# STATISTICAL ANALYSIS OF BIOMARKERS OF AGING

> **NIH NIH R01** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 1993 · $136,800

## Abstract

This proposal responds to Part B, "Statistical Analysis of Biomarkers of
Aging," of RFA AG-91-17, "Development of Biomarkers of Aging." Since
1988, several investigators in the NIA Biomarkers Initiative have been
gathering biometric and psychometric data comparing diverse aspects of
structure and function between rodents fed ad libitum and
dietary-restricted animals.  Collection of such data will continue over
the period for which the present funding is requested.  There result many
megabytes of data representing a great diversity of aspects of biological
structure and function measured in many different channels and on various
schedules (longitudinally, at death, at sacrifice at fixed ages) in seven
distinct genotypes for each sex.

From this variety of experimental designs and measurements we propose to
extract and calibrate assessments of gerontological age, or biomarkers,
in a form suggesting generalizations to other species and to humans.  The
operationalization of "biomarker" proposed for this project is a
quasilinear composite, a weighted sum of smoothly transformed versions of
raw measurements that covaries with a "composite time" in a statistically
optimal way.  Composite time is a weighted contrast of time-since-birth
with time-until-death, corresponding to the two criteria typically used
to characterize biomarkers in the literature.  Whenever the available
data comprise a truly longitudinal design, these composites can be
computed and validated, and various important gerontometric hypotheses
calibrated or tested with their aid.  These include the relative salience
of each measurement included in the biomarker panels, the extent to which
it leads or lags other members of the panel, the extent to which it
discriminates the two dietary groups, the extent to which its sensitivity
to gerontological age is shared between genotypes , and similar
questions.  These composite scores will be computed by the method of
nonlinear Partial Least Squares.

Composite biomarkers that emerge from the analysis of longitudinal data
can be used to calibrate similar series of age-specific means emerging
from the cross-sectional designs.  The collection of potential biomarkers
that results will be ordered along a few distinct dimensions of
functional or gerontological age and will be assessed by both power to
predict longevity and sensitivity to dietary restriction.  Their
synthesis into panels for future testing in primates and humans speaks
directly to the overall programmatic intent of the Biomarkers Initiative.

## Key facts

- **NIH application ID:** 3123023
- **Project number:** 1R01AG011037-01
- **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR
- **SAM.gov UEI:** GNJ7BBP73WE9
- **Principal Investigator:** FRED LEON BOOKSTEIN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $136,800
- **Award type:** 1
- **Project period:** 1993-04-15 → 1998-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3123023

## Citation

> US National Institutes of Health, RePORTER application 3123023, STATISTICAL ANALYSIS OF BIOMARKERS OF AGING (1R01AG011037-01). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3123023. Licensed CC0.

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