Ketogenic Dietary Effects on Sleep, Cognition and Behavior in MCI: Baseline Sleep Results

Abstract

AbstractBackgroundSleep disturbances in dementia occur often, are reported as neuropsychiatric symptoms, and are associated with higher caregiver burden and institutionalization. In mild cognitive impairment (MCI), sleep changes co‐occur with increasing neuropsychiatric symptoms and cognitive decline. Diet quality, like sleep, is a modifiable risk factor for Alzheimer’s disease. It is unknown how dietary interventions may impact sleep quality. This controlled clinical trial investigates for the first time a modified Mediterranean ketogenic diet (MMKD) compared to a low‐fat American Heart Association diet (AHAD) over 4 months on multiple sleep indices in adults with amnestic MCI. Here we report our baseline sleep findings.MethodThe WatchPAT Central Plus, an FDA approved home sleep test, was used to assess sleep quality. The WatchPAT quantifies numerous measures including total sleep time, pulse and sleep efficiency. Sleep‐disordered breathing is measured via the apnea‐hypopnea index (AHI) and oxygen‐desaturation index (ODI). Time spent in sleep stages is also quantified along with full night oxygen saturation and pulse rate. Independent samples t‐tests compared baseline sleep differences among male and female MCI participants.ResultA total of 64 MCI participants completed the baseline sleep assessments (mean age 70.2±7.0, BMI 27.0±4.3; 64.1% women). Mean sleep duration was 6 hrs46 min and 83.9% sleep efficiency. Mean AHI was 17.3±12.2 and mean ODI was 8.2±7.5 measured as >3% 02 desaturations, indicating on average moderate severity sleep apnea (AHI>15). Overnight sleep percentage by sleep stage (estimated from heart rate and accelerometer) averaged 15.4% in deep sleep and 22.3% in REM sleep. Mean REM latency was 105 minutes. Oxygen saturation averaged 94% and pulse, 61 bpm. Women had higher resting pulse (64.3bpm, p<.001). Sleep measures did not significantly differ by sex.ConclusionThe MCI sample, on average, had moderate severity sleep apnea at baseline, with sleep duration and efficiency slightly below standard recommendations of 7‐8 hours and efficiency > 85%, respectively. Future work will compare longitudinal changes in sleep quality across diet intervention groups. Understanding potential therapeutic effects of the MMKD on sleep quality and cognitive change will be vital in adding to the portfolio of targeted non‐pharmacological interventions for Alzheimer’s disease prevention.