Sleep Apnea – Michigan Brain & Spine Surgery Center

Do Sleep Patterns Affect the Risk of Cognitive Decline?

Michigan Brain & Spine — Tue, 18 Sep 2012 22:00:10 +0000

VANCOUVER—The quality and quantity of sleep may be associated with the risk for cognitive decline, according to four studies presented at the 2012 Alzheimer’s Association International Conference. Treatments for insomnia or circadian rhythm delay might reduce or prevent cognitive decline, investigators reported.

Sleep Duration and Cognition
Compared with a sleep duration of seven hours per day, sleep durations of five or fewer hours per day and of nine or more hours per day were associated with worse average memory at older ages, according to Elizabeth Devore, ScD, Associate Epidemiologist at Brigham and Women’s Hospital in Boston. Short and long sleep durations at midlife and in later life were both associated with worse memory in later life.

Dr. Devore and her colleagues examined 15,263 women age 70 or older who had participated in the Nurses’ Health Study. The researchers performed one initial cognitive assessment and three biennial follow-up assessments of each participant. At baseline, the subjects reported sleep duration in midlife and in later life. The investigators used multivariable-adjusted mixed linear regression models to estimate mean differences in slopes of cognitive decline in several categories of sleep duration. Multivariable-adjusted linear regression was used to estimate mean differences in overall cognitive status at older age.

Women with sleep durations that changed two hours per day or more between midlife and later life had worse average memory at older ages, compared with those whose sleep duration did not change. “Regardless of where women started out in midlife, in terms of their sleep duration, the big changes seemed to be a problem for memory,” said Dr. Devore. “These findings indicate that extreme sleep durations or greater changes in sleep duration over time may contribute to cognitive decrements in older adults.”

Delayed Acrophase May Increase Risk of Dementia
People who experienced a shift in circadian rhythm acrophase had a risk of dementia nearly double that of people whose circadian rhythm remained stable, said Kristine Yaffe, MD, Professor of Psychiatry, Neurology, Epidemiology, and Biostatistics at the University of California, San Francisco. The finding was particularly true for patients whose shift was toward the later part of the day. Circadian rhythms that were not pronounced were also associated with an increased risk of dementia and mild cognitive impairment.
The results stem from Dr. Yaffe’s prospective study of 3,000 community-dwelling women. At enrollment, all participants were age 65 or older. At year 15, Dr. Yaffe and her colleagues assessed patients’ sleep parameters through actigraphy and polysomnography. Five years later, the researchers assessed patients’ cognitive outcomes through a battery of neuropsychologic tests. Patients’ clinical cognitive status was adjudicated.

Women with sleep-disordered breathing at baseline had nearly double the risk of developing dementia or mild cognitive impairment five years later, compared with women without sleep-disordered breathing. “It seems to be the hypoxia that’s related to risk of dementia and mild cognitive impairment, [not] the sleep fragmentation issue,” Dr. Yaffe commented.

This study may help explain why people with advanced dementia have alterations in their sleep–wake cycles, she added. “There may be some links between circadian shifts and amyloid-beta deposition in the brain. It may be possible that we could intervene and then delay, or somehow prevent, some of the cognitive sequelae.”

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CPAP May Ease Depression

Michigan Brain & Spine — Mon, 18 Jun 2012 05:02:19 +0000

By Ed Susman, Contributing Writer, MedPage Today

Published: June 14, 2012.
Reviewed by Zalman S. Agus, MD; Emeritus Professor, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner

Obstructive sleep apnea patients who use — or even try to use — continuous positive airway pressure (CPAP) devices appear to reduce their overall depressive symptom scores, researchers said here.

In every category measured, patients reduced depressive symptoms, even if they were not using the CPAP devices as prescribed, Charles Bae, MD, of the Cleveland Clinic College of Medicine at Case Western Reserve University told attendees at the annual meeting of the Associated Professional Sleep Societies.

In the key endpoint of decrease of symptoms on the Patient Health Questionnaire, patients who used the devices for 4 hours or more achieved a 3.8-point reduction in scores, compared with a two-point reduction among patients who used the devices less than 4 hours a night (P=0.0009).

“All groups that we measured showed decreases in depressive symptom scores,” Bae told MedPage Today. “We observed reductions in people who used the devices correctly; in patients who didn’t use it correctly or used it less than 4 hours; we observed decreases in these scores if patients had daytime sleepiness; or if they were married or not married.”

He suggested that when people get better sleep, it tends to improve their outlook on other aspects of life.

Bae explained that multiple studies have shown that depressive symptoms are associated with sleep apnea, but there have been conflicting reports as to whether treatment with CPAP improves depressive symptoms. Until his work was performed, no studies had looked at the benefit of CPAP therapy on mood using the Patient Health Questionnaire 9 as a measure of the severity of depressive symptoms.

In his retrospective study, Bae reported on outcomes of 769 patients who filled out the questionnaire between 2008 and 2011. These patients had completed the health questionnaires in the office or at their homes.

The study included individuals 18 years of age or older who had been diagnosed with sleep apnea. They were required to have visited their doctors one time before starting treatment with CPAP and then to have made a second visit at least 30 days later. Patients were not included in the study if they failed to make a follow-up visit.

The average age of the patients in the study was 51.8; 47.3% of the cohort were men; about three-quarters were Caucasian; and 62% were married.

The 654 patients who were adherent in use of CPAP had an average baseline depressive symptom score of 11.2 on the Patient Health Questionnaire 9 and that score dropped 3.8 points, while the 115 non-adherent patients’ scores dropped from baseline of 11.8 to 9.8 – a two-point decrease. The difference in change was statistically significant between the groups (P=0.0009).

“The results were more robust if the patients had expressed sleepiness,” Bae reported. The 475 patients adherent with the therapy who had scored 10 or higher on the Epworth Sleepiness Scale achieved a four-point reduction on the Patient Health Questionnaire 9 compared with a 2.8-point reduction among sleepy subjects who did not adhere to therapy (P=0.0032).

In the 475 married patients, the Patient Health Questionnaire 9 showed a four-point drop after therapy; single individuals had a three-point drop and divorced patients achieved a 2.3-point drop. The difference between divorced and married patients was significant (P=0.0083), Bae said.

“Patients with sleep apnea who are adherent with positive airway pressure therapy – using it more than 4 hours a night — compared to those who are not adherent will have a greater decrease in the Patient Health Questionnaire 9 score,” Bae said.

“These results are not surprising,” said George Thommi, MD, clinical assistant professor of pulmonology at Creighton University School of Medicine, in Omaha, Neb., who was not involved in the study. “I have had several patients myself who have improved depressive symptoms after using positive airway pressure devices.”

He told MedPage Today that the devices help improve sleep. “When you sleep better, you are more likely to feel better and not be as depressed. This work is consistent with what I see in my clinical practice.”

CPAP for Sleep Apnea May Prevent New Hypertension

Michigan Brain & Spine — Sat, 26 May 2012 15:37:30 +0000

May 23, 2012 — A pair of studies released this week confirm an association between obstructive sleep apnea (OSA) and hypertension, and hint that adherent continuous positive airway pressure (CPAP) therapy may reduce the risk for new-onset hypertension.

Vishesh K. Kapur, MD, MPH, and Edward M. Weaver, MD, MPH, both from the University of Washington in Seattle, add that treatment of OSA “may not only reduce blood pressure (although modestly on average), but if confirmed by future studies also may prevent hypertension in at-risk patients. Thus, OSA deserves attention in patients with or at risk of developing hypertension as a potentially treatable cause of hypertension as well as other clinically important outcomes.”

A Modifiable Risk Factor

In their paper, José M. Marin, MD, from the Hospital Universitario Miguel Servet in Zaragoza, Spain, and colleagues report results of an observational cohort study of 1889 adults without hypertension referred for polysomnography between January 1, 1994, and December 31, 2000.

Among the 1579 patients with OSA, 462 were ineligible for CPAP therapy according to national treatment guidelines, 195 were eligible but declined CPAP, 98 were eligible and started CPAP but were nonadherent, and 824 were eligible and adhered to CPAP.

During a median follow-up of 12.2 years, 705 patients (37.3%) developed hypertension. “Compared with participants without OSA, untreated OSA was associated with an increased risk of new-onset hypertension, whereas treatment with CPAP therapy was associated with a lower risk of new-onset hypertension,” Dr. Marin told Medscape Medical News.

Table. Risk for Hypertension With OSA

Group	Adjusted Hazard Ratio (95% Confidence Interval)
Ineligible for CPAP	1.33 (1.01 – 1.75)
Declined CPAP	1.96 (1.44 – 2.66)
Nonadherent to CPAP	1.78 (1.23 – 2.58)
CPAP therapy	0.71 (0.53 – 0.94)

“OSA appears to be a modifiable risk factor for new-onset hypertension. Such findings are clinically relevant considering that OSA, despite a high prevalence in Western populations, remains overwhelmingly unrecognized and untreated,” Dr. Marin said.

In a separate paper, Ferran Barbé, MD, from the Institut de Recerca Biomedica, Lleida, Spain, and colleagues report results of a randomized, controlled trial (RCT) testing the effects of CPAP on incident hypertension or cardiovascular events in 723 adults with OSA but without daytime sleepiness. There were 357 adults in the CPAP group and 366 in the control group (usual care).

During follow-up lasting a median of 4 years, there were 68 cases of new hypertension and 28 cardiovascular events in the CPAP group, compared with 79 cases of new hypertension and 31 cardiovascular events in the control group.

In the CPAP group, there was a trend toward a reduction in the incidence of hypertension and cardiovascular events that did not reach statistical significance. The incidence of new hypertension or cardiovascular event per 100 person-years was 9.20 (95% confidence interval [CI], 7.36 – 11.04) in the CPAP group vs 11.02 (95% CI, 8.96 – 13.08) in the control group (incidence density ratio, 0.83; 95% CI, 0.63 – 1.1; P = .20).

However, the investigators note that their study may have limited power to detect a significant difference, and that a larger study or longer follow-up might have been able to identify a significant association between treatment and outcome.

They point out that a post hoc analysis “suggested that CPAP treatment may reduce the incidence of hypertension or cardiovascular events in patients with CPAP adherence of 4 h/night or longer.”

“This is the first RCT to focus on the effects of CPAP treatment in the prevention of hypertension and cardiovascular events in patients with sleep apnea,” Dr. Barbé added in comments to Medscape Medical News. “Our results show that when the patients use CPAP for more than 4 hours per night there is a reduction in the incidence of hypertension and cardiovascular events.”

Dr. Barbé’s advice: “If you want to prevent cardiovascular events or the development of hypertension, push your patients to use CPAP treatment for more than 4 hours per night.”

Questions Remain

In their editorial, Dr. Kapur and Dr. Weaver write that, “Taken together, these studies augment the evidence that the presence of OSA poses a risk for incident hypertension and provide strong but not definitive evidence that CPAP therapy may reduce the risk. In nonsleepy patients with OSA, the effect of CPAP therapy prescription remains unclear.”

They also note that many questions remain regarding OSA, hypertension, and treatment, including:

What are the susceptible and responsive subgroups (eg, OSA severity subgroups, sleepy vs nonsleepy patients, and demographic subgroups)?
How much CPAP use is necessary for an important treatment effect?
What are the effects of other OSA treatments?

These questions, Dr. Kapur and Dr. Weaver say, “will require RCTs when feasible, subgroup analyses within these trials, and well-controlled observational studies. Novel approaches are needed, such as treatment withdrawal protocols.”

Despite lingering questions, they conclude, “considerable evidence supports the role of identification and treatment of OSA to improve symptoms, quality of life, and cardiovascular end points.”

Both studies were supported by grants from the Instituto Carlos III, Ministry of Health, Madrid, and the Spanish Society of Respiratory Medicine. The study by Dr. Barbé was also supported by Resmed (Bella Vista, Australia), Air Products-Carburos Metalicos (Barcelona), Respironics (Murrysville, Pennsylvania) and Breas Medical (Madrid). The study authors have disclosed no relevant disclosures. Dr. Kapur reported having owned stock within the last 3 years in Merck, Johnson & Johnson, and Bristol-Myers Squibb. Dr. Weaver had disclosed no relevant financial relationships.

JAMA. 2012;307:2161-2168, 2169-2176, 2197-2198.