Supplementary Material for: Occupation, Retirement Age, and 20-Year Cognitive Decline: The Atherosclerosis Risk in Communities Neurocognitive Study

Introduction: We examined the association of both midlife occupation and age at retirement with cognitive decline in the Atherosclerosis Risk in Communities (ARIC) biracial community-based cohort. Methods: Current or most recent occupation at ARIC baseline (1987-89; ages 45-64y) was categorized based on 1980 US census major occupation groups and tertiles of the Nam-Powers-Boyd occupational status score (n=14,090). Retirement status via annual follow-up questionnaires administered ascertained in 1999-2007 was classified as occurring before or after age 70 (n=7,503). Generalized estimating equation models were used to examine associations of occupation and age at retirement with trajectories of global cognitive factor scores, assessed from visit 2 (1990-92) to visit 5 (2011–2013). Models were a priori stratified by race and sex and adjusted for demographics and comorbidities. Results: Low occupational status and blue-collar occupations were associated with low baseline cognitive scores in all race-sex strata. Low occupational status and homemaker status were associated with faster decline in White women but slower decline in Black women compared to high occupational status. Retirement before age 70 was associated with slower cognitive decline in White men and women and in Black men. Results did not change substantially after accounting for attrition. Conclusion: Low occupational status was associated with cognitive decline in women but not in men. Earlier retirement was associated with a slower cognitive decline in White participants and in Black men. Further research should explore reasons for the observed associations and race-sex differences

Supplementary Material for: The Metabolic Syndrome and Cognitive Decline in the Atherosclerosis Risk in Communities Study (ARIC)

<b><i>Background:</i></b> Midlife metabolic syndrome (MetS) may impact cognitive health as a construct independently of hypertension, hyperlipidemia and other components. <b><i>Methods:</i></b> 10,866 participants aged 45-64 years at baseline were assessed for MetS and completed cognitive testing at two later time points (3 and 9 years from the baseline visit). <b><i>Results:</i></b> MetS is associated with increased odds of low cognitive performance in the domains of executive function and word fluency, but not with 6-year cognitive decline. Individual MetS components explained this association (hypertension, diabetes, low HDL, elevated triglycerides and increased waist circumference). <b><i>Conclusions:</i></b> A focus on the individual risk factors as opposed to MetS during midlife is important to reduce the incidence of cognitive impairment in later life

Supplementary Material for: Serum Vitamin D Concentrations and Cognitive Change Over 20 Years: The Atherosclerosis Risk in Communities Neurocognitive Study

<b><i>Background/Aims:</i></b> 25-hydroxyvitamin D (25[OH]D) concentrations have been associated with cognitive decline and incident dementia in elderly populations; however, these relationships are susceptible to reverse causation. Less is known about the association of midlife 25(OH)D with long-term cognitive decline. <b><i>Methods:</i></b> This was a prospective cohort study of 13,044 participants (mean age 57 years at baseline) in the Atherosclerosis Risk in Communities Study. 25(OH)D was measured from serum collected at baseline (1990–1992) using liquid chromatography tandem high-sensitivity mass spectrometry. Cognition was assessed using 3 neuropsychological tests at 3 time points, which were combined into a composite cognitive <i>Z</i>-score. Multivariable-adjusted linear mixed-effects models with random intercepts and slopes were used to estimate associations between 25(OH)D and cognitive change over 20 years. <b><i>Results:</i></b> Compared to persons with sufficient 25(OH)D (≥30 ng/mL), those with deficient (< 20 ng/mL) and intermediate (20–< 30 ng/mL) 25(OH)D concentrations had similar cognitive decline in composite cognitive <i>Z</i>-scores (deficient versus sufficient: –0.035 [95% CI –0.104 to 0.033] and intermediate versus sufficient: –0.029 [95% CI –0.080 to 0.023]). <b><i>Conclusions:</i></b> Lower concentrations of 25(OH)D measured in midlife were not significantly associated with more rapid cognitive decline over a 20-year follow-up period. The results of this prospective study are less susceptible to reverse causation than prior studies