Muscle Strength and Muscle Mass in Older Patients during Hospitalization: The EMPOWER Study.

BACKGROUND: Low muscle strength and muscle mass are associated with an increased length of hospital stay and higher mortality rate in inpatients. To what extent hospitalization affects muscle strength and muscle mass is unclear. OBJECTIVE: We aimed to assess muscle strength and muscle mass at admission and during hospitalization in older patients and its relation with being at risk of geriatric conditions. METHODS: The EMPOWER study included patients aged 70 years and older, admitted to 4 wards of the VU University Medical Center in the Netherlands between April and December 2015. At admission, patients were screened for being at risk of 4 geriatric conditions: delirium, falls, malnutrition, and functional disability. At admission and at discharge, muscle strength and muscle mass were assessed. RESULTS: A total of 373 patients (mean age, standard deviation [SD]: 79.6, 6.38 years) were included at admission, and 224 patients (mean age, SD: 80.1, 6.32 years) at discharge. At admission, lower muscle strength in both female and male patients and low muscle mass in male patients were associated with being at risk of a higher cumulative number of geriatric conditions. Muscle strength increased during hospitalization, but no change in muscle mass was observed. Changes in muscle measures were not associated with being at risk of geriatric conditions. DISCUSSION: Older patients with lower muscle strength and muscle mass at admission were at risk of a higher cumulative number of geriatric conditions. However, being at risk of geriatric conditions did not forecast further decrease in muscle strength and muscle mass during hospitalization.

Change in muscle strength and muscle mass in older hospitalized patients: A systematic review and meta-analysis.

Hospitalization may induce a decrease of muscle strength and muscle mass in older patients due to physical inactivity, malnutrition and diseases, negatively affecting health outcome. We aimed to examine the literature on change in muscle strength and muscle mass in older patients during hospitalization. A literature search was performed in major electronic databases from inception to March 2016. Studies including hospitalized patients with a mean age≥65years, describing change of hand grip strength and/or muscle mass were found eligible. Extracted data were divided in hand grip strength or muscle mass and stratified by elective or acute admission. Meta-analysis was conducted using Comprehensive Meta-analysis. Twenty-five studies were included, describing a total of 1789 patients with a mean age range of 65 to 85.8years and an overall median length of stay of 14.7days. Pooled hand grip strength and muscle mass were found to significantly decrease in electively admitted older patients during hospitalization (standardized mean difference (95% confidence interval): -0.42 (-0.66, -0.17) and -0.44 (-0.61, -0.27)), but not in acutely admitted older patients (standardized mean difference (95% confidence interval): 0.18 (-0.02, 0.37) and -0.25 (-0.58, 0.09)). In conclusion, decrease in muscle strength and muscle mass in older patients is dependent on the type of admission.

D-amino acid aberrations in cerebrospinal fluid and plasma of smokers.

The glutamatergic neurotransmission system and the N-methyl-D-aspartate receptor (NMDAR) have been implicated in smoking and alcohol consumption behavior. Preclinical studies have demonstrated that nicotine and ethanol influence NMDAR functionality, which may have a role in tendencies to consume these substances. Nonetheless, little is known about concentrations of NMDAR coagonists in the cerebrospinal fluid (CSF) and plasma of individuals who smoke or consume alcohol. Glycine and L- and D-stereoisomers of alanine, serine, and proline were therefore measured using ultra-high-performance liquid chromatography-tandem mass spectrometry in 403 healthy subjects. Nicotine and alcohol consumption were quantified using questionnaires. Possible differences in NMDAR coagonist concentrations in plasma and CSF were investigated using ANCOVA with age, body mass index, and storage duration as covariates. The significance threshold was Bonferroni corrected (α=0.00625). Compared with non-smokers, smokers displayed lower levels of D-proline in plasma (p=0.0027, Cohen's d=-0.41) and D-proline in CSF (p=0.0026, Cohen's d=-0.43). D-Serine in CSF was higher in smokers than in non-smokers (p=0.0052, Cohen's d=0.41). After subdividing participants based on smoking quantity, dose-dependent decreases were demonstrated in smokers for D-proline in plasma (F=5.65, p=0.0039) and D-proline in CSF (F=5.20, p=0.0060). No differences in NMDAR coagonist levels between alcohol consumption groups were detected. To our knowledge, this is the first report to implicate D-amino acids in smoking behavior of humans. Whether such concentration differences lie at the root of or result from smoking habits may be addressed in prospective studies.