Kenji Obayashi1, Keigo Saeki1, Taeko Maegawa2, Junko Iwamoto3, Takahide Sakai4, Naoto Otaki5, Hiroshi Kataoka6, Norio Kurumatani1. 1. Department of Community Health and Epidemiology, Nara Medical University School of Medicine, Japan. 2. Kashihara Kenko Sports Club, Nara, Japan. 3. Department of Nursing, Tenri Health Care University, Nara, Japan. 4. Natural Therapy Taka, Nara, Japan. 5. Department of Dietary Life and Food Science, Mukogawa Women's University, Hyogo, Japan. 6. Department of Neurology, Nara Medical University School of Medicine, Japan.
Abstract
BACKGROUND: Decreased muscle strength is associated with functional limitation and disability and is a predictor of cardiovascular and all-cause mortality. Recently, oxidative stress and inflammation have been shown to contribute to the loss of muscle strength, and although melatonin has antioxidative and anti-inflammatory properties, the association between melatonin secretion and muscle strength remains unclear. METHODS: In this cross-sectional study of 760 community-based elderly individuals (mean age, 71.0 years), we measured overnight urinary 6-sulfatoxymelatonin excretion (UME) and grip strength and quadriceps strength. RESULTS: Median UME was 7.0 μg (interquartile range, 4.2-11.1), and mean grip and quadriceps strength were 27.5±8.4kg and 162.6±80.1 Nm, respectively. On dividing participants into quartiles by their UME level (lowest-highest UME, Q1-Q4), higher quartiles were significantly associated with increased grip strength and quadriceps strength (p for trend < .001, both). Multivariable analyses adjusted for potential confounders (age, gender, body mass index, smoking and drinking statuses, renal function, hypertension, diabetes, physical activity, depressed mood, cognitive impairment, bedtime, sleep duration, and day length) revealed that both grip and quadriceps strength were significantly increased in Q4 compared with that in Q1 (adjusted mean difference, Q4 - Q1: grip strength, 1.5kg; 95% confidence interval [CI], 0.4-2.6kg; p = .006; quadriceps strength, 14.2 Nm; 95% CI, 1.3-27.1 Nm; p = .031). CONCLUSIONS: Melatonin secretion was significantly associated with muscle strength in this elderly population. Further longitudinal studies are needed to ascertain the effect of melatonin levels on muscle strength.
BACKGROUND: Decreased muscle strength is associated with functional limitation and disability and is a predictor of cardiovascular and all-cause mortality. Recently, oxidative stress and inflammation have been shown to contribute to the loss of muscle strength, and although melatonin has antioxidative and anti-inflammatory properties, the association between melatonin secretion and muscle strength remains unclear. METHODS: In this cross-sectional study of 760 community-based elderly individuals (mean age, 71.0 years), we measured overnight urinary 6-sulfatoxymelatonin excretion (UME) and grip strength and quadriceps strength. RESULTS: Median UME was 7.0 μg (interquartile range, 4.2-11.1), and mean grip and quadriceps strength were 27.5±8.4kg and 162.6±80.1 Nm, respectively. On dividing participants into quartiles by their UME level (lowest-highest UME, Q1-Q4), higher quartiles were significantly associated with increased grip strength and quadriceps strength (p for trend < .001, both). Multivariable analyses adjusted for potential confounders (age, gender, body mass index, smoking and drinking statuses, renal function, hypertension, diabetes, physical activity, depressed mood, cognitive impairment, bedtime, sleep duration, and day length) revealed that both grip and quadriceps strength were significantly increased in Q4 compared with that in Q1 (adjusted mean difference, Q4 - Q1: grip strength, 1.5kg; 95% confidence interval [CI], 0.4-2.6kg; p = .006; quadriceps strength, 14.2 Nm; 95% CI, 1.3-27.1 Nm; p = .031). CONCLUSIONS:Melatonin secretion was significantly associated with muscle strength in this elderly population. Further longitudinal studies are needed to ascertain the effect of melatonin levels on muscle strength.
Authors: Elizabeth E Devore; Stephanie L Harrison; Katie L Stone; Kathleen F Holton; Elizabeth Barrett-Connor; Sonia Ancoli-Israel; Kristine Yaffe; Kristine Ensrud; Peggy M Cawthon; Susan Redline; Eric Orwoll; Eva S Schernhammer Journal: Sleep Med Date: 2016-08-04 Impact factor: 3.492
Authors: Pere Barceló; Cristina Nicolau; Antoni Gamundí; Maria A Fiol; Jesús A F Tresguerres; Mourad Akaârir; Rubén V Rial Journal: Oxid Med Cell Longev Date: 2016-12-05 Impact factor: 6.543