. In contrast, visfatin significantly correlated with C-reactive protein (CRP) in the control group and with white blood cell count (WBC) in both groups. In linear regression analysis, adjusted for PCOS, smoking, socioeconomic status, BMI or waist circumference, serum lipids and markers of glucose metabolism and hormone status, only WBC remained significantly associated with plasma visfatin levels.

CONCLUSION

Our results suggest that circulating visfatin levels correlate with WBC and CRP but are not associated with PCOS, obesity or metabolic markers, suggesting that visfatin may act as a proinflammatory cytokine.

Adipokines and cardiometabolic function: How are they interlinked?

OBJECTIVE

Adipokines contribute directly to the coexistence of insulin resistance and endothelial dysfunction. Most studies focus on a single adipokine. We therefore investigated the independent relationships of leptin, adiponectin, tumor necrosis factor-alpha, resistin and visfatin, as well as the gut hormone ghrelin with blood pressure and insulin resistance. Secondly we evaluated the interrelationships of adipokines and ghrelin in concert with various cardiometabolic markers.

METHODS AND RESULTS

Caucasian women (N=115) with varying levels of obesity (aged 31.3 + or - 9.18 years) were included. Significant correlations of leptin, adiponectin, ghrelin and visfatin with mean arterial pressure (p<0.05) disappeared after adjustment for age, body mass index and waist circumference. But significant correlations with insulin resistance (HOMA) (for leptin, adiponectin and ghrelin) remained significant after adjustments. Factor analyses yielded five factors, but two main clusters, namely a metabolic syndrome cluster (including leptin, adiponectin and ghrelin) and a vascular atherosclerotic cluster (including tumor necrosis factor-alpha, visfatin and resistin).

CONCLUSION

Factor analyses identified patterns which indicate specific roles of the various adipokines. Leptin, adiponectin and ghrelin were more closely related to insulin resistance and central obesity as core components of the metabolic syndrome. Visfatin, tumor necrosis factor-alpha and resistin seem to direct their effects onto the vascular system possibly by means of mechanisms such as inflammation, vasoconstriction and coagulation.