STRENGTH | MUSCLE – SARCOPENIA & DYNAPENIA – AGING


22 RESEARCH ARTICLES + 5 GRAPHICS – CLICK ON GRAPHIC TO ENLARGE


SARCOPENIA & DYNAPENIA


WHAT IS SARCOPENIA & DYNAPENIA?


DYNAPENIA
– Age-related loss of muscle strength and power not caused by neurologic or muscular diseases
– In Greek, Dyna refers to “power, strength, or force” and penia refers to “poverty.”
SARCOPENIA
– Research has largely focused on muscle size as the primary cause of dynapenia
– Recent findings show that muscle size plays a relatively minor role
NERVOUS SYSTEM
– Deficits in the structure and function of the nervous system and/or impairments in the intrinsic force-generating properties of skeletal muscle are potential antecedents to dynapenia


 – JUNE 15 – 2017
– Morphometric age – age based on muscle mass – more predictive of post-surgery mortality than chronological age


SCREENING FOR FRAILTY & SARCOPENIA AMONG OLDER PERSONS & ITS ASSOCIATIONS WITH HEALTHCARE BURDEN – 2017


RESULTS
– A total of 115 patients >65 years:
1) 44.3% (n = 51) of patients were sarcopenic
2) 27.0% (n = 31) were classified as frail
3) 23.5% (n = 27) were both frail and sarcopenic
4) 87.1% of frail patients were sarcopenic 5) 47.1% of sarcopenic patients were frail
– Sarcopenia and frailty were associated with:
1. higher comorbidity index
2. higher likelihood of requiring a caregiver
3. more medical specialty follow-ups
4. polypharmacy
5. more than 2 hospital admissions within a year
6. a higher number of falls and falls with serious consequences


SARCOPENIA AND CRITICAL ILLNESS – 2015


FRAILTY IS ASSOCIATED WITH SIGNIFICANT MORBIDITY & MORTALITY IN THE ELDERLY
– Underlying pathology results in disruption of the individual’s ability to tolerate internal and external stressors such as injury or illness
– Increased risk of falls and subsequent morbidity and mortality from the resulting traumatic injury
– Inability to recover from medical insults, resulting in critical illness
– Increased incidence of critical illness, resulting in a progressive downward spiral


MUSCLE QUALITY COMPOSITION AND METABOLISM IN LATER LIFE – 2014


FACTORS
– loss of muscle mass
– composition
– metabolism
– aerobic capacity
– insulin resistance
– fat infiltration
– fibrosis and neural activation


SARCOPENIA & DYNAPENIA – IMPACT OF ADVANCING AGE – 2012


DYNAPENIA
– Lack of strength is a more constant factor in compromised wellbeing in old age
– Decline in muscle mass and decline in strength can take quite different trajectories
MUSCLE QUALITY OR FORCE
– The force generating per capacity per unit cross-sectional area (CSA)
RESEARCH
– Loss of strength is 2–5x faster than loss of mass
– Loss of strength is a more consistent risk for disability and death than loss of muscle mass
(1) Sarcopenia or Muscle Mass Loss:
– At age 75, muscle mass is lost at a rate of 0.64–0.70% per year in women and 0.80–00.98% in men
(2) Dynapenia or Loss of Strength:
– At age 75, strength is lost at a rate of 3–4% per year in men and 2.5–3% per year in women


ALL EXERCISE


MUSCLE ATROPHY FROM DISUSE – DECREASED PROTEIN SYNTHESIS – 2014


Stuart M. Phillips*,1 and Chris McGlory
MPS MUSCLE PROTEIN SYNTHESIS or MPB MUSCLE PROTEIN BREAKDOWN
– Which one drives human muscle atrophy? 

– Declines in MPS are the predominant mechanism underpinning the decline in muscle CROSS-SECTIONAL AREA (CSA)


PREVALENCE OF AND INTERVENTIONS FOR SARCOPENIA – 2014


– Prevalence studies and intervention studies in adults aged ≥50 years
– Exercise interventions improve muscle strength and physical performance
– Essential amino acid (EAA) supplements, including ∼2.5 g Leucine, and HMB, show some effects in improving muscle mass and function parameters


LIFELONG PHYSICAL EXERCISE – DELAYS AGING SKELETAL MUSCLE DECLINE – 2014


– Compared muscle function and structure in:
(a) males, well-trained seniors (average 70 yrs) who exercised regularly in their previous 30 yrs
(b) age-matched healthy sedentary seniors
(c) active young men (average of 27 yrs)
– Regular physical activity is a good strategy to reduce age-related general decay of muscle structure and function


OLDER ADULTS – BUILD MUSCLE AND YOU WILL LIVE LONGER – 2014


– The more muscle mass older Americans have, the less likely they are to die prematurely


MUSCLE MASS INDEX AS A PREDICTOR OF LONGEVITY IN OLDER ADULTS – 2013


– Survival predication ability of relative muscle mass
– Look beyond total body mass in assessing the health of older adults


STRENGTH – MUSCLE MASS TRAINING


+


IMPROVED SKELETAL MUSCLE MASS AND STRENGTH AFTER HEAVY STRENGTH TRAINING IN INDIVIDUALS >83 – 2017


Bechshøft RLHolm L
PURPOSE

A) 12 wks of heavy resistance training (3×/week) (HRT)
B) non-training control group (CON)
– Both groups received similar protein supplementation
– 26 participants (86.9±3.2 83-94, range)
RESULTS
– Quadriceps cross-sectional area (CSA) differed between groups at post-test increasing in HRT only
– Thigh muscle isometric strength, isokinetic peak torque and power increased significantly only in HRT by 10-15%
– knee extension one-repetition maximum (1 RM) improved by 91%.
– Physical functional tests, muscle fiber type distribution and size did not differ significantly between groups


HIGHER DAILY PHYSICAL ACTIVITIES – PRESERVE STRENGTH BUT NOT MASS >75 – 2016


RESULTS
– 1,839 community-dwelling people aged >50 years in Taiwan; after adjusting for age lowest Physical Activity was associated with:
– multi-morbidity
– poorer functional capacity and nutritional status
– more depressive symptoms
– lower SMI Skeletal Muscle Index and lower handgrip strength
– lower free androgen index (FAI) in men


BAND RESISTANCE TRAINING & NUTRITIONAL SUPPLEMENTATION ON MUSCLE QUALITY & GROWTH – 2016


METHODS
91 women aged 83.6 (65.0-92.2) yrs were assigned to one of 3 groups:
1. RT, resistance training
2. RTS, resistance training plus nutritional supplementation
3. CT, cognitive training
– They were tested at baseline as well as after 3 and 6 months of intervention
CONCLUSION
– Strength training improves physical performance and Muscle Quality


EXERCISE & NUTRITION TO PREVENT MUSCLE WASTING – 2012


– Leigh Breen, Stuart M Phillips
MUSCLE ATROPHY
– Prolonged periods of net -ve muscle protein balance, brought about by imbalance between muscle protein synthesis (MPS) and muscle protein breakdown (MPB)
RESISTANCE TRAINING AND PROTEIN LEUCINE INTAKE
– Strength training and protein both act as a strong stimulus for MPS and, when combined, can induce a net +ve protein balance and muscle hypertrophy
– The dose, absorption kinetics, leucine content, but less-so the timing of ingestion, are important determinants
– Resistance exercise-induced rates of MPS and hypertrophy appear to be dependent on exercise volume (to achieve maximal muscle fibre recruitment), as opposed to the absolute load that is lifted


ENDURANCE TRAINING


SKELETAL MUSCLE MITOCHONDRIA – PHYSICAL FITNESS & TRAINING – 2014


CONTEXT
– Sarcopenia is thought to be associated with mitochondrial (Mito) loss
– Aging per se is not the primary culprit leading to Mito dysfunction
DESIGN & SUBJECTS
– Compared endurance-trained older adults (A) or sedentary (S) subjects matched for age and gender
– 4-month exercise intervention in S
– Mito volume density (MitoVd) was assessed
RESULTS
(1) VO2peak was strongly correlated with MitoVD in eighty 60-80 yr olds

(2) Comparison of A vs. S revealed differences in MitoVd, ATPmax and some protein complexes
(3) Exercise intervention confirmed that S are able to recover MitoVd, ATPmax and specific transcription factors


SLEEP


THE RELATIONSHIP OF SLEEP DURATION WITH OBESITY & SARCOPENIA – 2015


6-8 HOURS OF SLEEP
– 488 community-dwelling adults (224 men and 264 women) aged ≥65 years were included
– Compared to adults with 6-8 h of sleep, adults with <6 h of sleep had a nearly 3-fold increased likelihood of sarcopenia
– However, adults with ≥8 h of sleep had a nearly 2-fold increased risk of sarcopenia
– Older adults with a sleep duration <6 h were more prone to obesity


EVENING CHRONOTYPE ASSOCIATED WITH METABOLIC DISORDERS AND BODY COMPOSITION IN MIDDLE-AGED ADULTS – 2015


Yu JH1, Kim NH et al
OBJECTIVE
– Chronotype is a trait determining individual circadian preference in behavioral and biological rhythm relative to external light-dark cycle
– Examine whether late chronotype is related to metabolic abnormalities and body composition in middle-aged adults, independent of sleep duration and lifestyle
DESIGN AND PARTICIPANTS
– A total of 1620 participants aged 47-59 years were recruited from the Korean Genome and Epidemiology Study.
RESULTS
(1) Chronotype was classified as morning in 29.6% of subjects, evening in 5.9%, neither morning nor evening in 64.5%.
(2) Evening type, when compared with morning type, was significantly associated with diabetes, metabolic syndrome and sarcopenia
(3) Gender differences in the associations were evident. In men, evening type was associated with diabetes and sarcopenia; only metabolic syndrome was associated with evening type in women
CONCLUSIONS
(1) At the population level, evening chronotype was independently associated with diabetes, metabolic syndrome, and sarcopenia
(2) These results support the importance of circadian rhythms in metabolic regulation


SLEEP DURATION & DISTURBANCES WERE ASSOCIATED WITH TESTOSTERONE LEVEL, MUSCLE MASS & MUSCLE STRENGTH IN OLDER MEN – 2015


Auyeung TW1, Kwok T2, Leung J3, Lee JS2, Ohlsson C4, Vandenput L4, Wing YK5, Woo J2.
BACKGROUND
– Testosterone level follows a circadian rhythm
– Examine the relationship of sleep duration and disturbances to testosterone level, muscle mass, muscle strength, and walking speed
PARTICIPANTS AND METHODS
– 1274 community-dwelling men older than 65 years of age
RESULTS
(1) Testosterone increased with increasing sleep duration up to 9.9 hrs, after which it decreased, giving rise to an inverted U-shaped relationship
(2) A similar inverted U-shaped relationship occurred between sleep duration and muscle mass and function
(3) Earlier go-to-bed time, despite being associated with a higher testosterone level, was associated with weaker grip strength
(4) Earlier wake-up time was associated with higher muscle mass but neither grip strength nor walking speed
(5) Neither prolonged sleep latency nor insomnia was associated with testosterone levels
(6) However, prolonged sleep latency was associated with lower muscle mass, weaker grip strength, and slower walking speed
(7) Insomnia, on the other hand was associated with weaker grip strength and slower walking speed but not muscle mass
CONCLUSIONS
(1) Sleep duration and disturbances can affect testosterone level, muscle mass, and its function
(2) Whether optimization of sleep can ameliorate age-associated decline in sex hormone and muscle performance warrants further studies


NUTRITION


+


WHEY PROTEIN, AMINO ACIDS, VITAMIN D WITH PHYSICAL ACTIVITY INCREASES FAT-FREE MASS AND STRENGTH, FUNCTIONALITY, QUALITY OF LIFE, DECREASES INFLAMMATION IN SARCOPENIC ELDERLY – 2016
DESIGN
– Whey protein (22 g), essential amino acids (10.9 g, including 4 g leucine), and vitamin D [2.5 μg (100 IU)]
– 130 sarcopenic elderly people (53 men and 77 women; mean age: 80.3 y); 12-wks exercise program
CONCLUSION
– Increased fat-free mass and strength
– enhanced other aspects that contribute to well-being in sarcopenic elderly


KEEPING OLDER MUSCLE YOUNG: PROTEIN & PHYSICAL ACTIVITY – 2014


DIETARY PROTEIN
– Major cause of muscle loss: Blunted muscle protein synthetic response to dietary protein called “anabolic resistance”
– Inactive Lifestyle: Anabolic resistance is a hallmark of a sedentary lifestyle at any age
– Dietary strategies: Leucine enriched, rapidly digested proteins and/or greater protein ingestion in each main meal
EXERCISE → RESTORES THE SENSITIVITY OF OLDER MUSCLE TO DIETARY PROTEIN
– It is proposed that inactivity is the precipitating factor in the development of anabolic resistance


NUTRIENT MANAGEMENT OF SARCOPENIA IN THE ELDERLY – 2015


PROTEIN – VITAMIN D – OMEGA 3s
– In addition to proteins/amino acids, sarcopenic elderly subjects have an unbalance in VIT D synthesis and omega-6/omega-3 ratio


 

Comments are closed.