Ramadan fasting influences respiratory sarcopenia and plasma markers of neuromuscular junction health in older adults.

PURPOSE: Fasting during Ramadan affects physical performance and age-associated muscle decline, termed sarcopenia. However, the relevant effects on respiratory sarcopenia and neuromuscular junction (NMJ) degradation are unknown.

METHODS

We recruited older men (age = 60.4 ± 3.6 years, n = 53) and women (age = 62.6 ± 2.9 years, n = 48) for measurements of respiratory sarcopenia markers, including maximal expiratory pressure (MEP) and peak expiratory flow rate (PEFR). We also measured plasma markers of NMJ (c-terminal agrin fragment-22; CAF22) and neuronal (neurofilament light chain; NfL and brain-derived neurotrophic factor; BDNF) health. All assessments were performed one week before Ramadan (Pre-Ramadan; Pre-R) and on days 14 and 28 into Ramadan.

RESULTS

At day 28, men had lower MEP than pre-R (p < 0.05). Both men and women exhibited lower plasma CAF22 and NfL and higher BDNF at day 28 compared to pre-R (all p < 0.05). The presence of respiratory sarcopenia was associated with higher CAF22 and NfL and lower BDNF in both sexes at various time points (all p < 0.05). Multivariate regression analysis revealed significant associations of MEP and PEFR with CAF22, NfL, and BDNF in both sexes at various time points (all p < 0.05). Ramadan fasting also reduced systemic oxidative stress without affecting physical performance.

CONCLUSION

Ramadan fasting induces respiratory sarcopenia in men but not in women by adversely affecting the NMJ and nervous system. Further investigations are warranted to dissect underlying mechanisms.