Inactivity particularly damaging for hemodialysis patients
Being physically active is beneficial for everyone, but for hemodialysis patients it is a particularly important issue, say French researchers (Souweine JS et al, Physical inactivity and protein energy wasting play independent roles in muscle weakness in maintenance haemodialysis patients.
PLoS One. 2018; doi: 10.1371/journal.pone.0200061). It is already known that chronic hemodialysis patients with muscle weakness have an increased risk of mortality. The hypothesis of the French author team was that protein energy wasting (PEW) and low physical activity could impair muscle quality and contribute to muscle weakness beyond muscle wasting in these patients. The aim of their study was to assess clinical and biological parameters involved in the reduction of muscle strength of CHD patients.
The study encompassed 123 CHD patients with an average age of 68,8 years, in whom maximal voluntary force (MVF) of quadriceps and muscle quality (defined as the strength per unit of muscle mass) were evaluated. In addition, the authors estimated muscle mass using the lean tissue index (LTI) and skeletal muscle mass (SMM) by bioelectrical impedance analysis and creatinine index (CI). All participants filled out Voorrips questionnaires regarding physical activity. The criteria for the diagnosis of PEW were serum albumin, body mass index < 23 kg/m2, creatinine index < 18.82 mg/kg/d and low dietary protein intake estimated by nPCR < 0.80g/kg/d.
Thirty patients had dynapenia defined as impaired MVF, with maintained SMM, high hs-CRP (p = 0.001), PEW criteria (p<0.001) and low Voorrips score (p = 0.001), as well as reduced dialysis vintage (p<0.046). Only serum albumin, Voorrips score, and CI remained associated with muscle specific torque.
In CHD patients, physical inactivity and PEW together impair muscle strength and specific torque beyond atrophy. Both could be related to muscle quality, conclude the authors.
Link to the study: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0200061