PMID 35329952

Research
All papers

Cardiovascular Health Does Not Change Following High-Intensity Interval Training in Women with Polycystic Ovary Syndrome

Kiel IA, Jones H, Lionett S, Røsbjørgen R, Lydersen S, Vanky E, Moholdt T

Question

Do women with PCOS differ from BMI- and age-matched women without PCOS in cardiovascular risk markers, and does 16 weeks of HIIT change those markers?

Summary

This secondary analysis of PCOS exercise trials found that 16 weeks of semi-supervised HIIT had little effect on selected cardiovascular risk markers in women with PCOS. Resting heart rate decreased within the PCOS HIIT group, but FMD, IMT, MMP-9, and most blood pressure/metabolic markers did not improve. Low adherence and lifestyle changes in the control group make the cardiovascular findings hard to interpret.

Methodology

  • Women aged 18-45 with PCOS by Rotterdam criteria plus age- and BMI-matched women without PCOS.
  • 79 participants.
  • Treadmill walking/running supervised; outdoor walking/running allowed unsupervised.
  • Work intervals: Either 4 minutes or 1 minute depending on assigned HIIT protocol.
  • Recovery: HV-HIIT: 3 minutes active recovery at about 70% HRmax; LV-HIIT: 1 minute low-intensity walking or passive recovery.
  • Intensity: HV-HIIT 90-95% HRmax; LV-HIIT maximal intensity participants could sustain.
  • HV-HIIT about 38 minutes including 10 minute warm-up and 3 minute cool-down; LV-HIIT about 33 minutes including warm-up/cool-down.
  • Offered 3 sessions/week; up to 2 could be unsupervised.
  • 16 weeks.
  • Secondary analysis of a two-center RCT in women with PCOS plus case-control HIIT trial in women without PCOS
  • Endothelial function, Carotid intima-media thickness, Blood pressure and resting heart rate, and Circulating markers were tracked.

Outcomes

Resting heart rate

Resting heart rate declined within the PCOS HIIT group.

PCOS HIIT p=0.037; abstract reports -2.8 beats/min, 95% CI -5.4 to -0.2.

Improved

Vascular function

Women without PCOS increased resting brachial artery diameter after HIIT, while PCOS HIIT showed a different time-to-peak dilation response versus non-PCOS HIIT; FMD did not clearly improve.

Non-PCOS resting diameter +0.12 mm, 95% CI 0.01 to 0.24, p=0.038; time-to-peak difference PCOS HIIT vs Non-PCOS HIIT 55 s, 95% CI 13 to 96, p=0.012.

Mixed

MMP-9

MMP-9 did not differ by PCOS status and did not change within or between groups after 16 weeks.

No within- or between-group differences reported.

No clear change

Cardiometabolic markers

The PCOS non-exercise group unexpectedly improved body weight, BMI, systolic BP, HDL, insulin, and HOMA-IR, limiting interpretation of HIIT effects.

PCOS Non-Ex body weight and BMI p<0.001; systolic BP p=0.001; HDL p=0.010; insulin p=0.026; HOMA-IR p=0.032.

Mixed

Insights

  • HIIT did not clearly improve cardiovascular risk markers in this PCOS analysis beyond resting heart rate.
  • Low adherence can dilute expected HIIT effects; app programs need adherence support and realistic schedules.
  • Lifestyle changes in control groups can strongly affect exercise-study interpretation.

Limitations

  • Secondary outcome analysis not powered specifically for these vascular outcomes.
  • Low sample size for FMD and IMT subgroups.
  • Suboptimal adherence to prescribed HIIT protocols.
  • Control-group lifestyle changes limited between-group inference.
  • Some exercise training data were missing because sessions were not registered in Polar Flow.

Safety

  • Ten participants dropped out and five became pregnant during the intervention period and were excluded from analysis.
  • No exercise adverse events were described in the the paper.
  • Participants were screened to exclude cardiovascular disease and other endocrine disorders.