Abstract Introduction Mild cognitive impairment (MCI) is the transitional state between normal cognition and dementia. Early diagnosis and appropriate lifestyle interventions at the MCI stage are crucial for the preventing further cognitive decline. Sleep fragmentation and insufficient sleep can increase levels of beta-amyloid and phosphorylated tau. Hypertension has been recognized as a risk factor for cardiovascular diseases. However, there is no consensus regarding the impact of sleep fragmentation and hypertension on MCI in older adults. This study investigated the effects of sleep fragmentation and hypertension on cognitive function in community-dwelling older adults. Methods Thirty volunteers aged ≥ 60 years (mean age 71.8 ± 4.6 years) were included in this study. Participants taking tranquilizers or hypnotic medications and those with moderate-to-severe sleep-disordered breathing (SDB) were excluded. Cognitive performance was assessed using the Mini-Mental State Examination (MMSE) and Touch Panel-type Dementia Assessment Scale (TDAS). We evaluated the total sleep time (TST), sleep efficiency, and wake after sleep onset (WASO) using actigraphy. The sleep complaints were assessed using the Pittsburgh Sleep Quality Index (PSQI). Excessive daytime sleepiness was evaluated using the Epworth Sleepiness Scale (ESS). We compared the data on hypertension, diabetes mellitus, hyperlipidemia, ESS, PSQI, and cognitive performance parameters between participants with TDAS score 7 (non-MCI group) and those with TDAS score ≥ 7 (cognitive decline group). The Chubu University Ethics Review Committee approved the study protocol. All participants were informed of the study objectives and conditions of the study and provided written informed consent prior to the participation. Results The prevalence of hypertension was higher in the cognitive decline group than in the non-MCI group. WASO was significantly longer, and sleep efficiency was significantly lower in the cognitive decline group than in the non-MCI group. There were no significant differences in the age, ESS, or PSQI scores between the cognitive decline group and non-MCI groups. Conclusion Sleep fragmentation and hypertension were associated with cognitive decline in community-dwelling older adults. The evaluation of cognitive function along with actigraphy and blood pressure measurements could yield practical and theoretical implications for MCI. Support (if any)
Noda et al. (2026) studied this question.