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Biomedical subjects

R Hochschild

Publications and source records attributed to R Hochschild.

10 recordsLinked to original sources
PubMed1990

Can an index of aging be constructed for evaluating treatments to retard aging rates? A 2,462-person study.

Biomarkers of aging are needed to evaluate proposed treatments to retard aging rates. At present, the only validated biomarker of aging is maximum life span, which remains impractical for human use. Identification of other biomarkers awaits development of a method of biomarker validation. This paper outlines an approach for this purpose intended for selecting biomarkers usable in humans. Prospective biomarkers are validated and weighted according to their correlation with interventions that, in healthy individuals, influence life span, namely mortality risk factors. A general mathematical method is presented for combining biomarker scores into an index of aging rate. This method addresses problems encountered with the traditional (multiple regression) method of calculating biological age and develops an index termed standardized biological age, SBA. In applying the method to 2,462 office workers, SBA, based on 12 physiological tests under investigation as biomarkers of aging, was found to depend on most of 17 surveyed dietary, exercise, life style, and geographical risk factors for mortality or health, suggesting that many risk factors predict rates of common functional declines with age. The 12 candidate biomarkers of aging in this study differed widely in validity according to the criterion employed. The approach holds promise for assembling an experimentally useful battery of biomarkers of aging.

Adult↗
PubMed1989

Improving the precision of biological age determinations. Part 1: A new approach to calculating biological age.

In calculating biological age, almost all prior studies used multiple regression of chronological age on scores of biomarkers of aging. Multiple regression is invalid for this purpose for three, and in some circumstances four, reasons. These are: a) weighting of the contribution of each biomarker's scores according to strength of association with chronological age; b) regression of calculated ages to sample mean age and the inadequacy of proposed corrections; c) frequent occurrence of regression coefficients whose sign equates poorer adult performance on a test to younger biological ages; and d) multicollinearity when lung function scores and height are on the same side of the regression equation. An alternative method for calculating biological age is outlined. Regression to sample mean age and its solution are illustrated on data for highest audible pitch, one of 12 biomarkers measured in a study of 2462 office workers. Prior published studies employing multiple regression to calculate biological age appear to have been in error.

Adult↗
PubMed1989

Improving the precision of biological age determinations. Part 2: Automatic human tests, age norms and variability.

In order to eliminate variability due to test operators, procedures for measuring 12 physiological functions that are candidate biomarkers of aging have been automated. Data was collected from a norm group of 2462 male and female office workers using an instrument which requires no test operators, administers all 12 tests in about 45 min. per subject, computes biological age, prints out results, and stores data on floppy disks for transfer to other computers for analysis. This report a) describes the instrumentation and test procedures, b) presents normal age/sex standards for each of the 12 biomarkers, c) reports the variance of the data for each biomarker by sex, d) lists sources of biomarker variance, e) discusses criteria for biomarker selection and f) examines implications for information loss when biomarker data is combined to calculate biological age. After eliminating chronological age as a variable, the standard deviations of the frequency distributions of predicted age for individual biomarkers were found to vary from .226 to 1.075, a range of more than 4 to 1. Procedures are discussed for improving the ratio of useful-to-useless variance in calculating biological age.

Accommodation, Ocular↗