Combining beta-adrenergic and peroxisome proliferator-activated receptor gamma stimulation improves lipoprotein composition in healthy moderately obese subjects

Adenylate cyclase 3: a new target for anti-obesity drug development

Obesity has become epidemic worldwide, and abdominal obesity has a negative impact on health. Current treatment options on obesity, however, still remain limited. It is then of importance to find a new target for anti-obesity drug development based upon recent molecular studies in obesity. Adenylate cyclase 3 (ADCY3) is the third member of adenylyl cyclase family and catalyses the synthesis of cAMP from ATP. Genetic studies with candidate gene and genome-wide association study approaches have demonstrated that ADCY3 genetic polymorphisms are associated with obesity in European and Chinese populations. Epigenetic studies have indicated that increased DNA methylation levels in the ADCY3 gene are involved in the pathogenesis of obesity. Furthermore, biological analyses with animal models have implicated that ADCY3 dysfunction resulted in increased body weight and fat mass, while reduction of body weight is partially explained by ADCY3 activation. In this review, we describe genomic and biological features of ADCY3, summarize genetic and epigenetic association studies of the ADCY3 gene with obesity and discuss dysfunction and activation of ADCY3. Based upon all data, we suggest that ADCY3 is a new target for anti-obesity drug development. Further investigation on the effectiveness of ADCY3 activator and its delivery approach to treat abdominal obesity has been taken into our consideration.

The effect of pioglitazone and extended-release niacin on HDL-cholesterol in diabetes patients in a real-world setting

OBJECTIVE

This retrospective study was designed to assess the effects of the combination of pioglitazone and extended-release niacin on the lipid panel, particularly HDL-cholesterol, when used in patients with type 2 diabetes in an endocrinology specialty practice.

METHODS

The electronic medical records of 434 adult patients with type 2 diabetes receiving extended-release niacin and pioglitazone were screened for review. Patients with type 2 diabetes and hyperlipidemia were included for review if they received the combination of pioglitazone at doses ≥ 15 mg/day and extended-release niacin (Niaspan) at doses ≥ 1000 mg/day for ≥6 months. Statistical analysis used paired t-tests with p < 0.05 as statistically significant. Both ANOVA and the Tukey-Kramer test for multiple comparisons (α = 0.05) were also used.

RESULTS

A total of 47 patients, 83% were men with average age of 58, met all eligibility criteria for the study. Compared with baseline, a statistically significant increase in HDL-C (+ 25.13%, p < 0.0001) was observed at the conclusion of combination therapy. The HDL-C levels progressively increased with duration of combination treatment, and were not correlated with concomitant statin use. Significant decreases in total cholesterol and triglycerides were detected, and HbA1c decreased 0.84% during combination therapy for all therapies combined.

CONCLUSION

The combination of pioglitazone and extended-release niacin in patients with type 2 diabetes and hyperlipidemia, used in commonly prescribed doses for at least 6 months, resulted in statistically significant improvements in HDL-C, total cholesterol, and triglycerides, and did not result in deteriorations in glycemic control.

Pioglitazone improves the cardiovascular profile in patients with uncomplicated systemic lupus erythematosus: a double-blind randomized clinical trial

OBJECTIVE

We studied the effect of pioglitazone on insulin levels, inflammation markers, high-density lipoprotein (HDL) composition and subclasses distribution, in young women with uncomplicated systemic lupus erythematosus (SLE).

METHODS

This double-blind trial included 30 premenopausal women (30 ±8 years old) with SLE, who were randomized to pioglitazone (30 mg/day) or placebo treatment for 3 months. Plasma and HDL lipids were determined by colorimetric enzymatic assays, insulin by radioimmunometric assay, inflammation by immunonephelometry and HDL size and subclasses distribution by a native 4-30% polyacrylamide gradient gel electrophoresis.

RESULTS

Compared with placebo, pioglitazone significantly increased HDL-cholesterol plasma levels (14.2%), reduced fasting insulin plasma levels (23.6%) and the homeostasis model assessment-insulin resistance (31.7%). C-reactive protein (70.9%) and serum amyloid A (34.9%) were also significantly reduced with the pioglitazone use, whereas the HDL particle size was increased (8.80 nm vs. 8.95 nm; p = 0.044) by changes in the distribution of HDL(2b), HDL(3b), and HDL(3c) subclasses. The change in HDL size correlated with a rise in free and cholesterol-ester content in the HDL particles.

CONCLUSION

Pioglitazone significantly enhanced insulin sensitivity, reduced inflammation, and modified HDL characteristics, suggesting a potential beneficial effect of this drug in patients with SLE with a risk to develop cardiovascular disease.

TRIAL REGISTRATION

This trial is registered at ClinicalTrials.gov Protocol Registration System, with the number NCT01322308.

Rosiglitazone reverses salbutamol-induced β(2) -adrenoceptor tolerance in airway smooth muscle

BACKGROUND AND PURPOSE

β₂-Adrenoceptor agonists are important therapeutic agents in the treatment of asthma and chronic obstructive pulmonary disease. The regular use of these drugs has been associated with proasthmatic-like changes that limit their efficacy and increase the risk of severe adverse reactions. We investigated whether the peroxisome-proliferator-activated receptor (PPAR)γ agonist rosiglitazone modulated salbutamol-induced β₂-adrenoceptor desensitization in vivo and in vitro.

EXPERIMENTAL APPROACH

An in vivo model of homologous β₂-adrenoceptor desensitization, established in guinea-pigs by administering salbutamol continuously, was used to study the ability of rosiglitazone to prevent β₂-adrenoceptor tolerance. In vitro experiments on human bronchial smooth muscle cells were performed to increase the clinical relevance of the study.

KEY RESULTS

In tracheal smooth muscle tissues from desensitized animals, we observed a decrease in the protective effect of salbutamol on carbachol-induced contraction, a hyperresponsiveness to cholinergic stimuli, a modest underexpression of β₂-adrenoceptor gene and a marked decrease in β-adrenoceptor number, relative to control values. Treatment with rosiglitazone preserved salbutamol relaxant activity, mitigated carbachol hyperresponsiveness and partially restored β₂-adrenoceptor binding sites in tracheal tissues from homologously desensitized animals. The highly selective PPARγ agonist, GW1929, reproduced the effect of rosiglitazone, in vivo. In vitro β₂-adrenoceptor desensitization decreased salbutamol-mediated cAMP production, without affecting forskolin responses and β₂-adrenoceptor expression. Rosiglitazone and 15-deoxy-Δ¹²(,)¹⁴-prostaglandin J₂ restored salbutamol sensitivity in homologously desensitized cells.

CONCLUSIONS AND IMPLICATIONS

These data suggest a potential pharmacodynamic interaction between PPARγ agonists and salbutamol on airway smooth muscle responsiveness, supporting the therapeutic potential of this combination in chronic airway disease.

Pioglitazone treatment in type 2 diabetes mellitus when combined with portion control diet modifies the metabolic syndrome

BACKGROUND

Treatment with thiazolidinediones (TZDs) produces weight gain.

OBJECTIVE

To test whether a portion control diet could prevent weight gain during treatment with pioglitazone in patients with type 2 diabetes mellitus (T2DM).

DESIGN

This 16-week randomized, open-label, parallel arm study compared three groups: (i) pioglitazone plus the American Diabetes Association diet (Pio + ADA); (ii) pioglitazone plus a portion control weight loss diet (Pio + PC); (iii) metformin plus the American Diabetes Association diet (Met + ADA). All participants received the same advice about calorie reduction, lifestyle change and exercise.

METHODS

Fifty-one men and women with T2DM, naive to TZDs, were randomized to a 16-week study. Pioglitazone (Pio) was titrated to a dose of 45 mg/day and metformin (Met) to a dose of 2 g/day. Fasting blood was collected for lipids, insulin and glycosylated haemoglobin A1c (HbA1c) at baseline and 16 weeks.

RESULTS

Forty-eight of fifty-one randomized subjects completed the study. Patients treated with Pio + ADA gained 2.15 +/- 1.09 kg (mean +/- SD) compared with a weight loss of 2.59 +/- 1.25 kg (p < 0.05) in the Pio + PC group, and a weight loss of 3.21 +/- 0.7 kg (p < 0.05) in the Met + ADA group. Waist circumference and visceral adipose tissue decreased significantly more in the Pio + PC group than in the Pio + ADA group. High-density lipoprotein cholesterol levels were significantly increased in the Pio + PC group compared with the Met + ADA group. Pioglitazone reduced insulin resistance (homeostasis model assessment of insulin resistance (HOMA-IR)) more than metformin. No significant differences between groups were seen for glucose, insulin, HbA1c or low-density lipoprotein cholesterol levels.

CONCLUSIONS

Pio + PC, prevented weight gain, reduced waist circumference and visceral fat compared with Pio + ADA diet.

Effectiveness of mesotherapy on body contouring

BACKGROUND

Despite the increasing interest in mesotherapy as an alternative method for body contouring, there are few reports of its safety, efficacy, and mechanism of action. A clinical examination was performed to evaluate the efficacy of mesotherapy for body contouring.

METHODS

Twenty women were enrolled in this prospective, case-controlled study over a 12-week period. The authors injected a mixed solution (i.e., aminophylline, buflomedil, and lidocaine) into the superficial dermis of the medial aspect of one thigh weekly using a mechanical delivery gun. There was no treatment to the other thigh. The change in the fat level was evaluated by measuring the girth of the thighs and by computed tomographic scanning. The lipid profiles were checked to determine the effect of mesotherapy on lipid metabolism, and questionnaires were used to determine the satisfaction rate of the patients.

RESULTS

The loss of thigh girth on the treated side was not significantly different from that of the untreated side. The computed tomographic scans showed no statistically significant difference in the cross-sectional area or thickness of the fat layer between each group. There were no statistically significant changes in the lipid profiles except for the triglyceride level. A questionnaire asking about the effect of mesotherapy indicated poor patient satisfaction.

CONCLUSION

Mesotherapy is not an effective alternative treatment modality for body contouring.

Effects of the phytoestrogen genistein on some predictors of cardiovascular risk in osteopenic, postmenopausal women: a two-year randomized, double-blind, placebo-controlled study

CONTEXT

Genistein, a soy isoflavone, has received wide attention over the last few years because of its potential preventive role for cardiovascular disease.

OBJECTIVE

Our objective was to assess the effects of genistein administration (54 mg/d) on some predictors of cardiovascular risk in osteopenic, postmenopausal women.

DESIGN AND SETTING

We conducted a randomized, double-blind, placebo-controlled trial at three Italian university medical centers.

INTERVENTION

After a 4-wk stabilization on a standard isocaloric, fat-reduced diet, participants were randomly assigned to receive genistein (n = 198) or placebo (n = 191) daily for 24 months. Both intervention and placebo contained calcium and vitamin D(3).

OUTCOME MEASURES

Blood lipid profiles, fasting glucose and insulin, homeostasis model assessment for insulin resistance, fibrinogen, soluble intercellular adhesion molecule-1, soluble vascular cellular adhesion molecule-1, F2-isoprostanes, and osteoprotegerin at baseline and after 12 and 24 months of treatment were measured.

RESULTS

Compared with placebo, genistein significantly reduced fasting glucose and insulin as well as homeostasis model assessment for insulin resistance after both 12 and 24 months of treatment. By contrast, genistein administration did not affect blood lipid levels although fibrinogen, F2-isoprostanes, soluble intercellular adhesion molecule-1, and soluble vascular cellular adhesion molecule-1 decreased significantly compared with placebo after 24 months. Serum osteoprotegerin was higher in the genistein group compared with placebo. At 24 months, the genistein group showed no change in endometrial thickness compared with placebo. Most treatment-related adverse events were moderate and composed of gastrointestinal side effects [genistein, n = 37 (19%); placebo, n = 15 (8%)].

CONCLUSIONS

These results suggest that 54 mg genistein plus calcium, vitamin D(3), and a healthy diet was associated with favorable effects on both glycemic control and some cardiovascular risk markers in a cohort of osteopenic, postmenopausal women.

The effect of beta-adrenergic and peroxisome proliferator-activated receptor-gamma stimulation on target genes related to lipid metabolism in human subcutaneous adipose tissue

OBJECTIVE

The sympathetic nervous system and thiazolidinediones control lipid metabolism and have been implicated in body weight regulation. This study was conducted to determine whether the simultaneous activation of these two signaling systems might synergize to exert beneficial effects on the expression of key genes involved in lipid metabolism and mitochondrial biogenesis in subcutaneous fat in nondiabetic subjects.

RESEARCH DESIGN AND METHODS

A total of 57 women and men were randomized into four groups: 1) placebo/placebo (PP), 2) ephedrine HCl (25 mg, 3 times daily) plus caffeine (200 mg, 3 times daily)/placebo (ECP), 3) placebo/pioglitazone (45 mg) (PPio), and 4) ephedrine plus caffeine/pioglitazone (ECPio) for 16 weeks. Adipose tissue samples were obtained after 12 weeks of treatment to determine gene expression.

RESULTS

Body fat decreased by 6.0 and 4.6% in the ECP and ECPio groups, respectively, while remaining unchanged in the PPio and PP groups. Triglyceride levels decreased by -7.7, -24, -15.2, and -41 mg/dl after 16 weeks treatment in the PP, PPio, ECP, and ECPio groups, respectively. This indicates that pioglitazone groups with or without EC (ephedrine HCl plus caffeine) decreased triglycerides, and EC groups with or without pioglitazone decreased body weight. The mRNA for sirtuin 1 and CD36 increased only in the ECPio group. Carnitine palmitoyltransferase-1, medium-chain acyl CoA dehydrogenase, and malonyl-CoA decarboxylase increased with PPio and ECPio. Stearoyl-CoA desaturase decreased with ECP.

CONCLUSIONS

Combined activation of peroxisome proliferator-activated receptor-gamma and beta-adrenergic receptors has beneficial effects on body weight, plasma triglycerides, and lipid metabolism in subcutaneous fat by increasing the expression of genes required for fatty acid catabolism.