Low 25-Hydroxyvitamin D Concentrations and Risk of Incident Cognitive Impairment in Black and White Older Adults: The Health ABC Study

Using data from the Health, Aging, and Body Composition study, we examined whether low 25-hydroxyvitamin D (25[OH]D) concentrations were associated with prevalent or incident cognitive impairment. Serum 25(OH)D concentrations were measured in 2,786 older adults and categorized as <20 ng/mL, 20 to <30 ng/mL, or ≥30 ng/mL. Cognitive impairment was defined as a score >1.5 standard deviations below race and education specific means on either digit symbol substitution test or modified mini-mental state test. Logistic regression determined the odds of cognitive impairment at baseline and year 5 by 25(OH)D category. 25(OH)D concentrations were <30 ng/mL in 57.3% of whites and 84.6% of blacks. After excluding participants with baseline cognitive impairment (n = 340), 13% of whites and 13% of blacks developed cognitive impairment by year 5. In whites, 25(OH)D concentrations <30 ng/mL were not associated with prevalent or incident cognitive impairment. Black participants with 25(OH)D concentrations <20 ng/mL had a higher odds of prevalent, but not incident cognitive impairment (OR (95% CI): 2.05 (1.08-3.91), p = 0.03) compared to participants with 25(OH)D concentrations ≥30 ng/mL. Low 25(OH)D concentrations were associated with twofold higher odds of prevalent cognitive impairment in blacks.

Muscle fatigability and depressive symptoms in later life

OBJECTIVE

Fatigability is the degree to which performance decreases during a specific activity of a given intensity and duration. Depression is known to heighten subjective fatigue, but whether its association with physical fatigability is unknown. Further, whether fatigability is a precursor or risk factor for the development of subsequent depressive symptoms is also unclear.

METHODS

Data are from the Health Aging and Body Composition Study with fatigability assessed using isokinetic dynamometry of the knee extensors at year 3, and depressive symptoms ascertained longitudinally using the Center for Epidemiologic Studies Depression (CES-D) scale. The relationship between fatigability and depressive symptoms was evaluated using linear and Cox regression models.

RESULTS

There was a significant cross-sectional association between fatigability and depressive symptomatology (β = -0.06, p = 0.02), after adjusting for demographic variables, medical comorbidities, cognition, gait speed, and physical activity levels. Greater fatigability was associated with greater adjusted scores on the 10-item CES-D (F_{2, 1695}  = 38.65, p < 0.001), with individuals with greater fatigability on average reporting an adjusted CES-D score 0.5 point greater than those individuals with higher levels of resistance to fatigability (mean of 70% or better; p < 0.001). Fatigability however was not associated with the development of depression at follow-up (p = 0.828).

CONCLUSIONS

This study found an association between skeletal muscle fatigability and higher depressive symptoms in older adults, but no longitudinal association was identified. These findings suggest that age-related changes in energy capacity may affect the phenomenology of late life depression. Copyright © 2017 John Wiley & Sons, Ltd.

Association of JNC-8 and SPRINT Systolic Blood Pressure Levels With Cognitive Function and Related Racial Disparity

Importance

The Eighth Joint National Committee (JNC-8) recommended treating systolic blood pressure (SBP) to a target below 150 mm Hg in older adults, whereas data from the Systolic Blood Pressure Intervention Trial (SPRINT) suggested that a SBP level of lower than 120 mm Hg decreases cardiovascular event rates. Target SBP guidelines have not addressed the potential that black patients may have greater morbidity and mortality from hypertension, especially with regard to cognitive outcomes. The association of these discordant SBP targets with cognition and differences by race have not been systematically evaluated in the same population.

Objectives

To assess the long-term outcomes of the various recommended SBP levels and to determine if racial differences exist based on long-term cognitive trajectories.

Design, Setting, and Participants

A total of 1657 cognitively intact older adults receiving treatment for hypertension were studied from 1997 to 2007 in the Health Aging and Body Composition study. Data analysis was conducted from October 1, 2016, to January 1, 2017.

Main Outcomes and Measures

Cognition was assessed using the Modified Mini-Mental State Examination (3MSE) 4 times and the Digit Symbol Substitution Test (DSST) 5 times. At each visit, participants were classified as having an SBP level of 120 mm Hg or lower, 121 to 139 mm Hg, 140 to 149 mm Hg, or 150 mm Hg or higher based on the mean SBP level of 2 seated readings. Mixed models assessed the association of SBP levels with 10-year cognitive trajectories. The impact of race was tested using a race interaction term.

Results

During the 10-year study period, among the 1657 individuals (908 women and 784 black patients; mean [SE] age, 73.7 [0.1] years), there was a differential decrease in 3MSE and DSST scores by the SBP levels, with the greatest decrease in the group with SBP levels of 150 mm Hg or higher (adjusted decrease was 3.7 for 3MSE and 6.2 for DSST) and the lowest decrease in the group with SBP levels of 120 mm Hg or lower (adjusted decrease was 3.0 for 3MSE and 5.0 for DSST) (P < .001 for both). Compared with white patients, black patients had a greater difference between the higher and lower SBP levels in the decrease in cognition; adjusted differences between the group with SBP levels of 150 mm Hg or higher and the group with SBP levels of 120 mm Hg or lower were -0.05 in white patients and -0.08 in black patients for 3MSE (P = .03) and -0.07 in white patients and -0.13 in black patients for DSST (P = .05).

Conclusions and Relevance

For patients 70 years of age or older receiving treatment for hypertension, a SPRINT SBP level of 120 mm Hg or lower was not associated with worsening cognitive outcome and may be superior to the JNC-8 target for cognition. Lower SBP treatment levels may result in improved cognition in black patients.

Long-term changes in time spent walking and subsequent cognitive and structural brain changes in older adults

Previous studies have shown that more active older adults have better cognition and brain health based on a variety of structural neuroimaging measures. Nevertheless, the effects of maintaining physical activity (PA) over an extended period of time on future changes in older adults' cognition and brain structure are unknown. Participants were 141 initially well-functioning community-dwelling older adults (aged 70-79 years at baseline; 60% female; 42% black) studied over a 13-year period. PA (self-reported time spent walking) was assessed annually from years 1 to 10. Magnetic resonance imaging with diffusion tensor was performed at years 10 and 13. Time spent walking decreased on average by 8.4% annually from year 1 to year 10. Independent of initial time spent walking, demographics, and APOE e4 status, better maintenance of time spent walking over the decade predicted less reduction in hippocampal volume (p = 0.03), smaller increases in global gray matter mean diffusivity and white matter axial diffusivity (p < 0.01), and maintenance of general cognitive performance (p < 0.01). Maintenance of cognitive performance was associated with smaller increases in white matter axial diffusivity (p < 0.01). PA at baseline and at year 10, as well as changes in PA over a 5-year period, was less predictive of future changes in brain structure and cognition. Thus, how PA levels change over longer periods of aging may be an important contributor to cognitive and neural protection.

Are Preferences for Aggressive Medical Treatment Associated with Healthcare Utilization in the Very Old?

Objectives: To examine the relationship between end-of-life (EOL) treatment preferences and recent hospitalization or emergency department (ED) care in the very old. Design: Quarterly telephone follow-up of participants in the EOL in the Very Old cohort. Setting: The EOL in the Very Old Age cohort drew from 1403 participants in the Health, Aging, and Body Composition (Health ABC) study who were alive in year 15 of follow-up. 87.5% (n = 1227) were successfully recontacted and enrolled. Participants: Preferences for treatment at the EOL and reported hospital and ED use were examined for 1118 participants (18% involving proxy reports) over 6 months, 1021 (16% with proxy reports) over 12 months, and 945 (23% with proxy reports) over 18 months in 6-month intervals. Measurements: Preferences for eight EOL treatments, elicited once each year; hospitalization and ED use reported every six months. Results: Preferences for more aggressive treatment (endorsing ≥5 of 8 options) were not significantly associated with inpatient or ED treatment. Inpatient and ED treatment were not associated with changes in preferences for aggressive EOL treatment over 12 months. Conclusion: Alternative measures that tap attitudes toward routine care, rather than EOL treatment preferences, may be more highly associated with healthcare utilization.

Symptom Burden and End-of-Life Treatment Preferences in the Very Old

CONTEXT

End-of-life (EOL) treatment preferences among the very old (age 85+) may differ from preferences in younger aged populations because of high levels of symptom burden and disability and high risk of mortality. It is unclear if symptom burden or level of disability is more important for such preferences.

OBJECTIVES

To investigate whether distress from daily symptom burden was an independent correlate of EOL treatment preferences over two years of follow-up in people with median age 86 (participants) and 88 (reported by proxies) at baseline.

METHODS

The End of Life in Very Old Age is an ancillary study to the Health, Aging and Body Composition study. At baseline in Year 15 of Health, Aging and Body Composition, 1038 participants and 189 proxies reported levels of symptom distress every quarter, as well as 0-8 EOL treatment preferences elicited once each year.

RESULTS

At baseline, the mean (SD) count of EOL treatment preferences was 4.2 (2.1) in participants, and 2.9 (2.3) in proxies. EOL treatment preference was not associated with symptom distress. By contrast, black race, male gender, and reported ease walking a quarter mile were independently associated with more aggressive EOL treatment preferences.

CONCLUSION

Preferences for more aggressive EOL treatment were not related to daily symptom distress but were significantly more likely to be endorsed among those with better mobility, suggesting that disability is an independent predictor of EOL treatment preferences in the very old.

Association of Hearing Impairment and Anxiety in Older Adults

OBJECTIVE

The objective of the study is was investigate the association between hearing impairment and anxiety.

METHOD

We conducted a cross-sectional analysis of 1,732 community-based adults aged 76 to 85 years who participated in the Health Aging and Body Composition (ABC) study. Logistic regression models were adjusted for demographic and cardiovascular risk factors. Hearing impairment was defined by the speech-frequency pure tone average. Anxiety was defined as reporting two symptoms of at least "a little" or one symptom "quite a bit" on the three-item Hopkins Symptom Checklist.

RESULTS

Compared with individuals with no hearing impairment, the odds of prevalent anxiety were higher among individuals with mild hearing impairment (odds ratio [OR] = 1.32, 95% confidence interval [CI] = [1.01, 1.73]) and moderate or greater hearing impairment (OR = 1.59, 95% CI = [1.14, 2.22]). Hearing aid use was not significantly associated with lower odds of anxiety.

DISCUSSION

Hearing impairment is independently associated with greater odds of anxiety symptoms in older adults.

Trajectories of Depressive Symptoms in Older Adults and Risk of Dementia

IMPORTANCE

Depression has been identified as a risk factor for dementia. However, most studies have measured depressive symptoms at only one time point, and older adults may show different patterns of depressive symptoms over time.

OBJECTIVE

To investigate the association between trajectories of depressive symptoms and risk of dementia in older adults.

DESIGN, SETTING, AND PARTICIPANTS

This was a prospective cohort investigation of black and white community-dwelling older adults in the Health, Aging, and Body Composition study. Participants were enrolled between May 1997 and June 1998 and followed up through 2001-2002. The dates of this analysis were September 2014 to December 2015. The setting was community research centers in Memphis, Tennessee, and Pittsburgh, Pennsylvania. Trajectories of depressive symptoms were assessed from baseline to year 5. Symptoms were measured with the Center for Epidemiologic Studies Depression Scale Short Form, and trajectories were calculated using latent class growth curve analysis.

MAIN OUTCOMES AND MEASURES

Incident dementia through year 11, determined by dementia medication use, hospital records, or significant cognitive decline (≥1.5 SD race-specific decline on the Modified Mini-Mental State Examination). We examined the association between depressive symptom trajectories and dementia incidence using Cox proportional hazards regression models adjusted for demographics, health factors that differed between groups, and cognition during the depressive symptom assessment period (baseline to year 5).

RESULTS

The analytic cohort included 2488 black and white older adults with repeated depressive symptom assessments from baseline to year 5 who were free of dementia throughout that period. Their mean (SD) age at baseline was 74.0 (2.8) years, and 53.1% (n = 1322) were female. The following 3 depressive symptom trajectories were identified: consistently minimal symptoms (62.0% [n = 1542] of participants), moderate and increasing symptoms (32.2% [n = 801] of participants), and high and increasing symptoms (5.8% [n = 145] of participants). Compared with the consistently minimal trajectory, having a high and increasing depressive symptom trajectory was associated with significantly increased risk of dementia (fully adjusted hazard ratio, 1.94; 95% CI, 1.30-2.90), while the moderate and increasing trajectory was not associated with risk of dementia after full adjustment. Sensitivity analyses indicated that the high and increasing trajectory was associated with dementia incidence, while depressive symptoms at individual time points were not.

CONCLUSIONS AND RELEVANCE

Older adults with a longitudinal pattern of high and increasing depressive symptoms are at high risk for dementia. Individuals' trajectory of depressive symptoms may inform dementia risk more accurately than one-time assessment of depressive symptoms.

Antidepressant Use and Recurrent Falls in Community-Dwelling Older Adults: Findings From the Health ABC Study

BACKGROUND

Few studies have compared the risk of recurrent falls across various antidepressant agents-using detailed dosage and duration data-among community-dwelling older adults, including those who have a history of a fall/fracture.

OBJECTIVE

To examine the association of antidepressant use with recurrent falls, including among those with a history of falls/fractures, in community-dwelling elders.

METHODS

This was a longitudinal analysis of 2948 participants with data collected via interview at year 1 from the Health, Aging and Body Composition study and followed through year 7 (1997-2004). Any antidepressant medication use was self-reported at years 1, 2, 3, 5, and 6 and further categorized as (1) selective serotonin reuptake inhibitors (SSRIs), (2) tricyclic antidepressants, and (3) others. Dosage and duration were examined. The outcome was recurrent falls (≥2) in the ensuing 12-month period following each medication data collection.

RESULTS

Using multivariable generalized estimating equations models, we observed a 48% greater likelihood of recurrent falls in antidepressant users compared with nonusers (adjusted odds ratio [AOR] = 1.48; 95% CI = 1.12-1.96). Increased likelihood was also found among those taking SSRIs (AOR = 1.62; 95% CI = 1.15-2.28), with short duration of use (AOR = 1.47; 95% CI = 1.04-2.00), and taking moderate dosages (AOR = 1.59; 95% CI = 1.15-2.18), all compared with no antidepressant use. Stratified analysis revealed an increased likelihood among users with a baseline history of falls/fractures compared with nonusers (AOR = 1.83; 95% CI = 1.28-2.63).

CONCLUSION

Antidepressant use overall, SSRI use, short duration of use, and moderate dosage were associated with recurrent falls. Those with a history of falls/fractures also had an increased likelihood of recurrent falls.

An Evaluation of the Longitudinal, Bidirectional Associations Between Gait Speed and Cognition in Older Women and Men

BACKGROUND

Few cohort studies have examined longitudinal associations between age-related changes in cognition and physical performance. Further, whether these associations differ for men versus women or can be attributed to differences in physical activity (PA) is unknown.

METHODS

Participants were 2,876 initially well-functioning community-dwelling older adults (aged 70-79 years at baseline; 52% female; 39% black) studied over a 9-year period. Usual gait speed, self-reported PA, and two cognitive measures-Digit Symbol Substitution Test (DSST) and Mini-Modified Mental State examination (3MS)-were assessed years 0 (ie, baseline), 4, and 9.

RESULTS

Early decline between years 0 and 4 in gait speed predicted later decline between years 4 and 9 in performance on the 3MS (β = 0.10, p = .004) and on the DSST (β = 0.16, p < .001). In contrast, the associations between early decline in cognition and later decline in gait speed were weaker and were non-significant after correcting for multiple comparisons (β = 0.08, p = .019 for 3MS and β = .06, p = .051 for DSST). All associations were similar for women and men and were unaltered when accounting for PA levels.

CONCLUSIONS

The results indicate declining gait speed as a precursor to declining cognitive functioning, and suggest a weaker reciprocal process among older women and men.

Association of Hearing Impairment and Emotional Vitality in Older Adults

OBJECTIVES

To better understand the potential impact of hearing impairment (HI) and hearing aid use on emotional vitality and mental health in older adults.

METHOD

We investigated the cross-sectional association of HI with emotional vitality in 1,903 adults aged 76-85 years in the Health ABC study adjusted for demographic and cardiovascular risk factors. Hearing was defined by the speech frequency pure tone average (no impairment < 25 dB, mild impairment 25-40 dB, and moderate or greater impairment > 40 dB). Emotional vitality was defined as having a high sense of personal mastery, happiness, low depressive symptomatology, and low anxiety.

RESULTS

Compared with individuals with no HI, participants with moderate or greater HI had a 23% lower odds of emotional vitality (odds ratio [OR] = 0.77; 95% confidence interval [CI]: 0.59-0.99). Hearing aid use was not associated with better emotional vitality (OR = 0.98; 95% CI: 0.81-1.20).

DISCUSSION

HI is associated with lower odds of emotional vitality in older adults. Further studies are needed to examine the longitudinal impact of HI on mental health and well-being.

Association of Hearing Impairment With Incident Frailty and Falls in Older Adults

OBJECTIVE

We aimed to determine whether hearing impairment (HI) in older adults is associated with the development of frailty and falls.

METHOD

Longitudinal analysis of observational data from the Health, Aging and Body Composition study of 2,000 participants aged 70 to 79 was conducted. Hearing was defined by the pure-tone-average of hearing thresholds at 0.5, 1, 2, and 4 kHz in the better hearing ear. Frailty was defined as a gait speed of <0.60 m/s and/or inability to rise from a chair without using arms. Falls were assessed annually by self-report.

RESULTS

Older adults with moderate-or-greater HI had a 63% increased risk of developing frailty (adjusted hazard ratio [HR] = 1.63, 95% confidence interval [CI] = [1.26, 2.12]) compared with normal-hearing individuals. Moderate-or-greater HI was significantly associated with a greater annual percent increase in odds of falling over time (9.7%, 95% CI = [7.0, 12.4] compared with normal hearing, 4.4%, 95% CI = [2.6, 6.2]).

DISCUSSION

HI is independently associated with the risk of frailty in older adults and with greater odds of falling over time.

Inflammation, Depression, and Slow Gait: A High Mortality Phenotype in Later Life

BACKGROUND

Inflammation, slow gait, and depression individually are associated with mortality, yet little is known about the trajectories of these measures, their interrelationships, or their collective impact on mortality.

METHODS

Longitudinal latent class analysis was used to evaluate trajectories of depression (Center for Epidemiologic Studies Depression ≥ 10), slow gait (<1.0 m/s), and elevated inflammation (interleukin 6 > 3.2 pg/mL) using data from the Health Aging and Body Composition Study. Logistic regression was used to identify their associations with mortality.

RESULTS

For each outcome, low-probability (n inflammation = 1,656, n slow gait = 1,471, n depression = 1,458), increasing-probability (n inflammation = 847, n slow gait = 880, n depression = 1,062), and consistently high-probability (n inflammation = 572, n slow gait = 724, n depression = 555) trajectories were identified, with 22% of all participants classified as having increasing or consistently high-probability trajectories on inflammation, slow gait, and depression (meaning probability of impairment on each outcome increased from low to moderate/high or remained high over 10 years). Trajectories of slow gait were associated with inflammation (r = .40, p < .001) and depression (r = .49, p < .001). Although worsening trajectories of inflammation were independently associated with mortality (p < .001), the association between worsening trajectories of slow gait and mortality was only present in participants with worsening depression trajectories (p < .01). Participants with increasing/consistently high trajectories of depression and consistently high trajectories of inflammation and slow gait (n = 247) have an adjusted-morality rate of 85.2%, greater than all other classification permutations.

CONCLUSIONS

Comprehensive assessment of older adults is warranted for the development of treatment strategies targeting a high-mortality risk phenotype consisting of inflammation, depression, and slow gait speed.

Depressive Trajectories and Risk of Disability and Mortality in Older Adults: Longitudinal Findings From the Health, Aging, and Body Composition Study

BACKGROUND

Depression and disability are closely linked. Less is known regarding clinical and subclinical depressive symptoms over time and risk of disability and mortality.

METHODS

Responses to the Center for Epidemiologic Studies Short Depression scale (CES-D10) were assessed over a 4-year period in men (n = 1032) and women (n = 1070) aged 70-79 years initially free from disability. Depressive symptom trajectories were defined with group-based models. Disability (2 consecutive reports of severe difficulty walking one-quarter mile or climbing 10 steps) and mortality were determined for 9 subsequent years. Hazard ratios (HRs) were estimated using Cox proportional hazards adjusted for covariates.

RESULTS

Three trajectories were identified: persistently nondepressed (54% of men, 54% of women, mean baseline CES-D10: 1.16 and 1.46), mildly depressed and increasing (40% of men, 38% of women, mean baseline CES-D10: 3.60 and 4.35), and depressed and increasing (6% of men, 8% of women, mean baseline CES-D10: 7.44 and 9.61). Disability and mortality rates per 1,000 person years were 41.4 and 60.3 in men and 45.8 and 41.9 in women. Relative to nondepressed, men in the mildly depressed (HR = 1.45, 95% confidence interval [CI] 1.11-1.89) and depressed trajectories (HR = 2.12, 95% CI 1.33-3.38) had increased disability; women in the depressed trajectory had increased disability (HR = 2.02, 95% CI 1.37-2.96). Men in the mildly depressed (HR = 1.24, 95% CI 1.01-1.52) and depressed trajectories (HR = 1.63, 95% CI 1.10-2.41) had elevated mortality risk; women exhibited no mortality risk.

CONCLUSIONS

Trajectories of depressive symptoms without recovery may predict disability and mortality in apparently healthy older populations, thus underscoring the importance of monitoring depressive symptoms in geriatric care.

Cognitive resilience to apolipoprotein E ε4: contributing factors in black and white older adults

IMPORTANCE

Apolipoprotein E (APOE) ε4 is an established risk factor for cognitive decline and the development of dementia, but other factors may help to minimize its effects.

OBJECTIVE

Using APOE ε4 as an indicator of high risk, we investigated factors associated with cognitive resilience among black and white older adults who are APOE ε4 carriers.

DESIGN, SETTING, AND PARTICIPANTS

Participants included 2487 community-dwelling older (aged 69-80 years at baseline) black and white adults examined at 2 community clinics in the prospective cohort Health, Aging, and Body Composition (Health ABC) study. The baseline visits occurred from May 1997 through June 1998. Our primary analytic cohort consisted of 670 APOE ε4 carriers (329 black and 341 white participants) who were free of cognitive impairment at baseline and underwent repeated cognitive testing during an 11-year follow-up (through 2008) using the Modified Mini-Mental State Examination.

MAIN OUTCOMES AND MEASURES

We stratified all analyses by race. Using the Modified Mini-Mental State Examination scores, we assessed normative cognitive change in the entire cohort (n = 2487) and classified the APOE ε4 carriers as being cognitively resilient vs nonresilient by comparing their cognitive trajectories with those of the entire cohort. We then conducted bivariate analyses and multivariable random forest and logistic regression analyses to explore factors predictive of cognitive resilience in APOE ε4 carriers.

RESULTS

Among white APOE ε4 carriers, the strongest predictors of cognitive resilience were, in relative order of importance, no recent negative life events, a higher literacy level, advanced age, a higher educational level, and more time spent reading. Among black APOE ε4 carriers, the strongest predictors of cognitive resilience were, in relative order of importance, a higher literacy level, a higher educational level, female sex, and the absence of diabetes mellitus. In follow-up logistic regression models, higher literacy level (adjusted odds ratio [OR], 9.50 [95% CI, 2.67-60.89]), a higher educational level (adjusted OR for college graduate vs less than high school, 3.81 [95% CI, 1.13-17.56]), and age (adjusted OR for 73-76 vs 69-72 years, 2.01 [95% CI, 1.13-3.63]) had significant independent effects in predicting cognitive resilience among white APOE ε4 carriers. Among black APOE ε4 carriers, a higher literacy level (adjusted OR, 2.27 [95% CI, 1.29-4.06]) and a higher educational level (adjusted OR for high school graduate/some college vs less than high school, 2.86 [95% CI, 1.54-5.49]; adjusted OR for college graduate vs less than high school, 2.52 [95% CI, 1.14-5.62]) had significant independent effects in predicting cognitive resilience.

CONCLUSIONS AND RELEVANCE

Although APOE ε4 carriers are at high risk for cognitive decline, our findings suggest possible intervention targets, including the enhancement of cognitive reserve and improvement of other psychosocial and health factors, to promote cognitive resilience among black and white APOE ε4 carriers.

Association between the Mediterranean diet and cognitive decline in a biracial population

BACKGROUND

Results from numerous studies suggest protective effects of the Mediterranean diet for cardiovascular disease, cancer, and mortality. Evidence for an association with a decreased risk of cognitive decline is less consistent and studies are limited by a lack of diversity in their populations.

METHODS

We followed 2,326 older adults (38.2% black, 51.3% female, aged 70-79 at baseline) over 8 years in a prospective cohort study in the United States (Health, Aging and Body Composition study). To measure adherence to a Mediterranean diet, we calculated race-specific tertiles of the MedDiet score (range: 0-55) using baseline food frequency questionnaires. Cognitive decline was assessed using repeated Modified Mini Mental State Examination scores over the study. We used linear mixed models to assess the association between MedDiet score and trajectory of cognitive decline.

RESULTS

Among blacks, participants with high MedDiet scores had a significantly lower mean rate of decline on the Modified Mini Mental State Examination score compared with participants with lower MedDiet scores (middle and bottom tertiles). The mean difference in points per year was 0.22 (95% confidence interval: 0.05-0.39; p = .01) after adjustment for age, sex, education, body mass index, current smoking, physical activity, depression, diabetes, total energy intake, and socioeconomic status. No association between MedDiet scores and change in Modified Mini Mental State Examination score was seen among white participants (p = .14).

CONCLUSIONS

Stronger adherence to the Mediterranean diet may reduce the rate of cognitive decline among black, but not white older adults. Further studies in diverse populations are needed to confirm this association and pinpoint mechanisms that may explain these results.

Association between sleep duration and mortality is mediated by markers of inflammation and health in older adults: the Health, Aging and Body Composition Study

STUDY OBJECTIVES

Inflammation may represent a common physiological pathway linking both short and long sleep duration to mortality. We evaluated inflammatory markers as mediators of the relationship between sleep duration and mortality in community-dwelling older adults.

DESIGN

Prospective cohort with longitudinal follow-up for mortality outcomes.

SETTING

Pittsburgh, Pennsylvania, and Memphis, Tennessee.

PARTICIPANTS

Participants in the Health, Aging and Body Composition (Health ABC) Study (mean age 73.6 ± 2.9 years at baseline) were sampled and recruited from Medicare listings.

MEASUREMENTS AND RESULTS

Baseline measures of subjective sleep duration, markers of inflammation (serum interleukin-6, tumor necrosis factor-α, and C-reactive protein) and health status were evaluated as predictors of all-cause mortality (average follow-up = 8.2 ± 2.3 years). Sleep duration was related to mortality, and age-, sex-, and race-adjusted hazard ratios (HR) were highest for those with the shortest (< 6 h HR: 1.30, CI: 1.05-1.61) and longest (> 8 h HR: 1.49, CI: 1.15-1.93) sleep durations. Adjustment for inflammatory markers and health status attenuated the HR for short (< 6 h) sleepers (HR = 1.06, 95% CI = 0.83-1.34). Age-, sex-, and race-adjusted HRs for the > 8-h sleeper group were less strongly attenuated by adjustment for inflammatory markers than by other health factors associated with poor sleep with adjusted HR = 1.23, 95% CI = 0.93-1.63. Inflammatory markers remained significantly associated with mortality.

CONCLUSION

Inflammatory markers, lifestyle, and health status explained mortality risk associated with short sleep, while the mortality risk associated with long sleep was explained predominantly by lifestyle and health status.

Association of hearing impairment with declines in physical functioning and the risk of disability in older adults

BACKGROUND

Identifying factors associated with functional declines in older adults is important given the aging of the population. We investigated if hearing impairment is independently associated with objectively measured declines in physical functioning in a community-based sample of older adults.

METHODS

Prospective observational study of 2,190 individuals from the Health, Aging, and Body Composition study. Participants were followed annually for up to 11 visits. Hearing was measured with pure-tone audiometry. Physical functioning and gait speed were measured with the Short Physical Performance Battery (SPPB). Incident disability and requirement for nursing care were assessed semiannually through self-report.

RESULTS

In a mixed-effects model, greater hearing impairment was associated with poorer physical functioning. At both Visit 1 and Visit 11, SPPB scores were lower in individuals with mild (10.14 [95% CI 10.04-10.25], p < .01; 7.35 [95% CI 7.12-7.58], p < .05) and moderate or greater hearing impairment (10.04 [95% CI 9.90-10.19], p < .01; 7.00 [95% CI 6.69-7.32], p < .01) than scores in normal hearing individuals (10.36 [95% CI 10.26-10.46]; 7.71 [95% CI 7.49-7.92]). We observed that women with moderate or greater hearing impairment had a 31% increased risk of incident disability (Hazard ratio [HR] =1.31 [95% CI 1.08-1.60], p < .01) and a 31% increased risk of incident nursing care requirement (HR = 1.31 [95% CI 1.05-1.62], p = .02) compared to women with normal hearing.

CONCLUSIONS

Hearing impairment is independently associated with poorer objective physical functioning in older adults, and a 31% increased risk for incident disability and need for nursing care in women.

Race-related differences in depression onset and recovery in older persons over time: the health, aging, and body composition study

OBJECTIVES

To evaluate race-related differences in depression onset and recovery in older persons, overall and by sex, and examine race-related differences in mortality according to depression.

DESIGN

Prospective cohort study.

SETTING

General community in pre-designated zip code areas in Memphis, Tennessee, and Pittsburgh, Pennsylvania.

PARTICIPANTS

3,075 persons aged 70-79 years at baseline in the Health, Aging, and Body Composition study.

MEASUREMENTS

Depression was assessed at eight time points over 10 years using the 10-item Center for Epidemiologic Studies-Depression scale; patients were categorized as nondepressed (score less than 8) or depressed (score of 8 or higher). We created variables for transitions across each 18-month time interval, namely, from nondepressed or depressed to nondepressed, depressed, or death, and determined the association between race and the average likelihood of these transitions over time.

RESULTS

A higher percentage of blacks than whites were depressed at nearly all time points. Adjusting for demographics, common chronic conditions, and body mass index, blacks had a higher likelihood of experiencing depression onset than whites (odds ratio [OR]: 1.22; 95% confidence interval [CI]: 1.03-1.43); among men, blacks were more likely to experience depression onset than whites (OR: 1.44; 95% CI: 1.24-2.89). Blacks also had a higher likelihood of transitioning from nondepressed to death (OR: 1.79; 95% CI: 1.30-2.46). Overall and in sex-stratified analyses, race was not associated with recovery from depression or with the transition from depression to death.

CONCLUSION

Our findings highlight race differences in depression in older persons and encourage further research on the course of depression in older black patients.

Older adults with limited literacy are at increased risk for likely dementia

BACKGROUND

Low literacy is common among the elderly and possibly more reflective of educational attainment than years of school completed. We examined the association between literacy and risk of likely dementia in older adults.

METHODS

Participants were 2,458 black and white elders (aged 71-82) from the Health, Aging and Body Composition study, who completed the Rapid Estimate of Adult Literacy in Medicine and were followed for 8 years. Participants were free of dementia at baseline; incidence of likely dementia was defined by hospital records, prescription for dementia medication, or decline in Modified Mini-Mental State Examination score. We conducted Cox proportional hazard models to evaluate the association between literacy and incidence of likely dementia. Demographics, education, income, comorbidities, lifestyle variables, and apolipoprotein E (APOE) ε4 status were included in adjusted analyses.

RESULTS

Twenty-three percent of participants had limited literacy (<9th-grade level). Limited literacy, as opposed to adequate literacy (≥9th-grade level), was associated with greater incidence of likely dementia (25.5% vs17.0%; unadjusted hazard ratio [HR] = 1.75, 95% confidence interval 1.44-2.13); this association remained significant after adjustment. There was a trend for an interaction between literacy and APOE ε4 status (p = .07); the association between limited literacy and greater incidence of likely dementia was strong among ε4 noncarriers (unadjusted HR = 1.85) but nonsignificant among ε4 carriers (unadjusted HR = 1.25).

CONCLUSIONS

Limited literacy is an important risk factor for likely dementia, especially among APOE ε4-negative older adults, and may prove fruitful to target in interventions aimed at reducing dementia risk.

Trajectories of inflammatory markers and cognitive decline over 10 years

We aimed to examine trajectories of inflammatory markers and cognitive decline over 10 years. Cox proportional hazards models were used to examine the association between interleukin-6 and C-reactive protein (CRP) trajectory components (slope, variability, and baseline level) and cognitive decline among 1323 adults, aged 70-79 years in the Health, Aging, and Body Composition Study. We tested for interactions by sex and apolipoprotein E (APOE) genotype. In models adjusted for multiple covariates and comorbidities, extreme CRP variability was significantly associated with cognitive decline (hazard ratio [HR] 1.6, 95% confidence interval [CI]: 1.1-2.3). This association was modified by sex and APOE e4 (p < 0.001 for both), such that the association remained among women (HR = 1.8; 95% CI: 1.1, 3.0) and among those with no APOE e4 allele (HR = 1.6; 95% CI: 1.1, 2.5). There were no significant associations between slope or baseline level of CRP and cognitive decline nor between interleukin-6 and cognitive decline. We believe CRP variability likely reflects poor control of or greater changes in vascular or metabolic disease over time, which in turn is associated with cognitive decline.

Associations of BMI and adipose tissue area and density with incident mobility limitation and poor performance in older adults

BACKGROUND

Obesity is a risk factor for disability, but risk of specific adipose depots is not completely understood.

OBJECTIVE

We investigated associations between mobility limitation, performance, and the following adipose measures: body mass index (BMI) and areas and densities of visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), and intermuscular adipose tissue (IMAT) in older adults.

DESIGN

This was a prospective population-based study of men (n = 1459) and women (n = 1552) initially aged 70-79 y and free from mobility limitation. BMI was determined from measured height and weight. Adipose tissue area and density in Hounsfield units were measured in the thigh and abdomen by using computed tomography. Mobility limitation was defined as 2 consecutive reports of difficulty walking one-quarter mile or climbing 10 steps during semiannual assessments over 13 y. Poor performance was defined as a gait speed <1 m/s after 9 y of follow-up (n = 1542).

RESULTS

In models adjusted for disability risk factors, BMI, and areas of VAT, abdominal SAT, and IMAT were positively associated with mobility limitation in men and women. In women, thigh SAT area was positively associated with mobility limitation risk, whereas VAT density was inversely associated. Associations were similar for poor performance. BMI and thigh IMAT area (independent of BMI) were particularly strong indicators of incident mobility limitation and poor performance. For example, in women, the HR (95% CI) and OR (95% CI) associated with an SD increment in BMI for mobility limitation and poor performance were 1.31 (1.21, 1.42) and 1.41 (1.13, 1.76), respectively. In men, the HR (95% CI) and OR (95% CI) associated with an SD increment in thigh IMAT for mobility limitation and poor performance were 1.37 (1.27, 1.47) and 1.54 (1.18, 2.02), respectively.

CONCLUSIONS

Even into old age, higher BMI is associated with mobility limitation and poor performance. The amount of adipose tissue in abdominal and thigh depots may also convey risk beyond BMI.

Relationship between 25-hydroxyvitamin D and cognitive function in older adults: the Health, Aging and Body Composition Study

OBJECTIVES

To examine the relationship between 25-hydroxyvitamin D (25(OH)D) levels and cognitive performance over time in older adults in the Health, Aging and Body Composition (Health ABC) Study.

DESIGN

Prospective cohort study.

SETTING

Community-dwelling participants in Pittsburgh, Pennsylvania, and Memphis, Tennessee.

PARTICIPANTS

Well-functioning adults aged 70 to 79 at baseline with serum 25(OH)D measured at the 12-month follow-up visit and cognitive function measured at baseline and 4-year follow-up visit (N = 2,777).

MEASUREMENTS

Vitamin D status was categorized as 25(OH)D levels of less than 20.0 ng/mL, 20.0 to 29.9 ng/mL, or 30.0 ng/mL or greater. Cognition was measured using the modified Mini-Mental State Examination (3MS) and Digit Symbol Substitution Test (DSST). Linear regression models adjusting for multiple covariates, including age, education, sex, race, site, season, physical activity, and comorbidities, were used in the analysis.

RESULTS

Sixty-eight percent of participants had 25(OH)D levels of less than 30.0 ng/mL. Lower 25(OH)D levels were associated with lower baseline cognitive scores on the 3MS (adjusted mean 89.9, 95% confidence interval (CI) = 89.4-90.4 for <20.0 ng/mL; adjusted mean 90.8, 95% CI = 90.4-91.3 for 20.0-29.9 ng/mL; adjusted mean 90.6, 95% CI = 90.2-91.1 for ≥ 30.0 ng/mL; P trend = .02) and the DSST (adjusted mean 35.2, 95% CI = 34.5-36.0 for <20.0 ng/mL; adjusted mean 35.9, 95% CI = 35.2-36.6 for 20.0-29.9 ng/mL; adjusted mean 37.0, 95% CI = 36.3-37.8 for ≥ 30.0 ng/mL; P trend = .01). Participants with low 25(OH)D levels had greater declines in 3MS scores over 4 years than those with higher levels (least square mean change -1.0, 95% CI = -1.5 to -0.6 for <20.0 ng/mL; least square mean change -0.8, 95% CI = -1.2 to -0.3 for 20.0-29.9 ng/mL; least square mean change -0.2, 95% CI = -0.7 to 0.2 for ≥30.0 ng/mL; P = .05). There was no significant difference in DSST decline according to 25(OH)D level.

CONCLUSION

Low 25(OH)D levels were associated with worse global cognitive function and greater decline over time according to the 3MS. Intervention trials are needed to determine whether vitamin D supplementation can reduce cognitive decline.

Unhealthy lifestyles do not mediate the relationship between socioeconomic status and incident depressive symptoms: the Health ABC study

BACKGROUND

The relationship between low socioeconomic status (SES) and depressive symptoms is well described, also in older persons. Although studies have found associations between low SES and unhealthy lifestyle factors, and between unhealthy lifestyle factors and depressive symptoms, not much is known about unhealthy lifestyles as a potential explanation of socioeconomic differences in depressive symptoms in older persons.

METHODS

To study the independent pathways between SES (education, income, perceived income, and financial assets), lifestyle factors (smoking, alcohol use, body mass index, and physical activity), and incident depressive symptoms (Center for Epidemiologic Studies-Depression [CES-D 10] and reported use of antidepressant medication), we used 9 years of follow-up data (1997-2007) from 2,694 American black and white participants aged 70-79 years from the Health, Aging, and Body Composition (Health ABC) study. At baseline, 12.1% of the study population showed prevalent depressive symptoms, use of antidepressant medication, or treatment of depression in the 5 years prior to baseline. These persons were excluded from the analyses.

RESULTS

Over a period of 9 years time, 860 participants (31.9%) developed depressive symptoms. Adjusted hazard ratios for incident depressive symptoms were higher in participants from lower SES groups compared with the highest SES group. The strongest relationships were found for black men. Although unhealthy lifestyle factors were consistently associated with low SES, they were weakly related to incident depressive symptoms. Lifestyle factors did not significantly reduce hazard ratios for depressive symptoms by SES.

CONCLUSION

In generally healthy persons aged 70-79 years, lifestyle factors do not explain the relationship between SES and depressive symptoms.

Hearing loss and cognitive decline in older adults

BACKGROUND Whether hearing loss is independently associated with accelerated cognitive decline in older adults is unknown. METHODS We studied 1984 older adults (mean age, 77.4 years) enrolled in the Health ABC Study, a prospective observational study begun in 1997-1998. Our baseline cohort consisted of participants without prevalent cognitive impairment (Modified Mini-Mental State Examination [3MS] score, ≥80) who underwent audiometric testing in year 5. Participants were followed up for 6 years. Hearing was defined at baseline using a pure-tone average of thresholds at 0.5 to 4 kHz in the better-hearing ear. Cognitive testing was performed in years 5, 8, 10, and 11 and consisted of the 3MS (measuring global function) and the Digit Symbol Substitution test (measuring executive function). Incident cognitive impairment was defined as a 3MS score of less than 80 or a decline in 3MS score of more than 5 points from baseline. Mixed-effects regression and Cox proportional hazards regression models were adjusted for demographic and cardiovascular risk factors. RESULTS In total, 1162 individuals with baseline hearing loss (pure-tone average >25 dB) had annual rates of decline in 3MS and Digit Symbol Substitution test scores that were 41% and 32% greater, respectively, than those among individuals with normal hearing. On the 3MS, the annual score changes were -0.65 (95% CI, -0.73 to -0.56) vs -0.46 (95% CI, -0.55 to -0.36) points per year (P = .004). On the Digit Symbol Substitution test, the annual score changes were -0.83 (95% CI, -0.94 to -0.73) vs -0.63 (95% CI, -0.75 to -0.51) points per year (P = .02). Compared to those with normal hearing, individuals with hearing loss at baseline had a 24% (hazard ratio, 1.24; 95% CI, 1.05-1.48) increased risk for incident cognitive impairment. Rates of cognitive decline and the risk for incident cognitive impairment were linearly associated with the severity of an individual's baseline hearing loss. CONCLUSIONS Hearing loss is independently associated with accelerated cognitive decline and incident cognitive impairment in community-dwelling older adults. Further studies are needed to investigate what the mechanistic basis of this association is and whether hearing rehabilitative interventions could affect cognitive decline.

Plasma beta amyloid level and depression in older adults

BACKGROUND

Older adults with depression have an increased risk of developing dementia. Low plasma beta-amyloid 42 (Aβ42) and Aβ42/Aβ40 have emerged as promising biomarkers of dementia. The association between depression and plasma Aβ is unclear.

METHODS

In this longitudinal study of 988 community-dwelling elders from the Health Aging and Body Composition study, depression was assessed with the Center for Epidemiologic Studies-Depression Scale 10-item version. We determined the association between Aβ42 and Aβ42/Aβ40 tertile and depression at baseline and over 9 years. We also stratified the models to determine if apolipoprotein E e4 allele status modified the associations.

RESULTS

Mean baseline age was 74.0 ± 3.0 years, 51 (5.2%) participants had depression, 545 (55.2%) were women, 531 (53.7%) were black, and 286 (30.7%) had one or more apolipoprotein E e4 allele. At baseline, there was no association between Aβ42/Aβ40 or Aβ42 and depression. Over 9 years, 220 (23.5%) participants developed depression. In adjusted Cox proportional hazards models, among those with one or more e4 allele, low Aβ42/Aβ40 was associated with an increased risk of developing depression over time (low 10.8% vs high 3.2%, hazard ratio = 2.38, 95% confidence interval: 1.15-4.92). Among those with no e4 allele, there was no association between Aβ42/Aβ40 and risk of depression over time (13.3% vs 17.5%, hazard ratio = 0.80, 95% confidence interval: 0.52-1.23; p value for interaction = .003).

CONCLUSIONS

The association between low plasma Aβ42/Aβ40 and increased risk of incident depression among those with one or more apolipoprotein E e4 allele implies a synergistic relationship similar to that found with dementia. Future work should investigate the interrelationships among plasma Aβ42/Aβ40, depression, and dementia.

Associations of openness and conscientiousness with walking speed decline: findings from the Health, Aging, and Body Composition Study

OBJECTIVES

The objective of this study was to explore the associations between openness to experience and conscientiousness, two dimensions of the five-factor model of personality, and usual gait speed and gait speed decline.

METHOD

Baseline analyses were conducted on 907 men and women aged 71-82 years participating in the Cognitive Vitality substudy of the Health, Aging, and Body Composition study. The longitudinal analytic sample consisted of 740 participants who had walking speed assessed 3 years later.

RESULTS

At baseline, gait speed averaged 1.2 m/s, and an average decline of 5% over the 3-year follow-up period was observed. Higher conscientiousness was associated with faster initial walking speed and less decline in walking speed over the study period, independent of sociodemographic characteristics. Lifestyle factors and disease status appear to play a role in the baseline but not the longitudinal association between conscientiousness and gait speed. Openness was not associated with either initial or decline in gait speed.

DISCUSSION

These findings extend the body of evidence suggesting a protective association between conscientiousness and physical function to performance-based assessment of gait speed. Future studies are needed to confirm these associations and to explore mechanisms that underlie the conscientiousness mobility connection in aging adults.

Personality and reduced incidence of walking limitation in late life: findings from the Health, Aging, and Body Composition Study

OBJECTIVES

To examine the association between openness to experience and conscientiousness and incident reported walking limitation.

METHOD

The study population consisted of 786 men and women aged 71-81 years (M = 75 years, SD = 2.7) participating in the Health, Aging, and Body Composition-Cognitive Vitality Substudy.

RESULTS

Nearly 20% of participants (155/786) developed walking limitation during 6 years of follow-up. High openness was associated with a reduced risk of walking limitation (hazard ratio [HR] = 0.83, 95% confidence interval [CI] = 0.69-0.98), independent of sociodemographic factors, health conditions, and conscientiousness. This association was not mediated by lifestyle factors and was not substantially modified by other risk factors for functional disability. Conscientiousness was not associated with risk of walking limitation (HR = 0.91, 95% CI = 0.77-1.07).

DISCUSSION

Findings suggest that personality dimensions, specifically higher openness to experience, may contribute to functional resilience in late life.

Lower Digit Symbol Substitution Score in the Oldest Old is Related to Magnetization Transfer and Diffusion Tensor Imaging of the White Matter

Background: Slowing information processing is common among community-dwelling elderly and it predicts greater mortality and disability risk. Slowing information processing is related to brain macro-structural abnormalities. Specifically, greater global atrophy and greater small vessel disease of the white matter (WM) have been associated with slower processing speed. However, community-dwelling elderly with such macro-structural abnormalities can maintain processing speed. The roles of brain micro-structure for slow processing in very old adults living in the community is uncertain, as epidemiological studies relating these brain markers to cognition and in the context of other health characteristics are sparse. Hypothesis: Information processing is cross-sectionally associated with WM micro-structure independent of overt macro-structural abnormalities and also independent of health related characteristics. Methods: Imaging indices of micro-structure diffusion tensor imaging (DTI) and magnetization transfer imaging (MTI), macro-structure white matter hyperintensities (WMH), gray matter (GM) volume, digit symbol substitution test (DSST), and health characteristics were measured in 272 elderly (mean age 83 years old, 43% men, 40% black) living in the community. Results: The DTI- and MTI-indices of micro-structure from the normal appearing WM and not from the normal appearing GM were associated with DSST score independent of WMH and GM volumes. Associations were also independent of age, race, gender, mini-mental score, systolic blood pressure, and prevalent myocardial infarction. Interpretation: DTI and MTI-indices of normal appearing WM are indicators of information processing speed in this cohort of very old adults living in the community. Since processing slowing is a potent index of mortality and disability, these indices may serve as biomarkers in prevention or treatment trials of disability.

Race, socioeconomic resources, and late-life mobility and decline: findings from the Health, Aging, and Body Composition study

BACKGROUND

This study examines the relationship between race and mobility over 5 years in initially well-functioning older adults and evaluates how a broad set of socioeconomic status indicators affect this relationship.

METHODS

Data were from 2,969 black and white participants aged 70-79 from the Health, Aging, and Body Composition study. Mobility parameters included self-reported capacity to walk a quarter mile and climb 10 steps and usual gait speed. Incident mobility limitation was defined as reported difficulty walking a quarter mile or climbing 10 steps at two consecutive semiannual assessments. Gait speed decline was defined as a 4% reduction in speed per year.

RESULTS

At baseline, even though all participants were free of mobility limitation, blacks had slower walking speed than their white counterparts, which was not explained by poverty, education, reading level, or income adequacy. After 5 years, accounting for age, site, and baseline mobility, blacks were more likely to develop mobility limitation than whites. Adjusting for prevalent conditions at baseline eliminated this difference in women; controlling for education eliminated this difference in men. No differences in gait speed decline were identified.

CONCLUSIONS

Higher rates of mobility loss observed in older blacks relative to older whites appear to be a function of both poorer initial mobility status and existing health conditions particularly for women. Education may also play a role especially for men.

Association of plasma beta-amyloid level and cognitive reserve with subsequent cognitive decline

CONTEXT

Lower plasma β-amyloid 42 and 42/40 levels have been associated with incident dementia, but results are conflicting and few have investigated cognitive decline among elders without dementia.

OBJECTIVE

To determine if plasma β-amyloid is associated with cognitive decline and if this association is modified by measures of cognitive reserve.

DESIGN, SETTING, AND PARTICIPANTS

We studied 997 black and white community-dwelling older adults from Memphis, Tennessee, and Pittsburgh, Pennsylvania, who were enrolled in the Health ABC Study, a prospective observational study begun in 1997-1998 with 10-year follow-up in 2006-2007. Participant mean age was 74.0 (SD, 3.0) years; 55.2% (n = 550) were female; and 54.0% (n = 538) were black.

MAIN OUTCOME MEASURES

Association of near-baseline plasma β-amyloid levels (42 and 42/40 measured in 2010) and repeatedly measured Modified Mini-Mental State Examination (3MS) results.

RESULTS

Low β-amyloid 42/40 level was associated with greater 9-year 3MS cognitive decline (lowest β-amyloid tertile: mean change in 3MS score, -6.59 [95% confidence interval [CI], -5.21 to -7.67] points; middle tertile: -6.16 [95% CI, -4.92 to -7.32] points; and highest tertile: -3.60 [95% CI, -2.27 to -4.73] points; P < .001). Results were similar after multivariate adjustment for age, race, education, diabetes, smoking, and apolipoprotein E [APOE ] e4 status and after excluding the 72 participants with incident dementia. Measures of cognitive reserve modified this association whereby among those with high reserve (at least a high school diploma, higher than sixth-grade literacy, or no APOE e4 allele), β-amyloid 42/40 was less associated with multivariate adjusted 9-year decline. For example, among participants with less than a high school diploma, the 3MS score decline was -8.94 (95% CI, -6.94 to -10.94) for the lowest tertile compared with -4.45 (95% CI, -2.31 to -6.59) for the highest tertile, but for those with at least a high school diploma, 3MS score decline was -4.60 (95% CI,-3.07 to -6.13) for the lowest tertile and -2.88 (95% CI,-1.41 to -4.35) for the highest tertile (P = .004 for interaction). Interactions were also observed for literacy (P = .005) and for APOE e4 allele (P = .02).

CONCLUSION

Lower plasma β-amyloid 42/40 is associated with greater cognitive decline among elderly persons without dementia over 9 years, and this association is stronger among those with low measures of cognitive reserve.

Race, psychosocial factors, and aortic pulse wave velocity: the Health, Aging, and Body Composition Study

BACKGROUND

Increasingly, researchers have begun to explore pathways through which psychosocial factors might influence cardiovascular disease, with some emphasis on early markers. The current study examined the cross-sectional association between psychosocial factors and aortic pulse wave velocity (an early marker of cardiovascular disease) in a biracial cohort of older adults. We were particularly interested in determining whether the association between psychosocial factors and aortic pulse wave velocity differed for older blacks compared with whites.

METHODS

Participants were 2,488 (40% black and 52% female) older adults from the Health, Aging, and Body Composition Study. Carotid-femoral aortic pulse wave velocity was assessed using standard methodologies. Depressive symptoms, anxiety symptoms, negative life events, and inadequate emotional support were assessed, and a summary psychosocial risk index was created.

RESULTS

In multivariable linear regression models, psychosocial risk was not associated with aortic pulse wave velocity (Estimate [Est] = .00, p = .83), but there was a significant Race × Psychosocial risk interaction (Est = .07, p = .01), after adjusting for age, race, sex, and education. Further analyses revealed that this association was driven by the inadequate emotional support component of psychosocial risk (Race × Inadequate emotional support, p = .005). In race-stratified analyses, inadequate emotional support was associated with higher levels of arterial stiffness in older blacks (Est = .05, p = .04) but not whites (Est = -.04, p = .13). This association persisted after adjusting for demographics, cardiovascular risk factors, and social network characteristics.

CONCLUSIONS

Findings suggest that older blacks may be particularly vulnerable to the effects of inadequate emotional support on vascular health. Interventions aimed at increasing social support among this population might be beneficial in reducing cardiovascular disease risk.

The effect of maintaining cognition on risk of disability and death

OBJECTIVES

To determine whether long-term maintenance of cognition is associated with health advantages such as lower mortality or incident disability in older adults.

DESIGN

Longitudinal cohort study.

SETTING

Community clinics at two sites.

PARTICIPANTS

Two thousand seven hundred thirty-three adults with a mean age of 74 at baseline and 80 at follow-up.

MEASUREMENTS

Cognitive function was assessed using the Modified Mini-Mental State Examination (3MS), a test of global cognition, at least two times. Three cognitive groups were defined based on 4-year participant-specific slopes (maintainers, slopes of >or=0; minor decliners, slopes <0 but no more than 1 standard deviation (SD) below the mean; major decliners, slopes >1 SD below the mean). Whether the cognitive groups differed in mortality and incident disability during the subsequent 3 years was determined.

RESULTS

Nine hundred eighty-four (36%) participants were maintainers, 1,314 (48%) were minor decliners, and 435 (16%) were major decliners. Maintainers had lower mortality (7% vs 14%, hazard ratio (HR)=0.48, 95% confidence interval (CI)=0.36-0.63) and incident disability (22% vs 29%, HR=0.74, 95% CI=0.62-0.89) than minor decliners. After adjustment for age, race, sex, education, apolipoprotein E epsilon4, depression, body mass index, stroke, hypertension, and diabetes mellitus, these differences remained. As expected, major decliners had greater mortality (20%) and incident disability (40%) than minor decliners.

CONCLUSION

A substantial proportion of older adults maintain cognitive function in their eighth and ninth decades of life. These older adults demonstrate lower risk of death and functional decline than those with minor cognitive decline, supporting the concept of "successful" cognitive aging.

Telomere length and cognitive function in community-dwelling elders: findings from the Health ABC Study

Telomere shortening is a marker of cellular aging and has been associated with risk of Alzheimer's disease. Few studies have determined if telomere length is associated with cognitive decline in non-demented elders. We prospectively studied 2734 non-demented elders (mean age: 74 years). We measured cognition with the Modified Mini-Mental State Exam (3MS) and Digit Symbol Substitution Test (DSST) repeatedly over 7 years. Baseline telomere length was measured in blood leukocytes and classified by tertile as "short", "medium", or "long". At baseline, longer telomere length was associated with better DSST score (36.4, 34.9 and 34.4 points for long, medium and short, p<0.01) but not for change in score. However, 7-year 3MS change scores were less among those with longer telomere length (-1.7 points vs. -2.5 and -2.9, p=0.01). Findings were similar after multivariable adjustment for age, gender, race, education, assay batch, and baseline score. There was a borderline statistically significant interaction for telomere length and APOE e4 on 3MS change score (p=0.06). Thus, telomere length may serve as a biomarker for cognitive aging.

Moderate alcohol intake and risk of functional decline: the Health, Aging, and Body Composition study

OBJECTIVES

To investigate the prospective relationship between alcohol consumption and incident mobility limitation.

DESIGN

Cohort study.

SETTING

The Health Aging and Body Composition study, conducted in Memphis, Tennessee, and Pittsburgh, Pennsylvania.

PARTICIPANTS

Three thousand sixty-one adults aged 70 to 79 without mobility disability at baseline.

MEASUREMENTS

Incidence of mobility limitation, defined as self-report at two consecutive semiannual interviews of any difficulty walking one-quarter of a mile or climbing stairs, and incidence of mobility disability, defined as severe difficulty or inability to perform these tasks at two consecutive reports. Alcohol intake, lifestyle-related variables, diseases, and health status indicators were assessed at baseline.

RESULTS

During a follow-up time of 6.5 years, participants consuming moderate levels of alcohol had the lowest incidence of mobility limitation (total: 6.4 per 100 person-years (person-years); men: 6.4 per 100 person-years; women: 7.3 per 100 person-years) and mobility disability (total: 2.7 per 100 person-years; men: 2.5 per 100 person-years; women: 2.9 per 100 person-years). Adjusting for demographic characteristics, moderate alcohol intake was associated with lower risk of mobility limitation (hazard ratio (HR)=0.70, 95% confidence interval (CI)=0.55-0.89) and mobility disability (HR=0.66, 95% CI=0.45-0.95) than never or occasional consumption. Additional adjustment for lifestyle-related variables substantially reduced the strength of the associations (HR=0.85, 95% CI=0.66-1.08 and HR=0.81, 95% CI=0.56-1.18, respectively). Adjustment for diseases and health status indicators did not affect the strength of the associations, suggesting that lifestyle is most important in confounding this relationship.

CONCLUSION

Lifestyle-related characteristics mainly accounted for the association between moderate alcohol intake and lower risk of functional decline over time. These findings do not support a direct causal effect of alcohol intake on physical function.

Predictors of maintaining cognitive function in older adults: the Health ABC study

BACKGROUND

Although several risk factors for cognitive decline have been identified, much less is known about factors that predict maintenance of cognitive function in advanced age.

METHODS

We studied 2,509 well-functioning black and white elders enrolled in a prospective study. Cognitive function was measured using the Modified Mini-Mental State Examination at baseline and years 3, 5, and 8. Random effects models were used to classify participants as cognitive maintainers (cognitive change slope > or = 0), minor decliners (slope < 0 and > 1 SD below mean), or major decliners (slope < or = 1 SD below mean). Logistic regression was used to identify domain-specific factors associated with being a maintainer vs a minor decliner.

RESULTS

Over 8 years, 30% of the participants maintained cognitive function, 53% showed minor decline, and 16% had major cognitive decline. In the multivariate model, baseline variables significantly associated with being a maintainer vs a minor decliner were age (odds ratio [OR] = 0.65, 95% confidence interval [CI] 0.55-0.77 per 5 years), white race (OR = 1.72, 95% CI 1.30-2.28), high school education level or greater (OR = 2.75, 95% CI 1.78-4.26), ninth grade literacy level or greater (OR = 4.85, 95% CI 3.00-7.87), weekly moderate/vigorous exercise (OR = 1.31, 95% CI 1.06-1.62), and not smoking (OR = 1.84, 95% CI 1.14-2.97). Variables associated with major cognitive decline compared to minor cognitive decline are reported.

CONCLUSION

Elders who maintain cognitive function have a unique profile that differentiates them from those with minor decline. Importantly, some of these factors are modifiable and thus may be implemented in prevention programs to promote successful cognitive aging. Further, factors associated with maintenance may differ from factors associated with major cognitive decline, which may impact prevention vs treatment strategies.

Racial differences in self-rated health at similar levels of physical functioning: an examination of health pessimism in the health, aging, and body composition study

BACKGROUND

The health pessimism hypothesis suggests that Black elders are more pessimistic about health than Whites and therefore tend to report lower self-rated health (SRH) at comparable health status. The current analysis examined the factors associated with SRH and tested the health pessimism hypothesis among older adults at similar levels of physical functioning.

METHODS

The study example included 2,729 Health, Aging, and Body Composition study participants aged 70-79 years. We used hierarchical logistic regression to examine the association between race and SRH while adjusting for demographic, physical health, and psychosocial factors. The analyses were repeated for participants at similar levels of objective functioning to test the health pessimism hypothesis.

RESULTS

The association between race and SRH remained independent of physical and psychosocial health variables, with Whites being 3.7 times more likely than Black elders to report favorable SRH. This association was significant at each level of physical functioning and greater at the higher (odds ratio [OR] = 5.5) versus lower (OR = 2.2) levels of functioning.

CONCLUSIONS

The results suggest greater health pessimism among Black elders and expand previous work by including objective functioning in multidimensional models to deconstruct race variations in the SRH of older adults.

Parity and cardiovascular disease risk among older women: how do pregnancy complications mediate the association?

PURPOSE

To determine whether parity is associated with increased risk of cardiovascular disease (CVD) after accounting for perinatal complications.

METHODS

CVD prevalence, number of births, and a history of preeclampsia, term low birth weight, preterm or stillbirth were evaluated among 540 women (mean age, 80 years; 47% black) enrolled in the Pittsburgh, PA site of the Health, Aging and Body Composition Study. Biomarkers were measured and CVD status was determined by self-report and hospital records.

RESULTS

Nulliparous women (n = 89) had lower CVD prevalence compared with parous women (18.0% vs. 30.2%). Parous women without perinatal complications of interest (n = 321) had higher statin use compared with nulliparas, a trend accompanied by lower high-density lipoprotein (HDL) and higher triglycerides among women with perinatal complications (n = 130). After adjustment, parous women with no complicated births had a 1.95-fold (95% confidence interval [CI], 1.03-3.7) higher CVD prevalence compared to nulliparas. Among women with one or more pregnancy complications, CVD prevalence was 2.67 times (CI, 1.34-5.33) higher. Women with five or more births had the highest CVD prevalence (odds ratio [OR], 2.60; CI, 1.17-5.76) that was attenuated to 2.27 (1.00-5.15) after adjustment for complications of interest.

CONCLUSIONS

History of pregnancy complications and higher statin use accounted for some but not all of the excess CVD prevalence among older parous women.

Caregiving, mortality, and mobility decline: the Health, Aging, and Body Composition (Health ABC) Study

BACKGROUND

Although caregivers report more stress than noncaregivers, few studies have found greater health decline in older caregivers. We hypothesized that caregivers may be more physically active than noncaregivers, which may protect them from health decline.

METHODS

The sample included 3075 healthy adults from the Health, Aging, and Body Composition (Health ABC) Study. They were aged 70 to 79 years in April 1997 to June 1998 and resided in Memphis, Tennessee, or Pittsburgh, Pennsylvania. Caregivers (680 [22.1%]) were participants who provided regular care or assistance for a child or a disabled or sick adult. Outcomes included all-cause mortality and incident mobility limitation (defined as difficulty walking one-quarter mile or climbing 10 steps on 2 consecutive semiannual contacts) during 8 years. Total physical activity included daily routine, exercise, and caregiving activity.

RESULTS

Overall, 20.6% of caregivers died and 50.9% developed mobility limitations vs 22.0% and 48.9% of noncaregivers, respectively. Associations differed by race and sex. Mortality and mobility limitation rates were 1.5 times higher in white caregivers (eg, among white female caregivers, adjusted hazard ratio for mortality, 1.6; 95% confidence interval, 1.0-2.5) but not for black female caregivers vs noncaregivers (adjusted hazard ratio for mortality, 0.9; 95% confidence interval, 0.5-1.4). Physical activity mediated these associations in most race-sex groups. High-intensity caregivers (ie, caregiving > or =24 hours per week) had elevated rates of decline when adjusted for physical activity but lower rates when not adjusted for activity.

CONCLUSION

Older white caregivers have poorer health outcomes than black female caregivers. Physical activity appears to mask the adverse effects of high-intensity caregiving in most race-sex groups.

Vascular disease and future risk of depressive symptomatology in older adults: findings from the Health, Aging, and Body Composition study

BACKGROUND

The vascular depression hypothesis suggests that age-related vascular diseases and risk factors contribute to late-life depression. Although neuroimaging studies provide evidence for an association between depression and severity of vascular lesions in the brain, studies of depression and indicators of vascular risk have been less consistent.

METHODS

We examined 1796 elders ages 70-79 from the Health, Aging and Body Composition study without depression at baseline and examined the association between prevalent vascular disease and related conditions at baseline and 2-year incidence of elevated depressive symptoms, defined as a score > 8 on the 10-item Center for Epidemiologic Studies Depression (CES-D) scale.

RESULTS

After adjustment for demographic data and physical and cognitive functioning, several vascular conditions remained associated with increased risk of depressive symptomatology including metabolic syndrome and its components (low high-density lipoprotein cholesterol and high fasting glucose), coronary heart disease, a positive Rose questionnaire for angina, and high hemoglobin a1c. Cumulative vascular risk based upon a composite of 10 vascular diseases and risk factors was independently associated with incident elevated depression at 2-year follow-up after controlling for demographic data, physical and cognitive functioning, and selected comorbid medical conditions.

CONCLUSIONS

These results provide support for the vascular depression hypothesis in demonstrating an association between vascular conditions and risk factors and subsequent risk of depressive symptomatology. Older adults with vascular conditions and risk factors require close monitoring of depressive symptoms.

Racial disparities in health care access and cardiovascular disease indicators in Black and White older adults in the Health ABC Study

OBJECTIVE

Black adults consistently exhibit higher rates of and poorer health outcomes due to cardiovascular disease (CVD) than other racial groups, independent of differences in socioeconomic status (SES). Whether factors related to health care access can further explain racial disparities in CVD has not been thoroughly examined.

METHOD

Using logistic regression, the authors examined racial and health care (i.e., health insurance and access to care) associations with CVD indicators (i.e., hypertension, low ankle-arm index, and left ventricular hypertrophy) in the Health, Aging, and Body Composition Study, a longitudinal study of well-functioning older adults.

RESULTS

Older Black versus White adults had significantly worse health care. Overall, health care reduced the significant association between being Black and CVD only slightly, while race remained strongly associated with CVD after adjusting for demographics, SES, body mass index, and comorbidity.

DISCUSSION

Research on health care quality may contribute to our understanding of these disparities.

Diabetes mellitus, glycemic control, and incident depressive symptoms among 70- to 79-year-old persons: the health, aging, and body composition study

BACKGROUND

Cross-sectional studies find an elevated prevalence of depression among subjects with diabetes mellitus (DM). The causal mechanisms and temporal sequence of this association have not been clearly delineated. This study investigated the prospective relationship between DM and depressive symptoms.

METHODS

The Health, Aging, and Body Composition Study was a cohort study conducted in the metropolitan areas of Memphis, Tenn, and Pittsburgh, Pa. The analysis included 2522 community-dwelling subjects, aged 70 to 79 years, without baseline depressive symptoms. Incident depressed mood was defined as use of antidepressants at follow-up visits or presence of depressive symptoms (score >or=10 on the 10-item Center for Epidemiological Studies Depression scale). Presence of incident depressed mood at 2 consecutive annual clinic visits defined the incidence of recurrent depressed mood. Diabetes mellitus status, glycosylated hemoglobin (HbA1c) level, and DM-related comorbidities were assessed at baseline. Diabetes mellitus status was further characterized as absent, controlled (HbA1c level <7%), or uncontrolled (HbA1c level >or=7%). Discrete time survival analysis was used to estimate depressive events risk.

RESULTS

During a mean follow-up of 5.9 years, participants with DM had a higher age-, sex-, race-, and site-adjusted incidence of depressed mood (23.5% vs 19.0%) (P = .02) and recurrent depressed mood (8.8% vs 4.3%) (P<.001) than those without DM. Diabetes mellitus was associated with a 30% increased risk of incident depressed mood (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.07-1.61), which was attenuated after adjustment for DM-related comorbidities (OR, 1.20; CI, 0.97-1.48). A stronger relationship was observed between DM and recurrent depressed mood (OR, 1.91; CI, 1.32-2.76), particularly among participants with poor glycemic control.

CONCLUSION

Among well-functioning older adults, DM is associated with increased risk of depressive symptoms.

Multitasking: Association Between Poorer Performance and a History of Recurrent Falls

OBJECTIVES

To examine the association between poorer performance on concurrent walking and reaction time and recurrent falls.

DESIGN

Cross-sectional analysis.

SETTING

Community.

PARTICIPANTS

Three hundred seventy-seven older community-dwelling adults (mean age+/-standard deviation 78+/-3).

MEASUREMENTS

Reaction times on push-button and visual-spatial decision tasks were assessed while seated and while walking a 20-m course (straight walk) and a 20-m course with a turn at 10 m (turn walk). Walking times were recorded while walking only and while performing a reaction-time response. Dual-task performance was calculated as the percentage change in task times when done in dual-task versus single-task conditions. A history of recurrent falls (> or = 2 vs < or = 1 falls) in the prior 12 months was self-reported. Multivariate logistic regression models were used to predict the standardized odds ratios (ORs) of recurrent falls history. The standardized unit for dual-task performance ORs was interquartile range/2.

RESULTS

On the push-button task during the turn walk, poorer reaction time response (slower) was associated with 28% lower (P=.04) odds of recurrent fall history. On the visual-spatial task, poorer walking-time response (slower) was associated with 34% (P=.02) and 42% (P=.01) higher odds of recurrent falls history on the straight and turn walks, respectively.

CONCLUSION

These findings suggest that walking more slowly in response to a visual-spatial decision task may identify individuals at risk for multiple falls. Prospective studies are needed to confirm the prognostic value of poor walking responses in a dual-task setting for multiple falls.

Anxiety symptoms and decline in physical function over 5 years in the health, aging and body composition study

OBJECTIVES

To examine the relationship between anxiety and functional decline.

DESIGN

A 5-year longitudinal cohort study of well-functioning adults.

SETTING

The Health, Aging and Body Composition (Health ABC) Study.

PARTICIPANTS

Two thousand nine hundred forty adults aged 70 to 79 (48% male, 41% black), initially free of self-reported mobility difficulty.

MEASUREMENTS

In 1997/98, presence of three anxiety symptoms (feeling fearful, tense or keyed up, or shaky or nervous) from the Hopkins Symptom Checklist were ascertained. Physical function was examined over 5 years using the Health ABC performance battery (continuous range 0-4) consisting of chair stands, usual and narrow course gait speed, and difficulty with standing balance and self-reported mobility, defined as difficulty walking one-quarter of a mile or difficulty climbing 10 steps.

RESULTS

Participants with anxiety symptoms had similar baseline physical performance scores. After adjustment for potential confounders, subjects with anxiety symptoms had similar declines in physical performance over 5 years as participants without anxiety symptoms. Adults with anxiety symptoms were more likely to report incident mobility difficulty, with a hazard ratio of 1.4 (95% confidence interval=1.3-1.6), compared with adults without anxiety symptoms. These results persisted after adjustment for depressive symptoms, demographics, comorbidity, and use of antianxiety, depressant, and sedative hypnotic medications.

CONCLUSION

Anxiety symptoms are not associated with declines in objectively measured physical performance over 5 years but are associated with declines in self-reported functioning. Future studies are needed to determine why anxiety has a differential effect on performance-based and self-reported measures of functioning.

Scared to death: results from the Health, Aging, and Body Composition study

OBJECTIVE

The purpose of this study is to determine if anxiety is associated with mortality and if race moderates and depression mediates this relationship.

METHOD

Participants are 3,015 adults aged 70-79 years.

RESULTS

Anxiety symptoms were significant predictors of all-cause, cardiovascular, and noncardiovascular mortality among blacks but not whites. Depression was not related to mortality.

CONCLUSIONS

Although the mechanisms that underlie the relationship between anxiety and mortality are unknown, routine assessment of anxiety symptoms in clinical practice, particularly in black older adults, seems prudent.