Comparison of skeletal muscle strength between cardiac patients and age-matched healthy controls

Abstract

The purpose of the present study was to compare muscular strength of knee extensors and arm flexor muscles of cardiac patients (n = 638) and healthy controls (n = 961) in different age groups. Isometric torques were measured in a sitting position with the elbow, hip, and knee flexed to 900. For statistical analysis, age groups were pooled in decades from the age of 30 to 90 years. Additionally, the influence of physical lifestyle prior to disease on muscular strength was obtained in the patients. For statistical analysis three-way ANOVA (factors age, gender, and physical activity level) was used.Both in patients and in controls a significant age-dependent decline in maximal torque could be observed for arm flexors and knee extensors. Maximal leg extensor muscle showed statistically significant differences between healthy controls and cardiac patients as well as between subgroups of patients: Physically inactive patients showed lowest torques (male: 148 ± 18 Nm; female: 82 ± 25 Nm) while highest values were measured in control subjects (male: 167 ± 16 Nm; female: 93 ± 17 Nm). In contrast, arm flexor muscles did not show any significant influence of health status or sports history.This qualitative difference between weight-bearing leg muscles and the muscle group of the upper extremity suggest that lower skeletal muscle strength in heart patients is mainly a consequence of selective disuse of leg muscles rather than any pathological skeletal muscle metabolism. Since a certain level of skeletal muscle strength is a prerequisite to cope with everyday activities, strength training is recommended as an important part of cardiac rehabilitation.

Quadriceps Strength, Quadriceps Power, and Gait Speed in Older U.S. Adults with Diabetes Mellitus: Results from the National Health and Nutrition Examination Survey, 1999–2002

“…To our knowledge, we are the first to report a progressive loss of age-adjusted quadriceps strength by up to 6 Newton-meter per decade in men and women with diabetes which is smaller but comparable to age-related declines (21). Our findings add to the study by Park, et al (2006) (6) reporting that leg muscle quality is lowest in older adults (mean age~74 years) with a categorical diabetes duration ≥6 years.…”

Age-related and disease-related muscle loss: the effect of diabetes, obesity, and other diseases

“…17 However, it has become clear that decreases in muscle strength exceed what is expected on the basis of the decline in muscle mass during ageing, 18 especially after the age of 60–70 years. 19 The progressive mismatch between mass and strength probably occurs because of a deterioration of muscle quality. 20 Results of studies have also suggested that muscle strength might be more important than muscle mass as a determinant of functional limitations and mobility status in older age.…”

Acute effects of resistance exercise on heart rate variability in cardiopathic patients: cross-sectional study

“…It impairs common daily routine and professional activities. Thus, it has been included strength training in cardiac rehabilitation programs in order to improve muscle strength and functional capacity in submaximal activities [5][6][7][8][9].…”

“…The literature described those symptoms in myocardial ischemia, left ventricular dysfunction and cardiac arrhythmias [12][13][14]. It is believed that the acute performance of resistance exercise at high intensities increase the possibility of these complications [5,6,11].…”

“…The prescription of resistance exercise is important for cardiopathic subjects [5][6][7][8][9]. Nevertheless, we should be careful regarding its risks on the cardiovascular complications during and after resistance exercise [12][13][14], mainly if acutely applied and without safe criteria for prescription [5][6]11]. In addition, it lacks in the literature studies regarding resistance exercise intervention in cardiac patients with respect to cardiac autonomic modulation.…”