PubMed Health⌕ Search

Biomedical subjects

G McClearn

Publications and source records attributed to G McClearn.

7 recordsLinked to original sources
PubMed2003

Biochemical values in persons older than 82 years of age: report from a population-based study of twins.

According to international standards, reference values for biochemical tests should be obtained in disease-free subjects and for therapies that may influence measurement values. For elderly persons, especially the very old, such a requirement is difficult to meet, since few of these individuals are free of ongoing or former diseases. The present study of a population-based Swedish twin sample comprises 535 individuals (186 males, 349 females) who were at least 82 years of age at blood sampling. Survival over a 6-year period is used as a reference of overall health. Baseline test values for subjects surviving 6 years are compared with results for persons who died in the follow-up period. Results, including mean and median values, standard deviations and ranges, were given for both genders in the total sample. Cases outside the 5th and 95th percentiles were then excluded, as were those who died during the follow-up period. In a third step, cases with disorders and therapies known to influence measurement values were also excluded. The risk of dying during the observation period was calculated across measurements from the lowest and highest 10th and 20th percentiles. The specific impact of proximity to death on the biochemical values, in addition to age effects, was analysed by comparing co-twins discordant for survival over 7 years. Increased mortality was indicated for subjects of both genders with high serum levels of urea, urate, gamma-GT, free thyroxin and plasma homocysteine. In females, low serum values for albumin and total cholesterol were associated with increased mortality. A lower cholesterol level was found 4 years before death, while a lower HDL-cholesterol level was associated with an increased risk of death across the entire 7-year period.

Aged↗
PubMed2003

Association of biochemical values with morbidity in the elderly: a population-based Swedish study of persons aged 82 or more years.

BACKGROUND: Various inter-dependent factors influence serum biochemical values. In the elderly, the impact of these factors may differ compared with younger age groups and therefore population-based studies among older people are needed. The specific morbidity in old age, including also various types of drug therapy, should be observed. METHODS: Various biochemical tests in 349 females and 186 males over 81 years of age were carried out and the associations of biochemical values with morbidity, drug therapy, anthropometry and gender were estimated. RESULTS: Biochemical serum values deviate in various diseases, characterized by increased frequency in the elderly, i.e. congestive heart failure, osteoporosis, hip fractures, depression and dementia. All of these diseases present a tendency to increased homocysteine, usually combined with low folate. Cases with intact cognitive function throughout the six years after sampling are characterized by low homocysteine, which is the opposite of what is found in dementia. Furthermore, congestive heart failure is associated with impaired creatinine clearance and increased urea and urate, and osteoporosis and hip fractures are characterized by low albumin and cholesterol. Increased values for urate and impaired creatinine clearance are found in coronary diseases. In gout, multiple biochemical changes take place. For cases with a history of diabetes, arterial hypertension, peptic ulcer and malignancy, few changes are found compared with the values of the total sample. Furosemide therapy is associated with the same pattern as congestive heart failure, and laxative treatment is characterized by low folate and high homocysteine values.

Aged↗
PubMed1996

Multidimensional patterns of aging in 70-year-olds: survival differences.

This article examines the predictive ability for survival of five multidimensional patterns of aging found in 335 70-year-olds from the geriatric and gerontological studies in Gothenburg, Sweden (H-70). The multidimensional patterns were identified by cluster analysis of the domains of cognitive performance, physical health, functional capacity, subjective well-being, and social contacts. Survival differences are found among the patterns and between genders within the patterns. Patterns with higher domain scores at age 70 have higher median survival rates over 20 years. Conversely, patterns with lower domain scores at age 70 have earlier mortality. However, one group, with the lowest cognitive score, has a survival pattern similar to the group with low scores in every domain, substantiating the finding that poor cognitive performance is an important single predictor of mortality. Females exhibit at least a 4-year survival advantage over males in all but one group, in which the males resemble the females in their survival.

Aged↗
PubMed1993

High, usual and impaired functioning in community-dwelling older men and women: findings from the MacArthur Foundation Research Network on Successful Aging.

The objective of this study is to determine the range of complex physical and cognitive abilities of older men and women functioning at high, medium and impaired ranges and to determine the psychosocial and physiological conditions that discriminate those in the high functioning group from those functioning at middle or impaired ranges. The subjects for this study were drawn from men and women aged 70-79 from 3 Established Populations for the Epidemiologic Study of the Elderly (EPESE) programs in East Boston MA, New Haven CT, and Durham County NC screened on the basis of criteria of physical and cognitive function. In 1988, 4030 men and women were screened as part of their annual EPESE interview. 1192 men and women met criteria for "high functioning". Age and sex-matched subjects were selected to represent the medium (n = 80) and low (n = 82) functioning groups. Physical and cognitive functioning was assessed from performance-based examinations and self-reported abilities. Physical function measures focused on balance, gait, and upper body strength. Cognitive exams assessed memory, language, abstraction, and praxis. Significant differences for every performance-based examination of physical and cognitive function were observed across functioning groups. Low functioning subjects were almost 3 times as likely to have an income of < or = $5000 compared to the high functioning group. They were less likely to have completed high school. High functioning subjects smoked cigarettes less and exercised more than others. They had higher levels of DHEA-S and peak expiratory flow rate. High functioning elders were more likely to engage in volunteer activities and score higher on scales of self-efficacy, mastery and report fewer psychiatric symptoms.

Activities of Daily Living↗
PubMed1981

Ethanol-induced depressions in cerebellar and hippocampal neurons of mice selectively bred for differences in ethanol sensitivity: an electrophysiological study.

The recently discovered profound differential sensitivity of cerebellar Purkinje (P) cells in long-sleep (LS) verus short-sleep (SS) mice to the depressant effects of locally applied ethanol was extended in this study. First, the sensitivity of Purkinje neurons from HS mice (an outbred stock of mice from which the LS and SS lines were derived), was found to be almost exactly intermediate between the values for the long-sleep and short-sleep animals. Second, no differential sensitivity in long-sleep versus short-sleep hippocampal pyramidal neurons was observed. This was true using both spontaneous and evoked activity. Third, no differential sensitivity of P cells was seen in long- versus short-sleep mice with local application of halothane. Taken together with previous reports, these data strongly suggest that whatever genetically determined central nervous alterations result in the differential soporific effects of ethanol in the two (LS and SS) mouse lines, such alterations are brain region- and depressant drug-specific rather than generalized.

Action Potentials↗
PubMedDate not supplied

Multidimensional patterns of aging: a cluster-analytic approach.

A person-oriented approach, cluster analysis, was used to define patterns of aging in 335 subjects from the Gothenburg study of 70-year-olds (H-70). Five distinct patterns, based on the domains of well-being, physical health, functional capacity, cognitive abilities, and social contacts, were found, and members of the five groups were followed longitudinally over 9 years. Overall, the majority of the subjects were in relatively high performing groups at age 70. Two of the groups had very low levels on all of the domains. Group membership at age 70 was predictive of later performance, suggesting that there is utility in typologies of aging individuals and/or trajectories of aging. This study supports a multidimensional approach to the study of variability in aging. Refining the description of agers, and of aging, can contribute both to basic understanding of aging processes and to practical matters of meeting the long-term needs of elderly people.

Aged↗