CHAPTER 6: GENERAL DISCUSSION
6.5 Overarching conclusions
In summary, this thesis examined the relationship between cognition and OSA in older adults with and without MCI, and whether the treatment of sleep apnoea can improve cognitive functioning and mood in patients with comorbid OSA and MCI. Results indicated that
multiple aspects of OSA, including severity, intermittent hypoxia and SWS were significantly linked to the impairment in several cognitive domains (i.e., global cognition, working
memory, verbal declarative memory, attention and processing speed). The trial of CPAP therapy in patients with OSA and MCI showed promising results. Three months of CPAP therapy in this patient population can improve global cognition, logical memory, specific autobiographical memory and daytime sleepiness. Given the small sample size, these findings need to be confirmed in a larger study. However, these findings provide evidence that CPAP
149 therapy has the potential to improve cognitive functioning in a subset of MCI patients that have OSA. This is important information for clinicians as sleep apnoea is treatable and clinicians can potentially eliminate a significant risk factor of cognitive decline through proper management of sleep apnoea. The prevalence and incidence rates of dementia is projected to increase over the next 40 years (Brown, Hansnata & La, 2017). As there is no known cure, interventions to delay onset or reduce risk of conversion have mainly focused on treating modifiable factors. The current thesis provides preliminary evidence of OSA as a potential modifiable factor. Further longitudinal research is required to better understand the role of sleep apnoea on cognitive functioning and mood in MCI patients, and if early
150
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