Monday, October 25, 2010

Sleep Apnea Treatment, Stroke Recovery, and Cardiovascular Events

In the September 16th edition of the European Respiratory Journal, there was a study done to assess the benefits of early CPAP treatment on funtional outcome, quality of life, and rates of new cardiovascular events and mortality in patients who suffered their first stroke.

In this study, 325 patients were randomized to CPAP treatment or a control group that did not receive CPAP. 90.5% of the CPAP group had improvements in neurological assessments in one month, which was significantly greater than the 56.3% that showed improvement in the control group. Beyond one month though, results between the two groups did not differ significantly.

Cardiovascular mortality rates did not differ significantly between the two groups. However, the average time from the stroke to the first cardiovascular event was significantly longer in the CPAP group (15 months) than in controls (8 months). This implies that CPAP might help delay the onset of new cardiovascular events in a patient population already at high risk for cardiovascular disease.

Wednesday, October 20, 2010

Sleeping Pills and Death Risk

In the September issue of the Canadian Journal of Psychiatry, a study was performed to assess the mortality risk associated with sleeping pills and anti-anxiety medications. The study involved over 14,000 people aged 18 to 102 who participated in the National Population Health Survey in Canada between 1994 and 2007. Every two years, participants were asked if they used sleeping pills or anti-anxiety medications in the past month.

The overall mortality rate for the entire population was 11.55%. In respondents who took sleeping pills or anti-anxiety pills, the rate was 15.56%. In respondents who said they did not take sleeping pills or anti-anxiety medications, the mortality rate was 10.52%.

After controlling for other factors like alcohol and tobacco use, physical health, physical activity level, and the presence of depression, the mortality rate was still slightly higher in those participants who reported they took sleeping pills or anti-anxiety medications.

The study authors proposed different explanations. Benzodiazepines like Valium could impair reaction time, coordination, alertness, and memory, which then could lead to falls and other accidents. Benzodiazepines could also depress the respiratory system, which could aggravate sleep-related breathing disorders.

Limitations of the study include the fact that medication use was assessed using only two questions. There was no control for the presence of anxiety disorders, whereas the study did control for depression. Also, self-reported data like this survey can introduce a number of biases.

The authors recommend that physicians consider alternative, non-pharmacological treatment of insomnia and anxiety, like cognitive-behavioral therapy, a form of psychotherapy.

Saturday, October 9, 2010

Obstructive Sleep Apnea and Coronary Artery Disease

In 2005, a study was undertaken to to address the impact of continuous positive airway pressure (CPAP) on patients who had undergone revascularization for coronary artery disease (CAD) and who had documented obstructive sleep apnea (OSA). The study is still ongoing, and researchers have found that the prevalence of OSA is 64% in the CAD population. Hypertension, or high blood pressure, is 58% and obesity is 28% prevalent in CAD.

Patients with CAD and OSA were older, more obese, more often male gender, and had higher incidence of hypertension, diabetes, and atrial fibrillation than those patients with CAD but not OSA.

Interestingly, the risk of CAD was the same in patients with OSA, regardless of their level of sleepiness. And the only difference in the comorbidities of sleepy versus non-sleepy OSA patients was obesity, which was more common in the sleepy OSA patients.

The researchers also studied CPAP compliance. At one year of follow-up, 70% of sleepy OSA patients with CAD were still using their CPAP compared to 60% of non-sleepy OSA patients. This makes sense, as more symptomatic OSA patients are more likely to keep using their CPAP.

The study will conclude in 2012 and the researchers are hoping to prove that treatment of OSA with CPAP will offer patients a non-pharmacologic intervention to reduce the risk of cardiovascular disease.

Monday, October 4, 2010

Older Women and Sleep Apnea Symptoms

There is a summary from Reuters of an article in the September 3rd online paper in the European Respiratory Journal Express. The study authors examined 379 women and 262 men with obstructive sleep apnea (OSA) ages 65 to 70 years old. Specifically, it looked at the different symptoms of OSA in older men versus women.

In this study, more men had severe OSA than women. Men also had a greater body mass index. The women were less likely to report snoring, apnea, or sleepiness, and more likely to be anxious and depressed, and be taking antidepressants and anti-anxiety medications.

This goes along with my clinical experience. Women (not just older women) report less snoring and apneas than men. It could be because they don't snore as much or as loud. Also, their husbands are sometimes less in tune to their wives sleep problems. Since patients rely on bed partners to note snoring or apneas, some women might never realize they are doing that in their sleep. All they know is that they might not sleep well or feel tired or sleepy in the daytime.

Finally, the study authors said older women with OSA were a greater hypertensive (high blood pressure) risk than men, and therefore may have greater cardiovascular mortality and morbidity. This would emphasize the need for early diagnosis to prevent cardiovascular risk. This is true to a point. When a patient reaches a certain age, treating OSA just to prevent cardiovascular disease becomes a "numbers" game. In other words, treating asymptomatic OSA in an 85 year old (male or female) is less likely to prolong life than in a 55 year old, since the 85 year old has already lived longer than the average US lifespan. However, often I suggest treatment in the older patients to improve quality of life, even in those who do not endorse overwhelming symptoms.