[Different effects of exercise training in patients with myocardial infarction with or without diabetes mellitus].
OBJECTIVE
This study investigated whether myocardial infarction patients with diabetes mellitus had lower heart rate reserve to exercise by measuring the increment in heart rate (HR) divided by the increment of norepinephrine (NE) concentration from rest to peak exercise (delta HR/log delta NE). The difference in exercise training effects was also investigated.


METHODS
The 148 patients after myocardial infarction were divided into two groups, the DM group (n = 34) and the non-DM group (n = 114). Cardiopulmonary exercise testing was performed in each subject at 1 and 3 months after the onset. Blood samples were taken at rest and immediately after peak exercise, rest brain natriuretic peptide, rest and peak norepinephrine were analyzed. Exercise training was performed from 1 to 3 months after the onset.


RESULTS
Resting heart rates were significantly higher in the DM group than in the non-DM group both at 1 and 3 months although peak heart rates were not significantly different. Peak oxygen uptake were lower in the DM group both at 1 and 3 months after onset of myocardial infarction compared to the non-DM group. End-tidal carbon dioxide pressure was lower and the rate of increase of minute ventilation to carbon dioxide output was higher in the DM group. Plasma brain natriuretic peptide was higher in the DM group. delta HR/log delta NE was 19.4 +/- 4.0 in the DM group and 22.2 +/- 5.6 in the non-DM group (p < 0.01), and increased in only the non-DM group. delta HR/log delta NE was more closely correlated with peak oxygen uptake in the DM group than in the non-DM group.


CONCLUSIONS
Impaired response to exercise training may be caused, in part, by impaired heart rate reserve to exercise in patients with diabetes mellitus.
Suzuki
Kengo
K
Division of Cardiology, Department of Internal Medicine, St. Marianna University School of Medicine, Sugao 2-16-1, Miyamae-ku, Kawasaki 216-8511.
Omiya
Kazuto
K
Uno
Masato
M
Azuma
Nobuyuki
N
Tamura
Masachika
M
Itoh
Kae
K
Inoue
Kohji
K
Akashi
Yoshihiro
Y
Seki
Atsushi
A
Samejima
Hisanori
H
Suzuki
Noriyuki
N
Osada
Naohiko
N
Miyake
Fumihiko
F
Izawa
Kazuhiro
K
Yamada
Sumio
S
Itoh
Haruki
H
D000368:Aged; D048909:Diabetes Complications; D005081:Exercise Therapy; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology / Q000534:rehabilitation*; D010101:Oxygen Consumption; D010807:Physical Endurance