1
SLEEP & EXERCISE – AGING
SLEEP DEPTH AND CONTINUITY BEFORE AND AFTER EXERCISE IN OLDER MEN – 2014
Melancon MO1, Lorrain D2, Dionne IJ1.
INTRODUCTION & PURPOSE
– Later in life sleep depth (slow-wave sleep, SWS) and maintenance exhibit deleterious changes, with possible -ve effects on daytime function
METHOD
– 13 men aged 64±3yrs had sleep measured for a total of 6 nights: 3 before and 3 after the 16-week training intervention
– Each sequence involved 1 familiarization trial followed by 2 experimental nights (exercise night; nonexercise night)
– The exercise challenges consisted of inclined treadmill brisk walking (60min, 68-69% V˙O2peak)
RESULTS
1. Exercise following training resulted in a 71% increase in SWS during subsequent sleep
2. Following training, acute exercise reduced total wake time by 30% and REM onset latency by 14%
3. Acute exercise improved sleep continuity by decreasing total wake time
SLEEP & SARCOPENIA (MUSCLE LOSS WITH AGING)
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
SLEEP – T2 DIABETES, METABOLIC DISEASES, SARCOPENIA – AGING
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
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) 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
THE METABOLIC BURDEN OF SLEEP LOSS – 2014
Sebastian M Schmid; Manfred Hallschmid; Prof Bernd Schulte
SUMMARY
(1) Studies show association between short sleep duration, sleep disturbances, and circadian rhythm of sleep with adverse metabolic traits, in particular obesity and type 2 diabetes
(2) Outcomes: increased appetite, enhanced sensitivity to food stimuli, and, ultimately, a surplus in energy intake
SLEEP – TESTOSTERONE LEVELS IN MEN – AGING
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