Age-related muscle loss

Muscle shrinks in size and strength

Similar to osteoporosis’s effects on bone

Contributes to a number of chronic diseases and conditions…

0

5

10

15

20

25

30

% Muscle Loss

30 years

45 years

75 years

Average men & women over age 30 begin losing muscle at a rate of 15% per year

Sedentary adults risk losing up to 30% of muscle by age 75

Muscle of Average Healthy Adult

Muscle After Sarcopenia Occurs

Body composition in man as a function of age. black bar, Muscle; light grey, other tissues; dark grey, fat. (Adapted from Cohn et al. 1980.)

DECREASE OF LEAN MASS IS ASSOCIATED WITH AN INCREASE IN THE TOTAL AMOUNT OF LIPID STORES

Decreased muscle strength

Gait problems

Falls & fractures

Loss of physical function & independence

Reduced aerobic capacity

Frailty

Weak bones (osteoporosis)

Decreased basal metabolic rate

(middle-age weight gain)

Fast twitch(FT) neurons tend to die off first. Fast twitch(FT) neurons tend to die off first.

Adjacent motor neuron(slow twitch (ST) motor neuron), may reinnervate the muscle fibers: MOTOR UNIT REMODELLING.

Adjacent motor neuron(slow twitch (ST) motor neuron), may reinnervate the muscle fibers: MOTOR UNIT REMODELLING.

Less Efficient Motor Units.: MOTOR UNIT RESTRUCTURING

Less precise control of movements

Less precise control of movements

Less force production Less force production

Less coordinated and quick movements

Less coordinated and quick movements

Loss of balance and speed

Loss of balance and speed

Loss of satellite cell function

Loss of satellite cell function

LOSS OF ABILITY TO MUSCLE CELLS TO REGENRATE

LOSS OF ABILITY TO MUSCLE CELLS TO REGENRATE

DECREASE IN MUSCLE PROTEIN SYNTHESIS DECREASE IN MUSCLE PROTEIN SYNTHESIS

Loss of muscle mass

Decreased concentrations of : Decreased concentrations of :

GROWTH HARMONE TESTESTERONE

INSULIN LIKE GROWTH FACTOR

Reduced levels of growth hormone associated with aging contribute to age-related decreases in muscle mass, strength, and lipolysis.Reduced levels of growth hormone associated with aging contribute to age-related decreases in muscle mass, strength, and lipolysis.

Graph Showing Decline In testesterone with aging in men

Strength Training

#1 way to prevent or reverse muscle loss

Aerobic Activity

Walking, cycling, golfing, swimming

Proper DietProtein, Carbohydrates, Fiber

In 3 - 4 months, adults can increase strength by 2-3 times their current strength ability.

Weight training is especially important to slow the process of sarcopenia

Regular weight training has shown to: •reduce blood pressure •improve blood cholesterol levels •improve insulin sensitivity •increase bone mineral density •improve cardiovascular function •relieve depression •reduce body fat •improve functional abilities

Benefits of Weight Training for Older Adults

In a New England Journal of Medicine study, 100 nursing home residents in their 80s and 90s were put on a weight-training program

for 10 weeks.

At the end of the 10 weeks, some of the results were so positive that a number of residents were able to switch from a walker to a cane!

The results appear next…

Strength

Walking Speed

Stair-ClimbingPower

113%

28%

12%

% Increase

SARCOPENIA IN ELDERLY MEN AND WOMEN: THE RANCHO BERNARDO STUDY.Castillo EM, Goodman-Gruen D, Kritz-Silverstein D, Morton DJ, Wingard DL, Barrett-Connor E.American Journal of Preventive Medicine, 2003 Oct;25(3):226-31.

METHODS: Height, weight, muscle strength, fat-free mass (FFM), fat mass by bioelectric impedance analysis and grip strength(men) were measured for community-dwelling men (694) and women (1006) aged 55-98 years (mean=73)were selected; alcohol and medication use, smoking, and physical activity were ascertained.

RESULTS: •Mean FFM was 43.5 kg for women and 61.7 kg for men. Sarcopenia, defined as FFM of > or =2.0 standard deviations below the gender-specific mean of a young reference population, was present in 6.0% overall. Prevalence increased dramatically from 4% of men and 3% of women aged 70-75 to 16% of men and 13% of women aged 85 and older. •Both men and women with sarcopenia had a significantly lower fat mass and body mass index than those without sarcopenia.•Grip strength, but not quadriceps strength, was lower in men and women with sarcopenia.• Physically active women were about half as likely to have sarcopenia, but no association was found in men.• Few men and women were current smokers, but they were more likely to have sarcopenia.• Co morbidities (heart disease, diabetes, pulmonary disease, arthritis, cancer) and medications (thyroid hormones, corticosteroids, and hormone replacement therapy) were not associated with sarcopenia. CONCLUSIONS:This study also identified lack of physical activity and current smoking as reversible risk factors for sarcopenia.

SARCOPENIA IN ELDERLY MEN AND WOMEN: THE RANCHO BERNARDO STUDY.Castillo EM, Goodman-Gruen D, Kritz-Silverstein D, Morton DJ, Wingard DL, Barrett-Connor E.American Journal of Preventive Medicine, 2003 Oct;25(3):226-31.

METHODS: Height, weight, muscle strength, fat-free mass (FFM), fat mass by bioelectric impedance analysis and grip strength(men) were measured for community-dwelling men (694) and women (1006) aged 55-98 years (mean=73)were selected; alcohol and medication use, smoking, and physical activity were ascertained.

RESULTS: •Mean FFM was 43.5 kg for women and 61.7 kg for men. Sarcopenia, defined as FFM of > or =2.0 standard deviations below the gender-specific mean of a young reference population, was present in 6.0% overall. Prevalence increased dramatically from 4% of men and 3% of women aged 70-75 to 16% of men and 13% of women aged 85 and older. •Both men and women with sarcopenia had a significantly lower fat mass and body mass index than those without sarcopenia.•Grip strength, but not quadriceps strength, was lower in men and women with sarcopenia.• Physically active women were about half as likely to have sarcopenia, but no association was found in men.• Few men and women were current smokers, but they were more likely to have sarcopenia.• Co morbidities (heart disease, diabetes, pulmonary disease, arthritis, cancer) and medications (thyroid hormones, corticosteroids, and hormone replacement therapy) were not associated with sarcopenia. CONCLUSIONS:This study also identified lack of physical activity and current smoking as reversible risk factors for sarcopenia.

Journal of Applied Physiology 107: 1172-1180, 2009.

Effects of aging on human skeletal muscle after immobilization and retraining

C. Suetta, L. G. Hvid, L. Justesen, U. Christensen, K. Neergaard, L. Simonsen, N. Ortenblad, S. P. Magnusson, M. Kjaer, and P. Aagaard .

AIM: To investigate the effects of unilateral lower limb immobilization and subsequent retraining on muscle mass, muscle architecture, neuromuscular activation, and resting twitch characteristics in young and aged human individuals.

SUBJECTS: Twenty healthy men, 9 old (OM: 67.3 yr, range 61–74 yr) and 11 young (YM: 24.4 yr, range 21–27 yr), volunteered to participate in the study.

METHOD: All subjects were subjected to unilateral (randomly selected limb) lower limb casting from the hip to the ankle for 2 wk. All measurements were conducted at baseline previous to the immobilization procedure (Pre), after 2 wk of immobilization, and again after 4 wk of heavy resistance training (6 wk).

RESULTS:After retraining, both young and old regained their initial muscle strength, but old had

smaller gains in quadriceps volume compared with young.

CONCLUSIONThe present data shows that aging is accompanied by an attenuated rate of muscle atrophy

in response to immobilization compared with that of young individuals, and importantly that old subjects demonstrate a diminished capacity to restore muscle size and muscle architecture during subsequent retraining

PREVALENCE OF SARCOPENIA AND PREDICTORS OF SKELETAL MUSCLE MASS IN HEALTHY, OLDER MEN AND WOMEN The Journals of Gerontology: Series A, Volume57, Issue12Pp. M772-M777. Michele Iannuzzi-Sucich a ,. Karen M. Prestwood a and Anne M. Kenny a.

OBJECTIVE The objective of this study was to determine the prevalence of sarcopenia in a population of older, community-dwelling research volunteers.

METHODAppendicular skeletal muscle mass was measured by dual x-ray absorptiometry in 195 women aged 64 to 93 years and 142 men aged 64 to 92 years. Body mass index (BMI) was calculated and physical activity and performance were measured with the Physical Activity Scale for the Elderly, the Short Physical Performance Battery, and the Physical Performance Test. They measured health-related quality of life by using the SF-36 general health survey. Serum estrone, estradiol, sex hormone-binding globulin, parathyroid hormone, and 25-hydroxy vitamin D were measured in all participants and bioavailable testosterone was measured only in men. Leg press strength and leg press power were determined in men.

RESULTSThe prevalence of sarcopenia in our cohort was 22.6% in women and 26.8% in men. A subgroup analysis of women and men 80 years or older revealed prevalence rates of 31.0% and 52.9%, respectively. In women, skeletal muscle mass correlated significantly with BMI and levels of serum estrone, estradiol, and 25-hydroxy vitamin D; in men, it correlated significantly with BMI, single leg stance time, leg press strength, leg press power, SF-36 general health score, Physical Performance Test total score, and bioavailable testosterone levels.

PREVALENCE OF SARCOPENIA AND PREDICTORS OF SKELETAL MUSCLE MASS IN HEALTHY, OLDER MEN AND WOMEN The Journals of Gerontology: Series A, Volume57, Issue12Pp. M772-M777. Michele Iannuzzi-Sucich a ,. Karen M. Prestwood a and Anne M. Kenny a.

OBJECTIVE The objective of this study was to determine the prevalence of sarcopenia in a population of older, community-dwelling research volunteers.

METHODAppendicular skeletal muscle mass was measured by dual x-ray absorptiometry in 195 women aged 64 to 93 years and 142 men aged 64 to 92 years. Body mass index (BMI) was calculated and physical activity and performance were measured with the Physical Activity Scale for the Elderly, the Short Physical Performance Battery, and the Physical Performance Test. They measured health-related quality of life by using the SF-36 general health survey. Serum estrone, estradiol, sex hormone-binding globulin, parathyroid hormone, and 25-hydroxy vitamin D were measured in all participants and bioavailable testosterone was measured only in men. Leg press strength and leg press power were determined in men.

RESULTSThe prevalence of sarcopenia in our cohort was 22.6% in women and 26.8% in men. A subgroup analysis of women and men 80 years or older revealed prevalence rates of 31.0% and 52.9%, respectively. In women, skeletal muscle mass correlated significantly with BMI and levels of serum estrone, estradiol, and 25-hydroxy vitamin D; in men, it correlated significantly with BMI, single leg stance time, leg press strength, leg press power, SF-36 general health score, Physical Performance Test total score, and bioavailable testosterone levels.

LEUCINE: A KEY AMINO ACID IN AGEING-ASSOCIATED SARCOPENIA.Nutrition Research Reviews(2003), 16: 61-70

Dominique Dardevet, Isabelle Rieu, Pierre Fafournoux, Claire Sornet, Lydie Combaret, Alain Bruhat, Sylvie Mordier, Laurent Mosoni and Jean Grizard

AIM: To find out whether chronic oral leucine supplementation would be beneficial for maintaining muscle protein mass in elderly men and women.

SUBJECTS: The effect of meal Leucine supplementation on in vivo protein synthesis in adult and ageing rats.

FININDINGS :Leucine has been shown to stimulate insulin secretion, and the restoration of muscle protein synthesis in ageing rats

LEUCINE: A KEY AMINO ACID IN AGEING-ASSOCIATED SARCOPENIA.Nutrition Research Reviews(2003), 16: 61-70

Dominique Dardevet, Isabelle Rieu, Pierre Fafournoux, Claire Sornet, Lydie Combaret, Alain Bruhat, Sylvie Mordier, Laurent Mosoni and Jean Grizard

AIM: To find out whether chronic oral leucine supplementation would be beneficial for maintaining muscle protein mass in elderly men and women.

SUBJECTS: The effect of meal Leucine supplementation on in vivo protein synthesis in adult and ageing rats.

FININDINGS :Leucine has been shown to stimulate insulin secretion, and the restoration of muscle protein synthesis in ageing rats

GRAPH SHOWING EFFECT OF ORAL LEUCINE ON MUSCLE PROTEIN SYNTHESISGRAPH SHOWING EFFECT OF ORAL LEUCINE ON MUSCLE PROTEIN SYNTHESIS

Journal of Applied Physiology 104: 1452-1461, 2008

SKELETAL MUSCLE PROTEIN ANABOLIC RESPONSE TO RESISTANCE EXERCISE AND ESSENTIAL AMINO ACIDS IS DELAYED WITH AGINGMicah J. Drummond, Hans C. Dreyer, Bart Pennings, Christopher S. Fry, Shaheen Dhanani,Edgar L. Dillon, Melinda Sheffield-Moore, Elena Volpi, Blake B. Rasmussen

METHODSeven young and six old male subjects (age range: 24–77 yr) were selected. dual-energy X-ray absorptiometry scan (Hologic QDR 4500W, Bedford, MA) was performed to measure body composition and lean mass. Each subject ingested 20 g of EAA 1 h following leg resistance exercise

OBSERVATIONMuscle protein synthesis MPS increased early in young (1–3 h postexercise) and later in old (3–6 h postexercise). The acute muscle protein synthesis (MPS) response( usually delayed with aging) after resistance exercise and EAA ingestion is similar between young and old men.

CONCLUSION.Thus, the combination of resistance exercise and EAA ingestion should be a useful strategy to combat sarcopenia.

Journal of Applied Physiology 104: 1452-1461, 2008

SKELETAL MUSCLE PROTEIN ANABOLIC RESPONSE TO RESISTANCE EXERCISE AND ESSENTIAL AMINO ACIDS IS DELAYED WITH AGINGMicah J. Drummond, Hans C. Dreyer, Bart Pennings, Christopher S. Fry, Shaheen Dhanani,Edgar L. Dillon, Melinda Sheffield-Moore, Elena Volpi, Blake B. Rasmussen

METHODSeven young and six old male subjects (age range: 24–77 yr) were selected. dual-energy X-ray absorptiometry scan (Hologic QDR 4500W, Bedford, MA) was performed to measure body composition and lean mass. Each subject ingested 20 g of EAA 1 h following leg resistance exercise

OBSERVATIONMuscle protein synthesis MPS increased early in young (1–3 h postexercise) and later in old (3–6 h postexercise). The acute muscle protein synthesis (MPS) response( usually delayed with aging) after resistance exercise and EAA ingestion is similar between young and old men.

CONCLUSION.Thus, the combination of resistance exercise and EAA ingestion should be a useful strategy to combat sarcopenia.

REFERENCES

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7. Houston D.K, Nicklas B. J, Ding J., Harris T.B, Tylavsky F.A., Newman A.B, Lee J.S., Sahyoun N. R., Visser M., Kritchevsky S.B.,“Dietary protein intake is associated with lean mass change in older, community-dwelling adults: the health, aging, and body composition study”, AmericanJournalofClinicalNutrition,2008.87(1),150-155.

8. Iannuzzi S.M.,Prestwood K.M., KennyA.M. , “Prevalence of Sarcopenia and Predictors of Skeletal Muscle Mass in Healthy, Older Men and Women.” The Journals of Gerontology, 2002, 57(12) A ,M772-M777.

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REFERENCE10.Lenz T.L.,” Leucine With Resistance Training for the Treatment of Sarcopenia”, American journal of lifestyle medicine,2010 ,4 ( 4), 317-319.

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