Influence of carbohydrate and age on lymphocyte function following a marathon.
The influence of 6% carbohydrate ingestion and age on PHA-induced lymphocyte proliferation and in vitro cytokine production was studied in 48 runners following a competitive marathon. Runners were randomly assigned to carbohydrate (C; n = 23) and placebo (P; n= 25) groups, with blood samples taken before, immediately after, and 1.5 hr post-race. C versus P ingestion resulted in higher plasma glucose, lower plasma cortisol, reduced neutrophilia, and monocytosis during recovery, but had no effect on the post-exercise reduction in T-lymphocytes or NK cells, or on race times. No group differences were observed for PHA-induced lymphocyte proliferation or cytokine production. However, for all subjects combined, lymphocyte proliferation and IFN-gamma secretion decreased significantly below pre-race values by 1.5 hr of recovery, and these were negatively correlated with plasma cortisol. Young (<50 years; n = 36) and old (>or=50 years; n = 12) runners exhibited parallel post-race declines in lymphocyte proliferation and IFN-gamma secretion, with the older group exhibiting a 33-59% lower proliferation at each time point. In conclusion, PHA-induced lymphocyte proliferation and cytokine production decreased significantly following a marathon, and this decrease was strongly linked to cortisol and only partially linked to T-cell changes. This decrease occurred in both younger and older runners and was not influenced by carbohydrate.
Henson
Dru A
DA
Department of Biology, Appalachian State University, Boone, NC 28608, USA.
Nieman
David C
DC
Pistilli
E Edward
EE
Schilling
Brian
B
Colacino
AnnaRita
A
Utter
Allan C
AC
Fagoaga
Omar R
OR
Vinci
Debra M
DM
Nehlsen-Cannarella
Sandra L
SL
D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000097:blood / Q000276:immunology*; D001786:Blood Glucose / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis / Q000097:blood; D004040:Dietary Carbohydrates / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007371:Interferon-gamma / Q000097:blood; D008213:Lymphocyte Activation / Q000187:drug effects; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010835:Phytohemagglutinins / Q000276:immunology / Q000494:pharmacology; D012420:Running / Q000502:physiology*
D001786:Blood Glucose; D016207:Cytokines; D004040:Dietary Carbohydrates; D010835:Phytohemagglutinins; D007371:Interferon-gamma; D006854:Hydrocortisone