Cardiac function and tolerance to ischemia/reperfusion injury in a rat model of polycystic ovary syndrome during the postmenopausal period

Cardiac energy depletion in a rat model of polycystic ovarian syndrome is reversed by acetate and associated with inhibitory effect of HDAC2/mTOR

In addition to the clinical manifestation of polycystic ovarian syndrome (PCOS), life-threatening diseases, especially hypertension and cardiovascular disease (CVD) are emerging critical complications of PCOS. Changes in cardiac energy remains an independent risk factor of CVD. Histone deacetylase (HDAC) inhibitors, including acetate has received attention for its beneficial role in energy regulation. Herein we hypothesized that acetate improves cardiac energy homeostasis in experimentally induced PCOS. Female Wistar rats (8-week-old) were divided into groups. To induce PCOS, 1 mg/kg of letrozole was given for 21 days. After confirmation of PCOS, acetate (200 mg/kg) was administered for 6 weeks. Rats with PCOS showed multiple ovarian cysts with androgen excess and decreased SHBG. The rats also manifested impaired glucose tolerance/hyperinsulinemia and hypertriglyceridemia. Increased systemic oxidative stress (malondialdehyde)/inflammatory (NF-kB/SDF-1) markers and nitric oxide deficiency (NO/eNOS) were observed. Though, the body weight was increased without affecting the cardiac mass index of PCOS rats. Nevertheless, there was an increase in cardiac triglyceride and oxidative stress/inflammatory markers with consequent cardiac injury, revealed by decreased levels of SIRT-1/HIF-1α and increased levels of CTGF/TGFβ-1 and plasma troponin T. These led to cardiac ATP depletion with increased AMP and AMP/ATP ratio. These alterations were accompanied by elevated levels of mTOR and HDAC2, which were reversed when treated with acetate. The present results interestingly suggest that HDAC2 inhibition by acetate reversed cardiac energy depletion and attendant cardiomorbidities in experimental PCOS model. A beneficial effect that is accompanied by suppressed expression of mTOR.

Impact of Polycystic Ovary Syndrome on Silent Coronary Artery Disease and Cardiovascular Events; A Long-term Population-based Cohort Study

BACKGROUND

The existing data regarding the impact of Polycystic Ovary Syndrome (PCOS) on the risk of developing cardiovascular disease (CVD) are conflicting.

AIM

To explore the effect of PCOS status on the occurrence of silent coronary artery disease (CAD)/CVD.

METHODS

A total of 1591 women without CVD at baseline, aged 18-45 years, including 356 PCOS patients (defined by the Rotterdam criteria) and 1235 eumenorrheic non-hirsute women without polycystic ovarian morphology (controls), were selected from the Tehran Lipid and Glucose Study (TLGS). The median follow-up was 15.4 years, and most participants were in their late reproductive years at the end of the study. Silent CAD and CVD outcomes in PCOS and control groups were compared according to the multivariable-adjusted hazard ratios (HRs) and cumulative hazard functions.

RESULTS

There was no difference in CVD risk factors between the PCOS and control groups. After controlling for confounders, PCOS status did not increase the risk of silent CAD (HR: 0.96, 95% CI 0.86-1.08). Regardless of PCOS status, women with a history of silent CAD showed 2.25 times higher CVD events than those without this history (95% CI 1.63-3.10). PCOS status reduced the CVD incidence by 42%, independently of silent CAD or traditional risk factors (HR: 0.58, 95% CI 0.35-0.98).

CONCLUSIONS

Whereas silent CAD, regardless of PCOS, accelerated CVD, PCOS preserved it, most likely due to a combination of protective factors, including the endocrine pattern in the late reproductive period, environmental/social elements, and recruiting additional counseling and lifestyle modifications.