OxyFile #148

Red cell shape changes following trigger finger fatigue in subjects 
with chronic tiredness and healthy controls.

SO Simpson; JC Murdoch; GP Herbison

New Zealand Medical Journal
1993 Mar 24, 106(952):104-7.
(UI:  93234043)


AIMS. To investigate the possibility of a correlation between the 
percentage of nondiscocytic erythrocytes and muscle fatiguability in 
subjects with the symptom of chronic tiredness. 

METHODS. Sixty nine volunteers suffering from persisting or 
intermittent tiredness and 72 healthy controls provided 3-drop samples 
of venous blood for red cell shape analysis before and after inducing 
fatigue in the trigger finger muscles by repeatedly pulling the 
trigger of an antique revolver. Elapsed time and the number of pulls 
were recorded. A work index was calculated from the number of trigger 
pulls divided by the time in seconds then multiplied by the number of 
trigger pulls. RESULTS. Subjects with tiredness had fewer discoid 
cells (males 62.5% vs 69.2%, p = 0.029; females 65.8% vs 71.8%, p = 
0.002) than controls. They also had fewer trigger pulls (males 62.3 vs 
84.0, p =0.003; females 29.5 vs 36.8, p = 0.042) and lower "work 
indices" (males 75.6 vs 104.7, p = 0.001; females 26.1 vs 39.6, p = 
0.001) than controls at the first trigger pulling. After 5 minutes 
rest the number of trigger pulls for males was fewer than the controls 
(56.0 vs 64.2) but the difference was not significant, but the female 
values (24.3 vs 33.2) were significantly different (p = 0.008). Work 
indices for both sexes were significantly different from controls 
(males p = 0.020, females p = 0.001). 

CONCLUSIONS. The association of increased nondiscocytes and impaired 
muscle function could indicate a cause and effect relationship. This 
would be in agreement with the physiological concept of fatigue as a 
consequence of inadequate oxygen delivery.