s, muscle mass loss is greatest in the antigravity muscles (those used to sit up, stand up, and pull up) and can require up to 2 weeks of reconditioning to return to baseline function for each day of absolute bed rest.2 Patients should sit up in bed, transfer to a chair, stand, and exercise when safe to do so depending on their medical condition or surgical procedure.5 Patients need to be educated about the fact that avoiding sarcopenia is essential to recovery.5 Patients should be advised to avoid extended bed rest and immobilization when possible to prevent muscle weakness and joint stiffness.1
Growth Hormone Levels in Sarcopenia
Growth hormone (GH) levels decrease with aging; this decrease is probably one of many factors that contribute to sarcopenia.2 The age-related decrease in estrogen and testosterone may also reduce GH secretion.2 A number of the signs and symptoms of GH deficiency (e.g., decreased muscle mass, weakness, fatigue) are comparable to those that occur with normal aging.2 While increased muscle mass and decreased fat mass appear to occur with GH replacement therapy, muscle strength increases only to a small degree, if at all, unless GH is accompanied by weight training or is given with testosterone replacement therapy in hypogonadal men.2 GH supplementation should be used only as replacement therapy for those patients with a documented deficiency or for patients with muscle atrophy due to AIDS.2
Adverse effects associated with the supplementation of GH include arthralgias, carpal tunnel syndrome, fluid retention, glucose intolerance, gynecomastia, headaches, and lethargy.2 While long-term effects are unclear, elevated levels of GH and insulin-like growth factor I (IGF-I) in middle-aged individuals are associated with higher mortality rates than in those with lower levels of GH and IGF-I.2 While beyond the scope of this article, a broader discussion of the use and administration of GH supplementation, contraindications, IGF-I, and alternatives to GH may be found in Section 8, chapter 66 in Reference 2.
When older adults remain healthy, they usually can climb stairs, rise from a squatting position, walk along a straight line, hop on either foot, and perform typical activities of daily living with ease.2 However, while maximum isometric contraction force is reduced approximately 20% by age 50, by age 70 the reduction reaches about 50%.2 This occurs because slower-contracting type I fibers function to maintain posture and to perform rhythmic, endurance-type exercises, while the faster-contracting type II muscle fibers that contribute to sudden powerful muscle contractions decrease with aging to a greater extent than do type I fibers.2
Regular exercise can partially overcome or significantly delay loss of muscle mass and strength, and participation in regular strength-training exercises is considered essential to staying strong and vital in one's senior years.6 By stimulating the growth of muscle and bone, strength-training exercises help to prevent osteoporosis and frailty.6 When individuals feel physically strong, mental and emotional health is promoted as well.6 Programs to guide seniors with strength training (see Strength Training for Seniors, page 30) have the potential not only to help them become stronger, but to assist with maintenance of health and independence (TABLE 2). Extensive scientific study has shown that this type of exercise is safe and effective.7 Even seniors who have never exercised before can increase muscle mass and strength through strength-training exercises.1
Pharmacist Counseling: Safe Medication Use During Exercise
Pharmacists play an important role in counseling patients who receive medication therapy while engaging in strength-training exercises. The following are examples of medications requiring special instructions for the patient:
Beta-blockers prevent the use of the target heart rate method for monitoring of endurance intensity; these agents have the potential to mask hypoglycemic symptoms other than sweating.7-9
Insulin and oral hypoglycemic agents may require dosage a