Vascular biology of adiponectin

Risk stratification among metabolically unhealthy obese in independent physically inactive aged women

OBJECTIVES

To determine whether or not adiponectin levels or basal metabolic rate (BMR) could predict worse risk stratification in patients with insulin resistance (IR) among metabolically healthy and unhealthy obese (MUHO) elderly females with Metabolic syndrome (MetS).

METHODS

A cross-sectional survey was conducted on 109 elderly females in geriatric nursing home with MetS. The participants were reclassified according to adiponectin levels and IR.

RESULTS

Group (1) (with IR, n = 41) compared to group (2) (without IR, n = 45) had lower squared adiponectin level and higher fat mass and fat percent (p value = 0.037, 0.030, and 0.035 respectively). Quadratic adiponectin level was an independent predictor for better BMR in group (2) with higher R² compared to linear adiponectin level (R² = 0.19, 0.15 consecutively, p value = 0.02, 0.008 consecutively) in group (2) rather than group (1). This revealed U-shaped relation between adiponectin level and BMR in group (2). By ROC curve, fat and lean percentages were statically significant predictors of IR between groups (1) and (2) (AUC = 0.643, 0.636; p value = 0.024, 0.032 Sensitivity = 89.2%, 72.97%; and Specificity = 55.1%, 24.48% respectively).

CONCLUSION

Current findings supported the possibility of risk stratification among MUHO individuals based on IR, squared adiponectin level, lean and fat percentages.

Endothelial and Metabolic Function Interactions in Overweight/Obese Children

AIM

Although the underlined mechanisms are still unknown, metabolic/coagulation alterations related to childhood obesity can induce vascular impairments. The aim of this study was to investigate the relationship between metabolic/coagulation parameters and endothelial function/vascular morphology in overweight/obese children.

METHODS

Thirty-five obese/overweight children (22 pre-pubertal, mean age: 9.52±3.35 years) were enrolled. Body mass index (BMI), homeostasis model assessment index (HOMAIR), metabolic and coagulation parameters, [adiponectin, fibrinogen, high molecular weight adiponectin (HMW), endothelin-1, and vonWillebrand factor antigen] ultrasound early markers of atherosclerosis [flow-mediated dilatation (FMD), common carotid intima-media thickness (C-IMT), and anteroposterior diameter of infra-renal abdominal aorta (APAO)] were assessed.

RESULTS

APAO was related to anthropometric (age: r=0.520, p=0.001; height: r=0.679, p＜0.001; weight: r=0.548, p=0.001; BMI: r=0.607, p＜0.001; SBP: r=0.377, p=0.026) and metabolic (HOMAIR: r=0.357, p=0.035; HMW: r=－0.355, p=0.036) parameters. Age, height, and systolic blood pressure were positively related to increased C-IMT (r=0.352, p=0.038; r=0.356, p=0.036; r=0.346, p=0.042, respectively). FMD was not related to any clinical and biochemical characteristics of the pediatric population. Age, HOMAIR, fasting glucose levels, and HMW were independent predictors for APAO increase. Each unit decrease in HMW concentrations (1 μg/ml) induced a 0.065 mm increase in APAO.

CONCLUSION

High molecular weight adiponectin is related to cardiovascular risk in overweight/obese children.

Relations of plasma total and high-molecular-weight adiponectin to new-onset heart failure in adults ≥65 years of age (from the Cardiovascular Health study)

Adiponectin exhibits cardioprotective properties in experimental studies, but elevated levels have been linked to increased mortality in older adults and patients with chronic heart failure (HF). The adipokine's association with new-onset HF remains less well defined. The aim of this study was to investigate the associations of total and high-molecular weight (HMW) adiponectin with incident HF (n = 780) and, in a subset, echocardiographic parameters in a community-based cohort of adults aged ≥65 years. Total and HMW adiponectin were measured in 3,228 subjects without prevalent HF, atrial fibrillation or CVD. The relations of total and HMW adiponectin with HF were nonlinear, with significant associations observed only for concentrations greater than the median (12.4 and 6.2 mg/L, respectively). After adjustment for potential confounders, the hazard ratios per SD increment in total adiponectin were 0.93 (95% confidence interval 0.72 to 1.21) for concentrations less than the median and 1.25 (95% confidence interval 1.14 to 1.38) higher than the median. There was a suggestion of effect modification by body mass index, whereby the association appeared strongest in participants with lower body mass indexes. Consistent with the HF findings, higher adiponectin tended to be associated with left ventricular systolic dysfunction and left atrial enlargement. Results were similar for HMW adiponectin. In conclusion, total and HMW adiponectin showed comparable relations with incident HF in this older cohort, with a threshold effect of increasing risk occurring at their median concentrations. High levels of adiponectin may mark or mediate age-related processes that lead to HF in older adults.