Women Who Snore: Clinical Implications
By Carlos A. Vaz Fragoso, MD, FCCP
Medical Director, Gaylord Sleep Services
A recently published study in the Journal of the American College of Cardiology (2000; 35(2); 308-313) has broken new ground by investigating whether snoring in women increases the risk for cardiovascular disease (CVD). This study is important because previous research has been limited to men, sample sizes have been small, and the methodology has not been prospective.

The prevalence of snoring in all adults is relatively high. Thirty-four percent of adults report snoring, with the greatest number falling between 30-64 years of age. Of those who snore, 19 percent are so loud they can be heard through a closed door (National Sleep Foundation 1999 Onmibus “Sleep in America” Poll).

However, most people who snore do not have Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS). Only about four percent of men and two percent of women have symptomatic OSAHS with daytime drowsiness. Twenty-five percent of men and 10 percent of women, however, report asymptomatic OSAHS (Am J Respir Crit Care Med 1998; 157:335-341).

The newest study included 71,79 female nurses ages 40-65 years without previously diagnosed CVD or cancer at a baseline evaluation in1 986. Snoring frequency was also assessed by mailed questionnaires at baseline. Longitudinal follow-up was for eight years. After adjusting for smoking, body mass index, and other covariates, the association between snoring and CVD was statistically significant at an age-adjusted relative risk (RR) of 1.20 for occasional snorers [confidence intervals (CI)=1.01-1.43] and a RR of 1.33 for regular snorers [CI=1.15-1.77]. Overall, the age-adjusted RR was 1.43 for occasional snorers [CI=1.01-1.43] and 2.18 for regular snorers [CI=1.65-2.87]. This data suggests that snoring in women is associated with a modest but significant risk for CVD.

Previous studies have also demonstrated an increased prevalence of hypertension, CVD, cerebrovascular disease and cognitive impairment in those who snore (Chest 1996; 109:201-222; Sleep 1999; 22:205-209). In addition, snoring can be socially disruptive, necessitating complicated bedroom and social arrangements (Chest 1999; 115:762-770; Chest 1996; 109:201-222; May Clin Proc 1999; 74:955-958).

These studies clearly highlight the public health risk of snoring in both men and women, even when the condition falls outside the current clinical definition of the OSAHS. Future research, perhaps, will clarify exactly how snoring contributes to cardiovascular and other diseases.

Why Can’t Women Sleep?

Women are twice as likely as men to have difficulties falling asleep or staying asleep. Here’s why:

Menstrual Cycle

During the premenstrual period, sleep is disrupted by an increased number of awakenings, more vivid dreaming, and longer sleeping hours. This may lead to considerable daytime drowsiness and fatigue.

Pregnancy

The first trimester of pregnancy is characterized by longer sleeping hours and daytime fatigue. During the second and third trimesters, there is a progressive increase in the number of awakenings as well as a decline in the amount of deep sleep. Sleeping in certain positions may become problematic. After delivery, disrupted sleep can often be linked to postpartum depression and child abuse.

Perimenopause

As women age, sleep becomes more fragmented, with reductions in the amount of deep sleep. In the perimenopausal period, hot flashes and night sweats may cause repeated awakenings associated with sweating, palpitations and anxiety.

Postmenopause

In these later years women often experience continued disruption of sleep continuity and quality. As a result of these age-dependent changes, bedtimes occur earlier, sleep is shorter in duration and less restorative, and sleep-wakefulness is redistributed across the 24-hour day. The latter may result in perceived daytime fatigue and habitual napping. Medical illnesses will exacerbate the severity of these changes.