Sleep complaints associates with anxiety in individuals with Subjective Cognitive Decline from a South‐Brazilian cohort

Abstract Background Subjective cognitive decline (SCD) is defined by the presence of cognitive complaints in cognitively unimpaired (CU) individuals. Despite being part of the continuum of a neurodegenerative disease, the cause of the cognitive complaint is quite heterogeneous. Sleep disturbances may be associated with cognitive complaints and even objective cognitive decline. Therefore, our aim is to analyse sleep complaints in patients with SCD evaluated in a south‐Brazilian SCD (BRASCODE) cohort. Method We included CU individuals aged > 65 years‐old with cognitive complaints from the BRASCODE cohort. Exclusion criteria were uncontrolled psychiatric/clinical illness, cerebrovascular disease, and the use of psychotropic drugs. We applied the Memory Complaint Scale (MCS) (in both participant and informant), Geriatric Anxiety Inventory (GAI) and Geriatric Depression Scale (GDS), Pittsburgh Sleep Quality Index (PSQI), Mini Mental State Examination (MMSE), Mild Behavioral Impairment (MBI) and Neuropsychiatric Inventory (NPI) questionnaires. For this analysis we used the data collected in the 12‐month follow‐up only. Result Forty‐seven participants completed the 12‐month evaluation between March, 2022 and November, 2023. Of these, 74.5% (n = 35) were women, median age of 71 (69‐74.5) years‐old and 16 (11‐18) years of formal education. Their median interquartile range (IQR) on SCD‐patient and SCD‐informant scale was 8 (6‐9.5) and 4 (2‐6), respectively. The remaining scale’s ‐median and IQR scores‐ were the following: PSQI, 7 (4‐9); GAI, 6 (3‐9); GDS 2 (1‐4), MMSE, 29 (28‐30); NIP,1(0‐4); MBI‐patient, 3 (0.75‐6); and MBI‐informant, 3 (1‐9). The analysis showed that the PSQI scale only had correlation with GAI (p‐value = 0.02841, rho = 0.3466809). There was no association with the MCS‐participant and MCS‐informant scales, nor with MMSE, age, education and behavior scales, MBI or NPI. Conclusion This result obtained for the PSQI score suggests that poor sleep quality in SCD individuals from a south‐Brazilian cohort may be associated with anxiety symptoms. Larger sample may provide additional information about the relationship of cognitive, anxiety and sleep complaints.