Changes in exercise capacity in subjects with cardiac asymptomatic hereditary hemochromatosis during a follow-up after 5 yrs.
OBJECTIVE
A long-term effect of hereditary hemochromatosis (HH) on aerobic exercise capacity (AEC) has not been well described.


METHODS
Forty-three HH and 21 volunteer control subjects who were asymptomatic underwent cardiopulmonary exercise testing using the Bruce protocol. AEC was assessed with minute ventilation (V(E)), oxygen uptake (V(O)(2)), and carbon dioxide production (V(CO)(2)) at baseline and at a follow-up assessment after 5 yrs. A paired t test was used for analyses of normality data; otherwise, Wilcoxon's signed rank-sum test was used.


RESULTS
Thirty-three HH subjects and 18 volunteer control subjects returned for a repeat cardiopulmonary exercise testing at the fifth-year follow-up (80% overall return rate). At the fifth-year follow-up, AEC was not different between the two groups. Compared with baseline measurements, exercise time, peak V(O)(2), and the V(E)/V(CO)(2) slope did not differ statistically at the fifth-year follow-up between both groups. Iron depletion through phlebotomy for 5 yrs did not significantly affect AEC in newly diagnosed HH subjects at baseline (n = 14) and cardiac arrhythmias during exercise tended to decrease after 5 yrs of therapy in this group.


CONCLUSIONS
The AEC of asymptomatic HH subjects treated using conventional therapy is not statistically affected by the disease during a 5-yr period.
Cardiovascular and Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA.
Yukitaka
Y
Shizukuda
Kevin P
KP
Smith
Dorothy J
DJ
Tripodi
Ross
R
Arena
Yu-Ying
YY
Yau
Charles D
CD
Bolan
Myron A
MA
Waclawiw
Susan F
SF
Leitman
Douglas R
DR
Rosing
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006432:Hemochromatosis / Q000235:genetics* / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D018962:Phlebotomy; D013997:Time Factors