Effects of regular exercise and carnosine on muscle energy metabolism and cognitive performance in the overweight elderly population
J. Ukropec Diabetologia (2021) 64 (Suppl 1):S55
Background and aims: Sedentary ageing accelerates decline of
metabolic health and cognitive reserve, while regular exercise
effectively supports metabolic and cognitive health in ageing population. Here we tested the hypothesis that carnosine, a dipeptide
with the physiological function in skeletal muscle and brain,
enhances the adaptive response to regular exercise in the elderly
at the level of whole-body and muscle energy metabolism, physical
fitness and cognitive performance.
Materials and methods: Glucose tolerance (oral glucose tolerance
test), metabolic flexibility (ΔRQ) & insulin sensitivity (euglycemic
hyperinsulinemic clamp/EHC & indirect calorimetry), resting energy expenditure & metabolic substrate preference (indirect calorimetry), body composition (bioelectrical impedance), physical fitness
(Rockport 1 mile walk test, VO2max; sit-to-stand test) and cognitive functions (ACE-R, computerized CogState) were assessed.
Bergström needle biopsy of m. vastus lateralis was performed.
Oxygen consumption rate (pmol/s/mg tissue wet weight) was evaluated in saponin-permeabilized muscle fibers by O2k highresolution respirometry (Oroboros). Sixty sedentary (BMI 27.1
±3.9kg/m2) elderly volunteers (age 66.9±1.2yrs, MMSE score
28.2±1.2) were subjected to either 3-month supervised aerobic strength training (3x1h/week) (n=36) or stretching exercise training
(n=24, active controls). Half of the individuals in each intervention
group were randomized to take oral carnosine (2g/day), or placebo.
RM-2-way ANOVA and paired T-test was used.
Results: Training intervention combined with carnosine improved
performance in sit-to-stand test (9.2%, p<0.05), metabolic flexibility (ΔRQ 7.3%, p<0.05) and aerobic fitness (VO2max 14.8%,
p<0.05). Combination of exercise with carnosine has been more
effective in stimulating coupled mitochondrial respiration rate in
permeabilized muscle fibers, as compared to exercise alone
(36.5%, p<0.01). Addenbrooke's cognitive examination (ACE-R)
score correlated positively with lean body mass and muscle
strength and the training-induced change in ACE-R memory subscore correlated with concurrent change of lean body mass.
Metabolic flexibility (capacity to increase RQ during EHC) correlated positively with short term memory and executive functions
(CogState score).