Biomedical subjects

Yuxiao Tang

Publications and source records attributed to Yuxiao Tang.

8 recordsLinked to original sources

PubMed2006

Chronic psychological distress and risk of Alzheimer's disease in old age.

Clinical and pathological data from the Rush Memory and Aging Project were used to test the hypothesis that distress proneness is associated with increased risk of Alzheimer's disease (AD). More than 600 older persons without dementia completed a 6-item measure of neuroticism, a stable indicator of proneness to psychological distress. At annual intervals thereafter, they underwent uniform evaluations that included clinical classification of AD and administration of 18 cognitive tests. Those who died underwent brain autopsy from which composite measures of AD pathology were derived. During a mean of about 3 years of follow-up, 55 people were clinically diagnosed with AD. In analyses that controlled for age, sex, and education, persons with a high level of distress proneness (score = 24, 90th percentile) were 2.7 times more likely to develop AD than those not prone to distress (score = 6, 10th percentile). Adjustment for depressive symptomatology or frequency of cognitive, social, and physical activity did not substantially change this effect. Distress proneness was also associated with more rapid cognitive decline. Among 45 participants who died and underwent brain autopsy, distress proneness was unrelated to diverse measures of AD pathology and was inversely related to cognition after controlling for AD pathology. The results support the hypothesis that distress proneness is associated with increased risk of dementia and suggest that neurobiologic mechanisms other than AD pathology may underlie the association.

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PubMed2006

The effect of social networks on the relation between Alzheimer's disease pathology and level of cognitive function in old people: a longitudinal cohort study.

BACKGROUND: Few data are available about how social networks reduce the risk of cognitive impairment in old age. We aimed to measure this effect using data from a large, longitudinal, epidemiological clinicopathological study. METHODS: 89 elderly people without known dementia participating in the Rush Memory and Aging Project underwent annual clinical evaluation. Brain autopsy was done at the time of death. Social network data were obtained by structured interview. Cognitive function tests were Z scored and averaged to yield a global and specific measure of cognitive function. Alzheimer's disease pathology was quantified as a global measure based on modified Bielschowsky silver stain. Amyloid load and the density of paired helical filament tau tangles were also quantified with antibody-specific immunostains. We used linear regression to examine the relation of disease pathology scores and social networks to level of cognitive function. FINDINGS: Cognitive function was inversely related to all measures of disease pathology, indicating lower function at more severe levels of pathology. Social network size modified the association between pathology and cognitive function (parameter estimate 0.097, SE 0.039, p=0.016, R(2)=0.295). Even at more severe levels of global disease pathology, cognitive function remained higher for participants with larger network sizes. A similar modifying association was observed with tangles (parameter estimate 0.011, SE 0.003, p=0.001, R(2)=0.454). These modifying effects were most pronounced for semantic memory and working memory. Amyloid load did not modify the relation between pathology and network size. The results were unchanged after controlling for cognitive, physical, and social activities, depressive symptoms, or number of chronic diseases. INTERPRETATION: These findings suggest that social networks modify the relation of some measures of Alzheimer's disease pathology to level of cognitive function.

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PubMed2006

Personality and incident disability in older persons.

OBJECTIVE: to examine the relation of personality to the development of disability in old age. METHODS: participants are 813 older Catholic nuns, priests and brothers without dementia or disability at study onset. As part of a uniform baseline evaluation, they completed standard measures of the five principal dimensions of personality. Disability was assessed at baseline and annually thereafter with the Katz scale. The relation of each trait to incident disability was assessed in proportional hazard models controlled for age, sex, education and selected clinical variables. RESULTS: during a mean of about 6 years of observation, 255 persons (31%) became dependent on at least one activity of daily living. Risk of becoming disabled was 85% [95% confidence interval (CI) = 80.5-89.6%] lower in persons with high (90th percentile) compared to low (10th percentile) extraversion and 50% (95% CI = 46.6-54.2%) lower in those with high compared to low conscientiousness, and controlling for chronic medical conditions, depressive symptoms or social and cognitive activity did not substantially affect these associations. By contrast, neuroticism had a marginal association with disability risk that was eliminated after controlling for depressive symptomatology, and openness and agreeableness were unrelated to disability risk. CONCLUSIONS: The results suggest that higher levels of extraversion and conscientiousness may be associated with a reduced risk of incident disability in old age.

Activities of Daily Living↗

PubMed2005

Odor identification and decline in different cognitive domains in old age.

The authors examined the association of odor identification with rate of decline in different cognitive systems. Participants are 481 older persons from the Rush Memory and Aging Project. At baseline, the Brief Smell Identification Test was administered. At annual intervals for up to 3 years, a battery of 19 cognitive tests was administered from which previously established composite measures of 5 cognitive domains were derived. In mixed-effects models adjusted for age, sex, and education, lower odor identification score was associated with lower function at baseline in each cognitive domain. Lower score was also associated with more rapid decline in perceptual speed (estimate=0.015, SE=0.006, p=0.013) and episodic memory (estimate=0.012, SE=0.006, p=0.030) but not with rate of decline in semantic memory, working memory, or visuospatial ability. Thus, on average, a person with a low odor identification score (6, 10th percentile) declined more than twice as rapidly in perceptual speed and episodic memory as a person with a high score (11, 90th percentile). Results were unchanged in subsequent analyses that controlled for cigarette smoking or clinically diagnosed stroke. The results indicate that impaired odor identification in old age is associated with impaired global cognition and more rapid decline in perceptual processing speed and episodic memory.

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PubMed2005

Patient education and access of ESRD patients to renal replacement therapies beyond in-center hemodialysis.

BACKGROUND: Nephrologists report that patients' choice should play an important role in the selection of renal replacement therapy (RRT) for end-stage renal disease (ESRD). In the United States, kidney transplant rates remain low and <10% of patients utilize home dialysis therapies. This study examined the effect of pre-ESRD processes on the selection of RRT among incident ESRD patients. METHODS: Using surveys, data were collected for all patients admitted to 229 dialysis units in ESRD Network 18 between April 1, 2002 and May 31, 2002. A total of 1365 patients began chronic dialysis and 1193 facility (87%) and 428 patient (31%) surveys were returned. RESULTS: Substantial proportions of patients were unaware of their kidney disease (36%) or were not seeing a nephrologist (36%) until <4 months before first dialysis. The presentation of treatment options was delayed (48% either after or < 1 month before the first dialysis). The majority of ESRD patients were not presented with chronic peritoneal dialysis, home hemodialysis, or renal transplantation as options (66%, 88%, and 74%, respectively). Using multivariate analyses, variables significantly associated with selection of chronic peritoneal dialysis as dialysis modality were the probability of chronic peritoneal dialysis being presented as a treatment option and the time spent on patient education. CONCLUSION: An incomplete presentation of treatment options is an important reason for under-utilization of home dialysis therapies and probably delays access to transplantation. Improvements in and reimbursement for pre-ESRD education could provide an equal and timely access for all medically suitable patients to various RRTs.

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PubMed2005

Hallucinations and mortality in Alzheimer disease.

OBJECTIVE: The authors tested the relationship of hallucinations and delusions to mortality in Alzheimer disease (AD). METHODS: A group of 407 persons with clinically diagnosed AD completed a uniform clinical evaluation, after which vital status was monitored for a mean of 3.7 years. At the initial evaluation, a previously established, structured, informant interview was used to ascertain the presence of hallucinations and delusional thinking. The evaluation also included a structured medical history, inspection of all medications, and detailed assessment of cognitive functioning and parkinsonian signs. RESULTS: At study onset, hallucinations were present in 41.0% of participants and delusions in 54.4%. During follow-up, 146 deaths occurred. In a proportional-hazards model adjusted for age, sex, race, and education, hallucinations were associated with a 78% increase in risk of death. The association was not substantially altered in subsequent analyses that controlled for level of cognitive impairment, severity of parkinsonism, use of antipsychotic medications, and the presence of chronic medical conditions. Risk of death was more than doubled in those with both auditory and visual hallucinations. By contrast, we did not find evidence of an association of delusions with mortality. CONCLUSION: Hallucinations are associated with an increased risk of death in AD.

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PubMed2004

Mycophenolate therapy of SLE membranous nephropathy.

BACKGROUND: The immunosuppressant mycophenolic acid (MMF) has been used successfully to manage proliferative forms of systemic lupus erythematosus (SLE) glomerulonephritis (GN) World Health Organization (WHO) Classes III and IV. Less is known about MMF treatment of membranous SLE GN (WHO Class V, SLE MN). METHODS: We report our experience with MMF therapy in 13 consecutive SLE MN patients participating in a prospective study of risk factors for SLE flare. RESULTS: Baseline characteristics were: mean age 33 +/- 14 SD years, female/male ratio 11/2, Caucasians 7, African Americans 5, Oriental 1, serum creatinine 1.02 +/- 0.41, and mean 24-hour urine protein (P)/creatinine (C), ratio 5.1 +/- 4.1. Initial therapy was prednisone mean dose 31 +/- 17 mg/day, and MMF mean dose 1173 +/- 746 mg/day. Therapy also featured interventions to achieve renoprotection and proteinuria reduction. At 6 months of therapy, complete or partial remission was achieved in 10 of 13 patients. At most recent follow-up visit (mean follow-up 16 +/- 8 months), 9 of 13 patients were in complete remission, and in 11 of 13 patients, urine P/C ratio was < 0.8. During follow-up, serum creatinine either stabilized or was improved. The only serious complication during 208 patient months of follow-up was histoplasma pneumonia in 1 patient. CONCLUSION: These promising results suggest that moderate dose MMF in combination with renoprotective/antiproteinuria therapy warrants further study in the management of SLE MN.

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PubMedDate not supplied

Harm avoidance and disability in old age.

The relation of personality to disability in old age is not well understood. The authors examined the relation of harm avoidance, a trait indicating a tendency to worry, fear uncertainty, be shy, and tire easily, to disability in a group of 474 older persons without dementia. Participants completed the 35-item Harm Avoidance scale. Disability was assessed with the Rosow-Breslau scale, a self-report measure of physical mobility. Performance-based tests of lower limb functions were also administered from which composite measures of gait, balance, and strength were derived. In a logistic regression model controlled for age, sex, education, and lower limb function, persons with high levels of harm avoidance were nearly three times as likely to report mobility limitations as persons with low levels, and these effects largely reflected fatigability and fear of uncertainty. The association of harm avoidance with disability was not explained or modified by frailty, physical activity, depressive symptoms, neuroticism, extraversion, or cognition. The results suggest that harm avoidance is associated with disability in old age.

Activities of Daily Living↗