Fingernail growth rate as a biomarker of aging in the pigtailed macaque (Macaca nemestrina).
Rate of fingernail growth (FNG) of the middle digit of the right hand was assessed in 46 healthy pigtailed macaques at approximately 6-month intervals for 4 to 6 years. Mean FNG for 24 females, ranging in mean age at measurement from 7 to 24 years, was 104 mu/day; the mean for 22 males, ranging from 7 to 20 years, was 111 mu/day. Longitudinal analysis showed that FNG declined in animals of both sexes and that the rate of decline (-4.8 mu/day/year) did not differ between them, i.e., the mean regression coefficients (beta) of the two sexes were significantly different from zero and not significantly different from each other. Results of cross-sectional analysis differed from those of longitudinal analysis in that the mean FNG appeared to be more rapid in males than in females, particularly in the older animals. Inter- and intra-individual variability in FNG did not increase with age. FNG appears to be an excellent functional marker of the rate of aging because the direction of change is essentially decremental, a significant degree of change can be detected in a few years, and the rate of change is relatively constant across the adult lifespan. In addition, measurement of FNG is innocuous, quantitative, inexpensive, and simple.
Williams
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DD
Regional Primate Research Center, University of Washington, Seattle.
Short
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Bowden
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DM
D000375:Aging / Q000502:physiology*; D000818:Animals; D015415:Biomarkers; D003430:Cross-Sectional Studies; D005260:Female; D006706:Homeostasis; D008137:Longitudinal Studies; D008254:Macaca nemestrina / Q000254:growth & development*; D008297:Male; D009262:Nails / Q000254:growth & development*
D015415:Biomarkers