You are here

Trajectories of IGF-I Predict Mortality in Older Adults: The Cardiovascular Health Study.

TitleTrajectories of IGF-I Predict Mortality in Older Adults: The Cardiovascular Health Study.
Publication TypeJournal Article
Year of Publication2017
AuthorsSanders, JL, Guo, W, O'Meara, ES, Kaplan, RC, Pollak, MN, Bartz, TM, Newman, AB, Fried, LP, Cappola, AR
JournalJ Gerontol A Biol Sci Med Sci
Date Published2017 Jul 23
ISSN1758-535X
Abstract<p><b>Background: </b>Disruption of insulin-like growth factor-I (IGF-I) increases health and life span in animal models, though this is unconfirmed in humans. If IGF-I stability indicates homeostasis, the absolute level of IGF-I may be less clinically relevant than maintaining an IGF-I setpoint.</p><p><b>Methods: </b>Participants were 945 U.S. community-dwelling individuals aged ≥65 years enrolled in the Cardiovascular Health Study with IGF-I levels at 3-6 timepoints. We examined the association of baseline IGF-I level, trajectory slope, and variability around the trajectory with mortality.</p><p><b>Results: </b>There were 633 deaths over median 11.3 years of follow-up. Lower IGF-I levels, declining or increasing slope, and increasing variability were each individually associated with higher mortality (all p < .001). In an adjusted model including all three trajectory parameters, baseline IGF-I levels <70 ng/mL (hazard ratio [HR] 1.58, 95% CI 1.28-1.96 relative to IGF-I levels of 170 ng/mL), steep declines and steep increases in trajectory slope (HR 2.22, 1.30-3.80 for a 15% decline; HR 1.40, 1.07-1.84 for a 10% decline; HR 1.80, 1.12-2.89 for a 15% increase; HR 1.31, 1.00-1.72 for a 10% increase, each vs no change), and variability ≥10% (HR 1.59, 1.09-2.32 for ≥ 30%; HR 1.36, 1.06-1.75 for 20%; and HR 1.17, 1.03-1.32 for 10% variability, each vs 0%) in IGF-I levels were independently associated with mortality.</p><p><b>Conclusions: </b>In contrast to data from animal models, low IGF-I levels are associated with higher mortality in older humans. Irrespective of the actual IGF-I level, older individuals with stability of IGF-I levels have lower mortality than those whose IGF-I levels fluctuate over time.</p>
DOI10.1093/gerona/glx143
Alternate JournalJ. Gerontol. A Biol. Sci. Med. Sci.
PubMed ID28977343
ePub date: 
17/07