Assessment of cardiovascular autonomic function in patients with polycystic ovary syndrome

Exploring heart rate variability in polycystic ovary syndrome: implications for cardiovascular health: a systematic review and meta-analysis

OBJECTIVES

Polycystic ovary syndrome (PCOS) is a prevalent and complex endocrine disorder that affects women of reproductive age. It has significant implications for female endocrine function, reproductive health, and metabolic disturbances, including insulin resistance, impaired glucose tolerance, and dyslipidemia. Studies have shown that decreased heart rate variability (HRV), a marker of autonomic dysfunction, is associated with adverse cardiovascular events. Recent research has focused on investigating autonomic function in PCOS, and some studies have suggested altered autonomic drive in these patients. The aim of this systematic review and meta-analysis was to evaluate cardiac autonomic function by analyzing HRV in women with PCOS.

METHODS

This systematic review was prepared using PRISMA reporting guidelines. The databases searched were PubMed, Scopus, Web of Science, and Cochrane. Risk of Bias was assessed using ROBINS-I for non-RCTs. The GRADE approach was employed to evaluate the level of certainty in the evidence for each outcome. In order to identify the underlying cause of high heterogeneity, a subgroup analysis was conducted. Sensitivity analysis was checked. A random effect model was used and calculated a pooled standardized mean difference (SMD) with a 95% confidence interval (CI).

RESULTS

Seventeen articles were included in the final analysis, varied in quality, ranging from a "low" to a "high risk of bias". Combined analyses indicated a notable decrease in HRV among individuals with PCOS compared to the control group. Significant changes were observed in SDNN (SMD: -0.763, 95%CI [-1.289 to -0.237], p=0.004), PNN50 (SMD: -1.245, 95%CI [-2.07, -0.419], p=0.003), LF/HF ratio (SMD: 0.670, 95%CI [0.248, 1.091], p=0.002), HFnu (SMD: -0.873, 95%CI [-1.257, -0.489], p=0.000), LFnu (SMD: 0.840, 95%CI [0.428, 1.251], p=0.000) and TP (SMD: -1.997, 95%CI [-3.306, -0.687], p=0.003). The heterogeneity was partially explained by types of study design. Subgroup analysis revealed significant alterations of HRV in normal-weighted and overweight PCOS cases. Conversely, no significant changes in HRV were observed in obese PCOS cases.

CONCLUSION

The findings of this meta-analysis provide evidence suggesting diminished HRV in individuals with PCOS compared to non-PCOS control group.

The role of the autonomic nervous system in polycystic ovary syndrome

This article reviewed the relationship between the autonomic nervous system and the development of polycystic ovary syndrome (PCOS). PCOS is the most common reproductive endocrine disorder among women of reproductive age. Its primary characteristics include persistent anovulation, hyperandrogenism, and polycystic ovarian morphology, often accompanied by disturbances in glucose and lipid metabolism. The body's functions are regulated by the autonomic nervous system, which consists mainly of the sympathetic and parasympathetic nervous systems. The autonomic nervous system helps maintain homeostasis in the body. Research indicates that ovarian function in mammals is under autonomic neural control. The ovaries receive central nervous system information through the ovarian plexus nerves and the superior ovarian nerves. Neurotransmitters mediate neural function, with acetylcholine and norepinephrine being the predominant autonomic neurotransmitters. They influence the secretion of ovarian steroids and follicular development. In animal experiments, estrogen, androgens, and stress-induced rat models have been used to explore the relationship between PCOS and the autonomic nervous system. Results have shown that the activation of the autonomic nervous system contributes to the development of PCOS in rat. In clinical practice, assessments of autonomic nervous system function in PCOS patients have been gradually employed. These assessments include heart rate variability testing, measurement of muscle sympathetic nerve activity, skin sympathetic response testing, and post-exercise heart rate recovery evaluation. PCOS patients exhibit autonomic nervous system dysfunction, characterized by increased sympathetic nervous system activity and decreased vagal nerve activity. Abnormal metabolic indicators in PCOS women can also impact autonomic nervous system activity. Clinical studies have shown that various effective methods for managing PCOS regulate patients' autonomic nervous system activity during the treatment process. This suggests that improving autonomic nervous system activity may be an effective approach in treating PCOS.

Assessment of Cardiac Autonomic Function in Women With Polycystic Ovary Syndrome Through Ewing's Battery, Heart Rate Variability Analysis, and Composite Autonomic Symptom Score-31 Scale

Introduction Polycystic ovary syndrome (PCOS) is a frequently occurring endocrine condition prevalent in women of reproductive age characterized by chronic anovulation, hyperandrogenism, insulin resistance, and a low-grade inflammatory state. Patients with PCOS are more vulnerable to developing cardiac and metabolic co-morbidities. Sympathetic overactivity is also reported in PCOS patients. Objective This study aimed to assess cardiac autonomic function in PCOS by Heart Rate Variability Analysis, Ewing's Test, and Composite Autonomic Symptom Scale-31 (COMPASS-31). Methods Thirty female PCOS patients and 30 age-matched control females were enrolled in the study. Both cases and controls were subdivided into sub-groups based on body mass index (BMI) and waist-to-hip ratio (WHR). The cardiac autonomic functions were assessed by the COMPASS-31 questionnaire, Ewing's battery tests, and short-term heart rate variability analysis. Results There was no significant difference in age, BMI, and WHR of both groups. Additionally, cases had a significantly higher low frequency to high frequency (LF/HF) ratio and COMPASS-31 score and also reported more derangement in Ewing's battery test, indicating cardiac autonomic dysfunction in PCOS patients. Conclusion Patients with PCOS are more prone to developing cardiac and metabolic co-morbidities. Early assessment of cardiac autonomic function can prevent future complications with timely interventions. Altered autonomic function in PCOS patients can be due to hyperandrogenism and insulin resistance.

Transcutaneous auricular vagus nerve stimulation as a potential novel treatment for polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of childbearing age. The etiology of PCOS is multifactorial, and current treatments for PCOS are far from satisfactory. Recently, an imbalanced autonomic nervous system (ANS) with sympathetic hyperactivity and reduced parasympathetic nerve activity (vagal tone) has aroused increasing attention in the pathogenesis of PCOS. In this paper, we review an innovative therapy for the treatment of PCOS and related co-morbidities by targeting parasympathetic modulation based on non-invasive transcutaneous auricular vagal nerve stimulation (ta-VNS). In this work, we present the role of the ANS in the development of PCOS and describe a large number of experimental and clinical reports that support the favorable effects of VNS/ta-VNS in treating a variety of symptoms, including obesity, insulin resistance, type 2 diabetes mellitus, inflammation, microbiome dysregulation, cardiovascular disease, and depression, all of which are also commonly present in PCOS patients. We propose a model focusing on ta-VNS that may treat PCOS by (1) regulating energy metabolism via bidirectional vagal signaling; (2) reversing insulin resistance via its antidiabetic effect; (3) activating anti-inflammatory pathways; (4) restoring homeostasis of the microbiota-gut-brain axis; (5) restoring the sympatho-vagal balance to improve CVD outcomes; (6) and modulating mental disorders. ta-VNS is a safe clinical procedure and it might be a promising new treatment approach for PCOS, or at least a supplementary treatment for current therapeutics.

Hypertension Predisposition and Thermoregulation Delays in Adolescents with Polycystic Ovary Syndrome: A Pilot Study

Background: Polycystic ovary syndrome (PCOS) is a heterogeneous disorder in which clinical, sonographic, and endophenotypic features have been underinvestigated or inconclusive, especially in the early stages of the disease (adolescence/young adulthood). Objective: This prospective pilot study focused on the differences of multiple physiological functions between Greek adolescent/young adult females suffering from PCOS and age- and body mass index (BMI)- matched healthy controls. Study design: Nineteen PCOS patients and eighteen healthy controls (aged 13 to 23 years) were studied for: (i) biochemical and hormonal dysfunction by measuring circulating glucose, insulin, and androgen levels; (ii) arterial stiffness with pulse wave analysis (PWA) by Sphygmocord; (iii) intima-media thickness (IMT) by ultrasound; (iv) heart rate variability (HRV) by Task Force Monitor; and (v) QT, QRS, QT, P, QRSD by electrocardiogram (ECG). Statistical analysis included Hedge’s g correction for small samples bias, and the results are shown using the Hedge’s g effect size and 95% CI, in line with precision medicine prerequisites. Results: Significant differences in pulse wave velocity (PWV) (g = 0.964 [0.296, 1.632]), subendocardial viability ratio (SEVR) carotid (g = −0.679 [−1.329, −0.030]), pulse pressure (PP) carotid (g = 0.942 [0.275, 1.608]), systolic pressure (SP) carotid (g = 0.785 [0.129, 1.440]), free-testosterone (g = 0.677 [0.042, 0.312]), and Delta4-androstenedione (g = 0.735 [0.097, 0.373]) were observed between PCOS patients and controls. No differences were detected in the remaining endocrine and PWA or ECG biomarkers. Conclusions: Our multidisciplinary approach showed early onset of vascular dysfunction, predisposition to hypertension, thermoregulation delays, and metabolic syndrome changes in adolescent/young adult PCOS.

Epidemiology, pathogenesis, genetics & management of polycystic ovary syndrome in India

Polycystic ovary syndrome (PCOS) is a common endocrine disorder predominantly affecting women of reproductive age. Clinical manifestations are diverse including hyperandrogenism, anovulation, infertility and increased risk of metabolic diseases besides psychosocial dysfunction. This review provides information on the problem of PCOS in India, its pathophysiology, genetics and an overview of current management options to instigate further research in this field. Prevalence of PCOS in India ranges from 3.7 to 22.5 per cent depending on the population studied and the criteria used for diagnosis. Abnormalities in leptin-adiponectin (adipocyte biology), oxidative stress and autoimmunity are among the mechanisms studied regarding pathogenesis of PCOS. Many candidate gene studies have shown associations with PCOS in various studies. Studies have consistently demonstrated the relationship between the well-known manifestation of hyperandrogenism among Indian PCOS women and the metabolic morbidities including insulin resistance, glucose intolerance and cardiovascular risk. Management of individual components of PCOS can be achieved by medications or surgical methods, though further clarification regarding pathogenesis of PCOS is needed to sharpen our therapeutic armamentarium.

Weekly Osteopathic Manipulative Treatment to Improve Measures of Sympathetic Tone in Women With Polycystic Ovary Syndrome: A Randomized, Controlled Pilot Study

Background

Polycystic ovary syndrome (PCOS), a common hormone disorder affecting reproductive and metabolic health of reproductive-age women, was shown in a previous study from these authors to be associated with increased sympathetic tone. Increased sympathetic tone contributes to long-term health risks for cardiovascular disease and promotes PCOS pathogenesis.

Objective

To determine whether weekly osteopathic manipulative treatment (OMT) improves physiologic measures of sympathetic tone in women with PCOS.

Methods

In the second phase of a larger study from this author group, 25 women with PCOS, aged 22 to 43 years, living in Erie, Pennsylvania, were recruited to participate in a randomized, controlled evaluation of OMT intervention. Participants were randomly assigned to either an OMT intervention or control group. The OMT group received weekly manipulation of Chapman points and rib-raising for viscerosomatic reflexes associated with the ovaries, adrenal glands, and heart for 12 consecutive weeks. Physiologic measures of sympathetic tone were collected, along with metabolic, endocrine, and reproductive measurements, both before the 3-month intervention and within 1 week of completing the intervention. Measurements included heart rate and blood pressure at rest and after 15 minutes of aerobic exercise, heart rate recovery after exercise, resting heart rate variability, serum androgen levels, body mass index, fasting blood glucose and insulin levels, and menstrual cycle length.

Results

Nineteen women completed the study. Comparing pre- and postintervention parameters, women with PCOS in the OMT intervention group experienced an improvement in postexercise systolic blood pressure (135.8 vs 129.1 mm Hg) and a trend toward heart rate recovery (23.2 vs 29.4 seconds). No significant improvements were found in the control group or in any other physiologic parameters measured. No significant improvements were found in the endocrine, metabolic, or reproductive parameters measured, although free testosterone was slightly lower after 3 months of weekly OMT (5.69 vs 4.64 pg/mL).

Conclusion

Improvements in sympathetic tone after OMT suggest that weekly manipulation of Chapman points and viscerosomatic reflexes can be a useful adjunctive therapeutic option for women with PCOS. (ClinicalTrials.gov No. NCT03383484).

Effect of polycystic ovary syndrome on cardiac autonomic function at a late fertile age: a prospective Northern Finland Birth Cohort 1966 study

OBJECTIVES

Previous studies of women in their 20s and 30s have reported impaired autonomic function in women with polycystic ovary syndrome (PCOS). We aimed to study, for the first time, whether PCOS is associated with impaired cardiac autonomic function independent of metabolic and hormonal status in their late reproductive years.

DESIGN

A prospective Northern Finland Birth Cohort 1966 (NFBC1966) study including 5889 women born in 1966 and followed through the age of 46. At that age, n=3706/5123 women (72%) answered the postal questionnaires and n=3280/5123 women (64%) participated in the clinical examination.

SETTING

General community.

PARTICIPANTS

The sample included women presenting both irregular menses (oligomenorrhoea or amenorrhoea) and hirsutism at age 31 (n=125) or with formally diagnosed PCOS by age 46 (n=181) and women without PCOS symptoms or diagnosis (n=1577).

PRIMARY AND SECONDARY OUTCOME MEASURES

Heart rate variability parameters: the root mean square of successive R-R differences (rMSSD), spectral power densities (LF: low frequency and HF: high frequency) and baroreflex sensitivity (BRS).

RESULTS

We found that parasympathetic activity (assessed by rMSSD: 19.5 (12.4; 31.9) vs 24.3 (16.1; 34.8) ms, p=0.004 and HF: 172 (75; 399) vs 261 (112; 565) ms², p=0.002) and BRS (6.13±3.12 vs 6.99±3.52 ms/mm Hg, p=0.036) were lower in women with PCOS compared with the controls. However, in the multivariate regression analysis, PCOS, body mass index and the free androgen index did not significantly associate with rMSSD, whereas blood pressure, insulin resistance and triglycerides did.

CONCLUSIONS

We report here for the first time that late reproductive-aged women with PCOS display impaired cardiac autonomic function manifested as decreased vagal activity. Metabolic status, rather than hyperandrogenaemia and PCOS per se, was the strongest contributing factor. Given the link between cardiac morbidity and impaired autonomic function, the findings underline the importance of screening and treating metabolic abnormalities early on in women with PCOS.

Cardiac Autonomic Neuropathy in Obesity, the Metabolic Syndrome and Prediabetes: A Narrative Review

Cardiac autonomic neuropathy (CAN) is a major complication of type 1 and type 2 diabetes mellitus (T1DM and T2DM). The increased morbidity, cardiovascular and all-cause mortality associated with CAN is established from numerous epidemiological studies. However, CAN is increasingly recognised in people with prediabetes (pre-DM) and the metabolic syndrome (MetS) with a reported prevalence up to 11% and 24% respectively. CAN is associated with components of MetS including hypertension and obesity, predating hyperglycaemia. The aetiology of CAN is multifactorial and there is a reciprocal relationship with insulin resistance and MetS. Obstructive sleep apnoea (OSA) is also associated with CAN possibly through MetS and an independent mechanism. An estimated global prevalence of the impaired glucose tolerance (IGT) form of pre-DM of 587 million people by 2045 means CAN will become a major clinical problem. CAN is independently associated with silent myocardial ischaemia, major cardiovascular events, myocardial dysfunction and cardiovascular mortality. Screening for CAN in pre-DM using risk scores with analysis of heart rate variability (HRV) or Sudoscan is important to allow earlier treatment at a reversible stage. The link between obesity and CAN highlights the therapeutic potential of lifestyle interventions including diet and physical activity to reverse MetS and prevent CAN. Weight loss achieved using these dietary and exercise lifestyle interventions improves the sympathetic and parasympathetic HRV indices of cardiac autonomic function. Further research is needed to identify high-risk populations of people with pre-DM or obesity that might benefit from targeted pharmacotherapy including metformin, sodium/glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide 1 (GLP-1) analogues. Bariatric surgery also improves HRV through weight loss which might also prevent CAN in severe obesity. This article reviews the literature on CAN in obesity, pre-DM and MetS, to help determine a rationale for screening, early intervention treatment and formulate future research questions in this highly prevalent condition.

Correlation Between Physiologic and Osteopathic Measures of Sympathetic Activity in Women With Polycystic Ovary Syndrome

Background

Polycystic ovary syndrome (PCOS) is a common hormone disorder that affects the reproductive, metabolic, and psychological health of reproductive-aged females, with a number of long-term health risks, including type 2 diabetes mellitus and cardiovascular sequelae. Sympathetic hyperactivity in affected persons may be involved in the pathogenesis of the disorder.

Objective

To determine whether physiologic and osteopathic measures of increased sympathetic tone correlate in a population of women with PCOS.

Methods

For this descriptive observational study, women with PCOS between the ages of 20 and 44 years were recruited. Physiologic measures of sympathetic tone (resting heart rate and blood pressure, resting heart rate variability, and postexercise heart rate recovery and blood pressure) were compared with osteopathic measures of sympathetic tone (Chapman points and viscerosomatic reflexes) for the heart, adrenal glands, and ovaries.

Results

Twenty-four women participated in the study. Overall, the participants exhibited both physiologic and osteopathic signs of increased sympathetic tone compared with reference values. In some participants, the number of osteopathic findings were greater than the number of physiologic findings of increased sympathetic tone.

Conclusions

Women with PCOS exhibit increased sympathetic tone by physiologic and osteopathic measures, indicating the utility of assessing sympathetic hyperactivity in these patients by osteopathic methods. Osteopathic structural examination is a valuable diagnostic tool that may allow detection of sympathetic hyperactivity in women with PCOS even before physiologic symptoms manifest. The osteopathic indicators of increased sympathetic tone may represent potential therapeutic targets to improve health in this population. (ClinicalTrials.gov NCT03383484).

Regional Cerebral Activation Accompanies Sympathoexcitation in Women With Polycystic Ovary Syndrome

CONTEXT

Polycystic ovary syndrome (PCOS) is associated with increased sympathetic nervous system activation, but the cerebral pathways involved are unclear.

OBJECTIVE

To compare cerebral [blood oxygen level-dependent (BOLD) functional MRI], pressor [blood pressure (BP), heart rate (HR], and muscle sympathetic nerve activity (MSNA) responses to isometric forearm contraction (IFC) in women with PCOS and matched control subjects.

DESIGN

Case-control study.

SETTING

Referral center.

PARTICIPANTS

Patients with PCOS (n = 20; mean ± SD data: age, 29.8 ± 4.8 years; body mass index (BMI), 26.1 ± 4.9 kg/ m2) and 20 age- and BMI-matched control subjects (age, 29.7 ± 5.0 years; BMI, 26.1 ± 4.8 kg/ m2).

MAIN OUTCOME MEASURES

BP, HR, catecholamine, and MSNA responses to 30% IFC. BOLD signal change was modeled for BP response to 30% IFC.

RESULTS

Although HR and BP increased to a similar extent in both groups after IFC, MSNA burst frequency increased by 68% in the PCOS group compared with 11.9% in control subjects (n = 7 in both groups; P = 0.002). Brain activation indexed by the BOLD signal in response to IFC was significantly greater in the PCOS group (n = 15) compared with controls (n = 15) in the right orbitofrontal cortex (P < 0.0001). Adjustment for insulin sensitivity, but not hyperandrogenism, abolished these between-group differences.

CONCLUSION

Our study confirms enhanced sympathoexcitation in women with PCOS and demonstrates increased regional brain activation in response to IFC. The right orbitofrontal cortex BOLD signal change in women with PCOS is associated with insulin sensitivity. Additional studies are warranted to clarify whether this may offer a novel target for cardiovascular risk reduction.

Evaluating exercise challenge to validate cardiac autonomic dysfunction in lean PCOS phenotype

Background Polycystic ovary syndrome (PCOS) is frequently associated with infertility, obesity, hypertension, and diabetes mellitus. Cardiac autonomic dysfunction is well documented in long-term patients of PCOS, with impairment being proportionate to disease duration. However, there is paucity of literature on cardiac autonomic tone in the "lean" phenotype of PCOS. We used exercise challenge to probe for autonomic dysfunction, as assessed by heart rate variability (HRV), an index of cardiac autonomic tone. Methods Our study population consisted of 27 newly diagnosed PCOS patients and 25 healthy females matched by age and body mass index. Short-term HRV was assessed using time and frequency domain indices. Moderate, isotonic exercise was used as an interventional tool. Indices of both groups were compared in three bins - at baseline, immediate, and late postexercise stages. Results The groups had comparable HRV indices at baseline. However, low-frequency (LF) power was significantly reduced in PCOS patients during immediate and late postexercise phases when compared with controls (p = 0.03 and 0.03, respectively). Time domain indices also exhibited a fall postexercise, although not statistically significant. Conclusions Although "lean" phenotype PCOS patients had comparable HRV parameters as controls at baseline, the administration of exercise challenge led to reduced sympathetic drive, evident by reduced LF power in patient group. This may be due to latent autonomic dysfunction in "lean" PCOS, which is unmasked on exposure to exercise challenge. We propose that the evaluation of HRV response to exercise may serve as a sensitive screening tool to detect early cardiovascular dysfunction in newly diagnosed lean PCOS patients.

Women with Polycystic Ovarian Syndrome Exhibit Reduced Baroreflex Sensitivity That May Be Associated with Increased Body Fat

Background

Polycystic ovarian syndrome (PCOS) women have a high prevalence of obesity and alterations in cardiovascular autonomic control, mainly modifications in heart rate variability (HRV) autonomic modulation. However, there are few studies about other autonomic control parameters, such as blood pressure variability (BPV) and baroreflex sensitivity (BRS). In addition, there are still doubts about the obesity real contribution in altering autonomic control in these women.

Objective

To investigate BPV and BRS autonomic modulation alterations in PCOS women, as well as, to evaluate whether these alterations are due PCOS or increased body fat.

Methods

We studied 30 eutrophic volunteers [body mass index (BMI) < 25 kg/m²] without PCOS (control group) and 60 volunteers with PCOS divided into: eutrophic (BMI < 25 kg/m², N = 30) and obese women (BMI > 30 kg/m², N = 30). All volunteers were submitted to anthropometric evaluation, hemodynamic and cardiorespiratory parameters record at rest and during physical exercise, analysis of HRV, BPV and spontaneous BRS. The differences in p less than 5% (p < 0.05) were considered statistically significant.

Results

Related to eutrophics groups, there were no differences in autonomic parameters evaluated. The comparison between the PCOS groups showed that both PCOS groups did not differ in the BPV analysis. Although, the obese PCOS group presented lower values of spontaneous BRS and HRV, in low frequency and high frequency oscillations in absolute units.

Conclusion

Our results suggest that obesity did little to alter HRV in women with PCOS, but it may influence the spontaneous BRS.

Saturated Fat Intake Is Related to Heart Rate Variability in Women with Polycystic Ovary Syndrome

Background/Aims: There is a heightened risk for cardiovascular diseases in women with polycystic ovary syndrome (PCOS). Alterations in heart rate variability (HRV) may reflect subclinical cardiovascular disease, with a putative association between HRV and dietary fat. This study evaluated HRV in PCOS and control women based on the dietary intake of saturated fatty acid (SFA). Methods: Biochemical/hormonal profile, resting metabolic rate, physical activity, HRV in response to the Stroop test, and dietary intake were assessed in 84 PCOS and 54 control women stratified by median SFA intake in the PCOS group (8.5% of daily energy intake). Results: Body mass index (p = 0.041), blood pressure (p < 0.01), and HOMA-IR (p = 0.003) were higher in PCOS vs. controls. PCOS women had higher testosterone (p = 0.001), dehydroepiandrosterone sulfate (p = 0.012), and free androgen index (p = 0.001), and lower sex hormone-binding globulin levels than controls (p = 0.001). In both groups, the clinical profile and calorie intake were similar between SFA categories. In PCOS, testosterone was lower when SFA intake <8.5%. PCOS women with SFA <8.5% consumed more beans, fruits, and vegetables and had better frequency and time domain HRV indices. No differences in HRV were detected between SFA categories in controls. In PCOS, age and SFA intake were independent predictors of HRV. Conclusions: Lower SFA intake is related to improved cardiovascular autonomic function in PCOS.

Cardiovascular autonomic dysfunction in women with polycystic ovary syndrome: a systematic review and meta-analysis

Recent studies reveal that polycystic ovary syndrome (PCOS) might be associated with cardiovascular autonomic dysfunction, but with inconsistent results. The aim of this meta-analysis was to study whether women with PCOS have cardiovascular autonomic dysfunction. PubMed, Web of Science, Cochrane Library and SCOPUS were searched for studies comparing cardiovascular function between women with PCOS and controls. A random-effects model was used to evaluate cardiac autonomic modulation and muscle sympathetic nerve activity (MSNA) between women with PCOS and controls. Eight studies were included, including 243 PCOS and 211 controls. Overall, women with PCOS had significantly lower standard deviation of normal-to-normal RR intervals (SDNN) and percentage of the number of interval differences of successive normal-to-normal RR intervals greater than 50 ms among the total number of RR intervals (pNN50), higher MSNA frequency and higher MSNA incidence than controls. Therefore, this meta-analysis provides evidence that women with PCOS might show cardiovascular autonomic dysfunction, with reduced total and parasympathetic cardiac modulation, and increased sympathetic activity.

Heart rate variability in normal-weight patients with polycystic ovary syndrome

Objective:

Polycystic ovary syndrome (PCOS) is an endocrine disease closely related to several risk factors of cardiovascular disease. Obese women with PCOS show altered autonomic modulation. The results of studies investigating cardiac autonomic functions of normal-weight women with PCOS are conflicting. The aim of the study was to assess the reactivity of cardiac sympathovagal balance in normal-weight women with PCOS by heart rate variability analysis.

Methods:

We examined the heart rate variability in 60 normal-weight women with PCOS and compared them with that in 60 age-matched healthy women having a similar metabolic profile. Time and frequency domain parameters of heart rate variability were analyzed based on 5-min-long continuous electrocardiography recordings for the following 3 periods: (1) during rest in supine position, (2) during controlled breathing, and (3) during isometric handgrip exercise.

Results:

Time and frequency domain parameters of heart rate variability for the 3 periods assessed were similar in the two groups. Although modified Ferriman–Gallwey score and serum testosterone and luteinizing hormone levels were significantly higher in women with PCOS, homeostatic model assessment-insulin resistance (HOMA-IR) was not different the between the PCOS and control groups. There were no significant correlations between serum testosterone levels and heart rate variability parameters among the study population.

Conclusion:

The findings of this study suggest that the reactivity of cardiac sympathovagal balance is not altered in normal-weight women with PCOS having a normal HOMA-IR.

The role of stress in PCOS

Polycystic ovary syndrome (PCOS) is a complex endocrinopathy affecting a remarkable proportion of premenopausal women. Different studies have shown that stress is widely encountered in women with PCOS. Areas covered: As PCOS is a multifaceted disorder, 'stress' incorporates different translations. We performed a literature review, focusing on the most recent data, regarding the multipotent role of stress in the syndrome. Expert commentary: Stress is believed to be an important component of PCOS. It encompasses different definitions that are all equivalent, like metabolic, inflammatory, oxidative and emotional stress. However, the type of stress that distinguishes PCOS is metabolic stress. It becomes evident early in life and constitutes the pathophysiological heart of the syndrome. Metabolic stress along with the other types of stress are the progenitors of severe long-term health implications, which exacerbate further the reproductive, metabolic and psychological derangements of the syndrome, leading to an endless cycle of chronic illness.

Sympathetic activation and endothelial dysfunction in polycystic ovary syndrome are not explained by either obesity or insulin resistance

OBJECTIVE

Polycystic ovary syndrome (PCOS) is a common endocrine condition underpinned by insulin resistance and associated with increased risk of obesity, type 2 diabetes and adverse cardiovascular risk profile. Previous data suggest autonomic imbalance [elevated sympathetic nervous system (SNS) activity and decreased heart rate variability (HRV)] as well as endothelial dysfunction in PCOS. However, it is not clear whether these abnormalities are driven by obesity and metabolic disturbance or whether they are independently related to PCOS.

PARTICIPANTS AND METHODS

We examined multiunit and single-unit muscle SNS activity (by microneurography), HRV (time and frequency domain analysis) and endothelial function [ischaemic reactive hyperaemia index (RHI) using the EndoPAT device] in 19 overweight/obese women with PCOS (BMI: 31·3 ± 1·5 kg/m(2), age: 31·3 ± 1·6 years) and compared them with 21 control overweight/obese women (BMI: 33·0 ± 1·4 kg/m(2), age: 28·2 ± 1·6 years) presenting a similar metabolic profile (fasting total, HDL and LDL cholesterol, glucose, triglycerides, insulin sensitivity and blood pressure).

RESULTS

Women with PCOS had elevated multiunit muscle SNS activity (41 ± 2 vs 33 ± 3 bursts per 100 heartbeats, P < 0·05). Single-unit analysis showed that vasoconstrictor neurons were characterized by elevated firing rate and probability and incidence of multiple spikes (P < 0·01 for all parameters). Women with PCOS also had impaired endothelial function (RHI: 1·77 ± 0·14 vs 2·18 ± 0·14, P < 0·05). HRV did not differ between the groups.

CONCLUSION

Women with PCOS have increased sympathetic drive and impaired endothelial function independent of obesity and metabolic disturbances. Sympathetic activation and endothelial dysfunction may confer greater cardiovascular risk in women with PCOS.

Heart rate variability and heart rate turbulence in patients with polycystic ovary syndrome

OBJECTIVE

Cardiac autonomic dysfunction may develop in patients with polycystic ovary syndrome (PCOS). Heart rate variability (HRV) and heart rate turbulence (HRT) are used in assessing cardiac autonomic functions. The goal of this study was to compare the cardiac autonomic functions in patients with PCOS and healthy controls. To our knowledge, this is the first study evaluating cardiac autonomic functions in patients with PCOS with respect to both HRV and HRT.

METHODS

Twenty-three patients with PCOS (mean age 22.8±3.9 years) and 25 healthy female volunteers who were matched for age and body mass index (BMI) (mean age 23.5±6.2 years) were enrolled in this as case-control study. Twenty-four hour ambulatory electrocardiogram recordings of all participants were taken using Pathfinder software. The time domain parameters of HRV and HRT, including turbulence onset (TO) and turbulence slope, were calculated. Diagnosis of PCOS was made with physical and laboratory findings of hirsutism or biochemical hyperandrogenism and chronic anovulation. Diabetes mellitus, other hormon disorders or hormon therapy, pregnancy, atrial fibrilation, obesite, chronic diseases, disorders of the autonomic nervous system, a history of drug use affecting the autonomic nervous system were excluded.

RESULTS

There were no significant differences in HRV and HRT parameters between the two groups. Cardiovascular risk factors, such as BMI, blood pressure, fasting blood glucose, and lipid parameters, were also similar. Triangular index measure of HRV was negatively correlated with high density lipoprotein cholesterol levels (r=-0.47, p<0.05), while age and BMI were significantly correlated with TO (r=0.31 and 0.47, respectively; p<0.05 for all).

CONCLUSION

Cardiac autonomic functions were not found to be altered in patients with PCOS in comparison with healthy controls. These results may be explained with the absence of concomitant cardiovascular risk factors with the patients being in the early stage of the disease.

Ocular blood flow in polycystic ovary syndrome

AIM

The aim of this study was to evaluate whether the presence of polycystic ovary syndrome (PCOS) alters ocular blood flow parameters.

MATERIAL AND METHODS

Color Doppler imaging of the orbital vessels was performed in 41 eyes of 41 patients with PCOS. Forty-eight eyes of 48 age-matched volunteers served as controls. The ophthalmic artery (OA), the central retinal artery and the posterior ciliary artery were examined. Ocular blood flow indices of the peak systolic velocity, diastolic velocity, end-diastolic velocity, systolic/diastolic ratio, resistive index and pulsatility index were computed.

RESULTS

The peak systolic velocity, diastolic velocity and end-diastolic velocity of the OA, central retinal artery and posterior ciliary artery were significantly increased in PCOS patients in comparison to the controls (all P < 0.001). The mean systolic/diastolic ratio, resistive index and pulsatility index of the OA in PCOS patients were significantly decreased (all P < 0.05). Ocular blood flow velocity was positively correlated with serum luteinizing hormone, follicle-stimulating hormone and total cholesterol levels. There was a significant negative correlation between serum glucose and insulin levels and ocular blood flow velocity.

CONCLUSION

Ocular blood flow velocity is increased in PCOS patients and vascular resistance seems to decrease only in the OA.

Association of sympathovagal imbalance with cardiovascular risks in patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is associated with cardiovascular risks like obesity, insulin resistance, dyslipidemia that can lead to sympathovagal imbalance (SVI). The study was designed to assess the cardiovascular risk in PCOS and link of metabolic derangements to SVI. Thirty-five newly diagnosed PCOS patients and 32 age-matched controls were recruited. Waist-hip ratio, body mass index (BMI), basal cardiovascular parameters such as basal heart rate (BHR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and rate pressure product (RPP) were recorded. Autonomic functions were assessed using short-term heart rate variability (HRV) analysis, heart rate and blood pressure response to standing (30:15 ratio), deep breathing (E:I ratio) and isometric handgrip (ΔDBPihg). Fasting plasma glucose, insulin, lipid profile and testosterone were assayed. Insulin resistance (HOMA-IR) and lipid risk factors were calculated. The cases had increased BHR, BMI, SBP, DBP, MAP and RPP. The ratio of low-frequency to high-frequency (LF-HF) of HRV, the marker of SVI was significantly increased in cases. 30:15 ratio and ΔDBPihg were increased and E:I ratio was decreased in the cases. HOMA-IR, lipid risk factors and testosterone were significantly elevated in cases. There was a significant correlation of LF-HF with BMI, BHR, RPP, insulin resistance and lipid risk factors. On regression analysis, insulin resistance and lipid risk factors had independent association with LF-HF. PCOS patients have SVI, decreased HRV and increased RPP and the potential cardiovascular risks. The insulin resistance and dyslipidemia contribute to SVI and cardiovascular risks in PCOS patients.