Summary of key studies on RHR and HRV in women with PCOS.
| Author, year | Country | Sample (n) | PCOS phenotype | Main findings on RHR/HRV | Confounders considered | Measurement method |
|---|---|---|---|---|---|---|
| Yildirir et al., 2006 [14] | Turkey | 30 PCOS vs. 30 controls | Mixed | Lower HRV (↓HF, ↑LF/HF), suggesting sympathetic overactivity | Age and BMI matched | 24-h Holter ECG |
| Hashim et al., 2015 [13] | Iraq | 64 PCOS vs. 40 controls | Rotterdam criteria | Reduced HRV parameters (↓SDNN, ↓rMSSD, ↓pNN50), indicating vagal withdrawal | Age and BMI matched | Resting ECG, time/frequency analysis |
| Di Domenico et al., 2013 [36] | Brazil | 46 PCOS | Rotterdam criteria | Sympathetic predominance in hyperandrogenic phenotype; blunted HRV reactivity during stress | Controlled for BMI, age | Tilt test + HRV analysis |
| Ji et al., 2018 [11] | Korea | 35 PCOS vs. 32 controls | Rotterdam criteria | Elevated LF, LF/HF; reduced HFnu → sympatho-vagal imbalance | Adjusted for BMI, metabolic profile | 5-min ECG HRV |
| Ollila et al., 2019 [34] | Finland (Northern Finland Birth Cohort 1966) | 160 women (~46 years, 30 with PCOS) vs. 1029 controls | Self-reported + records | Lower vagal HRV indices (rMSSD, HF power) in PCOS, but attenuated after adjusting for metabolic factors | Adjusted for BMI, insulin, BP, lipids | Standardized short-term HRV |
| Sverrisdóttir et al., 2008 [30] | Sweden | 20 PCOS vs. 18 controls | Rotterdam criteria | Elevated MSNA; correlated with testosterone | BMI, age | Microneurography |
| Özkeçeci et al., 2016 [39] | Turkey | 23 PCOS vs. 25 controls | Mixed | Lower HRV + abnormal heart rate turbulence; indicates autonomic dysfunction | Excluded smokers, chronic disease | 24-h Holter ECG |
| Zachurzok-Buczynska et al., 2011 [10] | Poland | 34 PCOS vs. 17 controls (adolescent girls) | AES/AE-PCOS | PCOS participants, particularly those with obesity, exhibited higher mean 24-h and nocturnal heart rate compared with matched controls, alongside reduced parasympathetic HRV indices and increased sympathetic dominance | Age, BMI, blood pressure, insulin resistance, lipid profile | 24-h ambulatory ECG and blood pressure monitoring (Holter-based heart rate and HRV analysis) |
AES/AE-PCOS: Androgen Excess and Polycystic Ovary Syndrome Society Criteria; BMI: body mass index; BP: blood pressure; ECG: electrocardiogram; HF: high frequency; HFnu: HF normalized units; HRV: heart rate variability; LF: low frequency; LFnu: LF normalized units; MSNA: muscle sympathetic nerve activity; NIH: National Institutes of Health; PCOS: polycystic ovary syndrome; PNN50: percentage of NN intervals greater than 50 milliseconds; RHR: resting heart rate; rMSSD: root mean square of successive differences; SDNN: standard deviation of NN intervals; →: leads to.