Selected Articles by Category

Metabolic


Adiponectin as a biomarker of the metabolic syndrome

Author: Ryo M;Nakamura T;Kihara S;Kumada M;Shibazaki S;Takahashi M;Nagai M;Matsuzawa Y;Funahashi T;

BACKGROUND: The metabolic syndrome, a cluster of abdominal obesity, dyslipidemia, hypertension and hyperglycemia, is a common basis for atherosclerotic vascular diseases in industrial countries exposed to overnutrition. Adiponectin is an adipose-derived plasma protein with anti-atherogenic and insulin-sensitizing activities. METHODS AND RESULTS: A total of 661 Japanese adults (479 men, 53+/-10 years; 182 women 56+/-10 years) were enrolled. Plasma adiponectin concentrations correlated negatively with waist circumference, visceral fat area, serum triglyceride concentration, fasting plasma glucose, fasting plasma insulin, and systolic and diastolic blood pressure in both sexes. A positive correlation was found between plasma adiponectin and high-density lipoprotein cholesterol concentrations in both sexes. The mean number of components of the metabolic syndrome increased as the plasma adiponectin concentration decreased: 2.57+/-1.34 for men and 2.00+/-1.51 for women with adiponectin concentrations <4.0 microg/ml. In all, 52.3% of men and 37.5% of women with adiponectin concentrations <4.0 microg/ml fulfilled the criteria for metabolic syndrome. CONCLUSION: Hypoadiponectinemia is closely associated with the clinical phenotype of the metabolic syndrome and measuring the plasma concentration of adiponectin may be useful for management of the metabolic syndrome

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Eotaxin and obesity

Author: Vasudevan AR;Wu H;Xydakis AM;Jones PH;Smith EO;Sweeney JF;Corry DB;Ballantyne CM;

CONTEXT: Asthma and obesity incidence is increasing worldwide, and asthma is often more severe in the obese. Eotaxin, a CC chemokine, is important in extrinsic asthma, an inflammatory disorder. OBJECTIVE: Our objective was to examine the relation between eotaxin and obesity. DESIGN: We conducted a comparison study of eotaxin in mice fed high-fat vs. standard chow diet for 26 wk, in obese vs. lean humans, in obese humans before and after 4-6 wk of weight loss, and in sc vs. visceral adipose tissue from patients undergoing bariatric surgery. SETTING: Our clinical study occurred in an outpatient weight loss program. PATIENTS: Patients were obese adults with metabolic syndrome (n = 40) and nine morbidly obese bariatric surgery patients. INTERVENTION: Intervention was a very-low-calorie diet. MAIN OUTCOME MEASURES: We assessed circulating eotaxin and eotaxin mRNA levels in adipose tissue. RESULTS: Serum eotaxin levels were significantly higher in obese mice, and adipose mRNA levels correlated positively with serum eotaxin levels. Adipose tissue explants from obese mice showed increased secretion of eotaxin compared with explants from lean mice. In obese patients, plasma eotaxin levels were significantly higher than in lean controls and significantly reduced after weight loss, and eotaxin mRNA levels were 4.7-fold higher in visceral than sc adipose tissue. CONCLUSIONS: Circulating eotaxin and eotaxin mRNA levels in visceral adipose tissue were increased in obesity in mice and humans. Adipose tissue explants secrete eotaxin, and the stromal/vascular component of adipose tissue seems to be the predominant source of eotaxin. Diet-induced weight loss in humans led to reduction in plasma eotaxin levels, demonstrating that clinical interventions that target obesity can modulate systemic eotaxin levels

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The relationships of plasma adiponectin with a favorable lipid profile, decreased inflammation, and less ectopic fat accumulation depend on adiposity

Author: Kantartzis K;Rittig K;Balletshofer B;Machann J;Schick F;Porubska K;Fritsche A;Haring HU;Stefan N;

BACKGROUND: The metabolic effects of adiponectin, including insulin sensitivity, seem to become stronger with increasing adiposity. Adiposity may also affect the relationship of adiponectin concentrations with serum lipid profile; markers of inflammation, atherosclerosis, and endothelial function; and ectopic fat accumulation. METHODS: We measured plasma adiponectin concentrations, serum lipids, and serum markers of inflammation, atherosclerosis, and endothelial function in 242 Caucasians without type 2 diabetes. We also measured visceral adipose tissue with magnetic resonance tomography and liver and intramyocellular fat with (1)H magnetic resonance spectroscopy. RESULTS: We divided the study participants into 2 groups: lean [mean (SE) total body fat, 26% (0.6%); n = 119] and obese [36% (0.6%); n = 123]. In the obese group, plasma adiponectin concentrations showed a strong positive association with concentrations of HDL cholesterol (P <0.0001) and negative associations with LDL cholesterol, triglycerides, high-sensitivity C-reactive protein, interleukin 6, apolipoprotein B(100), soluble E-selectin, soluble vascular cellular adhesion molecule 1, plasminogen activator inhibitor 1, leukocyte count, and liver and intramyocellular fat (all P <0.03). In the lean group, adiponectin showed a less strong association with HDL cholesterol (P = 0.005) and liver fat (P = 0.03) and no significant associations with the other variables (all P >0.10). High visceral adipose tissue was a strong predictor of low adiponectin concentrations, particularly in the obese group, and attenuated many of the significant relationships. CONCLUSIONS: High adiponectin plasma concentrations are associated with favorable lipid profiles, decreased subclinical inflammation, decreased markers of atherosclerosis and endothelial function, and low ectopic fat accumulation, particularly in obese persons. Adiponectin may also have a concentration-related effect on the relationship between visceral adipose tissue and these metabolic characteristics, especially in obese persons

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Endocrine regulation of energy metabolism: review of pathobiochemical and clinical chemical aspects of leptin, ghrelin, adiponectin, and resistin

Author: Meier U;Gressner AM;

BACKGROUND: Recent studies point to the adipose tissue as a highly active endocrine organ secreting a range of hormones. Leptin, ghrelin, adiponectin, and resistin are considered to take part in the regulation of energy metabolism. APPROACH: This review summarizes recent knowledge on leptin and its receptor and on ghrelin, adiponectin, and resistin, and emphasizes their roles in pathobiochemistry and clinical chemistry. CONTENT: Leptin, adiponectin, and resistin are produced by the adipose tissue. The protein leptin, a satiety hormone, regulates appetite and energy balance of the body. Adiponectin could suppress the development of atherosclerosis and liver fibrosis and might play a role as an antiinflammatory hormone. Increased resistin concentrations might cause insulin resistance and thus could link obesity with type II diabetes. Ghrelin is produced in the stomach. In addition to its role in long-term regulation of energy metabolism, it is involved in the short-term regulation of feeding. These hormones have important roles in energy homeostasis, glucose and lipid metabolism, reproduction, cardiovascular function, and immunity. They directly influence other organ systems, including the brain, liver, and skeletal muscle, and are significantly regulated by nutritional status. This newly discovered secretory function has extended the biological relevance of adipose tissue, which is no longer considered as only an energy storage site. SUMMARY: The functional roles, structures, synthesis, analytical aspects, and clinical significance of leptin, ghrelin, adiponectin, and resistin are summarized

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