F-21 Free Communication/Poster - Clinical Exercise Physiology 4 (Clinical Exercise Physiology Association): JUNE 3, 2011 1:00 PM - 6:00 PM: ROOM: Hall B
The long-term effect of hereditary hemochromatosis (HH) on exercise capacity has not been reported. We compared exercise capacity of subjects with HH over 5 years with healthy volunteers.
PURPOSE: Analyze exercise capacity in HH subjects and volunteers over a 5 year period.
METHODS: 22 newly diagnosed subjects with HH (age 48±11, 6 females, GA) and 21 subjects with chronic HH (age 51±9, 7 females, GB) were recruited for 5 year follow up. 21 age-gender-matched volunteers (age 48±8, 7 females, GC) were followed during the same period. Subjects underwent baseline treadmill testing with measurements of peak VO2, anaerobic threshold (AT), and VE/VCO2 slope, and repeated same at 5 years. HH subjects were NYHA functional class I, positive for C282Y homozygote, and received conventional therapy. Volunteers were confirmed to have no HH genetic mutations.
RESULTS: 12 GA, 18 GB, and 14 GC subjects returned for testing at 5 years. In all groups, the rate pressure product at rest and peak exercise significantly decreased from baseline (p<0.05 with an unpaired Student t-test). Exercise time, AT, and peak VO2 did not differ statistically from baseline; however, VE/VCO2 slope increased over 5 years (24.0±2.1 to 26.6±2.4 in GA, 23.9±2.2 to 26.5±2.6 in GB, 23.4±4.2 to 26.9±3.0 in GC, data are mean±SD, baseline to 5 year follow up, p<0.05 for all with an unpaired Student t-test) indicating an aging-associated decline in ventilatory efficiency. Metabolic measurements did not differ significantly among the groups at 5 years with ANOVA.
CONCLUSIONS: Exercise capacity of HH subjects who receive conventional therapy is well preserved over five years. Change in VE/VCO2 slope might reflect an age related decline in ventilatory efficiency, although mean values remained within normal limits. This research was supported by the Intramural Research Program of the NIH, NHLBI.