Potential roles of pentosidine in age-related and disease-related impairment of pulmonary functions in patients with asthma.

Background: Pentosidine is well established as an intermolecular cross-linking type of advanced glycation end products, and it accumulates with aging in various connective tissues. Objective: To determine whether pentosidine contributes to age-related and disease-related impairment of pulmonary functions in patients with asthma. Methods: We measured pentosidine levels in induced sputum from young to elderly patients with asthma and assessed the slope of the nitrogen (N₂) alveolar plateau (delta N₂), closing volume (CV), and closing capacity (CC) from a nitrogen washout curve in a single breath. Results: Pentosidine levels in induced sputum were significantly higher in patients with asthma than in normal controls (patients with asthma: median, 20.1, interquartile range, 16.7-26.5 ng/mL; normal controls: median, 3.0, interquartile range, 0.7-7.5 ng/mL; P < .001). The levels were closely correlated with age in both normal controls and patients with asthma. However, the slope of age-related increase in pentosidine levels was markedly steeper in patients with asthma than in normal controls. CV/vital capacity, CC/total lung capacity, and delta N₂ increased with aging in both normal controls and patients with asthma. Moreover, in each range of age (21-40, 41-60, 61-80 years), CV/vital capacity, CC/total lung capacity, and delta N₂ were significantly higher in patients with asthma than in normal controls. In addition, pentosidine levels in patients with asthma were closely correlated with each of these variables. Conclusion: Our results demonstrated the association between sputum levels of pentosidine and age-related small airways function in both normal controls and patients with asthma. Moreover, the age-related increase in pentosidine levels was more pronounced in patients with asthma. These findings will herald new era in the pathophysiology of elderly asthma. [ABSTRACT FROM AUTHOR]