Muscle strength in relation to disease severity in patients with congestive heart failure.
OBJECTIVE
Indices of exercise capacity such as peak oxygen uptake (VO2peak) and muscle strength are important in association with reduced mortality. The present study compared differences in VO2peak and muscle strength indices (grip strength and knee extensor and flexor muscle strength) with disease severity and investigated the relation of these variables in congestive heart failure (CHF) patients.


METHODS
The study comprised 102 patients with stable CHF (93 men, age 61.4 +/- 10.2 yrs) with left ventricular ejection fraction (LVEF) <40% by echocardiography. We used New York Heart Association (NYHA) functional class to index disease severity. VO2peak, grip strength, knee extensor, and flexor muscle strength were determined. Patients were divided into three groups by NYHA class: class I (n = 39), class II (n = 49), and class III (n = 14).


RESULTS
Age, sex, and LVEF did not differ according to NYHA class. VO2peak and all muscle strength indices decreased with increases in NYHA class (P < 0.05). VO2peak correlated positively with all muscle strengths (P < 0.05). Stepwise linear regression analysis revealed that grip and knee extensor strength were important in predicting VO2peak.


CONCLUSIONS
Exercise capacity and disease severity in CHF patients may be influenced not only by lower-limb but also upper-limb muscle strength.
Izawa
Kazuhiro P
KP
Department of Rehabilitation Medicine, St. Marianna University School of Medicine Hospital, Kanagawa, Japan.
Watanabe
Satoshi
S
Yokoyama
Hitoshi
H
Hiraki
Koji
K
Morio
Yuji
Y
Oka
Koichiro
K
Osada
Naohiko
N
Omiya
Kazuto
K
D015444:Exercise; D005260:Female; D006333:Heart Failure / Q000145:classification* / Q000188:drug therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength; D010101:Oxygen Consumption; D012720:Severity of Illness Index; D016277:Ventricular Function, Left