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Biomedical subjects

Carlos F Mendes de Leon

Publications and source records attributed to Carlos F Mendes de Leon.

At least 19 recordsLinked to original sources
PubMed2006

Applying mixed regression models to the analysis of repeated-measures data in psychosomatic medicine.

OBJECTIVE: Although repeated-measures designs are increasingly common in research on psychosomatic medicine, they are not well suited to the conventional statistical techniques that scientists often apply to them. The goal of this article is to introduce readers to mixed regression models, which provide a more flexible and accurate framework for managing repeated-measures data. METHODS AND RESULTS: We begin with a summary of the advantages that mixed regression models have over conventional statistical techniques in the context of repeated-measures designs. Next, we outline the conceptual and mathematical underpinnings of mixed regression models for a nonstatistical audience. The article ends with two examples of how these models can be applied in psychosomatic research; one deals with a prospective investigation of depressive symptoms and change in body mass index in older adults and the other with a diary study of social interactions and cortisol secretion. CONCLUSIONS: Mixed regression models offer a flexible and powerful approach to analyzing repeated-measures data. They possess important advantages over more traditional strategies, and more widespread application of these models is likely to enhance the overall quality of psychosomatic research.

Body Mass Index↗
PubMed2006

Black-white differences in health-related quality of life among older adults.

Very little information exists on racial differences in quality of life among older adults. In this paper, we examine black-white differences in health-related quality of life (HRQOL) and identify factors that may account for these differences. The participants were 5,986 community-dwelling persons age 65+ (62% black at baseline) from the Chicago Health and Aging Project. Poor HRQOL was defined as having 14 or more self-reported physically or mentally unhealthy days over the past 30 days. A higher proportion of blacks (11.0%) than whites (9.7%) reported poor HRQOL. After adjusting for age and sex, blacks had increased odds of reporting poor HRQOL compared with whites (odds ratio [OR] = 1.72; 95% CI: 1.50-1.98). The black-white differences in HRQOL tended to increase with age (p < 0.05) and were greater among females (p < 0.05). Lifetime socioeconomic status, summary measures of medical conditions, and cognitive function accounted for most of the black-white difference (OR = 1.06; 95% CI: 0.89-1.27). Our results suggest that racial differences in HRQOL are associated with the combined effects of social disadvantage, poor physical health, and lower cognitive function.

Black or African American↗
PubMed2006

Association of fecal incontinence with physical disability and impaired cognitive function.

OBJECTIVES: Fecal incontinence is a common health problem for older people and is associated with significant morbidity and cost. In this study, we report on the association of fecal incontinence with physical disability and impaired cognitive function in a large bi-racial population of individuals aged 65 yr and older. METHODS: Study subjects are participants of the Chicago Health and Aging Project (CHAP), an ongoing study of older Chicago residents. A total of 6,099 participants completed the baseline in-home interview and assessments used in this analysis. Physical disability was assessed using a performance-based measure of basic physical functions and three commonly used self-report measures. Impaired cognitive function was assessed using a global measure of the averaged scores of four cognitive tests. The question used to determine the presence of fecal incontinence was: "In the past few months have you ever lost control of your bowels when you didn't want to?" RESULTS: In multiple logistic regression models adjusted for age, sex, and race, fecal incontinence was correlated with the presence of physical disability and impaired cognitive function on every measure. For example, using the performance-based measure of physical function, the odds of prevalent fecal incontinence were higher by 20% (OR 1.20, 95% CI 1.2-1.2) for each additional unit higher on the performance score, indicating a lower physical performance. The prevalence odds ratio for fecal incontinence was decreased by 51% for each one-point increase in the global cognitive score, indicating higher cognitive function. We found a statistically significant interaction between both race and physical disability and race and impaired cognitive function, such that the associations were stronger in blacks than in non-blacks. These associations remained after further adjustment for diabetes and stroke, and the intake of psychoactive medications. CONCLUSION: In urban, community-dwelling, older adults, fecal incontinence may be more common among persons with physical disability and impaired cognitive function.

Aged↗
PubMed2006

Relative weight and mobility: a longitudinal study in a biracial population of older adults.

PURPOSE: We examined the association of relative weight with mobility and changes in mobility over time and whether these associations differed by race. METHODS: Data come from a prospective, population-based, observational study of adults aged 65 years or older. Mobility outcomes were assessed at baseline and two follow-up interviews at 3-year intervals. The study included 4195 participants with a mean age of 73.8 +/- 6.3 (SD) years; 61.4% were women, and 60.9% were black. Assessment of mobility included a brief self-report instrument and a performance-based walk test. Body mass index (BMI, kilograms per square meter) was used as a measure of relative weight. We used generalized estimating equation models to examine change in mobility outcomes over time as a function of BMI. RESULTS: Average BMI was 26.6 +/- 5.7 kg/m(2), with 34.0% overweight and 23.4% obese. BMI showed a significant curvilinear association with mobility outcomes at baseline (p < 0.001), but was not associated with change in mobility during follow-up. Maximum mobility levels occurred at a significantly higher level of BMI among blacks than whites. CONCLUSIONS: Higher levels of BMI may lead to mobility impairments earlier in life, but there is little evidence that they increase the rate of decline in mobility in older age itself.

Aged↗
PubMed2006

Is lower cognitive function in one spouse associated with depressive symptoms in the other spouse?

This study examines whether lower cognitive function in one spouse is associated with depressive symptoms in the other spouse. The subjects were 528 community-dwelling spouse pairs aged 65+ who participated in the Chicago Health and Aging Project (CHAP), an ongoing longitudinal, bi-racial, population-based study of risk factors for incident Alzheimer's disease and other age-related chronic conditions. CHAP participants were assessed at 3-year intervals over a period of nearly ten years. The results show a cross-sectional association of wives' lower cognitive function at baseline with depressive symptoms in husbands; however, husbands' cognitive function was not associated with wives' depressive symptoms. There was no longitudinal association of cognitive function at baseline with increased depressive symptoms over time. Furthermore, change in cognitive function over time had no effect on depressive symptoms in either spouse. The relationship between cognitive function and depressive symptoms in spouse pairs is complex. Our findings suggest that husbands may be particularly psychologically vulnerable to the negative effects of their wives' cognitive impairment. This vulnerability may have a range of long-term health and caregiving implications.

Activities of Daily Living↗
PubMed2006

Childhood adversity and psychosocial adjustment in old age.

OBJECTIVE: The objective of this study was to test the hypothesis that higher level of childhood adversity is associated with lower level of psychosocial adjustment in old age. METHOD: Participants are 253 older persons (mean age: 79.8, standard deviation: 2.1; 73.9% women) from the Rush Memory and Aging Project, a clinicopathologic study of common chronic conditions of old age. Childhood adversity was assessed with a 16-item measure based on portions of the Childhood Trauma Questionnaire and other inventories. Psychosocial adjustment was assessed with multiple measures of neuroticism (i.e., proneness to negative emotions) and social engagement. RESULTS: Based in part on a factor analysis, composite measures of total adversity, emotional neglect, parental intimidation, parental violence, family turmoil, and financial need were developed. In a series of linear regression models adjusted for age, sex, own education, and parental education, the composite measure of childhood adversity was associated with all facets of neuroticism and accounted for more than 13% of the variance in the composite neuroticism measure. Emotional neglect and parental intimidation had the strongest associations with neuroticism. Childhood adversity was not related to frequency of participation in social activities, but more adversity was associated with having a smaller network (accounting for 3% of the variance) and feeling more emotionally isolated (accounting for 7% of the variance). CONCLUSION: Childhood adversity is associated with less adaptive psychosocial functioning in old age.

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PubMed2005

Changes in disability before and after myocardial infarction in older adults.

BACKGROUND: Disability in older adults is thought to occur primarily as a consequence of clinical disease episodes. However, the temporal relationship between clinical disease and disability has received little systematic attention. METHODS: Data from a prospective population-based study of 2812 older adults were analyzed to examine changes in disability before and after acute myocardial infarction. Disability outcomes included up to 9 yearly assessments of disability in activities in daily living, disability in basic physical functions, and disability in tasks requiring basic mobility and strength. RESULTS: A total of 279 myocardial infarctions occurred during 9 years of follow-up. After adjustment for age and sex, the average yearly increase in disability in activities of daily living and basic physical functions was not significantly greater in the 1-year period after myocardial infarction than in the 3-year period before myocardial infarction (P values >.20). Disability in basic mobility and strength showed a significantly greater increase in the year after myocardial infarction (P = .02). The results did not change after adjustment for comorbidity and chest pain or when restricted to incident cases of myocardial infarction or survivors. An additional exploratory analysis suggested that the rate of increase in some forms of disability may start to accelerate at about 1 year before the event, rather than after the event. CONCLUSIONS: The increase in disability after myocardial infarction may form a continuation of increases that occur before the event and challenge commonly held notions about the temporal relationship between clinical disease and disability. Changes in disability before acute disease episodes may be related to subclinical disease.

Activities of Daily Living↗
PubMed2005

Physical activity, cognitive activity, and cognitive decline in a biracial community population.

BACKGROUND: Findings from studies investigating whether physical activity reduces the risk of cognitive decline in old age have been inconsistent. OBJECTIVE: To examine whether participation in physical activity by older adults reduces the rate of cognitive decline after accounting for participation in cognitively stimulating activities. DESIGN: A prospective population study conducted from August 1993 to January 2003, with an average follow-up of 6.4 years. SETTING: A biracial community population on the south side of Chicago. PARTICIPANTS: Participants were 4055 community-dwelling adults 65 years and older who were able to walk across a small room and had participated in at least 2 of the 3 follow-up assessments. MAIN OUTCOME MEASURE: Annual rate of cognitive change as measured by a global cognitive score, which consisted of averaged standardized scores from 4 cognitive tests. RESULTS: In a mixed model adjusted for age, sex, race, and education, each additional physical activity hour per week was associated with a slower rate of cognitive decline by 0.0007 U/y (P = .04). However, with further adjustments (1) for participation in cognitive activities (beta = .0006, P = .10), (2) for depression and vascular diseases (beta = .0005, P = .19), and (3) by excluding participants whose global cognitive score at baseline was at or below the 10th percentile (beta = .0002, P = .45), the coefficients were smaller and no longer statistically significant. CONCLUSION: These data do not support the hypothesis that physical activity alone protects against cognitive decline among older adults.

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PubMed2005

Distress proneness and cognitive decline in a population of older persons.

The association between distress proneness and cognitive decline was examined in older residents of a biracial community in Chicago. At baseline, participants completed four cognitive tests that yielded a global measure (baseline mean=101.2; standard deviation (SD)=7.8), and a brief measure of the tendency to experience negative emotions (mean=16.5; SD=6.7) based on the Neuroticism scale of the NEO Five-Factor Inventory. Cognitive testing was repeated twice at three-year intervals. In mixed models that controlled age, sex, race, and education, for each point on the distress proneness scale, global cognitive score was 0.12 unit lower at baseline (p<0.001) and annual rate of decline increased by 0.01 unit (p=0.002), or about 2%. Thus, cognitive decline was about 30% faster in a person highly prone to distress (score=24, 90th percentile) compared to the one low in distress proneness (score=9, 10th percentile). This effect was unchanged after controlling for level of cognitive activity or excluding people with cognitive impairment at baseline, but it was reduced to a trend (p=0.059) after controlling for depressive symptoms. The results suggest that the tendency to experience psychological distress is associated with increased cognitive decline in old age.

Aged↗
PubMed2005

Black-white differences in depressive symptoms among older adults over time.

This study examines racial differences in depressive symptoms among older adults over time. The subjects were 4,275 community-dwelling persons aged 65 and older (62% Black) who participated in the Chicago Health and Aging Project (CHAP) during a period of 9 years. Depression was measured using a summary score of the 10-item Center for Epidemiologic Studies-Depression scale (CES-D). We modeled depressive symptoms using the method of General Estimating Equations and a Poisson error structure. We found a significant race effect at baseline with Blacks reporting approximately 60% more symptoms than Whites (beta = 0.467 on the log scale, p < .001). The differences were larger for men than for women. After controlling for age, sex, time, education, income, and related interaction terms, the baseline race effect was reduced by almost half (beta = 0.225, p < .001) but remained robust. The racial differences increased slightly over time. Our findings support heightened awareness of depression in older Black populations.

Activities of Daily Living↗
PubMed2005

Racial disparities in disability: recent evidence from self-reported and performance-based disability measures in a population-based study of older adults.

OBJECTIVE: Although disability levels have been declining in older adults, there is little current information on racial differences in disability. METHODS: Our data came from a longitudinal, population-based study of 6,158 Black and White adults aged 65 and older from the south side of Chicago. Data were collected during three face-to-face interviews between 1993 and 2002. We ascertained disability using three self-report measures and a performance-based measure of physical function. Using longitudinal data analysis, we examined overall racial differences in disability and the degree to which they varied by age and gender. RESULTS: After an average of 6 years of follow-up, Blacks reported significantly higher disability levels than Whites after adjustment for age and sex. There was a significant increase in disability during follow-up on all four measures. Racial differences in disability did not vary consistently by age at baseline or over time but were greater among women. Findings were largely similar for self-reported and performance-based measures of disability. Adjustment for socioeconomic status substantially reduced racial differences in disability, although some of the differences remained significant, especially among women. CONCLUSION: Racial disparities in disability have not been eliminated, are greater among women, and have their origins earlier in adulthood.

Black or African American↗
PubMed2004

A longitudinal study of parkinsonism and disability in a community population of older people.

BACKGROUND: Parkinsonian signs in patients without Parkinson's disease are often undetected but occur frequently in older people, and are often considered benign. We measured the association between parkinsonism and subsequent disability. METHODS: We conducted a prospective, longitudinal, community-based population study in East Boston, Massachusetts, using a stratified random sample of 455 community residents, aged 65 years and older. Four categories of parkinsonian signs were measured at baseline: bradykinesia, gait disturbance, rigidity, and tremor. Parkinsonism was defined as the presence of two or more categories of parkinsonian signs, and cases of Parkinson's disease were excluded from analyses. Disability was assessed annually over a mean of 4.7 years using the Katz, Rosow-Breslau, and Nagi disability measures. RESULTS: Parkinsonism at baseline strongly predicted subsequent disability as assessed with the three disability measures (on the Katz measure, beta = -1.30, p < .001). On average, a person with parkinsonism had a disability level at follow-up equal to that of a comparable person approximately 16.7 years for men and 8 years for women. The rate of developing disability for persons with parkinsonism increased each year; on the Katz measure, participants with parkinsonism declined on average 16.4% faster than those without. Gait impairment and bradykinesia strongly predicted subsequent disability; tremor and rigidity did not. The effect of parkinsonism was attenuated but still persistent in persons with coexistent moderate-to-severe cognitive impairment or stroke. CONCLUSIONS: Parkinsonism strongly predicts progressive disability in the older community population and has a marked aging effect on disability level.

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PubMed2004

Personality and mortality in old age.

We examined the relation of personality to mortality in 883 older Catholic clergy members (69% women). At baseline, they completed the NEO Five-Factor Inventory, which assesses the five principal dimensions of personality. They were followed for a mean of 5.1 years, during which 182 deaths occurred. Risk of death was nearly doubled in those with a high neuroticism score (90th percentile) compared with a low score (10th percentile) and was approximately halved in those with a high conscientiousness score compared with a low score. Findings for extraversion were mixed, and neither agreeableness nor openness was strongly related to mortality. The results suggest that personality is associated with mortality in old age.

Aged↗
PubMed2004

A longitudinal study of black-white differences in social resources.

OBJECTIVES: This study examined the differences in levels of social networks and social engagement between older Blacks and Whites and racial differences in rates of change in social resources over time. METHODS: The sample consisted of 5,102 Blacks and Whites, aged 65 and older, from the Chicago Health and Aging Project, who underwent up to three interviews during an average of 5.3 years of follow-up. Repeated measures of social networks were based on the number of children, relatives, and friends seen at least once a month. Social engagement was measured at each interview with four items related to social and productive activity. Random effects models were fitted to test the effect of race on social resources and change in resources over time. RESULTS: Blacks had smaller social networks and lower levels of social engagement than Whites. Racial differences in these resources were stable during follow-up. Socioeconomic status reduced racial differences in social engagement but not social networks. DISCUSSION: The findings provide evidence for lower levels of social resources among older Blacks. There was little evidence that racial differences were the result of greater decline during old age itself.

Black or African American↗
PubMed2003

Early life conditions and cognitive functioning in later life.

Early life conditions are related to cognitive development and abilities in childhood and cognitive function in adulthood. However, the association between early life conditions and cognitive change in old age is unknown. The authors examined the relation between socioeconomic position (SEP) and cognitive milieu in childhood and change in cognitive function in a population-based sample of 4,398 community-dwelling adults (62.1% female; 61.7% Black) aged 65 years or older from Chicago, Illinois. Baseline data were collected in 1993-1997. Change in cognitive function was assessed by means of a global cognitive index derived from measures of memory, perceptual speed, and overall cognitive function administered at three in-home assessments between 1993 and 2003, with an average of 5.3 years of follow-up. After results were controlled for age, sex, race, and education, interactions of time with childhood SEP (beta = -0.003, t = -1.0, p = 0.32) and childhood cognitive milieu (beta = -0.0008, t = -0.5, p = 0.62) were nonsignificant, indicating that early life conditions were not related to cognitive change. SEP (beta = 0.034, t = 2.4, p = 0.01) and cognitive milieu (beta = 0.017, t = 2.2, p = 0.03) were associated with absolute level of cognitive function, with better performance being related to higher SEP and a better cognitive milieu. A better SEP and a more stimulating cognitive milieu in childhood have small but significant effects on absolute level of cognitive function; however, they do not seem to protect against cognitive decline in old age.

Aged↗
PubMed2003

Negative affect and mortality in older persons.

The authors examined the relation of negative affect to mortality in the Religious Orders Study, a longitudinal cohort study of older persons, between 1994 and 2002. Participants were 851 Catholic clergy members without dementia at baseline (mean age, 75.4 (standard deviation, 6.9) years; 68% women). They completed standard measures of depressive symptoms, proneness to anxiety and anger, and patterns of anger expression at baseline and then underwent annual clinical evaluations for a mean of 4.7 (standard deviation, 2.7) years. The association of each scale with mortality was examined in proportional hazards models adjusted for age, sex, education, measures of cognitive function, lower limb function, chronic illness, smoking, alcohol, and obesity. During follow-up, 164 persons died. Measures of internally experienced negative affect, such as depressive symptoms and suppressed anger, were related to mortality, but measures of externally directed negative affect, such as the tendencies to be angry with others and to express anger overtly, were not. Persons with a high score (90th percentile) on a summary measure of internally experienced negative affect were nearly twice as likely to die as persons with a low score (10th percentile). The results suggest that negative affect in older persons, especially internally experienced distress, is associated with an increased mortality risk.

Affect↗
PubMed2003

Social engagement and disability in a community population of older adults: the New Haven EPESE.

This paper examines the effect of social engagement on disability among community-dwelling older adults in 1982-1991. Data were collected from the New Haven, Connecticut, site of the Established Populations for Epidemiologic Studies of the Elderly. Baseline social engagement was measured by using 11 items related to social and productive activity. Disability data consisted of a six-item measure of activities of daily living, a three-item measure of gross mobility, and a four-item measure of basic physical functions. Nine waves of yearly disability data were analyzed by using generalized estimating equations models. After adjustment for age, gender, race, and physical activity, significant cross-sectional associations (p's < 0.001) were found between social engagement and all three measures of disability, with more socially engaged older adults reporting less disability. Social engagement also showed small, but negative interaction effects with follow-up-time outcomes (p's < 0.01), indicating that the protective effect of social engagement decreased slightly during follow-up. Results suggest a strong, but not necessarily causal association of social engagement with disability. Promotion of social engagement may still be important for the prevention of disability.

Activities of Daily Living↗