Changes In Adiponectin Levels Research Articles

Changes of Serum Adiponectin Levels in Murine Experimental Sparganosis

The weight gain phenomenon associated with sparganosis has been well documented and was first recognized in the 1960s. Many studies have been conducted regarding the plerocercoid growth factor in the larva of Spirometra mansoni. In the present study, we hypothesized that the weight gain may be affected by the adipocyte secreted hormones, i.e., adiponectin, which is secreted from the adipose tissues in case of tissue migrating parasitic infections. Specifically, we attempted to ascertain whether the serum levels of adiponectin change in murine sparganosis. However, serum adiponectin levels assayed by ELISA evidenced no significant changes after an experimental infection (P > 0.05). Finally, the weight gain phenomenon in mouse sparganosis is not associated with changes in adiponectin levels, and further investigations involving parasitic infection-induced weight gain remain necessary.

Abstract 3429: Amlodipine Improves Endothelial Function and Metabolic Parameters in Patients with Hypertension

Background : Reciprocal relationships between endothelial dysfunction and insulin resistance imply that improvement in endothelial dysfunction will have beneficial metabolic consequences. We hypothesized that amlodipine therapy will improve endothelial dysfunction and metabolic parameters in hypertensive subjects. Methods : Amlodipine (10 mg daily for 8 weeks) or placebo was given to each 45 patients with mild to moderate hypertension in a randomized, double-blind, placebo-controlled, and paralleled study. Age, sex, and body mass index were matched. Results : Amlodipine therapy significantly reduced systolic and diastolic blood pressure and increased HDL-cholesterol to greater extent than placebo therapy (all P< 0.001). Amlodipine therapy significantly improved flow-mediated dilator response to hyperemia and reduced plasma malondialdehyde levels to greater extent than placebo therapy ( P< 0.001 and P =0.035). Amlodipine therapy significantly increased plasma adiponectin levels ( P =0.009) and decreased plasma leptin and resistin levels ( P< 0.001 and P =0.025, respectively) to greater extent than placebo therapy. Correlations were noted between percent changes in adiponectin levels and percent changes in HDL-cholesterol ( r =0.348, P =0.019) and QUICKI ( r =0.326, P =0.029) following amlodipine therapy. Only changes in HDL-cholesterol (β = 0.469, P = 0.019) and QUICKI (β = 1.786, P = 0.069) were independent predictors of changes in adiponectin levels (multivariate regression analysis). We also observed inverse correlations between percent changes in leptin levels and percent changes in QUICKI ( r = −0.569, P< 0.001) following amlodipine therapy with changes in QUICKI (β = 1.810, P < 0.001) as an independent predictor of changes in leptin levels. Conclusions : Amlodipine therapy improves blood pressure, endothelial function, and metabolic parameters in patients with hypertension.

Change of adiponectin level in retina of type 2 diabetic rats

目的 检测脂联素在2型糖尿病(DM)大鼠模型视网膜中的含量变化,探讨脂联素在2型糖尿病视网膜病变(DR)早期发生中的作用.方法 健康雄性SD大鼠12只,予以高脂肪饮食24周+小剂量链脲佐菌素(STZ)(0.5%,20 mg/kg)腹腔注射复制2型DM模型;随机选取6只DM大鼠经附睾静脉注射重组脂联素(20 μg/kg);并以8只普通喂养组SD大鼠作为对照.应用Western蛋白印迹和RT-PCR检测脂联素蛋白及mRNA在模型大鼠视网膜中的变化.结果 脂联素在早期2型DM大鼠视网膜中的含量较正常组显著减少(P＜0.01),注射重组脂联素可使视网膜表达较前者明显回升(P＜0.01).结论 脂联素可能与DR的早期发生有关,提高脂联素在视网膜局部的含量可减轻视网膜炎症反应,延缓DR发生。

Modulation of Adiponectin and Leptin during Refeeding of Female Anorexia Nervosa Patients

Several studies assessed adiponectin levels in anorexia nervosa (AN) patients, however, data regarding the dynamics of changes in adiponectin levels during refeeding of these patients is limited and contradicting. Our objective was to assess adiponectin levels and the distribution of its different isoforms in AN patients before and after long-term refeeding, and to relate them to alterations in body mass index, leptin, insulin sensitivity, and additional endocrine parameters. We conducted a longitudinal controlled study of 38 female adolescent malnourished AN inpatients, with 13 young, lean, healthy women serving as controls. Blood samples were obtained upon admission and thereafter at 1, 3, and 5 months (at target weight). Changes in body mass index, leptin, adiponectin, insulin sensitivity, and adiponectin multimeric forms were measured. At admission, leptin levels of AN patients were significantly lower, whereas insulin sensitivity (assessed by homeostasis model assessment-insulin resistance), adiponectin levels, and the ratio of high molecular weight (HMW) adiponectin to total adiponectin were significantly higher compared with controls. During weight recovery, leptin levels and homeostasis model assessment-insulin resistance increased significantly, whereas adiponectin and HMW adiponectin/total adiponectin ratio decreased significantly, to levels similar to controls. An initial increase in adiponectin levels was observed after 1 month of refeeding. There was no correlation between adiponectin and either T(4) or cortisol levels. Our study demonstrates hyperadiponectinemia, increased adiponectin HMW isoform, and increased insulin sensitivity in adolescent AN female patients and reversal of these findings with weight rehabilitation. We hypothesize that increased adiponectin levels may have a protective role in maintaining energy homeostasis during extreme malnourishment.

The Additive Beneficial Effects of Ramipril Combined with Candesartan in Hypertensive Patients on Insulin Resistance, Plasma Adiponectin

Background and Objectives：Ramipril and candesartan have decreased the incidence of new onset diabetes in large scale randomized clinical studies. Because ramipril and candesartan have distinct mechanisms of action in the renin angiotensin aldosterone system, we hypothesized that combination therapy would have additive beneficial metabolic effects in patients with hypertension. Subjects and Methods：Thirty-four patients were given ramipril 10 mg and placebo, ramipril 10 mg and candesartan 16 mg, or candesartan 16 mg and placebo daily in a randomized, double-blind, placebo-controlled cross-over trial with three treatment arms and two washout periods (each being 2 months). Results：Ramipril, combination therapy or candesartan significantly increased the plasma adiponectin levels relative to the baseline measurements by 17±6% (p=0.038), 25±5% (p<0.001), and 14±6% (p=0.016), respectively. Combination therapy significantly increased the plasma adiponectin levels more than either ramipril or candesartan alone (p=0.020 by ANOVA). Only combination therapy significantly increased the QUICKI level relative to the baseline measurements (p=0.002). There were no significant correlations between these changes of the metabolic parameters and reduction of the systolic blood pressure (-0.288≤r≤ 0.284) and reduction of the diastolic blood pressure (-0.282≤r≤0.190). On multivariate analysis, only the change of adiponectin levels was an independent predictor of the changes in the QUICKI levels (β=1.549, p=0.040) following combination therapy. Conclusion：Ramipril in combination with candesartan increases the plasma adiponectin levels to a greater extent than monotherapy with either drug alone. Only combination therapy significantly improves insulin sensitivity relative to the baseline measurements. The only predictor for the improvement of insulin sensitivity is the increase of plasma adiponectin levels by combination therapy. (Korean Circulation J 2007;37:173-179)

Additive beneficial cardiovascular and metabolic effects of combination therapy with ramipril and candesartan in hypertensive patients

Ramipril and candesartan have distinct mechanisms of action to improve endothelial function. Therefore, we hypothesized that combination therapy has additive beneficial effects to simultaneously improve endothelial dysfunction and adipocytokine profiles in patients with hypertension. Thirty-four patients were given ramipril 10 mg and placebo, ramipril 10 mg and candesartan 16 mg, or candesartan 16 mg and placebo daily in a randomized, double-blind, placebo-controlled cross-over trial with three treatment arms and two washout periods (each 2 months). Ramipril, candesartan, or combination therapy reduced blood pressure, improved flow-mediated dilation, and increased plasma adiponectin levels when compared with baseline values. However, combination therapy improved these outcome measures to a greater extent than either ramipril or candesartan alone (P < 0.001 and P = 0.016 for systolic and diastolic blood pressure, P < 0.001 and P = 0.048 for flow-mediated dilation and adiponectin levels by ANOVA). In addition, combination therapy reduced plasma leptin levels to a greater extent than either ramipril or candesartan alone (P = 0.042 by ANOVA). There were correlations between percent changes in adiponectin levels and percent changes in insulin sensitivity (determined by QUICKI) (r = 0.319, P = 0.066) following ramipril therapy, percent changes in QUICKI (r = 0.374, P = 0.029) following combination therapy, and percent changes in QUICKI (r = 0.607, P < 0.001) following candesartan therapy. Ramipril in combination with candesartan improves blood pressure, endothelial function, and adipocytokine profiles to a greater extent than monotherapy with either drug in hypertensive patients.

Changes in Serum Adipokine Levels During Pioglitazone Treatment for Nonalcoholic Steatohepatitis: Relationship to Histological Improvement

Thiazolidinedione (TZD) therapy improves liver histology in nonalcoholic steatohepatitis (NASH) through a mechanism possibly related to its insulin-sensitizing or anti-inflammatory activity. This study was conducted to assess changes in serum levels of selected adipokines and proinflammatory cytokines and to relate these changes to the improved liver histology resulting from pioglitazone therapy for NASH. Serum samples from 18 patients with NASH obtained at day 0 and week 48 of therapy during an open-label study of pioglitazone were tested for adiponectin, leptin, interleukin (IL)-1a, IL-6, and tumor necrosis factor (TNF)-alpha levels. Paired liver biopsy specimens were scored (0-4) for steatosis, parenchymal inflammation, cell injury, and fibrosis. Adiponectin levels increased from 3.7 to 10.3 mug/mL at week 48 (P < .01); the levels of the other cytokines were unchanged: TNF-alpha, 9.1 vs 8.8 pg/mL; IL-1a, 3.9 vs 3.4 pg/mL; IL-6, 19.4 vs 13.4 pg/mL; and leptin, 24.8 vs 29.6 ng/mL (P > .05 for all). Pioglitazone therapy was associated with improvements in steatosis (2.5 vs 1.0), parenchymal inflammation (3.3 vs 2.1), cell injury (2.2 vs 0.9), and fibrosis (2.0 vs 1.4). The change in adiponectin level was associated with the improvement in steatosis (P = .03) as well as in a summary NASH activity index score (P = .01). Changes in IL-1, IL-6, TNF-alpha, and leptin levels did not correlate with improvements in the histological features. Improvements in liver histology during TZD therapy may be modulated by an adiponectin-mediated effect on insulin sensitivity and hepatic fatty acid metabolism rather than by changes in proinflammatory cytokines.

The association of SNP276G&gt;T at adiponectin gene with circulating adiponectin and insulin resistance in response to mild weight loss

The purpose of this study was to determine whether common single nucleotide polymorphisms (SNPs) at the adiponectin (ADIPOQ) locus influence changes in circulating adiponectin and the features of insulin resistance in response to a weight loss intervention. In total, 294 nondiabetic/overweight-obese Koreans participated in a clinical intervention study lasting 12 weeks involving a caloric reduction of -300kcal/day. Plasma adiponectin, blood lipids, glucose and insulin concentrations were measured at baseline and after weight loss. Insulin resistance was estimated by homeostasis model assessment insulin resistance (HOMA-IR) derived from fasting glucose and insulin concentrations. We genotyped for three SNPs, 45T>G, 276G>T and -11377C>G. At baseline, HOMA-IR was significantly higher in GG homozygotes than in carriers of the T allele at SNP276G>T of the adiponectin gene (P<0.05). With regard to SNP45T>G and SNP -11377C>G, we did not find any genotype related differences in baseline levels of HOMA-IR and adiponectin. In the 45/276 haplotype test, homozygous for the TG haplotype had significantly lower concentrations of plasma adiponectin (P<0.05). After the 12-week weight loss intervention, the significant decreases in HOMA-IR (P<0.001) and increases in adiponectin (P<0.01) were observed in GG homozygotes at SNP276, which were not shown in carriers of the T allele. Furthermore, there was a significant difference in the decreases in HOMA-IR between the GG homozygotes and carriers of the T allele at SNP276 (P<0.05). Regarding SNP45T>G and SNP -11377C>G, there was no association between SNP45T>G and SNP -11377C>G and decreases in HOMA-IR. In the 45/276 haplotype test, there was a significant difference in changes of adiponectin levels among those with different haplotype combinations (P<0.05). The SNP276G>T of the ADIPOQ gene is associated with different responses of circulating adiponectin and insulin resistance to mild weight loss in overweight-obese subjects.

Improvements in insulin resistance with weight loss, in contrast to rosiglitazone, are not associated with changes in plasma adiponectin or adiponectin multimeric complexes

It has been suggested that changes in adiponectin levels may contribute to improved insulin sensitivity in insulin-resistant individuals both after weight loss and after treatment with thiazolidinedione compounds. If this is correct, then changes in total circulating adiponectin and/or distribution of its multimeric complexes should coincide with improvements in insulin sensitivity after both interventions. To address this issue, fasting adiponectin concentrations and distribution of adiponectin complexes were measured in plasma samples in 24 insulin-resistant, nondiabetic subjects before and after 3-4 mo of treatment with either rosiglitazone or caloric restriction. The degree of insulin resistance in each group of 12 subjects was equal at baseline and improved to a similar extent ( approximately 30%) after each therapy. Whereas total adiponectin levels increased by nearly threefold and the relative amount of several higher molecular weight adiponectin complexes increased significantly in the rosiglitazone treatment group, there were no discernible changes in adiponectin levels or in the distribution between high or low molecular weight complexes in the weight loss group. These data indicate that, although changes in total adiponectin and several specific adiponectin complexes paralleled improvements in insulin resistance in thiazolidinedione-treated subjects, neither circulating adiponectin concentrations nor multimeric complexes changed in association with enhanced insulin sensitivity after moderate weight loss in 12 insulin-resistant, obese individuals.

Effect of Walking with a Pedometer on Serum Lipid and Adiponectin Levels in Japanese Middle-aged Men

To clarify the effects of walking with a pedometer on metabolic parameters, including adiponectin (APN). We recruited 44 male Japanese volunteers (age, 37 +/- 9 yrs; body mass index (BMI), 24.2 +/- 2.9 kg/m2; fasting plasma glucose (FPG), 96 +/- 11 mg/dL; total cholesterol (TC) 190 +/- 26 mg/dL; triglycerides (TG) 119 +/- 80 mg/dL; HDL-C56 +/- 14 mg/dL). Subjects were instructed to walk with a pedometer and record the number of steps they walked every day for 50 days. Serum adiponectin (APN) levels were measured by enzyme immunoassay. Treatment effects were examined by Wilcoxon's rank test. The average number of steps was 8211 +/- 2084 per day. There were significant reductions in BMI, sBP, TG and TNF-alpha levels after 50 days, but no changes in adiponectin levels. We then divided the subjects into 2 groups according to the steps walked per day, namely, more than 8000 steps (MT group, n = 22) and less than 8000 steps (LT group, n = 22) and found that the reduction in TG and BP was observed only in the MT group. Walking with a pedometer is effective for improving metabolic parameters, such as TG and blood pressure, but is not sufficient to increase adiponectin levels in Japanese men.

Anti-inflammatory and metabolic effects of candesartan in hypertensive patients

Background Angiotensin II type 1 (AT1) receptor blocker therapy prevented or retarded the progression of coronary heart disease. The mechanisms of this benefit may relate to the ability of AT1 receptor blockers to reduce inflammation and insulin resistance. Methods We administered placebo or candesartan 16 mg daily during 2 months to 45 patients with mild to moderate hypertension. This study was randomized, double-blind, placebo-controlled, crossover in design. Results Candesartan therapy significantly lowered both systolic and diastolic blood pressure. Compared with placebo, candesartan therapy significantly lowered plasma hsCRP levels relative to baseline measurements from 1.10 to 0.70 mg/l ( P = 0.024) and soluble CD40 ligand levels by 30 ± 11% ( P < 0.001). There were significant inverse correlations between body mass index and baseline plasma adiponectin levels ( r = − 0.480, P = 0.009). There were significant correlations between baseline adiponectin levels and baseline insulin ( r = − 0.317, P = 0.034) or baseline Quantitative Insulin-Sensitivity Check Index (QUICKI), a surrogate index of insulin sensitivity ( r = 0.371, P = 0.012). Compared with placebo, candesartan therapy significantly lowered fasting insulin levels ( P = 0.011) and increased plasma levels of adiponectin by 15 ± 4% ( P = 0.012) and increased QUICKI by 8 ± 2% ( P = 0.007). There were significant correlations between percent changes in adiponectin levels and percent changes in insulin ( r = − 0.340, P = 0.022) or QUICKI ( r = 0.325, P = 0.029). Conclusions Candesartan therapy significantly reduced inflammation and increased adiponectin levels and improved insulin sensitivity in hypertensive patients.

Changes in insulin sensitivity induced by short-term growth hormone (GH) and insulin-like growth factor I (IGF-I) treatment in GH-deficient adults are not associated with changes in adiponectin levels

To test potential effects of altered insulin sensitivity on circulating adiponectin levels, we studied patients with GH deficiency (GHD) undergoing high dose GH and IGF-I treatment in a well-defined short-term setting. This design allowed to exclude confounding effects of GH and IGF-I treatment on body composition. Six patients (three women and three men) with acquired GHD were treated in a randomised cross-over trial with GH (subcutaneous injections of GH 0.03 IU/kg/daily) or IGF-I (continuous subcutaneous infusion of 5 μg/kg/h recombinant IGF-I) for 5 days. Median age of patients was 60 (range 25–72) years, BMI 24.7 (20.7–30.7) kg/m 2, and baseline IGF-I concentration 60 (30–83) μg/L. HOMA scores (to assess insulin sensitivity) at baseline were 0.8 (0.3–11.7) and adiponectin concentrations were 7.0 (2.5–14.8) mg/L. HOMA scores increased rapidly and significantly up to a maximum of 2.7-fold (from baseline) at day 5 of GH treatment and returned promptly to baseline when GH was stopped, while adiponectin serum levels remained within the baseline range throughout the study period. HOMA scores dropped to a nadir of 0.66 from baseline at day 2 of IGF-I treatment whereas adiponectin levels remained within the baseline range. These data suggest that changes in insulin sensitivity (induced by high dose and short-term GH and IGF-I treatment) in patients with GHD are not associated with changes in adiponectin levels.

Beneficial Effects of Fenofibrate to Improve Endothelial Dysfunction and Raise Adiponectin Levels in Patients With Primary Hypertriglyceridemia

Improvement in endothelial function is predicted to improve insulin sensitivity, and this may be one mechanism by which fenofibrate decreases the incidence of coronary heart disease. We hypothesize fenofibrate improves endothelial function by enhancing insulin sensitivity. We administered placebo or fenofibrate 200 mg daily for 8 weeks to 46 patients with primary hypertriglyceridemia (24 had metabolic syndrome). This study was randomized, double blind, placebo controlled, and crossover in design. Compared with placebo, fenofibrate decreased total cholesterol, non-HDL cholesterol, apolipoprotein B, and triglycerides and increased HDL cholesterol and apolipoprotein A-I (all P < 0.001) while tending to decrease LDL cholesterol (P = 0.069). Fenofibrate significantly improved percent flow-mediated dilator response to hyperemia by 48 +/- 5% (P < 0.001) and lowered plasma levels of high-sensitivity C-reactive protein (hsCRP) relative to baseline measurements from 0.80 to 0.70 mg/l (P = 0.001) and fibrinogen levels by 16 +/- 3% (P < 0.001). Compared with placebo, fenofibrate therapy significantly increased plasma levels of adiponectin by 14 +/- 5% (P = 0.008) and increased insulin sensitivity (assessed by quantitative insulin sensitivity check index [QUICKI]) by 6 +/- 2% (P = 0.048). There were significant correlations between percent changes in adiponectin levels and percent changes in flow-mediated dilation (r = 0.401, P = 0.006), hsCRP (r = -0.443, P = 0.002), or QUICKI (r = 0.292, P = 0.049). Multivariate regression analysis showed that only changes in adiponectin levels persisted as an independent predictor of changes in flow-mediated dilation (r = 0.504, P = 0.013). Overall, we observed similar results in 24 patients with metabolic syndrome. Fenofibrate therapy significantly improved percent flow-mediated dilator response to hyperemia, reduced inflammation marker levels, increased adiponectin levels, and improved insulin sensitivity in hypertriglyceridemic or metabolic syndrome patients.

Serum adiponectin correlates with viral characteristics but not histologic features in patients with chronic hepatitis C

Adiponectin induces insulin sensitivity and modulates inflammatory responses. We thus studied the implications of adiponectin in patients with chronic hepatitis C virus (HCV) infection inherently linked to insulin resistance. We analyzed the association of serum adiponectin levels with clinical, virologic, and histologic findings in 95 naive Taiwanese patients with chronic hepatitis C before and after antiviral therapy. At baseline, 14 (15%) of the 95 patients were obese and 26 (27%) had type 2 diabetes mellitus. Fifty-seven patients were infected with HCV genotype 1 and 38 with genotype 2. Steatosis and periportal fibrosis was present in 44 (46%) and 69 (73%), respectively. In multivariate analysis, male gender, insulin resistance, high HCV load and genotype 2 were significantly associated with a lower serum adiponectin level. In contrast, intrahepatic gene expression of adiponectin receptors was higher in genotype 2 compared with genotype 1. Serum adiponectin level did not correlate with other clinical or histologic parameters. After treatment, change of steatosis also did not correlate with the change of adiponectin level (P=0.61). Adiponectin correlated with hepatitis C viral factors at both serum and liver tissue levels. The interactions among adiponectin, insulin resistance and chronic HCV infection merit further studies.

Serum adiponectin concentrations during a 72-hour fast in over- and normal-weight humans

Adiponectin is currently considered an important link between obesity and insulin resistance, since circulating levels of this insulin sensitizing hormone have consistently been found to be reduced in obese subjects. However, until now it is not known how the secretion of adiponectin is regulated in response to acute metabolic changes. Here, we assessed the influence of complete fasting for 72 h on serum adiponectin levels. Between group comparison of repeated measurements. In total, 18 normal-weight (mean+/-s.e.m. BMI: 22.2+/-0.4 kg/m(2); age: 39.2+/-4.4 y) and nine over-weight (BMI: 33.2+/-1.8 kg/m(2); age: 36.9+/-4.5 y) subjects. Serum adiponectin levels were measured every 4 h during a 72-h fasting period. Additionally, concentrations of plasma glucose and serum insulin and leptin were assessed at the beginning and in the end of the fasting experiment. Insulin resistance was estimated using the homeostasis model assessment (HOMA). While concentrations of glucose, insulin, and leptin decreased across the fasting period by 31.0, 33.1 and 60.0%, respectively (all P<0.005), adiponectin levels remained unchanged (P=0.817). Overall, over-weight subjects exhibited slightly lower adiponectin levels than normal-weight subjects (P=0.092), but there was no difference in the time course of adiponectin levels during fasting between these two groups (P=0.970). Although, averaged adiponectin levels before and after fasting did not systematically differ, individual changes in adiponectin levels across fasting displayed a slight but significant inverse correlation with changes in plasma glucose concentration (r=-0.42, P=0.03). The data show that serum adiponectin concentrations remain remarkably stable during 72 h of fasting in normal- and over-weight subjects. Thus, adiponectin appears to reflect primarily long-term changes in body weight with little evidence for a dependence on short-term regulatory influences.

Determinants of plasma adiponectin levels in patients with anorexia nervosa examined before and after weight gain

To examine the determinants of adiponectin levels (i) in 23 women with anorexia nervosa (mean BMI 15.0 +/- 1.2) and 43 healthy normal weight females (mean BMI 22.3 +/- 2.3; cross-sectional design) as well as (ii) after six and twelve weeks of weight gain in subgroups of 18 and 11 anorectic patients (mean weight gain 5.8 kg; longitudinal design). Plasma adiponectin and leptin concentrations were measured and their relationships to body composition (fat mass by bioelectrical impedance analysis and anthropometrics), different hormones and metabolic parameters (insulin, ACTH, cortisol, glucose, FFA, lipid profile) were investigated. In anorectic patients, adiponectin levels were higher (+29 %) and leptin levels were lower (-75 %) than in control subjects. There was a high variance in adiponectin levels in patients ranging from 2.6 to 18 nM. Combining patients and controls, an inverse linear correlation was observed between adiponectin levels and fat mass (r = -0.36, p < 0.05), while a positive exponential relation was found between leptin levels and fat mass (r = 0.82, p < 0.001). In anorectic patients, there were no significant correlations between adiponectin and hormonal or metabolic parameters. Weight gain resulted in increasing leptin (+0.17 +/- 0.12 nM; p < 0.001) and a nonsignificant decrease in adiponectin concentrations (-1.12 +/- 2.51 nM). Changes in leptin levels were mainly explained by a gain in fat mass (r = 0.85, p < 0.001). In contrast, changes in adiponectin levels were closely linked to initial adiponectin levels (r = -0.84, p < 0.001) but not to changes in fat mass or BMI. Cross-sectionally serum adiponectin concentration followed a linear inverse function with fat mass when patients and controls were combined. Longitudinally gain in fat mass was not associated with changes in adiponectin levels suggesting other yet unidentified influences on adiponectin secretion in anorexia nervosa.

Effects of a Combination of rhGH and Metformin on Adiponectin Levels in Patients with Metabolic Syndrome

Adiponectin is a recently discovered adipocytokine that correlates negatively with body mass index and body fat. In patients with GH deficiency, treatment with recombinant human growth hormone (rhGH) reduces body fat mass and thus may also have a favorable effect in patients with metabolic syndrome, and would also be expected to increase adiponectin levels. However, due to its diabetogenic effect, rhGH treatment also bears an increased risk for the development of type 2 diabetes mellitus. We conducted a 18-month randomized, double-blind, placebo-controlled study to assess the effect of rhGH in combination with metformin (MGH) in 14 obese men (7 MGH; 7 Metformin+Placebo, 54 +/- 2 years, BMI 33.0 +/- 1.2 kg/m(2)) with mildly elevated fasting plasma glucose (FPG) at screening (6.1-8.0 mmol/l). All patients received metformin (850 mg twice daily) for treatment of type 2 diabetes mellitus/impaired glucose tolerance, either alone or in combination with rhGH (daily dose 9.5 mug/kg body weight). Glucose disposal rate (GDR) was measured using the euglycemic hyperinsulinemic clamp technique, and body composition was measured by DEXA at 0 and 18 months. After 18 months, the mean adiponectin concentration increased by 32 +/- 11 % (p = 0.018) in the MGH group and did not change in the MP group (- 10 +/- 13 %; p = n. s.). The difference in relative changes in adiponectin levels between the two groups after 18 months was statistically significant (p = 0.026). Improvement in insulin sensitivity (GDR) correlated positively with adiponectin levels (r = 0.73; p = 0.004). In conclusion, the additional administration of rhGH increased adiponectin levels in patients with metabolic syndrome, indicating its potential role in adiponectin-associated insulin sensitivity alterations.

Multiple Abnormalities in Glucose and Energy Metabolism and Coordinated Changes in Levels of Adiponectin, Cytokines, and Adhesion Molecules in Subjects With Metabolic Syndrome

Detailed metabolic defects in glucose and energy metabolism and abnormalities in a variety of cardiovascular risk factors are largely unknown in subjects with the metabolic syndrome. We characterized the metabolic syndrome in 119 nondiabetic offspring of diabetic probands. Cardiovascular risk factors, including cytokines and adhesion molecules, were measured. Insulin sensitivity was assessed by the euglycemic hyperinsulinemic clamp and indirect calorimetry; intra-abdominal fat and subcutaneous fat were assessed by CT; and maximal oxygen consumption was measured with a bicycle ergometer test. By applying factor analysis, we identified a single factor, the metabolic syndrome factor, from the following variables: 2-hour glucose, fasting insulin, body mass index, waist, HDL cholesterol, triglycerides, and mean blood pressure. Subjects with the highest factor score were defined as having the metabolic syndrome. During hyperinsulinemia, the highest factor score was associated with decreased rates of glucose oxidation and nonoxidative glucose disposal, high rates of lipid oxidation, low energy expenditure, and impaired suppression of free fatty acids during hyperinsulinemia. Furthermore, the metabolic syndrome was associated with a high amount of visceral fat, hypoadiponectinemia, a low maximum oxygen uptake, and high levels of C-reactive protein, proinflammatory cytokines, and adhesion molecules. The metabolic syndrome is characterized by an excess of intra-abdominal fat, hypoadiponectinemia, insulin resistance in skeletal muscle and adipose tissue, multiple defects in glucose and energy metabolism, and elevated levels of cytokines and adhesion molecules.

Adiponectin in Patients with Obstructive Sleep Apnea Syndrome: Course and Physiological Relevance

Background: Adiponectin is an adipocyte-derived hormone with anti-inflammatory and insulin-sensitizing properties. Insulin resistance is a typical feature of the obstructive sleep apnea syndrome (OSAS). Objectives: Since nasal continuous positive airway pressure (nCPAP) treatment improves insulin sensitivity in patients with OSAS, we investigated serum adiponectin levels before and during nCPAP treatment to clarify possible interactions between the adiponectin levels and insulin sensitivity in patients with OSAS. Methods: Thirty nondiabetic, obese patients with OSAS (mean age 56.4 ± 11.1 years; apnoea-hypopnoea index (AHI) 46.03 ± 19.57) underwent CPAP treatment. Adiponectin levels and the levels of proinflammatory cytokines and proteins reflecting platelet activation [regulated on activation normally T cell expressed and secreted (RANTES) and soluble P-selectin (sCD62p)], as well as the insulin sensitivity index were measured before, and after 2 days and 3 months of CPAP treatment. Results: Insulin sensitivity increased significantly under nCPAP treatment, whereas adiponectin levels decreased after 2 days of nCPAP treatment, but returned to baseline levels after 3 months of nCPAP treatment. The increase in insulin sensitivity was more pronounced in patients with the highest adiponectin levels at baseline (p = 0.021) after adjustment for body fat (p = 0.003). During treatment, changes in adiponectin levels were highly predictable by the insulin sensitivity index. Conclusions: We found a significant relation between adiponectin and the insulin sensitivity index in overweight patients with OSAS. The lack of a long-lasting change in adiponectin may be explained by the overwhelming influence of the body mass index on adiponectin secretion, which was unchanged during nCPAP treatment.

Ghrelin and adiponectin in patients with Cushing's disease before and after successful transsphenoidal surgery

Ghrelin, an endogenous ligand of the GH secretagogue receptor that exerts orexigenic activity, is negatively correlated with body mass index (BMI) and insulin resistance. Conversely, low levels of adiponectin (ApN), a circulating adipocytokine with antidiabetic, antiatherogenic and anti-inflammatory properties, have been found in several insulin-resistant conditions. Although Cushing's syndrome causes several metabolic and hormonal changes leading to insulin resistance and central obesity, few data concerning the impact of glucocorticoid excess on ghrelin and ApN levels are so far available. We evaluated ghrelin and ApN levels in 14 women (age +/- SE 39.5 +/- 3.9 years, BMI +/- SE 25.8 +/- 1.4 kg/m2) with Cushing's disease (CD) at baseline and after successful transsphenoidal surgery (TSS) and in 14 age- and BMI-matched healthy women. Despite similar levels of fasting glucose, insulin, homeostatic model assessment-estimated insulin resistance (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI) values, patients with CD had ghrelin levels lower than controls (117.8 +/- 21.5 vs. 269.6 +/- 51.4 pmol/l, P < 0.01), and ghrelin levels did not correlate with ACTH, cortisol, androgen and GH levels. Patients and controls showed similar ApN levels (11.1 +/- 1.6 vs. 11.5 +/- 2.0 mg/l), which correlated negatively with insulin, HOMA-IR and BMI and positively with QUICKI and high density lipoprotein (HDL)-cholesterol only in controls. At 10.2 +/- 0.7 months after successful TSS, patients showed a significant increase in ghrelin levels compared to pretreatment values (342.5 +/- 25.6 vs. 117.8 +/- 21.5 pmol/l, P < 0.005) along with significant modifications in BMI, insulin, HOMA-IR and HDL-cholesterol and no change in ApN levels. In two patients tested on days 2-4 after TSS, no modification in ghrelin and ApN levels was observed, despite a dramatic reduction in cortisol levels. Cortisol excess did not directly affect ghrelin and ApN levels in patients with CD. The observation that ghrelin levels were low during the active phase of CD and increased after recovery suggests that glucocorticoids may influence ghrelin levels indirectly by modulating adiposity and metabolic signals over the long term.