Effects of sleep-disordered breathing and hypertension on cognitive function in elderly adults

ABSTRACT

Purpose: The prevalence of sleep-disordered breathing (SDB) increases with aging. SDB is a risk of hypertension, and both might lead to cognitive decline. However, the role of SDB and hypertension on the pathogenesis of age-related cognitive decline remains unclear. We examined the effects of these two diseases on cognitive function in elderly adults.

Methods: Fifty-two elderly individuals (mean age, 69.6 ± 4.0 years) free from impairment in daily living activities participated in this study. Apnea/hypopnea index (AHI) and minimum oxygen saturation (SpO₂) were assessed using a portable home monitoring device. We evaluated excessive daytime sleepiness with the Epworth sleepiness scale (ESS). Cognitive performance was assessed using the Wisconsin card sorting test (WCST), continuous performance test-Identical pairs (CPT-IP), and N-back task. Hypertension and diabetes mellitus were evaluated via questionnaire and blood pressure value.

Results: The WCST category achievement was significantly lower in participants with minimum SpO₂ <90% than those with minimum SpO₂ ≥90%. The percentage of correct answer on the 0- and 1-back tasks was significantly lower in the hypertensives than normotensives. Minimum SpO₂ was correlated with category achievement on the WCST. Multiple regression analysis including age, sex, body mass index, AHI, minimum SpO₂, ESS, hypertension, and diabetes mellitus revealed that hypertension was the most significant factor for percentage correct answers on the 0- and 1-back tasks. There were no significant correlations between body mass index, ESS or diabetes mellitus and the parameters of WCST, CPT-IP, or N-back tasks.

Conclusion: In elderly adults, nocturnal hypoxia and hypertension had a negative effect on cognitive function.

KEYWORDS:

• Hypertension
• cognitive function
• sleep-disordered breathing
• aging

Disclosure statement

The authors declare no conflicts of interest.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This study was supported by the Japan Society for the Promotion of Science (KAKENHI Grant Number 25282210), Chubu University (Grant Number 28IM35A), Aichi Health Promotion Foundation (Grant Number 28128), the Ministry of Education, Culture, Sports, Science and Technology Center of Community (project 2013-2017), and AMED (Grant Number JP18dk0307060).