Monday, October 31, 2011

Obstructive Sleep Apnea Linked To Sexual Dysfunction

Untreated obstructive sleep apnea (OSA) has been linked to impotence in men and loss of libido in women. Many women report to me in my clinic that they are just too tired ot have sex. However, there are not many formal studies about women with OSA and sexual dysfunction. In the September edition of the Journal of Sexual Medicine, researchers studied the sexual functioning of women with OSA. They studied 80 female patients (28 to 64 years old) who were diagnosed with any severity of OSA after a sleep study. Sexual functioning was assessed with subjective questionnaires and the subjects' responses were compared to a population sample.

The results showed that females with OSA had a higher risk of sexual "distress" and sexual dysfunction. The sexual dysfunction was not related to OSA severity, meaning that even mild OSA can impact their sexual functioning. It's not clear whether treatment of their OSA improves sexual functioning. My clinical experience, however, is that women who report an improvement in sleep quality and daytime sleepiness with OSA treatment do report an improvement in sexual functioning.

Monday, October 24, 2011

Sleep Hygiene Education and College Students

I saw an abstract in the Journal of American College Health where researchers did online surveys of students about their sleep quality and quantity. The students were mostly freshman and many reported problems with sleep that were related to sleep environments that were not conducive to sleep - the room has too much light, too warm, or too noisy. Also, the students had a difficult time winding down before bed and went to bed feeling unprepared for the next day.

The researchers did an educational campaign on campus that included information in the campus newspaper and posters placed in dorms about sleep hygiene. The sleep hygiene tips are the ones commonly presented in other sources of media and include topics like sleep-wake schedule, caffeine, exercise, and sleep environment. The students were then surveyed again and some reported an improvement in sleep quality / quantity after the sleep hygiene educational campaign.

This study does have some limitations (in the way it was carried out) and other studies have not shown that sleep hygiene by itself helps chronic insomnia, but these students were not diagnosed with that disorder. Despite its limitations, this study points out that simple interventions like sleep education can be helpful in improving the sleep habits of college students. And better sleep could improve academic performance.

Monday, October 17, 2011

Duty Hour Restrictions and Resident Education

A few weeks ago, I posted about the financial implications of limiting the number of hours that resident physicians can work. Dr. Schuh and others have done a study on how limiting residents' work hours impact their education.

In this study, they surveyed resident sleepiness, personal study hours, quality of life, and resident satisfaction and faculty satisfaction during two separate months - one where the residents worked the usual hours and the other where the residents worked the new hours reduction as proposed by the Institute of Medicine.

The results showed that end-of-work shift sleepiness, mean weekly sleep hours, personal study hours, and hours spent in lectures did not differ between the control and intervention months. Resident quality of life declined in the intervention month. Resident education satisfaction declined as well, for issues related to continuity of care, patient hand-offs, and knowledge of their patients. Faculty satisfaction declined during the intervention month too. One issue brought up by an editorial on the study was that briefer shifts mean more patient hand-offs, and this could increase physician-to-physician miscommunication and medical errors.

The study authors concluded that limiting resident work hours negatively impacts their education and that further studies are needed prior to implementing widespread duty hour changes.

Thursday, October 13, 2011

CPAP's Long-Term Effects on the Heart

Obstructive sleep apnea (OSA) increases the risk of cardiovascular disease and CPAP has been shown to improve heart structure in the short-term. In the journal Chest, there is an article about how CPAP improves heart structure when used long-term. Researchers studied 47 patients with severe OSA who did not have heart failure. The patients' heart structure was evaluated with echocardiography and cardiac MRI at the start of the study and then serially for one year.

After as little as three months of CPAP use, echocardiography showed improvement in heart structure and lung blood pressures - and these changes continued to improve over the one year follow up. Cardiac MRI showed improvement in heart structure starting at 6 months of CPAP use, and improvements continued over the one year follow up.

The researchers point out that the results are limited by the fact that none of the patients had heart failure at the start of the study, so we really don't know if the same improvements would be seen in those with heart failure and long-term CPAP use.

Saturday, October 8, 2011

Insufficient Sleep in Adolescents Linked to Health-Risk Behaviors

There is a study in Preventive Medicine by the CDC examining the associations between insufficient sleep, defined as less than 8 hours on average on school nights, and health-risk behaviors. Researchers used survey data from 12,154 U.S. high school students. They found that sleeping less than 8 hours on school nights was associated with a higher risk of the following: cigarette, marijuana, and alcohol use; current sexual activity; feeling sad or hopeless and seriously considered attempting suicide; physical fighting, not being physically active, computer use at least 3 hours per day, and drinking soda more than 1 time per day. There was no difference in the amount of television watched between those who slept more or less than 8 hours.

The study authors concluded that insufficient sleep was associated with many health-risk behaviors and that lack of adequate sleep may be a warning sign for parents that their teenagers could have other problems.

I don't believe that the study authors think that teenagers will engage in more healthy behaviors if they get more sleep on school nights. I do wonder if the associations are as strong if teens make up for the lost sleep on the weekends.

Thursday, October 6, 2011

Leg Movements In Sleep and Cardiovascular Disease

Periodic leg movements in sleep (PLMS) are repetitive jerks of one or both legs at night while asleep. The bedpartner notices the leg jerks much more frequently than the patient. The leg jerks can wake up the patient, but usually the awakening is so brief that the person never notices it. These awakenings, however, can lead to daytime sleepiness. PLMS get more common with age. Sometimes they are associated with restless legs syndrome which is the uncomfortable urge to move the legs at night before falling asleep.

Studies have begun to suggest that PLMS can increase the risk of cardiovascular disease and neurocognitive deficits (like memory or concentration problems). Researchers think this occurs because the leg movements cause activation of the sympathetic nervous system - in some cases hundreds of times per night. This nervous system activation can temporarily increase blood pressure and heart rate - over time, this could damage the heart and blood vessels.

There is a study in the journal Circulation where researchers performed in-home sleep studies on 2911 men greater than 65 years old to assess for PLMS and followed them for upto 4 years to assess how many went on to develop cardiovascular disease. Results showed that 70% of the men had PLMS. Patients that had even a mild amount of PLMS had greater rates of cardiovascular disease. Those with more frequent PLMS had 25-30% greater risk of developing cardiovascular disease than those without PLMS.

I wonder if the men with PLMS had subtle obstructive sleep apnea (OSA), as repetitive leg movements in sleep can be due to collapse of the airway. OSA is known to increase the risk of cardiovascular disease. Even if the patients in this study had true PLMS not from OSA, it is not clear if treating the PLMS will reduce the risk of developing cardiovascular disease - more studies are needed for that. In the meantime, it is important to talk to your doctor if your bedpartner notes that you jerk your legs at night while asleep.

Monday, October 3, 2011

Financial Impact of Intern and Resident Duty Hour Changes on Training Institutions.

Interns are physicians who are in their first year of specialty training after graduating medical school. Residents are physicians that are still undergoing specialty training but have completed their internship year. Traditionally, these physicians in training have worked very long hours (ask my lovely wife!). This worked well for the training institutions, as interns' and residents' salaries are paid for by Medicare, meaning hospitals got cheap physician labor. However, medical errors have been blamed on physician fatigue and some physicians have had car accidents after falling asleep behind the wheel after being up all night on call. Over the past several years, there has been a movement to limit work hours of interns and residents in an effort to improve patient safety and physician health. In July 2011, new guidelines were instituted where interns can only work a maximum of 16 hours continuously and must have on-site supervision at all times. Residents can work upto 28 consecutive hours when they are on call.

There is a study in the July edition of the Journal of General Internal Medicine that reviewed how the new work hour limits will affect the financial health of the hospitals that train interns and residents. The results showed that the duty-hour changes would cost $177 to $982 million annually on a nationwide scale. The associated training environment changes will cost an additional $204 million annually. If medical errors decline by 7.2-25.8%, net costs to major teaching hospitals will be zero.

To make up for the extra hours not worked by interns and residents, hospitals would have to hire other providers. The cost of using these other workers depends on the type of worker used to substitute for the interns and residents. The study showed that the total direct annual cost nationwide would be up to $1.34 billion using nurse practitioners/physician assistants, $1.64 billion using attending physicians, $820 million hiring additional residents or $1.42 billion using a mixture of substitutes.

The study authors concluded that if the reforms in duty hours are successful at reducing patient errors, then the cost associated with the new rules will be a good value for the money from a societal perspective.