An examination of the impact of age and sleep quality on neurocognition within a multi‐ethnic sample

Abstract

AbstractBackgroundOlder adults and ethnoracially diverse groups (e.g., non‐Latinx Black (NLB), Latinx) are at higher risk of poor sleep quality. Poor sleep is linked to neurocognitive (NC) decline in middle/older adults, but much of the sleep literature has relied on global NC screening measures. This study examined the effects of age and sleep quality on NC functioning within a multi‐ethnic sample of middle/older adults utilizing a multi‐domain NC battery.MethodThis cross‐sectional study included 119 middle/older adults (M age = 65.3, SD age = 6.9; 46% NLB, 31% Latinx, and 23% non‐Latinx White (NLW); 63% female) who completed demographic questionnaires, the Pittsburgh Sleep Quality Index (PSQI), and a comprehensive NC battery. PSQI global and component scores (e.g., Daytime Dysfunction; PSQI‐DD) measured subjective reporting of sleep quality. Demographically‐adjusted NC T‐scores were used to compute 8 NC‐domain and global average T‐scores. Pearson’s correlations, ANOVA, and multiple regressions were used to test hypotheses.ResultGlobal NC was not related to any PSQI components, and the PSQI components did not differ across ethnoracial groups (all p’s<.05). However, within‐group correlations revealed that the relationship between PSQI components and NC domains significantly differed across ethnoracial groups. For example, frequency of sleep medication usage was significantly negatively correlated with executive functioning in the NLB group (r = ‐.39, p = .02), but not NLW or Latinx groups. Multiple regressions, including age and the interactions between race/ethnicity and PSQI component scores, significantly predicted 21‐39% of the variance in all NC domains (p’s<.05), except attention/working memory (p = .60). The interaction between PSQI‐DD and ethnoracial status significantly predicted memory (p’s<.05); this relationship was positive in the NLW group (B = 20.20), yet negative in the NLB (B = ‐1.16) and Latinx (B = ‐0.56) groups (ps<.05).ConclusionDisordered sleep may have a greater impact on NC functioning, namely memory, among middle/older adults from diverse ethnoracial groups, who are already at heightened risk for NC decline. Importantly, global cognitive screening may be insufficient in examining the effects of sleep quality on NC in middle/older adults. Given the ethnoracial differences in sleep quality, future research should consider culturally‐tailored sleep interventions. Using objective sleep quality measures (e.g., actigraphy) may better quantify sleep components.