The Effects of Sleep-Disordered Breathing on Depression-Related Cognitive Impairment (DepE) in Elderly Mexican Americans

Objective: Sleep-disordered breathing (SDB), such as found in excessive sleepiness (ES) & obstructive sleep apnea (OSA), has been recognized as a common occurrence in the elderly. SDB has been linked to a number of negative health outcomes in older persons, as well as both cognitive dysfunction and depression. Research shows that the likelihood of depression increased with the frequency of SDB. Likewise, breathing problems during sleep may also be linked to early mental decline and Alzheimer’s disease in Mexican Americans, a new study suggests. There remains, however, a dearth in the literature regarding the impact of SDB on the link between depression and cognition in this population. This study seeks to address the gap in knowledge on the relationship of SDB on depression-related cognitive impairment in Mexican Americans. Methods: Data were analyzed from 516 Mexican American participants from the Health and Aging Brain among Latino Elders (HABLE) study. Excessive sleepiness (ES) was determined based on having a score ≥10 on the Epworth Sleepiness Scale (ESS). Obstructive Sleep Apnea (OSA) was identified as those with a score ≥3 on the STOP-BANG Sleep Apnea Questionnaire. Depression-related cognitive impairment was determined based on the DepE (Depression endophenotype), which was coded on a five-point scale with the GDS-30. Linear regression models were utilized with the DepE as the dependent variable and the Epworth Sleepiness Scale, as well as the STOP-BANG Sleep Apnea Questionnaire, serving as two separate, independent variables. Covariates included age, gender, education, BMI, hypertension, dyslipidemia, and diabetes mellitus. Significance was set at p Results: SDB was found to be elevated among the Mexican American population in this study, with significant associations being shown among ES and DepE, as well as among OSA and DepE. Specifically, for those who met criteria for ES, a significant positive correlation was shown between the Epworth Sleepiness Scale (B[SE]= 0.93[0.27], t=3.47, p=0.001) and DepE. Additionally, among those who met criteria for OSA, a significant positive correlation was also shown between the STOP-BANG Questionnaire (B[SE]= 0.98[0.23], t=4.21, p) and DepE. Conclusions: Elevated ES and OSA show an increased risk for depression-related cognitive impairment (DepE) among Mexican Americans. Potential implications include treatment of ES and OSA as a means of therapeutic intervention for individuals with DepE. Further research should continue examining the effects of other SDB conditions on DepE, as well as exploring the role of DepE on SDB.