Effects of age and physical fitness on microcirculatory function.
Sedentary aging is associated with endothelial dysfunction and nitric oxide (NO) impairment. The aim of the present study was to assess the effects of regular physical exercise on nitrite/nitrate (NOx) concentrations and microcirculatory function in older men compared with young individuals. We measured NOx plasma concentrations and baseline and stimulated skin blood flow (SBF) by laser Doppler flowmetry in 39 male athletes [range, 22-72 years; maximal oxygen consumption (VO2max), 60.0 +/- 4.7 ml.min(-1).kg of body weight(-1) (mean +/- S.D.)] and 45 age- and sex-matched sedentary controls (VO2max, 38.0 +/- 7.1 ml.min(-1).kg of body weight(-1)). NOx concentrations were higher in athletes than in controls (50.4 +/- 16.3 compared with 39.0 +/- 15.4 micromol/l; P<0.005), whereas baseline SBF was comparable. Hand SBF after heating and ischaemia and foot SBF after heating were higher in athletes (P<0.0001) than in controls. By comparing the lowest and the highest tertile of age, sedentary young subjects had higher NOx concentrations than sedentary older subjects (43.3 +/- 13.4 compared with 31.8 +/- 12.2 micromol/l respectively; P<0.05). Exercise abolished this difference (49.1 +/- 9.6 micromol/l for young subjects and 52.1 +/- 11.5 micromol/l for older subjects; not significant). Resting SBF was similar in all the subgroups, but stimulated SBFs were lower in both subgroups of untrained compared with trained subjects. NOx concentrations were positively correlated with VO2max (r=0.46, P<0.001). Stimulated SBFs were correlated with NOx (r>0.30, P<0.05). These findings show that chronic exercise may improve endothelial function in older (and young) men, probably by increasing NO availability.
Franzoni
Ferdinando
F
Department of Internal Medicine, University of Pisa School of Medicine, Via Roma 67, Pisa 56100, Italy.
Galetta
Fabio
F
Morizzo
Carmela
C
Lubrano
Valter
V
Palombo
Carlo
C
Santoro
Gino
G
Ferrannini
Eleuterio
E
Quiñones-Galvan
Alfredo
A
D000328:Adult; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D001682:Biological Availability; D016022:Case-Control Studies; D004730:Endothelium, Vascular / Q000502:physiology*; D005528:Foot; D006225:Hand; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D009569:Nitric Oxide / Q000097:blood*; D010807:Physical Endurance / Q000502:physiology*; D012039:Regional Blood Flow; D012420:Running; D012867:Skin / Q000098:blood supply
D009569:Nitric Oxide