Cholinergic Modulation in Elderly Asthmatic Patients Compared to Young Asthmatic and Elderly Non-Asthmatic Patients.
Monday, March 7, 2016
South Exhibit Hall H (Convention Center)
Marie-Eve Boulay, MSc, Francine Deschesnes, BSc, Paul Poirier, MD, PhD, Louis-Philippe Boulet, MD
Rationale:   An increased parasympathetic activity may play a modulatory role in the pathogenesis of bronchial asthma. Early reports suggest a better effect of anticholinergic agents in elderly asthmatics. However, neurogenic influences have not been assessed in this population. Aim: To compare measures of cholinergic modulation in elderly (EA) and young (YA) asthmatic patients and in elderly non asthmatic (ENA) patients. Methods: Twenty-two elderly (>60 years old; 10 EA and 12 ENA) and 15 younger (range 18 to 35 years) asthmatic patients had pulmonary function measurements and a 24h ECG Holter monitoring. Heart rate variability (HRV) was calculated during 3 time periods: 1) 24 hours, 2) daytime (between 8 AM and 8 PM) and 3) nighttime (between 12 AM and 6 AM). High frequency (HF) domain, the square root of the mean squared differences of successive RR intervals (rMSSD) and the proportion of interval differences of successive mean RR intervals >50 ms (pNN50) were calculated and used as parasympathetic activity indices. Results: Asthmatic patients showed similar asthma severity and maintenance therapy needs. EA had more marked airway obstruction (FEV1/FVC, P=0.03). Heart rate was higher in YA than EA (P=0.002) and in all 3 groups during daytime compared to nighttime (P <0.001). This was associated with higher parasympathetic indices during nighttime (rMSSD, pNN50) in YA (P =0.002 and P =0.0003, respectively) and ENA (P =0.01 and P =0.05, respectively). Conclusions: Elderly asthmatics have increased daytime parasympathetic activity. This may contribute to the lower pulmonary function observed in this population.