Mild Cognitive Impairment and Obstructive Sleep Apnea
Condition: Obstructive Sleep Apnea; Mild Cognitive Impairment
MeSH terms: Apnea; Sleep Apnea Syndromes; Sleep Apnea, Obstructive; Cognitive Dysfunction
Study type: Interventional

Summary: 
      Obstructive sleep apnea (OSA) has been linked to increased risk for Alzheimer's disease (AD),
      but little prospective evidence exists on the effects of OSA treatment in preclinical AD. The
      objective was to determine if CPAP treatment adherence, controlling for baseline differences,
      predicts cognitive and everyday function after 1 year in older adults with MCI and to
      determine effect sizes for a larger trial. The aim of the Mild Cognitive Impairment and
      Obstructive Sleep Apnea (Memories 1) trial was to determine whether CPAP treatment adherence,
      controlling for any baseline differences in OSA severity, ApoE4, and other previously
      identified demographic and patient factors, might predict cognitive and everyday function
      after 1 year in older adults with amnestic MCI.
    

Detailed description: 
      In this prospective open label clinical trial, primary inclusions were age 55-89 years and
      apnea-hypopnea index ≥ 10. Groups were: (1) MCI, OSA, and CPAP adherent (MCI+CPAP); (2) MCI,
      OSA, CPAP nonadherent(MCI-CPAP). There were 68 MCI+OSA participants at baseline, and 14 (21%)
      dropped out during the 1 year follow-up. At 1 year, n=54, with MCI+CPAP group n=29, and
      MCI-CPAP group n=25. Statistically significant improvements in psychomotor/cognitive
      processing speed in the MCI+CPAP group versus the MCI-CPAP group were observed at 1 year
      after adjustment for age, race, and marital status. There were small to moderate effect sizes
      (ES) for memory, attention, daytime sleepiness, and everyday function, favoring the MCI+CPAP
      group versus the MCI-CPAP group.
    

Intervention name(s): CPAP adherence intervention; Attention control intervention
Intervention type(s): Behavioral; Behavioral
Intervention description(s): Critical factors were (1) OSA education, treatment expectations, and ways to minimize barriers and facilitate CPAP use; (2) promotion of a positive initial CPAP experience; (3) motivational interviewing to reinforce participants' health-related goals and CPAP self-efficacy; (4) anticipatory guidance and follow-up of common CPAP problems; and (5) social support by a study partner. Trained project staff provided the intervention by phone and face to face for a total of 12-14 hours over the 1 year project.; This intervention, provided by phone and face to face by project staff, provided equal time and attention. Critical factors were (1) education about OSA and risks, (2) education about memory, and other health topics of interest to the participants; (3) motivational interviewing to reinforce participants' health-related goals; (4) building rapport, and (5) social support by a study partner.
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Intervention model description: Memories 1 was originally designed as a 6-month double-blind randomized controlled pilot trial of active versus placebo CPAP followed by a 6-month open label trial. However, after 1 year of recruitment of 371 individuals, no one consented to be randomized. Both older adults with MCI and their physicians perceived the placebo arm as an unnecessary risk. Although CPAP eliminates OSA, it must be consistently used for at least 4 hours per night for a therapeutic response, and only 30-60% of individuals prescribed CPAP adhere to it. The investigators, the study Data Safety Monitoring Board, and the NIH approved a change to a quasi-experimental study with 2 comparison groups: 1) an MCI, OSA, and CPAP adherent group (MCI+CPAP, ≥4 hr mean CPAP use per night for 1 year); and (2) an MCI, OSA, CPAP non-adherent group (MCI-CPAP, <4 hr mean CPAP use per night for 1 year). The final sample at 1 year consisted of 54 older adults with MCI: (1) MCI+CPAP, n = 29; and (2) MCI-CPAP, n = 25.
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: apnea; cognition; memory; function; amnestic mild cognitive impairment; older adults; Alzheimer's Disease