Pioglitazone treatment increases spontaneous growth hormone (GH) secretion and stimulated GH levels in polycystic ovary syndrome

The Effect of Thiazolidinediones in Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a complex endocrine condition affecting women of reproductive age. It is characterised by insulin resistance and is a risk for type 2 diabetes mellitus (T2DM). The aim of this study was to review the literature on the effect of pioglitazone and rosiglitazone in women with PCOS.

METHODS

We searched PubMed, MEDLINE, Scopus, Embase, Cochrane Library and the Web of Science in April 2020 and updated in March 2023. Studies were deemed eligible if they were randomised controlled trials (RCTs) reporting the effect of pioglitazone and rosiglitazone in PCOS. The study follows the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Two reviewers independently extracted data and assessed the risk of bias using the Cochrane risk of bias tool.

RESULTS

Out of 814 initially retrieved citations, 24 randomised clinical trials (RCTs) involving 976 participants were deemed eligible. Among women with PCOS, treatment with rosiglitazone compared to metformin resulted in a significant increase in the mean body weight (mean difference (MD) 1.95 kg; 95% CI 0.03-3.87, p = 0.05). Metformin treatment was associated with a reduction in mean body mass index (BMI) compared to pioglitazone (MD 0.85 kg/m2; 95% CI 0.13-1.57, p = 0.02). Both pioglitazone compared to placebo (MD 2.56 kg/m2; 95% CI 1.77-3.34, p < 0.00001) and rosiglitazone compared to metformin (MD 0.74 kg/m2; 95% CI 0.07-1.41, p = 0.03) were associated with a significant increase in BMI. Treatment with pioglitazone compared to placebo showed a significant reduction in triglycerides (MD - 0.20 mmol/L; 95% CI - 0.38 to - 0.03, p = 0.02) and fasting insulin levels (MD - 11.47 mmol/L; 95% CI - 20.20, - 2.27, p = 0.01). Rosiglitazone compared to metformin was marginally significantly associated with a reduction in the luteinising hormone (LH) (MD - 0.62; 95% CI - 1.25-0.00, p = 0.05).

CONCLUSION

Both pioglitazone and rosiglitazone were associated with significant increases in body weight and BMI when compared with metformin or placebo. Pioglitazone significantly reduced triglycerides and fasting insulin when compared with placebo while rosiglitazone showed a modest reduction of LH when compared with metformin.

PROSPERO REGISTRATION NO

CRD42020178783.

Curcumin protects against lamotrigine-induced chronic ovarian and uterine toxicity in rats by regulating PPAR-γ and ROS production

Lamotrigine (LTG) is an antiepileptic drug with possible adverse effects on the female reproductive system. Curcumin was declared to improve ovarian performance. Therefore, this study aimed to clarify ovulatory dysfunction (OD) associated with LTG and the role of curcumin in ameliorating this dysfunction. Adult female Wister albino rats were assigned into four groups: negative control (received saline), positive control (received curcumin only), LTG, and LTG with curcumin groups. Drugs were administered for 90 days. The hormonal profile, including testosterone, estrogen, progesterone, luteinizing hormone, and follicle-stimulating hormone, in addition to the lipid profile and glycemic analysis, were tested. Oxidative stress biomarkers analysis in the ovaries and uterus and peroxisome proliferator-activated receptor-γ (PPAR-γ) gene expression were also included. Histopathological examination of ovarian and uterine tissues and immunohistochemical studies were also performed. Curcumin could improve the OD related to chronic LTG intake. That was proved by the normalization of the hormonal profile, glycemic control, lipidemic status, oxidative stress markers, and PPAR-γ gene expression. The histopathological and immunohistochemical examination of ovarian and uterine tissues revealed an improvement after curcumin administration. The results describe an obvious deterioration in ovarian performance with LTG through the effect on lipidemic status, PPAR-γ gene, and creating an oxidative stress condition in the ovaries of chronic users, with a prominent improvement with curcumin addition to the treatment protocol.

Impact of pharmacological interventions on anthropometric indices in women with polycystic ovary syndrome: A systematic review and meta-analysis of randomized controlled trials

CONTEXT

Polycystic ovary syndrome (PCOS) is a heterogeneous condition affecting women of reproductive age and is associated with increased body weight.

OBJECTIVE

To review the literature on the effect of different pharmacological interventions on the anthropometric indices in women with PCOS.

DATA SOURCES

We searched PubMed, MEDLINE, Scopus, Embase, Cochrane library, and the Web of Science in April 2020 with an update in PubMed in March 2021.

STUDY SELECTION

The study followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA)2020.

DATA EXTRACTION

Reviewers extracted data and assessed the risk of bias using the Cochrane risk of bias tool.

RESULTS

80 RCTs were included in the meta-analysis. Metformin vs placebo showed significant reduction in the mean body weight (MD: -3.13 kg; 95% confidence interval [CI]: -5.33 to -0.93, I² = 5%) and the mean body mass index (BMI) (MD: -0.75 kg/m² ; 95% CI: -1.15 to -0.36, I² = 0%). There was a significant reduction in the mean BMI with orlistat versus placebo (MD: -1.33 kg/m²; 95% CI: -2.16 to -0.66, I² = 0.0%), acarbose versus metformin (MD: -1.26 kg/m²; 95% CI: -2.13 to -0.38, I² = 0%), and metformin versus pioglitazone (MD: -0.91 kg/m²; 95% CI: -1.62 to -0.19, I² = 0%). A significant increase in the mean BMI was also observed in pioglitazone versus placebo (MD: + 2.59 kg/m²; 95% CI: 1.78-3.38, I² = 0%) and in rosiglitazone versus metformin (MD: + 0.80 kg/m²; 95% CI: 0.32-1.27, I² = 3%). There was a significant reduction in the mean waist circumference (WC) with metformin versus placebo (MD: -1.21 cm; 95% CI: -3.71 to 1.29, I² = 0%) while a significant increase in the mean WC with pioglitazone versus placebo (MD: + 5.45 cm; 95% CI: 2.18-8.71, I² = 0%).

CONCLUSION

Pharmacological interventions including metformin, sitagliptin, pioglitazone, rosiglitazone orlistat, and acarbose have significant effects on the anthropometric indices in women with PCOS.

Impact of pharmacological interventions on biochemical hyperandrogenemia in women with polycystic ovary syndrome: a systematic review and meta-analysis of randomised controlled trials

CONTEXT

Polycystic ovary syndrome (PCOS) is a complex endocrine disease that affects women of reproductive age and is characterised by biochemical and clinical androgen excess.

AIM

To evaluate the efficacy of pharmacological interventions used to decrease androgen hormones in women with PCOS.

DATA SOURCE

We searched PubMed, MEDLINE, Scopus, Embase, Cochrane library and the Web of Science from inception up to March 2021.

DATA SYNTHESIS

Two reviewers selected eligible studies and extracted data, and the review is reported according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

RESULTS

Of the 814 randomised clinical trials (RCTs) located in the search, 92 met the eligibility criteria. There were significant reductions in total testosterone level with metformin versus (vs) placebo (SMD: - 0.33; 95% CI  - 0.49 to  - 0.17, p < 0.0001, moderate grade evidence) and dexamethasone vs placebo (MD:-0.86 nmol/L; 95% CI  - 1.34 to  - 0.39, p = 0.0004, very low-grade evidence). Significant reductions in the free testosterone with sitagliptin vs placebo (SMD:  - 0.47; 95% CI  - 0.97 to 0.04, p = 0.07, very low-grade evidence), in dehydroepiandrosterone sulphate (DHEAS) with flutamide vs finasteride (MD:  - 0.37 µg/dL; 95% CI  - 0.05 to  - 0.58, p = 0.02, very low-grade evidence), a significant reduction in androstenedione (A4) with rosiglitazone vs placebo (SMD:  - 1.67; 95% CI  - 2.27 to  - 1.06; 59 participants, p < 0.00001, very low-grade evidence), and a significant increase in sex hormone-binding globulin (SHBG) with oral contraceptive pill (OCP) (35 µg Ethinyl Estradiol (EE)/2 mg cyproterone acetate (CPA)) vs placebo (MD: 103.30 nmol/L; 95% CI 55.54-151.05, p < 0.0001, very low-grade evidence) were observed.

CONCLUSION

Metformin, OCP, dexamethasone, flutamide, and rosiglitazone use were associated with a significant reduction in biochemical hyperandrogenemia in women with PCOS, though their individual use may be limited due to their side effects.

PROSPERO REGISTRATION NO

CRD42020178783.

Impact of pharmacological interventions on insulin resistance in women with polycystic ovary syndrome: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Polycystic ovary syndrome (PCOS) is a complex endocrine condition affecting women of reproductive age. It is characterized by insulin resistance and is a major risk factor for type 2 diabetes mellitus (T2DM). The objective was to review the literature on the effect of different pharmacological interventions on insulin resistance in women with PCOS.

DESIGN

We searched PubMed, MEDLINE, Scopus, Embase, Cochrane library and the Web of Science in April 2020 and updated in March 2021. The study follows the 2020 Preferred Reporting Items for Systematic reviews and Meta-ana. Reviwers extracted data and assessed the risk of bias using the Cochrane risk of bias tool.

RESULTS

In 58 randomized controlled trials there were significant reductions in the fasting blood glucose (FBG) with metformin versus placebo (standardized mean difference [SMD]: -0.23; 95% confidence interval [CI]: -0.40, -0.06; I² = 0%, low-grade evidence), and acarbose versus metformin (mean difference [MD]: -10.50 mg/dl; 95% CI: -15.76, -5.24; I² = 0%, low-grade evidence). Significant reductions in fasting insulin (FI) with pioglitazone versus placebo (SMD: -0.55; 95% CI: -1.03, -0.07; I² = 37%; p = .02, very-low-grade evidence). A significant reduction in homoeostatic model assessment of insulin resistance (HOMA-IR) was seen with exenatide versus metformin (MD: -0.34; 95% CI: -0.65, -0.03; I² = 0%, low-grade evidence). No effect on homoeostatic model assessment of beta cells (HOMA-B) was observed.

CONCLUSIONS

Pharmacological interventions, including metformin, acarbose, pioglitazone and exenatide have significant effects on FBG, FI, HOMA-IR but not on HOMA-B.

Insulin Sensitizers Modulate GnRH Receptor Expression in PCOS Rats

BACKGROUND

Insulin sensitizers like metformin and pioglitazone are clinically used since last decades for the treatment of PCOS, but their efficacy and possible role in PCOS patients remains questionable. Also, the mechanism by which these insulin sensitizers show effect is not clear.

AIM OF THE STUDY

To evaluate the effect of metformin and pioglitazone on leutinizing hormone and follicle stimulating hormone receptor mRNA expression, hyperandrogenism and insulin resistance in high fat diet induced and letrozole induced PCOS in rats.

METHODS

Pre-pubertal female rats were divided into four groups: group I received normal pellet diet and group II, III and IV received high fat diet. After 105 d of dietary manipulation, metformin and pioglitazone treatment was given to group III and group IV animals respectively for 21 d. Similarly, adult female rats were divided into four groups: group I received 1% carboxymethyl cellulose (CMC) and group II, III, IV received letrozole for 21 d. After 21 d of letrozole administration, metformin and pioglitazone treatment was given to group III and group IV animals respectively for 21 d. Oral glucose tolerance test, lipid profile, fasting glucose, insulin, estrus cycle, hormonal profile, ovary weight, leutinizing hormone receptor and follicle stimulating hormone receptor mRNA expression was measured. Polycystic ovarian morphology was assessed through histopathological changes of ovary.

RESULTS AND CONCLUSION

Metformin and pioglitazone treatment improve both metabolic and reproductive parameters of PCOS including hyperinsulinemia and hyperandrogenism. LH receptor and FSH receptor mRNA expression were altered by pioglitazone and metformin treatment.

Insulin-sensitising drugs (metformin, rosiglitazone, pioglitazone, D-chiro-inositol) for women with polycystic ovary syndrome, oligo amenorrhoea and subfertility

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterised by infrequent or absent ovulation, and high levels of androgens and insulin (hyperinsulinaemia). Hyperinsulinaemia occurs secondary to insulin resistance and is associated with increased risk of cardiovascular disease and diabetes mellitus. Insulin-sensitising agents such as metformin may be effective in treating PCOS-related anovulation.

OBJECTIVES

To evaluate the effectiveness and safety of insulin-sensitising drugs in improving reproductive and metabolic outcomes for women with PCOS undergoing ovulation induction.

SEARCH METHODS

We searched the following databases from inception to January 2017: Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO and CINAHL. We searched registers of ongoing trials and reference lists from relevant studies.

SELECTION CRITERIA

We included randomised controlled trials of insulin-sensitising drugs compared with placebo, no treatment, or an ovulation-induction agent for women with oligo and anovulatory PCOS.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for eligibility and bias. Primary outcomes were live birth rate and gastrointestinal adverse effects. Secondary outcomes included other pregnancy outcomes, menstrual frequency and metabolic effects. We combined data to calculate pooled odds ratios (ORs) and 95% confidence intervals (CIs). We assessed statistical heterogeneity using the I2 statistic and reported quality of the evidence for primary outcomes using GRADE methodology.

MAIN RESULTS

We assessed the interventions metformin, clomiphene citrate, metformin plus clomiphene citrate, D-chiro-inositol, rosiglitazone and pioglitazone. We compared these with each other, placebo or no treatment. We included 48 studies (4451 women), 42 of which investigated metformin (4024 women). Evidence quality ranged from very low to moderate. Limitations were risk of bias (poor reporting of methodology and incomplete outcome data), imprecision and inconsistency. Metformin versus placebo or no treatmentThe evidence suggests that metformin may improve live birth rates compared with placebo (OR 1.59, 95% CI 1.00 to 2.51, 4 studies, 435 women, I2 = 0%, low-quality evidence). The metformin group experienced more gastrointestinal side effects (OR 4.76, 95% CI 3.06 to 7.41, 7 studies, 670 women, I2 = 61%, moderate-quality evidence) but had higher rates of clinical pregnancy (OR 1.93, 95% CI 1.42 to 2.64, 9 studies, 1027 women, I2 = 43%, moderate-quality evidence), ovulation (OR 2.55, 95% CI 1.81 to 3.59, 14 studies, 701 women, I2 = 58%, moderate-quality evidence) and menstrual frequency (OR 1.72, 95% CI 1.14 to 2.61, 7 studies, 427 women, I2 = 54%, low-quality evidence). There was no clear evidence of a difference in miscarriage rates (OR 1.08, 95% CI 0.50 to 2.35, 4 studies, 748 women, I2 = 0%, low-quality evidence). Metformin plus clomiphene citrate versus clomiphene citrate alone There was no conclusive evidence of a difference between the groups in live birth rates (OR 1.21, 95% CI 0.92 to 1.59, 9 studies, 1079 women, I2 = 20%, low-quality evidence), but gastrointestinal side effects were more common with combined therapy (OR 3.97, 95% CI 2.59 to 6.08, 3 studies, 591 women, I2 = 47%, moderate-quality evidence). However, the combined therapy group had higher rates of clinical pregnancy (OR 1.59, 95% CI 1.27 to 1.99, 16 studies, 1529 women, I2 = 33%, moderate-quality evidence) and ovulation (OR 1.57, 95% CI 1.28 to 1.92, 21 studies, 1624 women, I2 = 64%, moderate-quality evidence). There was a statistically significant difference in miscarriage rate per woman, with higher rates in the combined therapy group (OR 1.59, 95% CI 1.03 to 2.46, 9 studies, 1096 women, I2 = 0%, low-quality evidence) but this is of uncertain clinical significance due to low-quality evidence, and no clear difference between groups when we analysed miscarriage per pregnancy (OR 1.30, 95% CI 0.80 to 2.12, 8 studies; 400 pregnancies, I2 = 0%, low-quality evidence). Metformin versus clomiphene citrateWhen all studies were combined, findings for live birth were inconclusive and inconsistent (OR 0.71, 95% CI 0.49 to 1.01, 5 studies, 741 women, I2 = 86%, very low-quality evidence). In subgroup analysis by obesity status, obese women had a lower birth rate in the metformin group (OR 0.30, 95% CI 0.17 to 0.52, 2 studies, 500 women, I2 = 0%, very low-quality evidence), while data from the non-obese group showed a possible benefit from metformin, with high heterogeneity (OR 1.71, 95% CI 1.00 to 2.94, 3 studies, 241 women, I2 = 78%, very low-quality evidence). Similarly, among obese women taking metformin there were lower rates of clinical pregnancy (OR 0.34, 95% CI 0.21 to 0.55, 2 studies, 500 women, I2 = 0%, very low-quality evidence) and ovulation (OR 0.29, 95% CI 0.20 to 0.43 2 studies, 500 women, I2 = 0%, low-quality evidence) while among non-obese women, the metformin group had more pregnancies (OR 1.56, 95% CI 1.05 to 2.33, 5 studies, 490 women, I2 = 41%, very low-quality evidence) and no clear difference in ovulation rates (OR 0.81, 95% CI 0.51 to 1.28, 4 studies, 312 women, low-quality evidence, I2=0%). There was no clear evidence of a difference in miscarriage rates (overall: OR 0.92, 95% CI 0.50 to 1.67, 5 studies, 741 women, I2 = 52%, very low-quality evidence). D-chiro-inositol (2 studies), rosiglitazone (1 study) or pioglitazone (1 study) versus placebo or no treatmentWe were unable to draw conclusions regarding other insulin-sensitising drugs as no studies reported primary outcomes.

AUTHORS' CONCLUSIONS

Our updated review suggests that metformin alone may be beneficial over placebo for live birth, although the evidence quality was low. When metformin was compared with clomiphene citrate, data for live birth were inconclusive, and our findings were limited by lack of evidence. Results differed by body mass index (BMI), emphasising the importance of stratifying results by BMI. An improvement in clinical pregnancy and ovulation suggests that clomiphene citrate remains preferable to metformin for ovulation induction in obese women with PCOS.An improved clinical pregnancy and ovulation rate with metformin and clomiphene citrate versus clomiphene citrate alone suggests that combined therapy may be useful although we do not know whether this translates into increased live births. Women taking metformin alone or with combined therapy should be advised that there is no evidence of increased miscarriages, but gastrointestinal side effects are more likely.

Fracture Risk Is Decreased in Women With Polycystic Ovary Syndrome: A Register-Based and Population-Based Cohort Study

Hyperandrogenism, obesity, and hyperinsulinemia may protect against osteoporosis, whereas amenorrhea, increased cortisol, and low growth hormone may be associated with higher fracture risk in polycystic ovary syndrome (PCOS). The objective of this study was to investigate fracture risk in PCOS. In the PCOS Denmark study, women with PCOS and/or hirsutism were identified in the Danish National Patient Register (1995-2012). Each patient was assigned three age-matched controls on the index date of PCOS diagnosis. Individuals with a previous endocrine diagnosis were excluded. Within PCOS Denmark, we embedded a well-characterized subcohort of patients, PCOS OUH, diagnosed with PCOS at Odense University Hospital (n = 1217). We identified incident fractures by International Classification of Diseases, 10th Revision (ICD-10) codes and used conditional Cox regression analyses to compare fracture risk. In the PCOS Denmark study, there were 19,199 women with PCOS and 57,483 controls were included, mean age 30.6 years (range, 12-60 years). Fracture rates were decreased in PCOS Denmark (10.3/1000 patient years) versus controls (13.6/1000 patient years). The adjusted ORs were 0.76 (95% CI, 0.71 to 0.80) for all fractures, 0.82 (95% CI, 0.74 to 0.92) for major osteoporotic fractures, and 0.57 (95% CI, 0.47 to 0.70) for fractures of head and face. The risk reduction was more pronounced below the age of 30 years at diagnosis. Women with PCOS had significant more hospital contacts due to strains and sprains. In the PCOS OUH subcohort, the risk reduction of fractures did not differ between PCOS women with elevated versus normal testosterone levels and the risk reduction was nominally smaller in overweight versus normal weight PCOS women. Women with PCOS had reduced risk of fractures, in particular of the appendicular skeleton. The risk reduction was greater in women with younger age at diagnosis suggesting that the skeletal effects of PCOS may be greater in women who have not yet reached peak bone mass. Reduced participation in sports activities was probably not the reason for the reduced risk of fractures.

The robustness of diagnostic tests for GH deficiency in adults

Since the 1970s, GH treatment has been an important tool in paediatric endocrinology for the management of growth retardation. It is now accepted that adults with severe GH deficiency (GHD) demonstrate impaired physical and psychological well-being and may benefit from replacement therapy with recombinant human GH. There is, however, an ongoing debate on how to diagnose GHD, especially in adults. A GH response below the cut-off limit of a GH-stimulation test is required in most cases for establishing GHD in adults. No 'gold standard' GH-stimulation test exists, but some GH stimulation tests may be more robust to variations in patient characteristics such as age and gender, as well as to pre-test conditions like heat exposure due to a hot bath or bicycling. However, body mass index (BMI) is negatively associated with GH-responses to all available GH-stimulation tests and glucocorticoid treatment, including conventional substitution therapy, influences the GH-responses. Recently, the role of IGF-I measurements in the clinical decision making has been discussed. The aim of this review is to discuss the available GH-stimulation tests. In this author's opinion, tests which include growth-hormone-releasing hormone (GHRH) tend to be more potent and robust, especially the GHRH+arginine test which has been proven to be of clinical use. In contrast, the insulin tolerance test (ITT) and the glucagon test appear to have too many drawbacks.

Interventions for the metabolic dysfunction in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is associated with metabolic disturbances including obesity, insulin resistance, diabetes and dyslipidemia. Cardiometabolic risk should be assessed at regular intervals starting from diagnosis. A comprehensive clinical evaluation includes determination of body mass index, waist circumference, blood pressure and measurement of serum lipid and glucose levels in all women with PCOS. A standard 2-h 75g oral glucose tolerance test is required for women with a body mass index over 25kg/m(2) and with other risk factors for glucose intolerance. No long-term data are available for the risk or benefit of any medical intervention for metabolic dysfunction of PCOS. For the initial management of metabolic dysfunction in PCOS, available guidelines recommend lifestyle intervention which improves androgen excess and insulin resistance without significant effect on glucose intolerance or dyslipidemia. Pharmacological interventions include insulin sensitizing agents and statins. Metformin is the most commonly prescribed insulin sensitizer in PCOS. Available randomized controlled trials suggest that metformin improves insulin resistance without any effect on body mass index, fasting glucose or lipid levels. Short term use of statins alone or in combination with metformin decreases total cholesterol, low-density lipoprotein-cholesterol and triglycerides in PCOS patients with dyslipidemia. Low dose oral contraception in PCOS appears not to be associated with clinically significant metabolic dysfunction.

Metabolic and other effects of pioglitazone as an add-on therapy to metformin in the treatment of polycystic ovary syndrome (PCOS)

Insulin resistance is a key pathogenic defect of the clustered metabolic disturbances seen in polycystic ovary syndrome (PCOS). Metformin is an insulin sensitizer acting in the liver and the peripheral tissues that ameliorates the metabolic and reproductive defects in PCOS. In addition, pioglitazone is an insulin sensitizer used in diabetes mellitus type 2 (T2DM), improving insulin resistance (IR) in adipose tissue and muscles. In T2DM, these drugs are also used as a combined treatment due to their "add-on effect" on insulin resistance. Although the beneficial role of troglitazone (a member of the thiazolidinediones (TZDs) family) in PCOS has been shown in the past, currently only pioglitazone is available in the market. A few small randomized controlled trials have directly compared the effectiveness of pioglitazone in women with PCOS, while there are a limited number of small studies that support the beneficial metabolic add-on effect of pioglitazone on metformin-treated PCOS women as compared to metformin or pioglitazone monotherapy. These findings suggest a potentially promising role for combined pioglitazone/metformin treatment in the management of PCOS in metformin-resistant patients. In view of recent concerns regarding pioglitazone usage and its associated health risk, we aim to compare the pros and cons of each drug regarding their metabolic and other hormonal effects in women with PCOS and to explore the possible beneficial effect of combined therapy in certain cases, taking into consideration the teratogenic effect of pioglitazone. Finally, we discuss the need for a randomized controlled trial that will evaluate the metabolic and other hormonal effects of combined metformin/pioglitazone treatment in PCOS with selective treatment targets.

Pioglitazone in acromegaly - an open-label, prospective study

OBJECTIVE

Preclinical studies demonstrate that thiazolidinediones (TZDs) decrease growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels, suggesting that they might be effective treatments for acromegaly. This study investigated the effect of pioglitazone on biochemical indices of disease activity in acromegaly.

DESIGN AND PARTICIPANTS

This was a 4-month open-label prospective study in 16 patients with active acromegaly who were attending public hospital endocrinology clinics.

METHODS

The intervention was pioglitazone 45 mg/day. The primary outcome was change in serum IGF-1; the secondary outcome was change in area under the curve of glucose-suppressed GH.

RESULTS

Serum IGF-1 did not change during treatment with pioglitazone (P = 0·95). After 4 months, the mean (95% CI) change from baseline was -1 μg/l (-51, 49). GH levels following oral glucose loading were unchanged during pioglitazone therapy. After 4 months, the mean (95% CI) change from baseline in area under curve for glucose-suppressed GH was 31 μg/l (-75, 138, P = 0·54).

CONCLUSIONS

Short-term treatment with conventional doses of pioglitazone did not improve biochemical measures of disease activity in acromegaly.

Free carnitine and acylcarnitines in obese patients with polycystic ovary syndrome and effects of pioglitazone treatment

OBJECTIVE

To determine fasting and insulin-stimulated levels of carnitine precursors, total and free carnitine, and acylcarnitines, and evaluate the impact of pioglitazone treatment in obese patients with polycystic ovary syndrome (PCOS).

DESIGN

The present study is a secondary analysis of a previously published case-control study, followed by a double-blind randomized clinical trial.

SETTING

Academic tertiary care medical center.

PATIENT(S)

Thirty obese premenopausal patients with PCOS and 14 healthy women.

INTERVENTION(S)

Sixteen weeks of blinded treatment with pioglitazone (30 mg/d) or placebo.

MAIN OUTCOME MEASURE(S)

Total and free carnitine and acylcarnitines.

RESULT(S)

Contrary to controls, patients with PCOS were characterized with slightly lower levels of fasting total and free carnitine, its precursors, and derivatives. Total and free carnitine correlated inversely to sex hormone-binding globulin (SHBG) in patients with PCOS, whereas no associations were found between acylcarnitines and androgenes. Insulin stimulation-induced changes in the levels of total and free carnitine, carnitine precursors, and acylcarnitines in the PCOS group followed the same trends as in the control group. Pioglitazone treatment significantly increased fasting levels of serum-free carnitine, propionyl carnitine, and total carnitine. The analysis of between group differences revealed significant changes in the isovaleryl carnitine levels and lipid oxidation rates after pioglitazone treatment compared with placebo.

CONCLUSION(S)

Acute insulin stimulation was associated with increased serum levels of free carnitine in both patients and healthy controls. Treatment with pioglitazone is able to redistribute free fatty acids from insulin-sensitive tissues, diminish demand for carnitine, and influence the overall carnitine turnover.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00145340.

Positive associations between serum levels of IGF-I and subcutaneous fat depots in young men. The Odense Androgen Study

INTRODUCTION

Serum levels of IGF-I are of growing interest due to the associations with morbidity and mortality. Despite markedly suppressed GH secretion, total IGF-I levels are often within normal range in obese adults.

AIM

To study associations between IGF-I and estimated muscle mass in the Odense Androgen Study population and secondly to investigate associations between serum IGF-I and regional fat depots.

METHOD

The Odense Androgen Study is a population-based, cross-sectional study of 776 randomly selected men aged 20-29 years. Regional lean and fat mass were measured by dual-energy X-ray absorptiometry, whereas regional muscle and fat areas were assessed by magnetic resonance imaging.

RESULTS

Age-adjusted IGF-I levels correlated significantly with different estimates of muscle mass (r-values between 0.15 and 0.19; p<0.001). Using multiple linear regression, serum IGF-I correlated positively with subcutaneous adipose tissue on the abdomen (SAT) after controlling for visceral adipose tissue (VAT) in the whole group and in the subgroup of men with normal waist circumference (r-values between 0.13 and 0.15; p<0.03). In addition, IGF-I correlated positively with subcutaneous thigh fat area (TFA) after controlling for intramyocellular lipid (imcl) r=0.18; p<0.004) and IGF-I correlated negatively with TFAimcl in the whole group and in the subgroup of men with normal waist circumference.

CONCLUSION

SAT and subcutaneous TFAs were positively associated with IGF-I in regression analyses. Conversely, imcl of the thigh was inversely associated with IGF-I levels. These findings emphasize the differential associations between IGF-I and regional fat deposits. Future studies may provide further insight regarding the interplay between circulating IGF-I levels and regional muscle and fat mass.

Insulin-sensitising drugs (metformin, rosiglitazone, pioglitazone, D-chiro-inositol) for women with polycystic ovary syndrome, oligo amenorrhoea and subfertility

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterised by infrequent or absent ovulation (anovulation), high levels of male hormones (hyperandrogenaemia) and high levels of insulin (hyperinsulinaemia secondary to increased insulin resistance). Hyperinsulinaemia is associated with an increase in cardiovascular risk and the development of diabetes mellitus. Insulin-sensitising agents such as metformin may be effective in treating the features of PCOS, including anovulation.

OBJECTIVES

To assess the effectiveness of insulin-sensitising drugs in improving reproductive outcomes and metabolic parameters for women with PCOS.

SEARCH METHODS

We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register (October 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 3rd Quarter 2011), CINAHL (October 2011), MEDLINE (January 1966 to October 2011), and EMBASE (January 1985 to October 2011).

SELECTION CRITERIA

Randomised controlled trials of insulin sensitising drugs compared with either placebo, no treatment, or an ovulation induction agent for women with PCOS, menstrual disturbance and subfertility.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion and trial quality, and extracted data.  

MAIN RESULTS

Forty-four trials (3992 women) were included for analysis, 38 of them using metformin and involving 3495 women.There was no evidence that metformin improved live birth rates, whether it was used alone (pooled OR 1.80, 95% CI 0.52 to 6.16, 3 trials, 115 women) or in combination with clomiphene (pooled OR 1.16, 95% CI 0.85 to 1.56, 7 trials, 907 women). However, clinical pregnancy rates were improved for metformin versus placebo (pooled OR 2.31, 95% CI 1.52 to 3.51, 8 trials, 707 women) and for metformin and clomiphene versus clomiphene alone (pooled OR 1.51, 95% CI 1.17 to 1.96, 11 trials, 1208 women). In the studies that compared metformin and clomiphene alone, there was evidence of an improved live birth rate (pooled OR 0.3, 95% CI 0.17 to 0.52, 2 trials, 500 women) and clinical pregnancy rate (pooled OR 0.34, 95% 0.21 to 0.55, 2 trials, 500 women) in the group of obese women who took clomiphene.Metformin was also associated with a significantly higher incidence of gastrointestinal disturbances than placebo (pooled OR 4.27, 95% CI 2.4 to 7.59, 5 trials, 318 women) but no serious adverse effects were reported.

AUTHORS' CONCLUSIONS

In agreement with the previous review, metformin was associated with improved clinical pregnancy but there was no evidence that metformin improves live birth rates whether it is used alone or in combination with clomiphene, or when compared with clomiphene. Therefore, the role of metformin in improving reproductive outcomes in women with PCOS appears to be limited.

PPARs and Female Reproduction: Evidence from Genetically Manipulated Mice

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated nuclear receptors controlling many important physiological processes, including lipid and glucose metabolism, energy homeostasis, inflammation, as well as cell proliferation and differentiation. In the past decade, intensive study of PPARs has shed novel insight into prevention and treatment of dyslipidemia, insulin resistance, and type 2 diabetes. Recently, a large body of research revealed that PPARs are also functionally expressed in reproductive organs and various parts of placenta during pregnancy, which strongly suggests that PPARs might play a critical role in reproduction and development, in addition to their central actions in energy homeostasis. In this review, we summarize recent findings elucidating the role of PPARs in female reproduction, with particular focus on evidence from gene knockout and transgenic animal model study.

The Genetic Basis of the Polycystic Ovary Syndrome: A Literature Review Including Discussion of PPAR-gamma

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of the women of reproductive age. Familial clustering of PCOS has been consistently reported suggesting that genetic factors play a role in the development of the syndrome although PCOS cases do not exhibit a clear pattern of Mendelian inheritance. It is now well established that PCOS represents a complex trait similar to type-2 diabetes and obesity, and that both inherited and environmental factors contribute to the PCOS pathogenesis. A large number of functional candidate genes have been tested for association or linkage with PCOS phenotypes with more negative than positive findings. Lack of universally accepted diagnostic criteria, difficulties in the assignment of male phenotype, obscurity in the mode of inheritance, and particularly small sample size of the study populations appear to be major limitations for the genetic studies of PCOS. In the near future, utilizing the genome-wide scan approach and the HapMap project will provide a stronger potential for the genetic analysis of the syndrome.

Thiazolinedione treatment in PCOS--an update

Polycystic ovary syndrome (PCOS) is characterised by anovulation, hyperandrogenism, and polycystic ovaries. Fifty percent of patients fulfil the criteria for the metabolic syndrome. The pathogenesis of PCOS may be looked as a vicious cycle involving hyperandrogenemia, central obesity, and insulin resistance and medical treatment should aim at breaking this cycle. Lifestyle intervention, oral contraceptives, and insulin sensitises such as metformin are the most commonly used treatment modalities. The thiazolidinediones rosiglitazone and pioglitazone were recently applied as insulin sensitising treatment in patients with PCOS. Thiazolidinediones activate the transcription of genes that affect glucose and lipid metabolism mediating decreased free fatty acid levels and decreased visceral fat mass. In the present article, we give an overview of the diverse effects of glitazone treatment in patients with PCOS. We review the studies comparing glitazone versus metformin and oral contraceptive treatment and recommend which patients should be treated with glitazones in daily praxis.

An update on the pathogenesis, inflammation, and metabolism in hirsutism and polycystic ovary syndrome

Hirsutism is a common endocrine disorder, defined as increased growth of terminal hairs in a male pattern. Hirsutism is most often caused by polycystic ovary syndrome (PCOS), whereas only 5% patients are diagnosed with rare endocrine diseases. PCOS may be considered a multiorgan disease causing not only increased adrenal and ovarian sex hormone secretion but also changed secretion of gonadotrophins, growth hormone, and adrenocorticotrophic hormone (ACTH) from the pituitary. The majority of patients with PCOS are insulin resistant and PCOS is characterized by an increased inflammatory state with abdominal obesity and increased secretion of interleukins, chemokines, and adipokines. PCOS is therefore associated with an increased risk of the metabolic syndrome and type 2 diabetes (T2D). Patients with hirsutism present with increased bone mineral density despite decreased D-vitamin levels. The etiology to hirsutism and PCOS is most likely multifactorial including both genetic and environmental factors such as increased fetal stress and intrauterine growth retardation. In the present review, we give a comprehensive overview of the pathophysiology and multiple endocrine disturbances of hirsutism and PCOS.

Insulin-sensitising drugs (metformin, rosiglitazone, pioglitazone, D-chiro-inositol) for women with polycystic ovary syndrome, oligo amenorrhoea and subfertility

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterised by anovulation, hyperandrogaenemia and insulin resistance. Hyperinsulinaemia is associated with an increase in cardiovascular risk and the development of diabetes mellitus. If insulin sensitising agents such as metformin are effective in treating features of PCOS, then they could have wider health benefits than just treating the symptoms of the syndrome.

OBJECTIVES

To assess the effectiveness of insulin sensitising drugs in improving reproductive outcomes and metabolic parameters for women with PCOS and menstrual disturbance.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders & Subfertility Group trials register (searched September 2008), the Cochrane Central Register of Controlled Trials (Cochrane Library, third Quarter 2008), CINAHL (searched September 2008), MEDLINE (January 1966 to September 2008), and EMBASE (January 1985 to September 2008). All searches were rerun 13 August 2009 17 RCTs were located and await classification.

SELECTION CRITERIA

Randomised controlled trials which investigated the effect of insulin sensitising drugs compared with either placebo or no treatment, or compared with an ovulation induction agent.

DATA COLLECTION AND ANALYSIS

Thirty one trials (2537 women) were included for analysis, 27 of them using metformin and involving 2150 women.

MAIN RESULTS

There is no evidence that metformin improves live birth rates whether it is used alone (Pooled OR = 1.00, 95% CI 0.16 to 6.39) or in combination with clomiphene (Pooled OR = 1.48, 95% CI 1.12 to 1.95). However, clinical pregnancy rates are improved for metformin versus placebo (Pooled OR = OR 3.86, 95% C.I. 2.18 to 6.84) and for metformin and clomiphene versus clomiphene alone (Pooled OR =1.48, 95% C.I. 1.12 to 1.95) ). In the studies that compared metformin and clomiphene alone, there was no evidence of an improved live birth rate (OR= 0.67, 95% CI 0.44 to 1.02) but the pooled OR resulted in improved clinical pregnancy rate in in the clomiphene group (OR = 0.63 , 95% 0.43 to 0.92), although there was significant heterogeneity.There is also evidence that ovulation rates are improved with metformin in women with PCOS for metformin versus placebo (Pooled OR 2.12, 95% CI 1.50 to 3.0) and for metformin and clomiphene versus clomiphene alone (Pooled OR = 3.46, 95% CI 1.97 to 6.07).Metformin was also associated with a significantly higher incidence of gastrointestinal disturbance, but no serious adverse effects were reported.

AUTHORS' CONCLUSIONS

In agreement with the previous review, metformin is still of benefit in improving clinical pregnancy and ovulation rates. However, there is no evidence that metformin improves live birth rates whether it is used alone or in combination with clomiphene, or when compared with clomiphene. Therefore, the use of metformin in improving reproductive outcomes in women with PCOS appears to be limited.

Plasma monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1alpha are increased in patients with polycystic ovary syndrome (PCOS) and associated with adiposity, but unaffected by pioglitazone treatment

OBJECTIVE

Hirsutism is most often caused by polycystic ovary syndrome (PCOS). PCOS patients are characterized by insulin resistance, abdominal obesity and low-grade inflammation. Insulin sensitizing treatment reduces the inflammatory state, but the effect on serum levels of migration inhibitor factor (MIF), monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory protein (MIP)-1alpha have not been evaluated before in PCOS.

RESEARCH DESIGN AND METHODS

Plasma chemokine levels (MCP-1, MIP-1alpha and MIF) were measured in two study designs. (i) 51 hirsute patients and 63 matched controls and (ii) 30 PCOS patients before and after randomized treatment with 30 mg pioglitazone/placebo for 16 weeks. Clinical evaluations and whole body DXA-scans were performed in all participants.

RESULTS

Hirsute patients (n = 51) had significantly increased MCP-1 [121 (15-950) vs. 81 (18-365) pg/ml; P < 0.05] and MIP-1alpha[179 (8-4202) vs. 103 (4-1598) pg/ml; P < 0.05] than controls of matched body composition [geometric mean (-2SD to +2SD)]. In PCOS (n = 30), MCP-1, MIP-1alpha and MIF correlated positively with central fat mass. A BMI independent positive association was found between MIF and free testosterone (r = 0.49, P = 0.01) in PCOS. Pioglitazone treatment significantly improved insulin sensitivity without affecting testosterone, body composition, MCP-1, MIP-1alpha and MIF levels.

CONCLUSIONS

Chemokine levels were significantly increased and showed close associations with measures of adiposity in PCOS patients, but were unchanged during insulin sensitizing treatment with pioglitazone. Our data suggests a fat mass independent association between testosterone and MIF levels in PCOS and the effect of anti-androgen treatment on chemokine levels needs to be examined.

Current understanding of the role of PPARγ in gastrointestinal cancers

Numerous studies have indicated that PPARγ plays multiple roles such as in inflammation, cell cycle control, cell proliferation, apoptosis, and carcinogenesis, thus PPARγ contributes to the homeostasis. Many in vitro studies have showed that ligand-induced activation of PPARγ possess antitumor effect in many cancers including CRC. However, the role of PPARγ in gastrointestinal cancers, especially in colorectal cancer, is rather controversial. Nevertheless, some recent studies with the positive results on the possible application of PPARγ ligands, such as Bezafibrate or Rosiglitazone in gastrointestinal cancers, have suggested a potential usefulness of PPARγ agonists in cancer prevention and therapy. In this review, the authors discuss the recent developments in the role of PPARγ in gastrointestinal cancers.

Insulin-sensitising drugs (metformin, rosiglitazone, pioglitazone, D-chiro-inositol) for women with polycystic ovary syndrome, oligo amenorrhoea and subfertility

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterised by anovulation, hyperandrogaenemia and insulin resistance. Hyperinsulinaemia is associated with an increase in cardiovascular risk and the development of diabetes mellitus. If insulin sensitising agents such as metformin are effective in treating features of PCOS, then they could have wider health benefits than just treating the symptoms of the syndrome.

OBJECTIVES

To assess the effectiveness of insulin sensitising drugs in improving reproductive outcomes and metabolic parameters for women with PCOS and menstrual disturbance.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders & Subfertility Group trials register (searched September 2008), the Cochrane Central Register of Controlled Trials (Cochrane Library, third Quarter 2008), CINAHL (searched September 2008), MEDLINE (January 1966 to September 2008), and EMBASE (January 1985 to September 2008). All searches were rerun 13 August 2009 17 RCTs were located and await classification.

SELECTION CRITERIA

Randomised controlled trials which investigated the effect of insulin sensitising drugs compared with either placebo or no treatment, or compared with an ovulation induction agent.

DATA COLLECTION AND ANALYSIS

Thirty one trials (2537 women) were included for analysis, 27 of them using metformin and involving 2150 women.

MAIN RESULTS

There is no evidence that metformin improves live birth rates whether it is used alone (Pooled OR = 1.00, 95% CI 0.16 to 6.39) or in combination with clomiphene (Pooled OR = 1.48, 95% CI 1.12 to 1.95). However, clinical pregnancy rates are improved for metformin versus placebo (Pooled OR = OR 3.86, 95% C.I. 2.18 to 6.84) and for metformin and clomiphene versus clomiphene alone (Pooled OR =1.48, 95% C.I. 1.12 to 1.95) ). In the studies that compared metformin and clomiphene alone, there was no evidence of an improved live birth rate (OR= 0.67, 95% CI 0.44 to 1.02) but the pooled OR resulted in improved clinical pregnancy rate in in the clomiphene group (OR = 0.63 , 95% 0.43 to 0.92), although there was significant heterogeneity.There is also evidence that ovulation rates are improved with metformin in women with PCOS for metformin versus placebo (Pooled OR 2.12, 95% CI 1.50 to 3.0) and for metformin and clomiphene versus clomiphene alone (Pooled OR = 3.46, 95% CI 1.97 to 6.07).Metformin was also associated with a significantly higher incidence of gastrointestinal disturbance, but no serious adverse effects were reported.

AUTHORS' CONCLUSIONS

In agreement with the previous review, metformin is still of benefit in improving clinical pregnancy and ovulation rates. However, there is no evidence that metformin improves live birth rates whether it is used alone or in combination with clomiphene, or when compared with clomiphene. Therefore, the use of metformin in improving reproductive outcomes in women with PCOS appears to be limited.

Peroxisome proliferator-activated receptor gamma (PPAR) agonism reduces the insulin-stimulated increase in circulating interleukin-6 in GH replaced GH-deficient adults

CONTEXT

Peroxisome proliferator-activated receptor gamma (PPARgamma) agonists modify cardiovascular risk factors and inflammatory markers in patients with type 2 diabetes. GH treatment in GH-deficient (GHD) patients may cause insulin resistance and exerts ambiguous effects on inflammatory markers.

OBJECTIVE

To investigate circulating markers of inflammation and endothelial function in GH replaced GHD patients before and after 12 weeks administration of either pioglitazone 30 mg/day (N = 10) or placebo (N = 10) in a randomized double-blind parallel design.

METHODS

Circulating levels of interleukins (ILs)-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, tumour necrosis factor (TNF)-alpha, high sensitivity C-reactive protein, vascular cell adhesion molecule-I, and osteoprotegerin (OPG) were measured in the basal state and after a 2.5 h hyperinsulinaemic euglycaemic clamp.

RESULTS

Insulin sensitivity improved in the group receiving PPARgamma agonist (P = 0.03). Serum IL-6 levels increased by 114 +/- 31% (mean +/- SE) in the entire group (N = 20) following the hyperinsulinaemic euglycaemic clamp (P = 0.01) performed at study start. Twelve weeks of PPARgamma agonist treatment significantly abrogated this insulin-stimulated increment in IL-6 levels compared to placebo (P = 0.01). Furthermore PPARgamma agonist treatment significantly lowered basal IL-4 levels (P < 0.05).

CONCLUSIONS

(i) IL-6 levels increase during a hyperinsulinaemic clamp in GH replaced patients (ii) This increase in IL-6 is abrogated by PPARgamma agonist treatment (iii) we hypothesize that PPARgamma agonist-induced improvement of insulin sensitivity may obviate a compensatory rise in IL-6.

WITHDRAWN: Insulin-sensitising drugs for polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterised by anovulation, hyperandrogaenemia and insulin resistance. Hyperinsulinaemia is associated with an increase in cardiovascular risk and the development of diabetes mellitus. If insulin sensitising agents such as metformin are effective in treating features of PCOS, then they could have wider health benefits than just treating the symptoms of the syndrome.

OBJECTIVES

To assess the effectiveness of insulin sensitising drugs in improving clinical and biochemical features of PCOS.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders & Subfertility Group trials register (searched September 2008 ), the Cochrane Central Register of Controlled Trials (Cochrane Library, September 2008), MEDLINE (January 1966 to September 2008), and EMBASE (January 1985 to September 2008).

SELECTION CRITERIA

Randomised controlled trials which investigated the effect of insulin sensitising drugs compared with either placebo or no treatment, or compared with an ovulation induction agent.

DATA COLLECTION AND ANALYSIS

Thirty nine trials (3576 subjects) were included for analysis, 31 of them using metformin and involving 2625 participants.

MAIN RESULTS

Meta-analysis showed that metformin is effective in achieving ovulation in women with PCOS with odds ratios of 2.21(CI 1.57 to 3.10) for metformin versus placebo and 3.93(CI 2.32 to 6.65) for metformin and clomiphene versus clomiphene alone. An analysis of pregnancy rates suggests a significant treatment effect for metformin and clomiphene (OR 1.58, CI 1.20 to 2.07). Nevertheless, these benefits were not translated into live birth rates.Metformin has a significant effect in reducing fasting insulin levels (WMD -4.20 mIU/L, CI -7.68 to -0.73); however, the reduction was only significant in the non-obese group (BMI < 30 kg/m2). Treatment effect on serum testosterone concentration was observed; but the magnitude of the reduction was greater in the non-obese group compared with the obese group (WMD -1.79 versus. -0.30 nmol/L). Metformin has no effect on serum lipid profiles. Metformin was also associated with a significantly higher incidence of gastrointestinal disturbance, but no serious adverse effects were reported.

AUTHORS' CONCLUSIONS

In agreement with the previous review, metformin is still of benefit in improving ovulation and pregnancy rates. However, metformin does not improve live birth whether it is used alone or in combination with clomiphene. In addition, metformin has limited effect on metabolic parameters, especially in obese women with PCOS. Therefore, the use of metformin in improvement of reproductive outcomes or in reducing the risk of developing metabolic syndrome in women with PCOS appears to be limited.

Pioglitazone and cardiovascular risk. A comprehensive meta-analysis of randomized clinical trials

AIM

The aim of this meta-analysis of randomized clinical trials (RCT) was to assess whether pioglitazone is also associated with increased cardiovascular risk, as recently reported for rosiglitazone.

METHODS

RCT of pioglitazone were retrieved from Medline (any date up to 31 August 2007; English language only). Unpublished RCT were identified through http://www.clinicaltrials.gov or http://www.fda.gov websites, and results on cardiovascular outcomes were retrieved from investigators and/or sponsors, whenever possible. RCT were included in meta-analysis if pioglitazone was compared with other treatments (placebo, active comparators or no treatment) for at least 4 weeks. Ninety-four trials, 10 of which were unpublished, were retrieved; those included in the analysis, which excluded PROspective PioglitAzone Clinical Trial In MacroVascular Events (PROACTIVE), enrolled 11 268 and 9912 patients in the pioglitazone and comparator groups respectively. Data for analysis, extracted independently by two observers, included all-cause and cardiovascular mortality and incidence of non-fatal coronary events and heart failure. Proportions of outcome measures across treatment groups were compared by odds ratios (ORs) and 95% confidence interval.

RESULTS

Pioglitazone was associated with reduced all-cause mortality [OR 0.30 (0.14-0.63); p < 0.05], with no relevant effect on non-fatal coronary events. The observed increase in incidence of non-fatal heart failure was not statistically significant [OR 1.38 (0.90-2.12)].

CONCLUSION

The use of pioglitazone does not appear to be harmful in terms of cardiovascular events and all-cause deaths.

Association of pioglitazone treatment with decreased bone mineral density in obese premenopausal patients with polycystic ovary syndrome: a randomized, placebo-controlled trial

OBJECTIVE

Our objective was to investigate the effect of pioglitazone on bone mineral density (BMD) and bone turnover markers in polycystic ovary syndrome (PCOS).

DESIGN AND SETTING

We conducted a randomized, placebo-controlled study at an outpatient clinic at a university hospital.

PATIENTS

Thirty premenopausal patients with PCOS and 14 age- and weight-matched healthy females participated.

INTERVENTIONS

Pioglitazone (30 mg/d) or placebo was given for 16 wk.

MAIN OUTCOME MEASURES

Measurements of BMD [hip (neck and total) and lumbar spine (L2-L4)], bone metabolic parameters [alkaline phosphatase (ALP), 25-hydroxyvitamin D, C-telopeptide of type I collagen (ICTP), osteocalcin, and PTH], endocrine profiles (testosterone, estradiol, and insulin), and body composition (waist to hip ratio, body mass index, and whole-body dual-energy x-ray absorptiometry scans) were performed.

RESULTS

Patients with PCOS had significantly higher levels of ICTP, fasting insulin, and testosterone than controls, whereas no differences were measured in ALP, PTH, body composition, or BMD. Pioglitazone treatment was followed by reduced BMD [geometric means (-2 to +2 sd)]: lumbar spine 1.140 (0.964-1.348) vs. 1.127 (0.948-1.341) g/cm(2) (average decline 1.1%) and femoral neck 0.966 (0.767-1.217) vs. 0.952 (0.760-1.192) g/cm(2) (average decline 1.4%), both P < 0.05. Both ALP and PTH decreased significantly during pioglitazone treatment, whereas no significant changes were measured in 25-hydroxyvitamin D, ICTP, osteocalcin, sex hormones, and body composition.

CONCLUSION

Pioglitazone treatment was followed by decreased lumbar and hip BMD and decreased measures of bone turnover in a premenopausal study population relatively protected from bone mineral loss.

Total and high molecular weight (HMW) adiponectin levels and measures of glucose and lipid metabolism following pioglitazone treatment in a randomized placebo-controlled study in polycystic ovary syndrome

OBJECTIVE

Recent studies suggested that the effect of adiponectin on insulin-stimulated glucose metabolism is mediated primarily by the high molecular weight (HMW) form of adiponectin. In the present study we evaluated total and HMW adiponectin in polycystic ovary syndrome (PCOS) patients and controls and examined possible mechanisms for increased insulin sensitivity during pioglitazone treatment.

STUDY SUBJECTS

Thirty PCOS patients randomized to pioglitazone, 30 mg/day, or placebo for 16 weeks and 14 weight-matched healthy females were studied.

DESIGN

Total and HMW adiponectin levels were measured, and euglycaemic hyperinsulinaemic clamps and indirect calorimetry were performed. Delta-values denoted changes during pioglitazone treatment (16 weeks--basal).

RESULTS

Pretreatment adiponectin levels were decreased in PCOS patients vs. controls (P < 0.05), whereas no significant differences were found in HMW adiponectin levels. Following pioglitazone treatment, total and HMW adiponectin increased (all P < 0.05), whereas no significant changes were observed with placebo. Delta-total adiponectin levels correlated positively with the rate of Delta-insulin-stimulated glucose disposal (R(d)) (r = 0.89) and Delta-oxidative glucose metabolism (r = 0.71) and inversely with Delta-fasting free fatty acid (FFA) levels (r = -0.69) and Delta-lipid oxidation (r = -0.73) during insulin stimulation (all P < 0.01). Weaker correlations were found between Delta-HMW adiponectin levels and Delta-measures of glucose and lipid metabolism during insulin stimulation than with Delta-total adiponectin.

CONCLUSION

A close correlation between increased total adiponectin levels and increased insulin-stimulated glucose metabolism during pioglitzone treatment supports the hypothesis that the insulin-sensitizing effect of pioglitazone in PCOS is, at least in part, mediated by adiponectin. Measures of changes in HMW adiponectin did not add further information to this relationship.

Soluble CD36 and risk markers of insulin resistance and atherosclerosis are elevated in polycystic ovary syndrome and significantly reduced during pioglitazone treatment

OBJECTIVE

We investigated the relation between soluble CD36 (sCD36), risk markers of atherosclerosis and body composition, and glucose and lipid metabolism in polycystic ovary syndrome (PCOS).

RESEARCH DESIGN AND METHODS

Thirty PCOS patients were randomized to 30 mg/day pioglitazone or placebo for 16 weeks. Fourteen weight-matched healthy female subjects were included as control subjects. sCD36, oxidized LDL (oxLDL), high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, euglycemic-hyperinsulinemic clamps, and whole-body dual-energy X-ray absorptiometry scans were performed.

RESULTS

sCD36 (2.87 relative units [0.88-9.36] vs. 1.67 relative units [0.72-3.89]), oxLDL (44.9 units/l [26.9-75.1] vs. 36.1 units/l [23.4-55.5]), and hsCRP (0.26 mg/dl [0.03-2.41] vs. 0.12 mg/dl [0.02-0.81]) were significantly increased in PCOS patients versus control subjects (geometric mean +/- 2 SD). In PCOS, positive correlations were found between central fat mass and sCD36 (r = 0.43), hsCRP (r = 0.43), and IL-6 (r = 0.42) (all P < 0.05). After adjusting for fat mass, sCD36 and oxLDL correlated inversely with measures of insulin-stimulated glucose metabolism and positively with lipid oxidation during insulin stimulation in PCOS patients and control subjects (n = 44). sCD36 and oxLDL were significant independent predictors of glucose and lipid metabolism, whereas hsCRP and IL-6 showed no significant contribution. Following pioglitazone treatment, insulin sensitivity increased, whereas sCD36 (3.21 relative units [0.76-13.6] vs. 2.33 relative units [0.84-6.46]) and hsCRP decreased (P < 0.05). No significant changes were measured in body composition.

CONCLUSIONS

sCD36 and oxLDL correlated with measures of insulin sensitivity independent of central fat mass. Pioglitazone treatment reduced sCD36 while improving insulin-stimulated glucose metabolism, further supporting the association between sCD36 and insulin resistance in PCOS.

Peroxisome proliferator-activated receptor-gamma agonists and diabetes: current evidence and future perspectives

Since their initial availability in 1997, the thiazolidinediones (TZDs) have become one of the most commonly prescribed classes of medications for type 2 diabetes. In addition to glucose control, the TZDs have a number of pleiotropic effects on myriad traditional and non-traditional risk factors for diabetes. TZDs may benefit cardiovascular parameters, such as lipids, blood pressure, inflammatory biomarkers, endothelial function and fibrinolytic state. In this review, we summarise the experimental, preclinical and clinical data regarding the effects of the TZDs in conditions for which they are indicated and discuss their potential in the treatment of other conditions.

Peroxisome proliferator-activated receptors: new players in the field of reproduction

Peroxisome proliferator-activated receptors (PPAR) are members of the nuclear hormone receptor superfamily. Synthetic ligands to one family member, PPARgamma, are currently widely used as treatment for chronic diseases such as diabetes type II and other insulin resistances, e.g. as seen in polycystic ovary syndrome (PCOS). Moreover, novel approaches employing knock-out mice demonstrated that PPARgamma seems to play a key role in placental and fetal development. This review describes recent insights into the role of PPARs in human reproduction with specific reference to infertility, placental maturation and fetal development as well as disturbed pregnancy. Further, we highlight the current knowledge on synthetic ligands to PPARgamma used as a treatment in women with PCOS.

Combined low-dose pioglitazone, flutamide, and metformin for women with androgen excess

CONTEXT AND OBJECTIVE

One of the treatments for hyperinsulinemic hyperandrogenism in nonobese women is combined androgen receptor blockade (with flutamide; Flu), insulin sensitization (with metformin; Met) plus an estroprogestagen contraceptive. We tested whether adding low-dose pioglitazone (Pio; 7.5 mg/d) confers more benefit.

SETTING

The study was conducted at a university hospital.

STUDY POPULATION AND DESIGN

This double-blind study enrolled 38 young women with hyperinsulinemic hyperandrogenism [mean body mass index (BMI) 24 kg/m(2)], all of whom started on Flu (62.5 mg/d) and Met (850 mg/d) plus a transdermal estroprogestagen, each for 21 of 28 d over 6 months. Patients were randomly assigned to receive, in addition, placebo (n=19) or Pio (n=19; 7.5 mg/d) for the same 21 of 28 d over 6 months.

MAIN OUTCOMES

BMI, waist to hip ratio, hirsutism score, fasting endocrine-metabolic markers, body composition, abdominal fat (visceral vs. sc), and carotid intima-media thickness were measured at study start and after 6 months.

RESULTS

PioFluMet reduced intima-media thickness more than FluMet and lowered glucose, IGF-I, and C-reactive protein more as well as the ratio of low-density lipoprotein to high-density lipoprotein cholesterol and the ratio of neutrophils to lymphocytes. PioFluMet treatment was followed by a leaner body composition and a loss of visceral fat (both P < 0.001). In the total group, the changes included not only decreases in waist to hip ratio, hirsutism score, and testosterone (all P < 0.001) but also minor drops in alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, and lactate dehydrogenase (all P < 0.005), indicating absence of hepatotoxicity; BMI remained unchanged. Clinical side effects were not detected.

CONCLUSION

In this proof-of-concept study, addition of Pio to FluMet plus an estroprogestagen led to improvements in the endocrine-metabolic condition, in low-grade inflammation, in total and visceral adiposity, and in markers of cardiovascular health.

Modulation of the growth hormone-insulin-like growth factor (GH-IGF) axis by pharmaceutical, nutraceutical and environmental xenobiotics: an emerging role for xenobiotic-metabolizing enzymes and the transcription factors regulating their expression. A review

The growth hormone-insulin-like growth factor (GH-IGF) axis has gained considerable focus over recent years. One cause of this increased interest is due to a correlation of age-related decline in plasma GH/IGF levels with age-related degenerative processes, and it has led to the prescribing of GH replacement therapy by some practitioners. On the other hand, however, research has also focused on the pro-carcinogenic effects of high GH-IGF levels, providing strong impetus for finding regimes that reduce its activity. Whereas the effects of GH/IGF activity on the action of xenobiotic-metabolizing enzyme systems is reasonably well appreciated, the effects of xenobiotic exposure on the GH-IGF axis has not received substantial review. Relevant xenobiotics are derived from pharmaceutical, nutraceutical and environmental exposure, and many of the mechanisms involved are highly complex in nature, not easily predictable from existing in vitro tests and do not always predict well from in vivo animal models. After a review of the human and animal in vivo and in vitro literature, a framework for considering the different levels of direct and indirect modulation by xenobiotics is developed herein, and areas that still require further investigation are highlighted, i.e. the actions of common endocrine disruptors such as pesticides and phytoestrogens, as well as the role of xenobiotic-metabolizing enzymes and the transcription factors regulating their expression. It is anticipated that a fuller appreciation of the existing human paradigms for GH-IGF axis modulation gained through this review may help explain some of the variation in levels of plasma IGF-1 and its binding proteins in the population, aid in the prescription of particular dietary regimens to certain individuals such as those with particular medical conditions, guide the direction of long-term drug/nutraceutical safety trials, and stimulate ideas for future research. It also serves to warn athletes that using compounds touted as performance enhancing because they promote short-term GH release could in fact be detrimental to performance in the long-run.

Effect of pioglitazone on glucose metabolism and luteinizing hormone secretion in women with polycystic ovary syndrome

OBJECTIVE

To thoroughly examine the mechanisms for insulin resistance in polycystic ovary syndrome (PCOS) and to evaluate the effects of pioglitazone treatment on insulin resistance, beta-cell function, LH secretion, and glucose metabolism.

DESIGN

Randomized, blinded, placebo-controlled study.

SETTING

Outpatient clinic, at a university hospital in Denmark.

PATIENT(S)

Thirty obese women with PCOS and 14 weight-matched healthy females.

INTERVENTION(S)

Sixteen weeks of blinded treatment with pioglitazone (30 mg/d) or placebo.

MAIN OUTCOME MEASURE(S)

Fasting blood samples, 24-hour 20-minute integrated blood sampling (LH, insulin, and C-peptide), euglycemic hyperinsulinemic clamps including 3-(3)H glucose, and indirect calorimetry were performed before and after the intervention period.

RESULT(S)

Patients with PCOS had significantly lower insulin sensitivity compared with controls, including significantly decreased insulin-stimulated oxidative and nonoxidative glucose metabolism. Pioglitazone treatment resulted in significantly lower levels of fasting insulin and significantly higher insulin sensitivity, increased insulin-stimulated glucose oxidation, and increased insulin-stimulated inhibition of lipid oxidation. During 24-hour blood sampling, significantly lower area under-the-curve insulin and lower median insulin levels were observed. Secretion profiles of LH and E(2) and T levels did not change significantly.

CONCLUSION(S)

Insulin resistance in PCOS was characterized by hyperinsulinemia, impaired insulin-stimulated oxidative and nonoxidative glucose metabolism, which was partly reversed by pioglitazone treatment.