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

Abstract

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.