Subjective memory complaints and cardiovascular risk factors: a cross-sectional study of the HABS-HD cohort

Background: Subjective memory complaints (SMC) are considered as subjects' interpretation of their cognitive aspects, such as memory and perception. Cardiovascular risk factors such as hypertension, diabetes, dyslipidemia, and obesity may contribute to cognitive decline and their relationship with dementia has been documented extensively. However, there is a lack of literature on the relationship between CVRFs and SMC. Depression has been linked to cardiovascular disease and it is strongly associated with SMC, so it is important to consider the contribution of CVRFs and depression as potentially modifiable factors of SMC. Despite the importance of SMC as a risk factor for cognitive decline, and the higher burden of CVRFs, cognitive decline and dementia among minorities like Mexican Americans (MA), not much attention has been paid to the study of SMC in this population. This study examined the factors associated with SMC in community-dwelling older MA and non - Hispanic Whites (NHW), particularly CVRFs and depression. We hypothesized that CVRFs will be associated with SMC, and that the association will be independent of depression. Methods: We studied 1,376 cognitively normal participants (673 MA and 673 NHW) from the Health and Aging Brain Study (HABS - HD). Baseline characteristics were analyzed using t and chi square tests. The presence of SMC was ascertained by the Subjective Memory Complaints Questionnaire (SCMQ). A logistic regression was conducted to examine the relationship of subjective memory complaints with CVRFs and depression. Age, gender, and education were entered as covariates in the model. Results: MA with SMC had a higher prevalence of dyslipidemia (p=0.008), and depression (p< 0.0001) than those without SMC. Fifty nine percent of the NHW sample were female. NHW with SMC were less educated than those without SMC (mean education years 15.26 vs 15.83), and have a higher prevalence of diabetes (p=0.04) and depression (p< 0.0001). When comparing baseline characteristics of MA (323) and NHW (269) with SMC, we found that MA were younger (mean age 63.74 vs 68.85) and less educated (mean education years 9.38 vs 15.26). MA with SMC had a higher prevalence of diabetes (p< 0.0001) and obesity (p=0.0001) when compared with NHW with SMC. Depression was strongly associated with SMC in MA (OR 3.46; 95% CI = 2.45 - 4.89) and NHW (OR 2.22; 95% CI = 1.59 - 3.10). Dyslipidemia was also associated with SMC in MA (OR 1.73; 95% CI = 1.25 - 2.40). NHW with less education had an increased likelihood of exhibiting SMC. Conclusions: Our findings suggest that the association of CVRF and SMC differs among MA and NHW. Depression was strongly associated with SMC in both groups. In MA, dyslipidemia was also associated with SMC in MA, while education was a significant factor only in NHW. The complex relationship between memory complains, vascular risk factors, and depression requires longitudinal studies for further clarification. Understanding SMC and its racial differences may allow early interventions to prevent cognitive decline.