Overnight Heart Rate Variability During Sleep Disturbance In Peri- And Postmenopausal Women

ABSTRACT

Objectives

Disturbed sleep, common during the climacteric, is associated with increased sympathetic activity, a cardiovascular risk factor. We evaluated sleep disturbance effect on autonomic nervous function in climacteric women

Methods

Seventeen perimenopausal and 18 postmenopausal women underwent a sleep study protocol: an adaptation night, a reference night, and a sleep disturbance night, with a hand loosely tied to the bed to allow blood sampling. This procedure was repeated after six months of menopausal hormone therapy (MHT) or placebo. Sleep disturbance and MHT effects on overnight heart rate variability (HRV) were analyzed.

Results

At baseline, sleep disturbance increased vagal HRV in postmenopausal women, but no changes were seen in perimenopausal women. At six months, sleep disturbance increased total HRV power in the perimenopausal placebo group, and increased nonlinear vagal HRV in the postmenopausal placebo group, but no other changes were seen. MHT did not have any effects on HRV, neither at perimenopause nor at postmenopause.

Conclusions

External sleep disturbance had only minor effects on HRV across menopause. MHT had no detectable HRV effects.

KEYWORDS:

• Sleep
• menopause
• HRV
• aging
• gender
• hormone therapy

Acknowledgments

This study was financially supported by grants from the European Commission (QLK6-CT-2000-00499), the Väinö and Laina Kivi Foundation (P.P-K., N.K.), The Finnish Menopause Society Foundation (P.P-K.), The Finnish Medical Foundation (P.P-K.) the Turku University Foundation (P.P-K.), the TYKS foundation (N.K.), the Finnish Anti-Tuberculosis Foundation (N.K.) and the Finnish Government (I.V.). The funding sources have not been involved in the design or reporting of the study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the Finnish menopause society foundation Finnish government Suomen Lääketieteen Säätiö Suomen Tuberkuloosin Vastustamisyhdistyksen Säätiö Turun Yliopistollisen Keskussairaalan Koulutus- ja Tutkimussäätiö Turun Yliopistosäätiö Väinö ja Laina Kiven Säätiö .