Cardiac autonomic modulation in polycystic ovary syndrome: does the phenotype matter?

Metabolic and endocrine status associate with obstructive sleep apnea risk among patients with polycystic ovary syndrome

STUDY OBJECTIVES

Risk of obstructive sleep apnea (OSA) appears to be increased among patients with polycystic ovary syndrome (PCOS), but the underlying physiology is unclear. We sought to identify predictors of OSA risk among patients with PCOS.

METHODS

A cross-sectional analysis of patients evaluated for PCOS at a single tertiary center from 2017-2022 was completed. Inclusion criteria included patients 18-44 years of age who had Rotterdam criteria for PCOS and had completed a Berlin Questionnaire (BQ) for OSA risk assessment. All patients underwent standardized anthropometric, ultrasound, endocrine, and metabolic phenotyping.

RESULTS

Of the 572 patients screened during the study period, 309 patients with PCOS met inclusion criteria, and 104 (33.7%) had a high-risk BQ. Those with a high-risk BQ, compared with those without, had significantly (P < .05) higher waist:hip ratio, low-density-lipoprotein cholesterol, triglycerides, fasting insulin, 2-hour insulin, fasting glucose, 2-hour glucose, homeostatic model assessment for insulin resistance, hemoglobin A1C, C-reactive protein, free testosterone, and free androgen index and had lower high-density-lipoprotein cholesterol and sex hormone binding globulin. In multivariable modeling controlling for all significantly differing variables in univariate analyses, hemoglobin A1C (β [standard error] 1.05 [0.45], P = .02), C-reactive protein (0.09 [0.04], P = .01), and sex hormone binding globulin (-0.02 [0.01], P = .02) associated with high-risk BQ.

CONCLUSIONS

Dysglycemia, inflammation, and androgen status independently associate with predicted OSA risk by BQ. Future studies are needed to comprehensively assess the impact of treatment of OSA on these outcomes among patients with PCOS to better clarify the directionality and clinical implications of these associations.

CITATION

Christ JP, Shinkai K, Corley J, Pasch L, Cedars MI, Huddleston HG. Metabolic and endocrine status associate with obstructive sleep apnea risk among patients with polycystic ovary syndrome. J Clin Sleep Med. 2024;20(6):871-877.

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.

Lean mass and associated factors in women with PCOS with different phenotypes

Although current evidence suggests increased risk of obesity, insulin resistance, and metabolic alterations in patients with polycystic ovary syndrome (PCOS), especially of a hyperandrogenic phenotype, the impact of each one of these variables on muscle mass remains uncertain. In this case-control study, we evaluated clinical and hormonal characteristics related to lean body mass according to the different PCOS phenotypes. We performed clinical, metabolic, and hormonal assessments and evaluated body compartments by dual-energy X-ray absorptiometry in 133 women of reproductive age. Creatinine served as an indirect marker of lean mass. Median age was 28 (range, 17-37) years. Women with phenotypes A and B (n = 59) had higher body mass index (BMI) and metabolic syndrome prevalence than those with phenotype C (n = 23) and controls (n = 51) (p<0.005). Women with phenotypes A and B also had higher Ferriman-Gallwey score (p<0.001), insulin levels (p = 0.006), HOMA-IR (p = 0.008), testosterone (p = 0.008), free androgen index (FAI) (p<0.001), fat mass index (FMI) (p = 0.015), android-to-gynoid fat ratio (p = 0.036), and bone mineral density (BMD) at lumbar spine (p = 0.027) and total femur (p = 0.013) than controls. Median appendicular lean mass index (ALMI) was higher in phenotypes A and B than in controls (7.01 [IQR, 6.33-8.02] vs. 6.69 [IQR, 5.94-7.09], p = 0.024), but it did not differ significantly from that in phenotype C (6.60 [IQR, 6.16-7.22], p = 0.222). Even after adjusting for BMI, ALMI correlated positively with creatinine in women with phenotypes A and B (rho = 0.319, p = 0.023) but not in those with phenotype C (p = 0.238) or controls (p = 0.097). In multivariate linear regression analyses, ALMI was positively associated with insulin, FAI, FMI, and total femur BMD. The present results suggest that fasting insulin, FAI, fat mass, and total femur BMD were positively associated with increased lean mass in women with PCOS phenotypes A and B.

The effect of oral contraceptive use on sympatic nerve activity in patients with polycystic ovary syndrome

OBJECTIVE

High sympathetic nerve activity, is thought to be a cardiovascular risk factor, has been shown to correlate with circulating high testosterone levels. However its role on the pathophysiology of the polycystic ovarian syndrome has not been clearly established. The aim of our study is to compare the sympathetic nerve activity between polycystic ovarian syndrome and control group and to determine whether the use of oral contraceptives for contraception has any effect on this activity.

MATERIALS AND METHODS

Our study has designed as a prospective, case-control study including patients diagnosed with polycystic ovarian syndrome. Antropometric measurements were calculated, hormone levels were measured and sympathetic skin response and heart rate variability measurements were performed in the laboratory to assess sympathetic activity before starting oral contraceptive pill therapy and at the end of 1 month follow up.

RESULTS

In the baseline condition LH/FSH ratio, LH, DHEAS, and total testosterone levels were significantly higher in women with PCOS. After 1 month of treatment, reductions in Ferriman-Gallwey score, ovarian volumes, number of follicles, LH/FSH ratio, LH, and androgen hormone levels were statistically significant. The mean values of sympathetic skin response amplitude and R-R analysis-Valsalva test were higher in PCOS group as compared to the control group. However, these differences were not statistically significant. Similarly, no statistically significant difference in SSR latency and R-R analysis-standup test were demonstrated between PCOS and control groups.

CONCLUSION

In conclusion, our study supports the increased sympatovagal activity in patients with polycystic ovarian syndrome.

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.

Effects of vitamin D supplementation on metabolic parameters of women with polycystic ovary syndrome: a meta-analysis of randomized controlled trials

OBJECTIVE

The purpose of this meta-analysis was to evaluate the effects of vitamin D supplementation on metabolic parameters of women with polycystic ovary syndrome (PCOS).

METHODS

We performed a literature search of databases and identified randomized controlled trials (RCTs) published prior to December 2019. A meta-analysis was conducted using RevMan 5.3 and Stata 12.0 software. We compared the effects of vitamin D supplementation alone to the administration of placebos on metabolic parameters of PCOS women with vitamin D deficiency.

RESULTS

Ten articles of RCTs were included and analyzed in this meta-analysis, which included a total of 520 PCOS women. Our meta-analysis results showed no significant effects of vitamin D supplementation on BMI (p = .43), systolic blood pressure (p = .05), diastolic blood pressure (p = .87), fasting insulin concentration (p = .86), HOMA-IR (p = .47), HDL-C (p = .76), LDL-C (p = .23) and triglyceride (p = .77). Both low dose vitamin D supplementation (<4000 IU/day) and high dose vitamin D supplementation (≥4000 IU/day) were found to significantly decreased the fasting glucose concentration (p = .01, p = .001, respectively). Vitamin D supplementation significantly decreased total cholesterol concentration (p = .03).

CONCLUSIONS

The results of this meta-analysis suggested that vitamin D supplementation decreases fasting glucose concentration and total cholesterol concentration in PCOS women with vitamin D deficiency.

Hypertension Risk in Young Women With Polycystic Ovary Syndrome: A Nationwide Population-Based Cohort Study

Objective: A number of publications have assessed the prevalence of hypertension in polycystic ovary syndrome (PCOS) patients with inconclusive results. Since in general populations the occurrence of hypertension is related to age and comorbidities, we investigated the incidence rate and hazard ratios (HRs) of hypertension between healthy subjects and young women with PCOS as well as comorbidities.

Methods: We conducted a population-based retrospective cohort study by using the National Health Insurance Research Database in Taiwan. The cohort included women with the diagnosis of PCOS between 2000 and 2012. Those without PCOS were selected as the control group at a ratio of 4:1 by an age-matched systematic random-sampling method. Cox proportional hazard regression analysis was used to determine the effects of PCOS on the risks of developing hypertension. Stratification analysis was performed to elucidate the interaction among PCOS and the comorbidities, which affect the incidence of hypertension.

Results: The PCOS cohort consisted of 20,652 patients with PCOS and the comparison cohort consisted of 82,608 matched patients without PCOS. There was no difference in the distribution of age between the PCOS cohort and the comparison cohort (29.1 ± 6.8 vs. 29.0 ± 6.5, p = 0.32). The incidence rates of hypertension were 7.85 and 4.23 per 1,000 person-years in the PCOS and comparison groups, respectively. A statistically significant higher risk of hypertension was found in the PCOS cohort (adjusted HR = 1.62, 95% confidence interval = 1.48–1.76) than in the comparison cohort. After a joint analysis of comorbidities, the adjusted HR of hypertension was 9.44 (95% confidence interval = 7.27–12.24) for PCOS patients with comorbidities of diabetes mellitus (DM) and hyperlipidemia compared with women with neither PCOS nor DM and hyperlipidemia.

Conclusion: The risk of developing hypertension in young women with PCOS was higher than in controls in this cohort study. The comorbidities of DM and hyperlipidemia could interact with PCOS patients and further increase the risk of hypertension. An earlier screening for hypertension and comorbidities in patients with PCOS may be warranted, even in young women.

Vitamin D Deficiency Is Associated With Metabolic Risk Factors in Women With Polycystic Ovary Syndrome: A Cross-Sectional Study in Shaanxi China

Background: Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women at reproductive age, which is characterized by obesity, hyperandrogenemia, and insulin resistance (IR). This study aimed to investigate the vitamin D status, and analyze the relationship between vitamin D deficiency and metabolic risk factors in PCOS women in Shaanxi China. Methods: A cross-sectional study included 169 women diagnosed with PCOS and 114 control women without PCOS. The serum 25(OH)D and metabolic markers were measured. Vitamin D deficiency was defined as serum 25(OH)D concentration less than 20 ng/mL. The primary outcome was the difference in vitamin D status between the PCOS and control groups, the secondary outcomes were correlations between serum 25(OH)D concentration and metabolic risk factors in women with PCOS. Results: The serum 25(OH)D concentration was significantly lower in women with PCOS than in controls (P < 0.05), and the prevalence rates of 25(OH)D deficiency and insufficiency were significantly higher in women with PCOS than in controls (P < 0.05). The serum 25(OH)D concentration was significantly lower in PCOS women with obesity or IR than in women without obesity or IR (P < 0.05), and the prevalence of 25(OH)D deficiency in PCOS women with obesity or IR was significantly higher than in women without obesity or IR (P < 0.05). Serum 25(OH)D concentration was significantly negatively correlated with body mass index (BMI), waist-to-hip ratio (WHR), fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), total cholesterol, low-density lipoprotein cholesterol (LDL-C), and high-sensitivity C-reactive protein (hs-CRP) (P < 0.05). In comparison, serum 25(OH)D concentration was significantly positively correlated with high-density lipoprotein cholesterol (HDL-C) (P < 0.05). Increased BMI and WHR, high levels of fasting insulin, HOMA-IR, total cholesterol, LDL-C and hs-CRP were regarded as risk factors, but high level of HDL-C was considered to be protective factor of vitamin D deficiency in PCOS women. Conclusions: Vitamin D deficiency is prevalent in PCOS women in Shaanxi China, especially in those with obesity and IR. The serum 25(OH)D level was correlated with metabolic risk factors in PCOS women. Multi-center randomized controlled trials with large sample sizes are needed to probe the metabolic effect of vitamin D supplementation in PCOS women.

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.

Prevalence of vitamin D deficiency in women from southern Brazil and association with vitamin D-binding protein levels and GC-DBP gene polymorphisms

Vitamin D deficiency is highly prevalent worldwide, and vitamin D-binding protein (DBP) a major regulator of serum vitamin D levels. The rs4588 and rs7041 polymorphisms of the GC gene constitute the genetic basis of the three major isoforms of circulating DBP (GC1s, GC1f, and GC2), while the rs2282679 variant is located in an important regulatory region of the GC gene. The aim of this study was to assess the prevalence of 25-hydroxyvitamin D [25(OH)D] deficiency and to ascertain whether it is associated with DBP levels and with GC gene variants. Biorepository samples of 443 women aged 20 to 72 years, with no evidence of clinical disease, were analyzed. Circulating levels of 25(OH)D were considered sufficient if ≥20 ng/mL and deficient if <20 ng/mL. Genotype analysis was performed by RT-PCR. Mean age was 53.4±9.4 years; mean BMI was 27.8±5.8 kg/m2. The overall sample had mean 25(OH)D levels of 22.8±8.3 ng/mL; 39.7% of participants had deficient circulating 25(OH)D levels. Higher prevalence ratios (PR) of 25(OH)D deficiency were found for the CC genotype of rs2282679 (PR 1.74; 95%CI 1.30 to 2.24; p<0.001), GC2 isoform (PR 1.66; 95%CI 1.17 to 2.38; p = 0.005), time since menopause (PR 1.02; 95%CI 1.003 to 1.03, p = 0.016), and HOMA-IR (PR 1.02; 95%CI 1.01 to 1.03, p = 0.004). DBP levels (per 30 μg/mL increase in DBP) were associated with lower PR for 25(OH)D deficiency (PR 0.89; 95%CI 0.80;0.99; p = 0.027). Except for HOMA-IR, these prevalence ratios remained significant after adjustment for age and BMI. In conclusion, the rs2282679 polymorphism and the GC2 isoform of DBP were associated with lower serum DBP levels and with susceptibility to 25(OH)D deficiency in Brazilian women with no evidence of clinical disease.

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).

Heat therapy reduces sympathetic activity and improves cardiovascular risk profile in women who are obese with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) affects up to 15% of women and is associated with increased risk of obesity and cardiovascular disease. Repeated passive heat exposure [termed "heat therapy" (HT)] is a lifestyle intervention with the potential to reduce cardiovascular risk in obesity and PCOS. Women with obesity (n = 18) with PCOS [age 27 ± 4 yr, body mass index (BMI) 41.3 ± 4.7 kg/m²] were matched for age and BMI, then assigned to HT (n = 9) or time control (CON; n = 9). HT subjects underwent 30 one-hour hot tub sessions over 8-10 wk, whereas CON subjects did not undergo HT. Muscle sympathetic nerve activity (MSNA), blood pressure, cholesterol, C-reactive protein, and markers of vascular function were assessed at the start (Pre) and end (Post) of 8-10 wk. These measures included carotid and femoral artery wall thickness and flow-mediated dilation (FMD), measured both before and after 20 min of ischemia-20 min of reperfusion (I/R) stress. HT subjects exhibited reduced MSNA burst frequency (Pre: 20 ± 8 bursts/min, Post: 13 ± 5 bursts/min, P = 0.012), systolic (Pre: 124 ± 5 mmHg, Post: 114 ± 6 mmHg; P < 0.001) and diastolic blood pressure (Pre: 77 ± 6 mmHg, Post: 68 ± 3 mmHg; P < 0.001), C-reactive protein (Pre: 19.4 ± 13.7 nmol/L, Post: 15.2 ± 12.3 nmol/L; P = 0.018), total cholesterol (Pre: 5.4 ± 1.1 mmol/L, Post: 5.0 ± 0.8 mmol/L; P = 0.028), carotid wall thickness (Pre: 0.054 ± 0.005 cm, Post: 0.044 ± 0.005 cm; P = 0.010), and femoral wall thickness (Pre: 0.056 ± 0.009 cm, Post: 0.042 ± 0.005 cm; P = 0.003). FMD significantly improved in HT subjects over time following I/R (Pre: 5.6 ± 2.5%, Post: 9.5 ± 1.7%; P < 0.001). No parameters changed over time in CON, and BMI did not change in either group. These findings indicate that HT reduces sympathetic nerve activity, provides protection from I/R stress, and substantially improves cardiovascular risk profiles in women who are obese with PCOS.

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.

Apa-I polymorphism in VDR gene is related to metabolic syndrome in polycystic ovary syndrome: a cross-sectional study

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine disorder determined by polygenic traits as well as environmental factors. Lower vitamin D levels have been detected in PCOS women and related to hormone and metabolic disturbances. Vitamin D acts in tissues through the vitamin D receptor (VDR). VDR gene variants have been associated with worse metabolic profile in the general population. We investigated the genotype and haplotype distribution of the Bsm-I (rs1544410), Apa-I (rs7975232), and Taq-I (rs731236) VDR gene polymorphisms in PCOS and non-hirsute women from southern Brazil. We further investigated the associations of these gene variants and their haplotypes with PCOS, vitamin D levels, and metabolic abnormalities, including the metabolic syndrome (MetS).

METHODS

A group of 191 women with PCOS (Rotterdam criteria) and 100 non-hirsute controls with regular ovulatory cycles were genotyped for all polymorphisms by real-time PCR, with allelic discrimination assays. MetS and the cutoffs for its isolated components were defined in accordance with the Joint Scientific Statement.

RESULTS

Women with PCOS were younger and had significantly higher BMI and total testosterone levels than controls (p < 0.05). The frequency of MetS in PCOS and controls was 26.5% and 4.8% respectively. The CC genotype of Apa-I entailed higher risk of MetS in PCOS (OR: 2.133; 95% CI 1.020-4.464, p = 0.042), and was associated with higher systolic blood pressure (p = 0.009), total cholesterol (p = 0.040), and LDL-cholesterol (p = 0.038) in both PCOS and control groups (two-way ANOVA). The frequencies of VDR haplotypes were similar in PCOS and control women.

CONCLUSIONS

The present results suggest that the Apa-I variant in VDR gene may be associated with MetS in southern Brazilian women with PCOS, and with blood pressure, total cholesterol, and LDL-c in women with and without PCOS.

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.

Risk factors associated with metabolic syndrome and cardiovascular disease among women with polycystic ovary syndrome in Tabuk, Saudi Arabia

BACKGROUND

Polycystic ovary syndrome (PCOS) is the commonest endocrine disorder at a reproductive age. It is associated with a high risk of metabolic syndrome (MS) and cardiovascular diseases (CVD).

OBJECTIVE

To measure the prevalence of MS in women with PCOS and to assess the global cardiovascular risk (CVR) among them.

METHODS

This cross-sectional study was conducted at King Khalid Hospital, Tabuk, Saudi Arabia during the period from February through December 2014. A total of 404 infertile women were randomly selected, and checked for diagnosing PCOS, MS and estimated CVD probability. Data were analyzed by IBM-SPSS version 22, using independent-samples t-test, Chi-square, and conditional logistic regression. A p-value of <0.05 was considered significant.

RESULTS

MS was diagnosed in 58% and 32% of women with and without PCOS respectively (p<0.00). Results showed a statistically significant association between the two syndromes. Patients with the two syndromes showed high averages of clinical and biochemical values (p<0.00), high rate of predicted CVR, a high percentage of clustering of MS factors, and that weight-waist circumference - HDL are predictive for the occurrence of MS.

CONCLUSION

PCOS is associated with the risk of development of MS, and CVD. Screening for early detection of PCOS and MS and the application of cohort studies are recommended to better explore the role of PCOS in the development of CVD and to assess the significance of interventions.

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.

Genetic variant in vitamin D-binding protein is associated with metabolic syndrome and lower 25-hydroxyvitamin D levels in polycystic ovary syndrome: A cross-sectional study

Vitamin D deficiency has been related to metabolic syndrome (MetS) in polycystic ovary syndrome (PCOS). The vitamin D-binding protein (DBP) is the main protein involved in vitamin D transport. Two single-nucleotide polymorphisms (SNPs) of the DBP gene, rs4588 and rs7041, have been associated with low circulating levels of 25-hydroxyvitamin D [25(OH)D] in various populations, but not in women with PCOS. Therefore, we determined the genotype and haplotype distribution of DBP gene polymorphisms and investigated the associations between these genetic variants and their haplotypes with PCOS, MetS, and 25(OH)D levels in women with PCOS and controls from the South of Brazil. The sample included 291 women (191 with PCOS and 100 controls). All participants were genotyped for polymorphisms rs2282679, rs4588, and rs7041. Serum 25(OH)D levels were determined in a subset of 102 participants. Women with PCOS were younger and had significantly higher body mass index, blood pressure, and insulin resistance than the control group (p<0.05). The prevalence of MetS in PCOS and controls was 26.5% and 4.8% respectively. Levels of 25(OH)D were lower in PCOS women with MetS, even after adjustment for age (p = 0.033). No associations were observed between PCOS and the polymorphisms or their haplotypes. A higher frequency of genotype TT of rs7041 was found in PCOS participants with MetS (OR: 2.21, 95%CI:1.08–4.52; p = 0.027). This same genotype was associated with lower 25(OH)D levels in both PCOS and control women (OR: 4.40, 95%CI:1.62–12.00; p = 0.002). In conclusion, these findings indicate that DBP gene polymorphisms and their haplotypes are not directly associated with PCOS. In contrast, the TT genotype of SNP rs7041 was associated with MetS in PCOS women, and with lower 25(OH)D levels in both PCOS and control groups.

Autonomic dysfunction in patients with polycystic ovary syndrome

OBJECTIVE

To assess the autonomic system in patients with polycystic ovary syndrome (PCOS).

MATERIALS AND METHODS

Thirty-seven adult patients with PCOS and 33 healthy controls were enrolled in the study. The electrophysiological assessments of the autonomic nervous system function were performed using sympathetic skin response and R-R interval variation tests.

RESULTS

The mean latency of sympathetic skin response in PCOS patients was significantly delayed compared with the controls (p = 0.001). The mean amplitude of sympathetic skin response was significantly lower in comparison with the controls (p = 0.01). Mean R-R interval variation during deep breathing was also significantly delayed (p = 0.04).

CONCLUSION

There are parasympathetic dysfunction and sympathetic dysfunction in patients with PCOS. This may be easily demonstrated with sympathetic skin response and R-R interval variation tests.

[New populations at increased cardiovascular risk: Cardiovascular disease in dermatological diseases]

The increased cardiovascular risk in some dermatological diseases has been demonstrated in recent decades. Diseases such as psoriasis and systemic lupus erythematosus are currently included in the guidelines for prevention of cardiovascular disease. Other diseases such as androgenic alopecia, polycystic ovary syndrome, hidradenitis suppurativa or lichen planus have numerous studies that point to an increased risk, however, they have not been included in these guidelines. In this article we review the evidence supporting this association, in order to alert the clinician to the need for greater control in cardiovascular risk factors in these patients.

Scientific Statement on the Diagnostic Criteria, Epidemiology, Pathophysiology, and Molecular Genetics of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a heterogeneous and complex disorder that has both adverse reproductive and metabolic implications for affected women. However, there is generally poor understanding of its etiology. Varying expert-based diagnostic criteria utilize some combination of oligo-ovulation, hyperandrogenism, and the presence of polycystic ovaries. Criteria that require hyperandrogenism tend to identify a more severe reproductive and metabolic phenotype. The phenotype can vary by race and ethnicity, is difficult to define in the perimenarchal and perimenopausal period, and is exacerbated by obesity. The pathophysiology involves abnormal gonadotropin secretion from a reduced hypothalamic feedback response to circulating sex steroids, altered ovarian morphology and functional changes, and disordered insulin action in a variety of target tissues. PCOS clusters in families and both female and male relatives can show stigmata of the syndrome, including metabolic abnormalities. Genome-wide association studies have identified a number of candidate regions, although their role in contributing to PCOS is still largely unknown.

Bak Foong pills combined with metformin in the treatment of a polycystic ovarian syndrome rat model

The aim of the present study was to investigate the treatment effects and associated mechanism of Bak Foong pills (BFPs) combined with metformin in the treatment of polycystic ovarian syndrome (PCOS). BFPs and/or metformin were administrated to treat the PCOS rats, and the weights and morphologies of the ovary, uterus and adrenal gland were measured. The levels of fasting blood glucose (FBG), serum testosterone (T), luteinizing hormone, fasting insulin (FIN) and insulin-like growth factor-1 were also measured, and the homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. The expression level of androgen receptor (AR) in the ovarian tissue, and the cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc) mRNA levels in the ovary and adrenal tissues were detected. The levels of T, FIN, FBG and HOMA-IR in the combination group were significantly reduced; the wet weights of the ovary and the adrenal gland were decreased significantly, while that of the uterus was increased, and the histological morphology benignly recovered. The rats of each treatment group all experienced restored ovulation. The AR expression level in the treatment group was reduced, and the P450scc mRNA levels in the ovary and the adrenal gland of the combined treatment group were decreased. BFPs combined with metformin significantly affected PCOS, and the possible mechanism involved in the treatment may have been through the reduction of P450scc generation. BFPs may reduce the androgen levels, thus allowing the ovary to restore ovulation.

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.

Polycystic ovary syndrome: reviewing diagnosis and management of metabolic disturbances

Polycystic ovary syndrome (PCOS) is a common condition in women at reproductive age associated with reproductive and metabolic dysfunction. Proposed diagnosed criteria for PCOS include two out of three features: androgen excess, menstrual irregularity, and polycystic ovary appearance on ultrasound (PCO), after other causes of hyperandrogenism and dysovulation are excluded. Based on these diagnostic criteria, the most common phenotypes are the "classic PCOS"--hyperandrogenism and oligomenorrhea, with or without PCO; the "ovulatory phenotype"--hyperandrogenism and PCO in ovulatory women; and the "non-hyperandrogenic phenotype", in which there is oligomenorrhea and PCO, without overt hyperandrogenism. The presence of obesity may exacerbate the metabolic and reproductive disorders associated with the syndrome. In addition, PCOS women present higher risk for type 2 diabetes and higher prevalence of cardiovascular risk factors that seems to be associated with the classic phenotype. The main interventions to minimize cardiovascular and metabolic risks in PCOS are lifestyle changes, pharmacological therapy, and bariatric surgery. Treatment with metformin has been shown to improve insulin sensitivity, lowering blood glucose and androgen levels. These effects are more potent when combined with lifestyle interventions. In conclusion, besides reproductive abnormalities, PCOS has been associated to metabolic comorbidities, most of them linked to obesity. Confounders, such as the lack of standard diagnostic criteria, heterogeneity of the clinical presentation, and presence of obesity, make management of PCOS difficult. Therefore, the approach to metabolic abnormalities should be tailored to the risks and treatment goals of each individual woman.

Heart rate variability in adolescents with functional hypothalamic amenorrhea and anorexia nervosa

Aim of this study consisted in assessing the 24-h heart rate variability (HRV), a measure of autonomic nervous system (ANS) imbalance, in 21 adolescents with functional hypothalamic amenorrhea (FHA, 11 normogonadotropic, N-FHA, and 10 hypogonadotropic, Hy-FHA) compared to 21 patients with anorexia nervosa (AN) and 21 controls. As expected, subjects with AN showed a significant dysregulation in multiple HRV parameters, while Hy-FHA patients presented with a dysregulation in a few domains (SDNN, HFr), which was not present in girls with N-FHA, who showed values largely similar to controls. FHA might represent part of the AN biological spectrum, and a link between these two conditions might exist, possibly related to the degree of psychological and/or hormonal dysfunction.

Polymorphisms of TCF7L2 gene in South Brazilian women with polycystic ovary syndrome: a cross-sectional study

OBJECTIVE

To assess whether TCF7L2 single nucleotide polymorphisms rs7903146 C/T and rs11196236 C/T are associated with polycystic ovary syndrome (PCOS) in South Brazilian women.

DESIGN

Cross-sectional study.

METHODS

Two hundred PCOS patients and 102 non-hirsute, ovulatory controls were genotyped by real-time PCR. Haplotypes were constructed from the combination of both polymorphisms. Frequencies were inferred using the PHASE 2.1.1 software.

RESULTS AND CONCLUSIONS

The distribution of rs7903146 (PCOS, 54.4% CC; 28.5% CT; 17.1% TT; controls, 51.0% CC; 37.0% CT; 12.0% TT) and rs11196236 (PCOS, 4.3% CC; 33.5% CT; 62.2% TT; controls, 3.2% CC; 35.5% CT; 61.3% TT) was similar between the groups. rs7903146 and rs11196236 were not in linkage disequilibrium (|D'|=0.34; r(2)=0.07). PCOS participants were younger, with higher age-adjusted BMI, waist circumference, blood pressure, triglycerides, insulin, homeostasis model assessment index to estimate insulin resistance and total testosterone, and lower HDL-C and sex hormone binding globulin vs controls. In PCOS, no differences between genotypes and haplotypes were found for clinical and metabolic variables. However, for each T (rs7903146) and T (rs11196236) allele added to the haplotypes, a variation of 5.87 cm in waist (P trend=0.01), 10.7 mg/dl in total cholesterol (P trend=0.03), and 10.3 mg/dl in LDL-C (P trend=0.01) was recorded. TCF7L2 variants are probably not implicated in PCOS development in South Brazilian women.

Assessment of cardiovascular autonomic function in patients with polycystic ovary syndrome

AIM

The study was conducted to assess the sympathovagal balance in patients with polycystic ovary syndrome (PCOS) using short-term heart rate variability (HRV) analysis and conventional autonomic function tests (CAFT).

METHODS

Thirty-one newly diagnosed patients with PCOS and 30 age-matched controls were recruited. Body mass index (BMI), waist : hip ratio (WHR), cardiovascular parameters such as basal heart rate (BHR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and rate-pressure product (RPP), and fasting blood glucose (FBG) were measured in both groups. Cardiovascular autonomic functions assessed were spectral analysis of HRV, heart rate and blood pressure response to standing (30:15 ratio), deep breathing (E:I ratio) and isometric handgrip (ΔDBP(ihg)).

RESULTS

The cases had significantly increased BMI, WHR, BHR, SBP, DBP and RPP. Ratio of low-frequency to high-frequency power of HRV (LF-HF ratio), the marker of sympathovagal balance was significantly increased in cases compared to controls. Time-domain indices of HRV and E:I ratio were decreased, and 30:15 ratio, ΔDBP(ihg) and FBG were increased in cases. Though there was a significant correlation of LF-HF ratio with BMI, WHR, BHR, RPP and FBG, only BHR and RPP had independent contribution to LF-HF ratio.

CONCLUSION

We conclude that PCOS patients have altered autonomic modulation in the form of increased sympathetic and decreased parasympathetic reactivity and HRV. The sympathovagal imbalance exposes them to cardiovascular morbidities.