The Association Between Physical Activity and Cognition in a Racially/Ethnically Diverse Cohort of Older Adults: Results From the Kaiser Healthy Aging and Diverse Life Experiences Study.

OBJECTIVE: Most prior research on physical activity (PA) and cognition is based on predominantly white cohorts and focused on associations of PA with mean (average) cognition versus the distribution of cognition. Quantile regression offers a novel way to quantify how PA affects cognition across the entire distribution. METHODS: The Kaiser Healthy Aging and Diverse Life Experiences study includes 30% white, 19% black, 25% Asian, and 26% Latinx adults age 65+ living in Northern California (n = 1600). The frequency of light or heavy PA was summarized as 2 continuous variables. Outcomes were z-scored executive function, semantic memory, and verbal episodic memory. We tested associations of PA with mean cognition using linear regression and used quantile regression to estimate the association of PA with the 10th-90th percentiles of cognitive scores. RESULTS: Higher levels of PA were associated with higher mean semantic memory (b = 0.10; 95% CI: 0.06, 0.14) and executive function (b = 0.05; 95% CI: 0.01, 0.09). Associations of PA across all 3 cognitive domains were stronger at low quantiles of cognition. CONCLUSION: PA is associated with cognition in this racially/ethnically diverse sample and may have larger benefits for individuals with low cognitive scores, who are most vulnerable to dementia.

Elevated Depressive Symptoms and the Risk of Stroke among the Mexican Older Population.

BACKGROUND/OBJECTIVES: Several longitudinal studies in high-income countries suggest that depression increases stroke risk. However, few prior studies have evaluated this association in low- and middle-income countries (LMICs), where rapidly aging populations may have markedly different vascular risk profiles. DESIGN: Prospective cohort study. SETTING: The Mexican Health and Aging Study is a national population-based study of older adults in Mexico. PARTICIPANTS: A total of 10,693 Mexican adults aged 50 and older enrolled in 2001 with no history of prior stroke. MEASUREMENTS: Depressive symptoms were assessed with a modified 9-item Centers for Epidemiologic Studies Depression Scale (elevated depressive symptom cutoff ≥5) in 2001 and 2003. We evaluated associations between baseline and short-term (2-year) changes in elevated depressive symptoms (categorized as stable low, recently remitted, recent-onset, or stable high symptoms) with incident self-reported or next-of-kin reported doctor-diagnosed stroke through 2015 using Cox proportional hazards models and sensitivity analyses applying inverse probability weights. RESULTS: Over an average follow-up of 11.4 years (standard deviation = 4.2), 10,693 respondents reported 546 incident strokes. Individuals with elevated baseline depressive symptoms experienced a moderately higher hazard of incident stroke (hazard ratio [HR] = 1.13; 95% confidence interval [CI] = .95-1.36) compared with those without elevated baseline depressive symptoms. In analyses of short-term changes in elevated depressive symptoms (n = 8,808; 414 incident stokes), participants with recent-onset (HR = 1.38; 95% CI = 1.06-1.81) or stable high (HR = 1.42; 95% CI = 1.10-1.84) elevated depressive symptoms had a greater hazard of incident stroke compared to those with stable low/no depressive symptoms, whereas recently remitted (HR = 1.01; 95% CI = .74-1.37) symptoms was not associated with stroke hazard. CONCLUSION: Strategies to reduce depressive symptoms merit evaluation as approaches to prevent stroke in middle-income countries. Findings are similar to those in high-income countries but should be replicated in other LMICs.

Adiposity predicts carotid intima-media thickness in healthy children and adolescents.

OBJECTIVE: To examine whether anthropometric measurements, blood pressure (BP), fasting total cholesterol, and low-density lipoprotein are related to ultrasound measures of carotid intima-media thickness (CIMT) in children and teenagers with no known risk factors for cardiovascular disease. STUDY DESIGN: This cross-sectional study included 599 subjects, 6 to 20 years of age (292 males, 307 females; 224 Hispanics, 210 European-Americans, 126 African-Americans, and 39 Asian-Americans) whose body mass index, waist circumference, BP, lipid profiles, and values for CIMT were determined. RESULTS: Measures of CIMT were significantly greater in males than females (P=.006) and in African-Americans when compared with other ethnic groups (all P < .05). There were no relations between age, diastolic BP, or fasting levels of triglycerides, total cholesterol, or low-density lipoprotein values and CIMT measures, regardless of sex or ethnic background. Stratified multiple regression analysis indicated that body mass index and waist circumference independently predicted CIMT in both males and females, even after controlling for age, weight, BP, fasting lipid levels, and ethnic background. CONCLUSION: Increased body mass and adiposity are associated with increased intima-media thickness in children and teenagers. This association is present in children not considered overweight, underscoring the need for the continued promotion of adequate nutritional and physical exercise behavior during childhood.