Biomedical subjects

Michael J Helms

Publications and source records attributed to Michael J Helms.

7 recordsLinked to original sources

PubMed2006

Vascular risk factors and cognitive decline among elderly male twins.

BACKGROUND: Studies investigating the association between cardiovascular risk factors and cognitive decline report discrepant outcomes. The co-twin control method improves on traditional case-control approaches by controlling for within-twin pair similarities of genetic and early environmental influences. OBJECTIVE: To examine the association of diabetes, hypertension, hypercholesterolemia, and elevated body mass index (BMI) (>30 kg/m(2)), individually and combined, with cognitive decline over a 12-year period in members of the National Academy of Sciences-National Research Council Twin Registry of World War II male veterans. METHODS: Modified Telephone Interview for Cognitive Status (TICS-m) was administered four times at approximately 4-year intervals from 1990 to 2002 as part of an epidemiologic study of dementia. Self-report medical information was collected from 1996 to 2002. We examined the difference in cognitive decline within twin pairs discordant for the vascular risk factors while controlling for baseline TICS-m, education, smoking, and alcohol history. RESULTS: Among twin pairs discordant for diabetes (n = 177), the diabetic twins declined an average of almost 1 point more than their nondiabetic co-twins (p = 0.018) at the last screening time point. Further analyses showed that this was in large part due to greater decline among older men (age 76 to 84 years). Cognitive change was not significantly different between members of pairs discordant for hypertension (n = 326), hypercholesterolemia (n = 282), or elevated BMI (n = 166). CONCLUSION: Based on this study of twin pairs who share similar genetic and early environmental risks for cardiovascular risk factors, diabetes is associated with greater cognitive decline, particularly among the oldest individuals.

Age Factors↗

PubMed2006

Prediction of all-cause mortality by the Minnesota Multiphasic Personality Inventory Optimism-Pessimism Scale scores: study of a college sample during a 40-year follow-up period.

OBJECTIVE: To examine a measure of explanatory style, the Optimism-Pessimism (PSM) scale derived from college-entry Minnesota Multiphasic Personality Inventory scores, as a predictor of all-cause mortality. SUBJECTS AND METHODS: A total of 7007 students entering the University of North Carolina at Chapel Hill completed the Minnesota Multiphasic Personality Inventory during the mid-1960s. Of those students, 6958 had scores on the PSM scale and data for all-cause mortality through 2006. Scores on the PSM scale were evaluated as predictors of mortality using the Cox proportional hazards regression model, adjusted for sex. During the 40-year follow-up period, 476 deaths occurred. RESULTS: Pessimistic individuals who scored in the upper tertile of the distribution had decreased rates of longevity (hazard ratio, 1.42; 95% confidence Interval, 1.13-1.77) compared with optimistic individuals who scored in the bottom tertile of the distribution. CONCLUSION: In a model that adjusted only for sex, a measure of optimistic vs pessimistic explanatory style was a significant predictor of survival during a 40-year follow-up period such that optimists had Increased longevity.

Female↗

PubMed2002

Serotonin-related gene polymorphisms and central nervous system serotonin function.

Central nervous system (CNS) serotonergic function affects a wide range of biological and behavioral functions affecting health and disease. Our objective in this study was to determine whether functional polymorphisms of the genes that encode for the serotonin transporter promoter (5HTTLPR) and monoamine oxidase A (MAOA-uVNTR) are associated with CNS serotonin turnover-indexed by cerebrospinal fluid levels of 5-hydroxyindoleacetic acid (5-HIAA)-in a community sample of healthy adults. Subjects were 165 community volunteers without current medical or psychiatric illness, stratified with respect to ethnicity, gender, and socioeconomic status who underwent inpatient evaluation in the General Clinical Research Center of a university medical center. A significant ethnicity x genotype interaction (P=0.008) indicated that, compared to the long/long and long/short genotypes, the 5HTTLPR short/short genotype was associated with higher CSF 5-HIAA levels in African Americans, but with lower levels in Caucasians. A gender x genotype interaction (P=0.04) indicated that 5HTTLPR short/short genotype was associated with higher 5-HIAA levels in women but with lower levels in men. MAOA-uVNTR 3.5 and 4 repeat alleles were associated with higher 5-HIAA (P=0.03) levels in men, but were unrelated to 5-HIAA levels in women. These findings suggest that effects of serotonin-related gene polymorphisms on CNS serotonergic function vary as a function of both ethnicity and gender. Further research will be required to determine the mechanism(s) underlying these differential effects. In the meanwhile, both ethnicity and gender should be taken into account in research evaluating effects of these and related polymorphisms on CNS serotonergic function, as well as the broad range of biological and behavioral functions that are regulated by CNS serotonergic function.

Adult↗

PubMed2002

Head injury in early adulthood and the lifetime risk of depression.

BACKGROUND: Depressive symptoms are common and can be debilitating in the months after head injury. Head injury can also have long-term cognitive effects, but little is known about the long-term risk of depression associated with head injury. We investigated the lifetime rates of depressive illness 50 years after closed head injury. METHODS: Participants were male World War II veterans who served during 1944-1945 and were hospitalized at that time for a head injury, pneumonia, or laceration, puncture, or incision wounds. We used military medical records to establish the presence and severity of closed head injuries. Veterans with (n = 520) and without (n = 1198) head injuries were interviewed in 1996-1997 for their lifetime history of depressive illness. Men with dementia were excluded. RESULTS: Veterans with head injury were more likely to report major depression in subsequent years and were more often currently depressed. Using logistic regression and controlling for age and education, the lifetime prevalence of major depression in the head injured group was 18.5% vs 13.4% in those with no head injury (odds ratio = 1.54, 95% confidence interval = 1.17-2.04). Current major depression was detected in 11.2% of the veterans with head injuries vs 8.5% of those without head injury (odds ratio = 1.63, 95% confidence interval = 1.07-2.50). This increase in depression could not be explained by a history of myocardial infarction, a history of cerebrovascular accident, or history of alcohol abuse. The lifetime risk of depression increased with severity of the head injury. CONCLUSION: The risk of depression remains elevated for decades following head injury and seems to be highest in those who have had a severe head injury.

Adult↗

PubMedDate not supplied

Patterns of change in hostility from college to midlife in the UNC Alumni Heart Study predict high-risk status.

OBJECTIVE: To examine hostility measured in college and patterns of change in hostility from college to midlife as predictors of high health-related risk later in midlife. METHODS: Logistic regression models were used to test hostility/risk associations. RESULTS: College hostility predicted being a current smoker, consuming more than two drinks of alcohol, low social support, achieving less than expected in career and in relationships, risk for depression, and appraisal of life changing for the worse in terms of family events at midlife. Change in hostility did not predict smoking and drinking; however, it did significantly predict social isolation, lower income (only for women), obesity, avoidance of exercise, high-fat diet, and negative changes in economic life, work life, and physical health events-all risk indicators measured during the next decade. Appraisals of social support, lowered expectations, risk for depression, and reports of family life changing for the worse were predicted at both time periods. When change in hostility was modeled with college hostility, all risk indicators were significantly predicted by college hostility. CONCLUSIONS: High hostility in college and change in hostility from college to midlife predicts a full range of health risk indicators. When compared with the average population decline in hostility, gains in hostility at midlife are related to increased risk while declines in hostility are related to reduced risk. Higher midlife hostility is associated with increased odds of being in the higher risk group. Future research should focus on developing interventions to reduce hostility.

Achievement↗

PubMedDate not supplied

Hostility as a predictor of survival in patients with coronary artery disease.

OBJECTIVE: This article presents a reanalysis of an earlier study that reported a nonsignificant relation between the 50-item Cook-Medley Hostility Scale (CMHS) and survival in a sample of coronary patients. Since publication of those results, there have been significant developments in the measurement of hostility that suggest that an abbreviated scale may be a better predictor of health outcomes. This study examined the ability of the total CMHS and an abbreviated form of the CMHS (ACM) to predict survival in a sample of patients with documented coronary artery disease (CAD) with increased statistical power. METHODS: Nine hundred thirty-six patients (83% were male; mean age = 51.48) with CAD who were followed for an average of 14.9 years. The ACM consisted of the combination of the cynicism, hostile attribution, hostile affect, and aggressive responding subscales that were identified in an earlier study (Barefoot et al. [1989]) by a rational analysis of the item content. The relation between hostility and survival was examined with Cox proportional hazard models (hazard ratios [HRs] based on a two standard deviation difference). RESULTS: Controlling for disease severity, the ACM was a significant predictor for both CHD mortality (HR = 1.33, p <.009) and total mortality (HR = 1.28, p <.02). The total CMHS was only a marginally significant predictor of either outcome (p values < 0.06). CONCLUSION: The results of this study suggest that hostility is associated with poorer survival in CAD patients, and it may be possible to refine measures of hostility in order to improve prediction of health outcomes.

Cause of Death↗

PubMedDate not supplied

Prevalence and clinical correlates of neuropsychiatric symptoms in dementia.

The purpose of this research was to assess the frequency and severity of neuropsychiatric and behavioral symptoms and to examine the association between preexisting medical conditions and specific neuropsychiatric symptoms in demented individuals. We studied 211 demented subjects (87.7 percent male) who were participants in epidemiological studies of dementia. Using the Neuropsychiatric Inventory (NPI), we assessed the frequency and severity of neuropsychiatric symptoms. We collected medical history information during a structured telephone interview. Our analyses focused on determining prevalence of neuropsychiatric symptoms by dementia diagnosis and severity. We also examined the association of history of head injury, alcohol abuse, and stroke with development of neuropsychiatric symptoms. We found that neuropsychiatric symptoms were common, with approximately three-fourths of the subjects exhibiting at least one symptom during the preceding month. Apathy (39.3 percent), agitation (31.8 percent), and aberrant motor behavior (31.1 percent) were the most frequent symptoms. Frequency and severity of symptoms were similar for the all-dementia and Alzheimer's disease-only groups, neuropsychiatric symptoms varied by severity of dementia, but generally not in a consistent ordinal pattern. History of alcohol abuse, head injury, or stroke was associated with presence of specific neuropsychiatric symptoms in dementia. While psychiatric symptoms are common in dementia, they also vary by type and severity of dementia. The finding that certain medical conditions may increase risk for specific types of neuropsychiatric symptoms expands our knowledge of the natural history of dementia and should improve management of dementia in medically ill patients. Our results may also shed light on mechanisms that underlie neuropsychiatric symptoms.

Aged↗