TY - JOUR
T1 - Serum levels of the immune activation marker neopterin change with age and gender and are modified by race, BMI, and percentage of body fat
AU - Spencer, Monique E.
AU - Jain, Alka
AU - Matteini, Amy Mahoney
AU - Beamer, Brock A.
AU - Wang, Nae Yuh
AU - Leng, Sean X.
AU - Punjabi, Naresh M
AU - Walston, Jeremy D.
AU - Fedarko, Neal S.
N1 - Funding Information:
This research was supported by National Institutes of Health (NIH) grants CA 87311 and 113865 (N.S.F.). M.E.S. was supported by grant T35 AG026758 and the Medical Student Training in Aging Research Program run jointly by American Federation on Aging Research and the John A. Hartford Foundation. N.-Y.W. was supported by grant UL1 RR 025005 and A.M. by grant T32 AG000120. The Johns Hopkins Bayview Medical Center Clinical Research Unit is supported by grant UL1 RR 025005 from the National Center for Research Resources, a component of the NIH and NIH Roadmap for Medical Research.
PY - 2010/8
Y1 - 2010/8
N2 - Background. Neopterin, a GTP metabolite expressed by macrophages, is a marker of immune activation. We hypothesize that levels of this serum marker alter with donor age, reflecting increased chronic immune activation in normal aging. In addition to age, we assessed gender, race, body mass index (BMI), and percentage of body fat (%fat) as potential covariates. Methods. Serum was obtained from 426 healthy participants whose age ranged from 18 to 87 years. Anthropometric measures included %fat and BMI. Neopterin concentrations were measured by competitive ELISA. The paired associations between neopterin and age, BMI, or %fat were analyzed by Spearman's correlation or by linear regression of log-transformed neopterin, whereas overall associations were modeled by multiple regression of log-transformed neopterin as a function of age, gender, race, BMI, %fat, and interaction terms. Results. Across all participants, neopterin exhibited a positive association with age, BMI, and %fat. Multiple regression modeling of neopterin in women and men as a function of age, BMI, and race revealed that each covariate contributed significantly to neopterin values and that optimal modeling required an interaction term between race and BMI. The covariate %fat was highly correlated with BMI and could be substituted for BMI to yield similar regression coefficients. Conclusion. The association of age and gender with neopterin levels and their modification by race, BMI, or %fat reflect the biology underlying chronic immune activation and perhaps gender differences in disease incidence, morbidity, and mortality.
AB - Background. Neopterin, a GTP metabolite expressed by macrophages, is a marker of immune activation. We hypothesize that levels of this serum marker alter with donor age, reflecting increased chronic immune activation in normal aging. In addition to age, we assessed gender, race, body mass index (BMI), and percentage of body fat (%fat) as potential covariates. Methods. Serum was obtained from 426 healthy participants whose age ranged from 18 to 87 years. Anthropometric measures included %fat and BMI. Neopterin concentrations were measured by competitive ELISA. The paired associations between neopterin and age, BMI, or %fat were analyzed by Spearman's correlation or by linear regression of log-transformed neopterin, whereas overall associations were modeled by multiple regression of log-transformed neopterin as a function of age, gender, race, BMI, %fat, and interaction terms. Results. Across all participants, neopterin exhibited a positive association with age, BMI, and %fat. Multiple regression modeling of neopterin in women and men as a function of age, BMI, and race revealed that each covariate contributed significantly to neopterin values and that optimal modeling required an interaction term between race and BMI. The covariate %fat was highly correlated with BMI and could be substituted for BMI to yield similar regression coefficients. Conclusion. The association of age and gender with neopterin levels and their modification by race, BMI, or %fat reflect the biology underlying chronic immune activation and perhaps gender differences in disease incidence, morbidity, and mortality.
KW - BMI
KW - Homeostasis
KW - Immune activation
KW - Inflammation
KW - Neopterin
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U2 - 10.1093/gerona/glq066
DO - 10.1093/gerona/glq066
M3 - Article
C2 - 20478905
AN - SCOPUS:77954851565
SN - 1079-5006
VL - 65 A
SP - 858
EP - 865
JO - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
JF - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
IS - 8
ER -