Metabolic syndrome, adiponectin and fat ROS

The metabolic syndrome, a cluster of insulin resistance, elevated blood pressure, and atherogenic dyslipidemia, is a common basis of atherosclerosis. Accumulation of intra-abdominal visceral fat stands upstream of the metabolic syndrome. Adipose tissue expresses a variety of genes for bioactive secretory proteins conceptualized as adipocytokines. We discovered a novel adipose-specific protein named adiponectin from human fat cDNAs. Adiponectin circulates in the plasma and its serum level is decreased in visceral fat accumulation. Results of experimental and clinical researches have demonstrated that hypoadiponectinemia underlies the pathogenesis of multiple diseases related to visceral fat accumulation, including atherosclerosis, hypertension, cardiac failure, insulin resistance, diabetes, hepatic steatosis, inflammatory bowel disease, and cancers. Recently, we revealed fat-derived reactive oxygen species (fat ROS) as an upstream factor in the development of hypoadiponectinemia and metabolic syndrome. Intervention targeting visceral fat accumulation, hypoadiponectinemia and fat ROS should be the way to therapeutically tackle the metabolic syndrome.Biomedical Reviews 2006; 17: 1-10

Clinical significance of visceral fat reduction through health education in preventing atherosclerotic cardiovascular disease - Lesson from the Amagasaki Visceral Fat Study: A Japanese perspective

The metabolic syndrome has received worldwide recognition and is useful clinical aid in early-preventing atherosclerosis. Visceral adiposity is the main component of the metabolic syndrome in Japan, based on ethnic and racial difference in the pattern of adiposity. In the Amagasaki Visceral Fat Study, subjects had undergone annual health check-ups and then received health education by medical personnel. Visceral fat reduction improved hypoadiponectinemia and the number of obesity-related cardiovascular risk factors, and effectively prevented cardiovascular events. The health education that includes voluntary lifestyle modification aimed at reducing visceral fat could be useful in preventing cardiovascular events in the metabolic syndrome

Hyperinsulinemia correlates with low levels of plasma B-type natriuretic peptide in Japanese men irrespective of fat distribution

<p>Abstract</p> <p>Background</p> <p>B-type natriuretic peptide (BNP), a member of the natriuretic peptide family, is a cardiac-derived secretory hormone with natriuretic, diuretic, and vasorelaxant activities. Intraabdominal fat accumulation is associated with atherosclerotic cardiovascular diseases and cardiac dysfunction. Circulating BNP levels are relatively low (within the normal limits) in obesity and the metabolic syndrome. However, the relationship between plasma BNP levels and visceral fat accumulation in general population has not been reported. The present study analyzed the relationships between plasma BNP levels and various clinical variables, including insulin, visceral and subcutaneous fat area (VFA and SFA, respectively), in normal Japanese men.</p> <p>Methods</p> <p>The study (Victor-J study) subjects were consecutive 500 Japanese male workers, who underwent a health checkup and were measured VFA and SFA by computed tomography.</p> <p>Results</p> <p>Age-adjusted simple linear regression analysis showed that log-BNP correlated positively with HDL-cholesterol, and negatively with VFA, log-immunoreactive insulin (IRI), log-triglyceride, and LDL-cholesterol, but not body mass index or SFA. Stepwise multiple regression analysis identified log-IRI and HDL-cholesterol as significant determinants of log-BNP. Subjects with IRI ≥5.5 μIU/mL had lower plasma BNP levels than those with IRI < 5.5 μIU/mL, irrespective of obesity (body mass index, cutoff value 25 kg/m²), visceral fat accumulation (VFA, cutoff value 100 cm²) and subcutaneous fat accumulation (SFA, cutoff value 128 cm²).</p> <p>Conclusions</p> <p>Our study showed that hyperinsulinemia correlated with low levels of plasma BNP in general men, irrespective of fat distribution.</p> <p>Trial registration</p> <p>UMIN 000004318.</p

Treatment-Induced Changes in Plasma Adiponectin Do Not Reduce Urinary Albumin Excretion in the Diabetes Prevention Program Cohort.

BACKGROUND AND OBJECTIVES: Molecular data suggests that adiponectin may directly regulate urinary albumin excretion. In the Diabetes Prevention Program (DPP) we measured adiponectin and albuminuria before and after intervention, and we previously reported increases in adiponectin with interventions. Here we have used the DPP dataset to test the hypothesis that treatment-related increases in adiponectin may reduce albuminuria in obesity. DESIGN, SETTING, PARTICIPANTS AND METHODS: We evaluated cross-sectional correlations between plasma adiponectin and urinary albumin excretion at baseline, and the relationship of treatment-related changes in adiponectin and albuminuria. Baseline and follow-up urine albumin to creatinine ratios (ACR (albumin to creatinine ratio)) and plasma adiponectin concentration were available in 2553 subjects. RESULTS: Adjusting for age, sex and race/ethnicity, we observed a statistically significant but weak inverse relationship between adiponectin and ACR at baseline (conditional Spearman\u27s rho = (-) 0.04, p = 0.04). Although DPP treatments significantly increased plasma adiponectin, there were no treatment effects on ACR and no differences in ACR across treatment groups. There was a weak direct (not inverse) association between change in adiponectin and change in albuminuria (adjusted Spearman\u27s rho = (+) 0.04, p = 0.03). CONCLUSIONS: In a large, well-characterized cohort of obese dysglycemic subjects we observed a weak inverse association between circulating adiponectin concentrations and urinary albumin excretion at baseline. Contrary to the hypothesized effect, treatment-related increases in plasma adiponectin were not associated with a reduction in ACR. The association of change in adiponectin with change in ACR should be assessed in populations with overt albuminuria before excluding a beneficial effect of increasing adiponectin to reduce ACR in obesity

mRNA concentrations of MIF in subcutaneous abdominal adipose cells are associated with adipocyte size and insulin action

Objective To determine whether the mRNA concentrations of inflammation response genes in isolated adipocytes and in cultured preadipocytes are related to adipocyte size and in vivo insulin action in obese individuals. Design Cross-sectional inpatient study. Subjects Obese Pima Indians with normal glucose tolerance. Measurements Adipocyte diameter (by microscope technique; n=29), expression of candidate genes (by quantitative real-time PCR) in freshly isolated adipocytes (monocyte chemoattractant protein [MCP] 1 and MCP2, macrophage inflammatory protein [MIP] 1α, MIP1β and MIP2, macrophage migration inhibitory factor [MIF], tumor necrosis factor alpha, interleukin [IL] 6 and IL8; n=22) and cultured preadipocytes (MCP1, MIP1α, MIF, IL6 and matrix metalloproteinase 2; n=33) from subcutaneous abdominal adipose tissue (by aspiration biopsy, n=34), body fat by dual-energy X-ray absorptiometry, glucose tolerance by 75-gram oral glucose tolerance test, and insulin action by euglycemic-hyperinsulinemic clamp (insulin infusion rate 40 mU/m2.min)(all n=34). Results MIF was the only gene whose expression in both freshly isolated adipocytes and cultured preadipocytes was positively associated with adipocytes diameter and negatively associated with peripheral and hepatic insulin action (all P<0.05). In multivariate analysis, the association between adipocyte MIF mRNA concentrations and adipocytes diameter was independent of percent body fat (P=0.03), whereas adipocyte MIF mRNA concentrations but not adipocytes diameter independently predicted peripheral insulin action. The mRNA expression concentrations of MIF gene in adipocytes were not associated with plasma concentrations of MIF, but were negatively associated with plasma adiponectin concentrations (P=0.004). In multivariate analysis, adipocyte MIF RNA concentrations (P=0.03) but not plasma adiponectin concentrations (P=0.4) remained a significant predictor of insulin action. Conclusions Increased expression of MIF gene in adipose cells may be an important link between obesity characterized by enlarged adipocytes and insulin resistance in normal glucose tolerant people

Metabolic syndrome correlates intracoronary stenosis detected by multislice computed tomography in male subjects with sleep-disordered breathing

<p>Abstract</p> <p>Background</p> <p>Sleep-disordered breathing (SDB), especially obstructive sleep apnea (OSA), has frequent complications include hypertension, dyslipidemia and insulin resistance based on abdominal obesity or excess visceral fat (called Syndrome Z). OSA is a potential risk factor for cardiovascular diseases. The clinical characteristics of Japanese OSA subjects with OSA remain unclear. The present study investigated prevalence and predictive factors of intracoronary stenosis detected by multislice computed tomography (MSCT) in Japanese male subjects with SDB/OSA.</p> <p>Findings</p> <p>The study (O-VFStudy) subjects were 39 Japanese men with SDB/OSA who underwent all-night cardiorespiratory monitoring with fully attended polysomnography, and moreover both fat computed tomography (CT) scan and 64-row MSCT coronary angiography. The prevalence of coronary stenosis in this selected population with SDB/OSA was 15%. Logistic regression analysis showed a significant relationship between age-adjusted CAD and metabolic syndrome (<it>p </it>< 0.05), but not serum adiponectin levels and nocturnal fall in adiponectin. Subjects with the metabolic syndrome had significantly higher prevalence of CAD (31.3 versus 4.3%, <it>p </it>= 0.033), and lower levels of serum adiponectin (4.5 ± 0.6 versus 6.4 ± 0.6 μg/mL, <it>p </it>= 0.014), compared with groups without the metabolic syndrome.</p> <p>Conclusions</p> <p>The present study describes that the prevalence of greater than 50% intracoronary stenotic lesions detected by MSCT was 15% and the metabolic syndrome was correlated with intracoronary stenosis detected by MSCT in Japanese SDB/OSA subjects.</p> <p>Trial Registration</p> <p>UMIN 000002997</p> <p><url>https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&type=summary&recptno=R000003633&language=E</url>.</p

Smoking cessation is associated with increased plasma adiponectin levels in men

SummaryObjectivesLow levels of adiponectin, an adipocytokine with anti-diabetic and anti-atherogenic properties, are associated with increased risk of future myocardial infarction in men. Previous studies have demonstrated that cigarette smoking is involved in the development of insulin resistance, and current smokers have been shown to have reduced plasma adiponectin levels. However, the influence of smoking cessation on adiponectin levels remains unknown. We sought to assess whether smoking cessation is associated with increased plasma adiponectin levels in men.MethodsThe study includes 72 men (47 non-smokers and 25 current smokers at baseline) with stable angina pectoris who underwent percutaneous coronary intervention and follow-up coronary angiography 6 months later. During the 6-month follow-up period, all 47 non-smokers remained non-smokers, while 15 men of the 25 baseline current smokers successfully quit smoking. We evaluated plasma adiponectin levels at coronary intervention and 6 months later.ResultsPlasma adiponectin levels at coronary intervention were comparable to those after 6 months in non-smokers (4.22 [3.15–6.43] vs. 4.58 [3.03–6.26]μg/mL, P=0.124) and in persistent smokers (4.77 [4.25–10.53] vs. 5.16 [4.11–8.10]μg/mL, P=0.721). Meanwhile, an increase in adiponectin level was observed in patients who quit smoking for 6 months (4.24 [3.30–5.70] vs. 5.50 [4.03–8.00]μg/mL, P=0.002). Univariate analysis revealed that the percent increase in adiponectin levels correlated positively with smoking cessation (P=0.003) and negatively with additional use of β-blockers (P=0.049). In addition, increases in adiponectin levels were closely associated with increase in high-density lipoprotein cholesterol (P=0.148), decrease in triglycerides (P=0.140), and additional use of renin–angiotensin system inhibitors (P=0.069). Multivariate analysis demonstrated that smoking cessation was an independent determinant of the increase in adiponectin (P=0.036).ConclusionsSmoking cessation is associated with increased plasma adiponectin levels in men with stable angina, suggesting that the significance of smoking cessation may be partly explained by the increase in adiponectin level