EFFECT OF SMOKING ON THE RESULTS OF ESOPHAGEAL PH MEASUREMENT IN CLINICAL ROUTINE

Because data on the effects of smoking on gastroesophageal reflux are controversial, we evaluated the effect of smoking on the results of es ophageal 24-hour pH-metry in clinical routine. Participants were 280 c onsecutive patients with symptoms suggestive of reflux disease, 78 smo kers, and 202 nonsmokers. Of the smokers, 45 actually smoked during th e pH measurement and 33 abstained from smoking. The frequency of reflu x episodes, the fraction of time pH was <4, and the percentage of abno rmal 24-hour pH-metry results were compared among actual smokers, abst aining smokers, and nonsmokers. In actual smokers, the effect of smoki ng on gastroesophageal reflux was further analyzed by comparing the re flux frequency and the fraction of time that pH was <4 for a 10-minute period before, during, and after smoking. We found no difference in r eflux frequency and fraction of time that pH was <4 among actual smoke rs, abstaining smokers, and nonsmokers, regardless of a normal or an a bnormal pH-metry result. The percentage of patients with a pH-metry re sult indicating disease was similar in the three groups, at 5396, 52%, and 50%, respectively. Gastroesophageal reflux was not increased duri ng smoking a cigarette or in the postsmoking period compared with the presmoking period. Neither being a smoker nor actually smoking a cigar ette had a negative influence on gastroesophageal reflux. Thus smoking or abstaining from smoking does not modify the results of pH-metry in clinical routine.