BACKGROUNDGenioglossal dysfuntion takes an important role in pathogenesis of obstructive sleep apnea hypopnea syndrome (OSAHS) in which chronic intermittent hypoxia (CIH) is the major pathological origin. Recent studies have suggested genioglossal injury induced by CIH might be improved by adiponectin. The aim of this study was to investigate the effects of adiponectin on genioglossus contractile properties in rats exposed to CIH.

METHODSThirty-nine healthy male Wistar rats were randomly divided into three groups: normal control (NC), CIH and adiponectin supplement (CIH+Ad) with 13 rats in each. Rats in NC were kept breathing normal air, while rats in CIH and CIH+Ad experienced the same CIH environment eight hours per day for 35 successive days. Rats in CIH+Ad were given intravenous adiponectin of 10 µg twice a week for 30 successive days. Rats in the NC and CIH were injected with normal saline as a control. After 35 days' CIH exposure, the levels of serum adiponectin and genioglossus contractile properties were compared.

RESULTSSerum adiponectin level was significantly lower in CIH than in NC (1210 ng/ml vs. 2236 ng/ml). Serum adiponectin level in CIH+Ad (1844 ng/ml) was significantly higher than CIH but lower than NC. Twitch tension, time to peak tension, half relaxation time and tetanic tension were significantly lower in CIH than NC and improved in CIH+Ad. All mean tetanic fatigue indices decreased more rapidly in the first 20 seconds than during the subsequent 100 seconds. Tetanic fatigue indices in NC and CIH+Ad were significantly higher compared to CIH.

CONCLUSIONSCIH could lead to hypoadiponectinaemia, impaired genioglossus contractile properties and decreased fatigue resistance in rats. Such changes could be partially offset by supplementation of adiponectin.

Adiponectin ; blood ; therapeutic use ; Animals ; Hypoxia ; blood ; physiopathology ; Male ; Muscle Contraction ; physiology ; Rats ; Rats, Wistar ; Sleep Apnea, Obstructive ; blood ; drug therapy ; physiopathology

PURPOSE: Plasma adiponectin concentrations are inversely related with metabolic syndrome (MetS), and MetS is associated with increased risk for heart failure (HF). However, the relationship between adiponectin and MetS in HF remains undetermined. Therefore, we tested whether MetS was associated with the degree of plasma adiponectin concentrations in HF patients. MATERIALS AND METHODS: One hundred twenty eight ambulatory HF patients with left ventricular ejection fraction of <50% (80 males, 61.8+/-11.9 years old) were enrolled for this cross-sectional study. Echocardiographic measurements were performed, and plasma concentrations of adiponectin, lipoproteins, apolipoproteins (apoB, apoA1) and high sensitive C-reactive protein (hsCRP) were measured. RESULTS: Adiponectin concentrations in HF patients with MetS (n=43) were significantly lower than those without MetS (n=85) (9.7+/-7.0 vs. 15.8+/-10.9 microg/mL, p=0.001). Higher concentrations of apoB (p=0.017), apoB/A1 ratio (p<0.001), blood urea nitrogen (p=0.034), creatinine (p=0.003), and fasting insulin (p=0.004) were observed in HF patients with MetS compared with those without MetS. In HF patients with MetS, adiponectin concentrations were negatively correlated with hsCRP (r=-0.388, p=0.015) and positively correlated with the ratio of early mitral inflow velocity to early diastolic mitral annular velocity, E/E' (r=0.399, p=0.015). There was a significant trend towards decreased adiponectin concentrations with an increasing number of components of MetS (p for trend=0.012). CONCLUSION: Our study demonstrated that adiponectin concentrations decreased in HF patients with MetS, and that relationship between adiponectin, inflammation and abnormal diastolic function, possibly leading to the progression of HF.
Adiponectin/*blood ; Aged ; Diabetes Mellitus, Type 2/epidemiology/metabolism ; Female ; Heart Failure/*epidemiology/*metabolism/ultrasonography ; Humans ; Male ; Metabolic Syndrome X/*epidemiology/*metabolism ; Middle Aged ; Risk Factors ; Ventricular Function, Left/physiology

OBJECTIVE: To examine the plasma adiponectin concentration in coronary heart disease (CHD) patients combined with abnormal glucose metabolism, and to explore the clinical significance of adiponectin. METHODS: Eighty-seven hospitalized CHD patients confirmed by coronary angiography from August 2009 to April 2010 at Xiangya Hospital were enrolled and divided into 3 groups according to their glucose metabolic state: 31 patients were selected as a simple CHD group, 28 were selected as a CHD combined with impaired glucose tolerance group (CHD+IGT group), and the other 28 as a CHD combined with diabetes mellitus group (CHD+DM group). The 31 healthy subjects who got health checkup at the same time were enrolled as a normal control group (NC group). Plasma adiponectin was measured by enzyme linked immunosorbent assay. The height, weight,waistline and blood pressure of all the subjects were checked, and the fasting blood glucose (FBG), insulin, lipids, high-sensitivity C-reactive protein (hs-CRP), free fatty acids (FFA), the liver function and the renal function were checked as well. The body mass index and the homeostasis model were assessed for insulin resistance. RESULTS: 1) Plasma adiponectin in the CHD group, the CHD+IGT group, and the CHD+DM group was all lower than that in the NC group (P<0.05); 2) Compared with the CHD group, the plasma adiponectin in the CHD+DM group was the lowest, followed by the CHD+IGT group, and there was significant difference in the 3 groups (P<0.05); 3) Plasma adiponectin level was positively related with the high density lipoprotein cholesterol-C (HDL-C) (r=0.483, P<0.01), while it was negatively related with the hs-CRP and Gensini score (r=-0.489, P<0.05;r=-0.252, P<0.05). CONCLUSION Plasma adiponectin concentration is reduced in the CHD patients, and significantly reduced in CHD patients combined with abnormal glucose metabolism. Plasma adiponectin concentration decreases significantly with the severity of abnormal glucose metabolism. CHD and the abnormal glucose metabolism are important influence factors for plasma adiponectin. That plasma adiponectin level significantly decreases may be the superimposed results of CHD and abnormal glucose metabolism. Plasma adiponectin combined with HDL-C, hs-CRP and Gensini score may provide the reference in the judgement of the severity of CHD patients with abnormal glucose metabolism.
Adiponectin ; blood ; Aged ; Coronary Disease ; blood ; complications ; metabolism ; Diabetes Mellitus, Type 2 ; blood ; complications ; Female ; Humans ; Insulin Resistance ; physiology ; Male ; Middle Aged

BACKGROUNDAdiponectin is an adipokine with insulin-sensitising and anti-atherogenic properties. The aim of this study was to investigate whether low adiponectin levels predict the impairment of endothelial function in newly diagnosed type 2 diabetic patients in an 8-year prospective study.

METHODSIn the prospective study, we enrolled 133 newly diagnosed type 2 diabetic patients without subclinical atherosclerosis and gave them intensive therapy; the mean treatment period was 8 years. Intensive treatment was a stepwise implementation of behavior modification and pharmacological therapy targeting hyperglycaemia, hypertension, dyslipidaemia and obesity. We measured baseline circulating adiponectin with an enzyme-linked immunosorbent assay, endothelium-dependent and -independent vasodilation by high-resolution vascular ultrasound. At year 8, 102 patients were reexamined for endothelium-dependent and -independent vasodilation.

RESULTSSex-adjusted adiponectin level was positively correlated with endothelium-independent vasodilation both at baseline (r = 0.150, P = 0.043) and at year 8 (r = 0.339, P = 0.001), whereas no association was found between adiponectin and endothelium-dependent vasodilation. In a stepwise multivariate linear regression model, adiponectin was an independent predictor for impaired endothelium-independent vasodilation at year 8 (P = 0.001).

CONCLUSIONSPlasma adiponectin concentration was associated with endothelium-independent vasodilation and hypoadiponectinemia predicted the impairment of endothelium-independent vasodilation in newly diagnosed type 2 diabetic patients under multifactorial intervention. These data support the causative link of impairment of endothelium-independent vasodilation with hypoadiponectinemia.

Adiponectin ; blood ; Diabetes Mellitus, Type 2 ; blood ; physiopathology ; Endothelium, Vascular ; physiology ; Female ; Humans ; Male ; Middle Aged ; Prospective Studies ; Vasodilation ; physiology

Retinol binding protein 4 (RBP4) has been postulated to provide a new link between obesity and insulin resistance. We aimed to assess the relationship between serum RBP4 and insulin resistance by investigating serum RBP4 levels in children and adolescents according to degree of obesity and pubertal stage. A total of 103 (30 lean, 39 overweight, 34 obese) were evaluated for serum RBP4, adiponectin, insulin, glucose and lipid profiles. RBP4 levels of obese and overweight groups were higher than those of lean group. RBP4 level was higher in pubertal group than in prepubertal group. RBP4 was positively correlated with age, height, weight, body mass index (BMI), abdominal circumference, systolic blood pressure, fasting insulin, homeostatic model assessment of insulin resistance (HOMA-IR), total cholesterol and triglyceride, and inversely with adiponectin. In the multiple linear regression analysis, RBP4 was found to be independently associated with pubertal stage, BMI and triglyceride but not with HOMA-IR. In conclusion, serum RBP4 level is related with degree of adiposity and pubertal development. The association of RBP4 with insulin resistance is supposed to be secondary to the relation between RBP4 and adipose tissue in children and adolescents.
Adiponectin/blood ; *Adiposity ; Adolescent ; Age Factors ; Blood Glucose/analysis ; Blood Pressure ; Body Mass Index ; Child ; Cholesterol/blood ; Female ; Humans ; Insulin/blood ; Insulin Resistance ; Male ; Obesity/*blood/metabolism/physiopathology ; Puberty/*blood/metabolism/physiology ; Republic of Korea ; Retinol-Binding Proteins, Plasma/*metabolism ; Sex Factors ; Triglycerides/blood ; Waist Circumference

PURPOSE: Growing evidence suggests that hypoadiponectinemia may play a significant role in the development of metabolic syndrome (MetS). Therefore, the relationships between serum adiponectin with MetS and components of MetS were investigated in non-diabetic samples of drawn from the Koreans general population. MATERIALS AND METHODS: We performed a cross-sectional study in samples of older Koreans (age > 40 years) including 2,471 men and 3,463 women. MetS was defined according to the Asian modified criteria of the National Cholesterol Education Program Adult Treatment Panel III report. Serum adiponectin concentrations were measured by radioimmunoassay. RESULTS: The median adiponectin level in MetS was significantly lower than that in non-MetS subjects in men (6.00 vs. 8.00 microg/mL, p < 0.001) and women (10.12 vs. 11.74 microg/mL, p < 0.001). Adiponectin concentration was negatively correlated with waist circumference and levels of triglyceride, C-reactive protein (CRP), fasting glucose, and insulin, and positively correlated with high-density lipoprotein and age in both genders (p < 0.001). In a multivariate regression model after adjustment for age, body mass index, smoking, CRP, and lipid profiles, the odds ratio of MetS comparing extreme quartiles of adiponectin distribution was 0.32 [95% confidence interval (CI), 0.20 to 0.50] in men and 0.57 (95% CI, 0.43 to 0.76) in women. CONCLUSION: Adiponectin levels are independently associated with the phenotype of MetS, as well as components of MetS in the non-diabetic Korean general population.
Adiponectin/*blood/physiology ; Blood Glucose/analysis ; Body Mass Index ; C-Reactive Protein/analysis ; Cross-Sectional Studies ; Female ; Humans ; Insulin/blood ; Lipoproteins, HDL/blood ; Male ; Metabolic Syndrome X/*blood/physiopathology ; Middle Aged ; Multivariate Analysis ; Odds Ratio ; Republic of Korea ; Sex Ratio ; Triglycerides/blood ; Waist Circumference/physiology

BACKGROUNDHyperinsulinemic euglycemic clamp is the gold standard to evaluate the insulin sensitivity, but it is too complicated and expensive to use in clinic. We tried to find an alternative indicator to reflect insulin sensitivity. To evaluate the association between the four adipokines, adiponectin, leptin, resistin and tumor necrosis factor-alpha (TNF-alpha) with insulin sensitivity, we used a hyperinsulinemic euglycemic clamp to test insulin sensitivity in Chinese patients with obesity and type 1 or type 2 diabetes mellitus versus controls.

METHODSIn this parallel control study, we tested insulin sensitivity using a hyperinsulinemic euglycemic clamp in different groups, then examined levels of adiponectin, leptin, resistin and TNF-alpha in serum, and the relationship between the different adipokines and glucose disposal rate (M value), as well as insulin sensitivity index (M value/insulin, M/I), which are the "gold standard" indices of insulin sensitivity.

RESULTSThere were significant differences in mean leptin values in the four adipokines from the four different groups (P < 0.001; comparison of the variation between different groups was analyzed by variance analysis). Compared to controls (using multiple comparison two-way Dunnett t test), only the leptin level showed significant differences in the four adipokines from the four different groups at the same time (P < 0.001). The association analysis between the different adipokines and M or M/I values also showed that only leptin negatively correlated with M (r = -0.64, P < 0.001) or M/I values (r = -0.56, P < 0.001); there was no relationship between the other three adipokines and M or M/I values.

CONCLUSIONOnly leptin was associated with M or M/I values. Therefore, leptin might be one of the predictive factors of the degree of insulin resistance and risk of the accompanying disease.

Adipokines ; blood ; Adiponectin ; blood ; Asian Continental Ancestry Group ; Diabetes Mellitus, Type 1 ; blood ; Diabetes Mellitus, Type 2 ; blood ; Glucose Clamp Technique ; Humans ; Insulin Resistance ; physiology ; Leptin ; blood ; Obesity ; blood ; Resistin ; blood ; Tumor Necrosis Factor-alpha ; blood

BACKGROUNDThe genioglossus (GG) is involved in the maintenance of an open airway for effective breathing. Although the pathogenesis of obstructive sleep apnea hypopnea syndrome (OSAHS) was closely associated with GG dysfunction, its causes and possible treatment have not been elucidated. The aim of the study was to investigate the effects of chronic intermittent hypoxia (CIH) on serum adiponectin levels, electromyograph (EMG) activity and ultrastructure of GG, as well as the effect of an adiponectin supplement in anesthetized rats.

METHODSForty-two healthy male Wistar rats were randomly divided into normal control (A), CIH (B) and adiponectin treatment (C) groups, 14 rats in each group. CIH was performed eight hours per day for five weeks in both groups B and C. Group C received transvenous injection of adiponectin at the dosage of 10 microg per injection, twice a week for five weeks. At the end of the 5th week the GG EMG voltage was measured and compared among the three groups. Transmission electron microscope was used to observe the ultrastructure of the GG.

RESULTSCIH caused significant hypoadiponectinemia, weakened activity of GG EMG at both baseline and hypoxia stimulation, and induced ultrastructural pathological changes, such as, myofibril discontinuities, lysis of myofilament, edema of mitochondria and disruption of cristae, vacuolus and lysis of some mitochondria. Venous supplement of adiponectin improved the above pathological changes resulting from CIH.

CONCLUSIONCIH resulted in pathological changes in GG's EMG and ultrastructure, which could be improved by supplement of adiponectin and be associated with hypoadiponectinemia caused by CIH.

Adiponectin ; administration & dosage ; blood ; Animals ; Electromyography ; Hypoxia ; blood ; physiopathology ; Male ; Microscopy, Electron, Transmission ; Muscle, Skeletal ; physiology ; ultrastructure ; Random Allocation ; Rats ; Rats, Wistar ; Sleep Apnea, Obstructive ; blood ; physiopathology ; Tongue ; physiology ; ultrastructure

It is the intent of this investigation to gain an insight into the relationship of serum total adiponectin with polycystic ovary syndrome (PCOS) and insulin resistance. Fifty-eight PCOS patients were enrolled (29 with high serum insulin level and 29 without), at the same time, 29 non-PCOS women with normal weight were included as control. The influencing factors of total adiponectin, PCOS and insulin resistance were analyzed. The serum total adiponectin of PCOS patients and all participants were found to be negatively related to waist hip ratio (r = -0.39, r = -0.36) and InHOMA-IR (r = -0.53, r = -0.45), respectively. Adiponectin was not a protective factor of PCOS (P > 0.1), but it was that of PCOS-insulin resistance (OR = 0.81; 95% CI: 0.67-0.97; P = 0.02). LH/FSH (OR = 1.51; 95% CI: 1.16-1.96; P = 0.01) and InHOMA-IR (OR = 1.26; 95% CI: 1.10-1.44; P = 0.01) were risk factors of PCOS, and waist hip ratio was that of PCOS-insulin resistance (OR = 8.57; 95% CI, 2.14-34.30, P = 0.01). Adiponectin might influence fasting insulin and InHOMA-IR (B = -0.22, P = 0.001; B = -0.02, P = 0.002). These data signify that adiponectin is not directly related with PCOS, but it is related with PCOS-HL Adiponectin might participate in the pathophysiologic mechanism of PCOS by influencing insulin sensitivity.
Adiponectin ; blood ; Adult ; Female ; Humans ; Insulin Resistance ; physiology ; Polycystic Ovary Syndrome ; blood ; physiopathology ; Waist-Hip Ratio ; Young Adult

PURPOSE: The aim of this study was to determine whether retinol-binding protein 4 (RBP4), adiponectin and high molecular weight (HMW) adiponectin are associated with insulin resistance (IR) and metabolic parameters in non-diabetic hypertensive patients. Also, we sought to compare the predictive values of these adipocytokines for IR in non-diabetic hypertensive patients. MATERIALS AND METHODS: Analyses of RBP4, adiponectin, and HMW adiponectin were performed on 308 non-diabetic hypertensives (148 males, age 58 +/- 10 years, 189 non-metabolic syndrome and 119 metabolic syndrome). The homeostasis model assessment (HOMA) index for IR, lipid profiles, and anthropometric measure-ments were assessed. RESULTS: There was no significant difference in RBP4 levels according to the presence of metabolic syndrome, although adiponectin and HMW adiponectin were significantly lower in metabolic syndrome. Correlation analysis of log RBP4 with IR and metabolic indices revealed that there was no significant correlation of RBP4 with waist circumference (r = 0.056, p = 0.324), HDL cholesterol (r = 0.005, p = 0.934), ApoB/ApoAI ratio (r = 0.066, p = 0.270), and the HOMA index (r = 0.017, p = 0.756). However, adiponectin and HMW adiponectin showed significant correlations with the HOMA index (r = - 0.247, p < 0.001; r = - 0.296, p < 0.001) and metabolic parameters. With IR defined as HOMA index > or = 2.5, HMW adiponectin did not demonstrate a superior predictive value for IR compared to adiponectin (AUC = 0.680 vs. 0.648, p = 0.083). The predictive value of RBP4 for IR was minimal (AUC = 0.534). CONCLUSION: RBP4 was not associated with IR or metabolic indices and the predictive value for IR was minimal in hypertensives. HMW adiponectin didn't have a superior predictive value for IR compared to adiponectin. Therefore, we can suggest that RBP4 and HMW adiponectin don't have more additive information than adiponectin in non-diabetic hypertensives.
Adiponectin/*blood ; Aged ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Hypertension/*blood/*physiopathology ; Insulin Resistance/*physiology ; Male ; Middle Aged ; Radioimmunoassay ; Retinol-Binding Proteins, Plasma/*metabolism ; Risk Factors ; Waist Circumference/physiology