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Table 2 Baseline characteristics of subjects

From: Response of the airways and autonomic nervous system to acid perfusion of the esophagus in patients with asthma: a laboratory study

  Asthmatics without reflux(n=20) Asthmatics with reflux( n= 20) All asthmatics (n=40)
Age, yrs 33.6 ± 1.9 34.9 ± 1.9 34.3 ± 1.3
Gender, (M:F) 9:11 6:14 15:25
BMI, (kg/m2) 20.6 ± 0.6 20.5 ± 0.7 20.5 ± 0.4
GERD symptom score (frequency x severity)* 22.0 ± 3.2 30.5 ± 4.6 26.2 ± 2.9
DeMeester score* 5.3 ± 0.9 44.2 ± 7.1 24.8 ± 4.7
Asthma severity* (no of subjects)    
 Mild intermittent 11 3 14
 Mild persistent 6 11 17
 Moderate or severe persistent 3 6 9
Asthma medication (no of subjects) - - -
 Oral salbutamol 10 13 23
 Inhaled salbutamol 6 7 13
 Oral theophylline 2 5 7
 Oral steroids 2 6 8
 Inhaled steroids 6 10 16
Spirometry results, mean ± SE    
 FVC (L) 3.3 ± 0.1 3.1 ± 0.1 3.2 ± 0.1
 FEV1 (L) 2.7 ± 0.1 2.6 ± 0.1 2.7 ± 0.1
 PEFR (L) 4.3 ± 0.2 4.1 ± 0.2 4.2 ± 0.1
Autonomic function testing results   1.1 ± 0.03 1.2 ± 0.02
HR ratio* 1.21 ± 0.04 1.1 ± 0.03 1.2 ± 0.02
HR difference 23.1 ± 1.8 23.1 ± 1.5 23.01 ± 1.2
Valsalva ratio 1.3 ± 0.1 1.2 ± 0.05 1.2 ± 0.04
  1. BMI Body Mass Index, GERD gastro-esophageal reflux disease, FVC Forced Vital Capacity, FEV 1 Forced Expiratory Volume in 1st second, PEFR Peak Expiratory Flow Rate.
  2. HR Ratio Heart rate ratio (30th beat/ 15th beat) on standing from supine position.
  3. HR difference Heart rate difference between inspiration and expiration during deep breathing at 6 cycles per minute.
  4. Valsalva ratio ratio of maximum heart rate during the valsalva maneuver to the maximum heart rate around the 20th beat after stopping the maneuver.
  5. All values mean ± SE unless specified otherwise.
  6. * P <0.05; asthmatics with reflux compared to asthmatics without reflux.