WATER INGESTION DYNAMICS IN PATIENTS WITH ACHALASIA: INFLUENCE OF SEX AND AGE.

BACKGROUND: Achalasia is a disease that affects esophageal bolus transit due to the absence of esophageal peristaltic contractions and impaired or absent relaxation of the lower esophageal sphincter.

OBJECTIVE: The objective of this investigation was: a) to evaluate the dynamics of water ingestion in patients with achalasia, idiopathic or caused by Chagas' disease; b) to evaluate the influence of sex and age on water ingestion dynamics.

METHODS: The investigation was conducted with 79 patients with achalasia (27 idiopathic and 52 Chagas' disease) and 91 healthy volunteers, all evaluated by the water-drinking test. The individuals drank, in triplicate, 50 mL of water without interruption. The time and the number of swallows for this task were counted. We also measured: (a) inter-swallow interval - the time to complete the task, divided by the number of swallows during the task; (b) swallowing rate - volume drunk divided by the time; (c) volume per swallow - volume drunk divided by the number of swallows.

RESULTS: Patients with achalasia took longer to ingest all the volume (mean 12.2 seconds) than healthy controls (mean 5.4 seconds), had greater number of swallows, longer interval between swallows, lower swallowing rate (5.2 mL/s vs 10.9 mL/s in controls) and lower volume per swallow (9.1 mL vs 14.4 mL in controls, P<0.01). Among healthy volunteers, women had a shorter interval between swallows and lower volume per swallow compared with men, and in the achalasia group, women had a longer interval between swallows and lower ingestion rate. No difference in the drinking test results was found between younger and older subjects in achalasia or control group. Also, no differences were observed between patients with Chagas' disease and those with idiopathic achalasia, or between patients with increased and normal esophageal diameter.

CONCLUSION: Patients with achalasia have difficulty in ingesting water, taking a longer time to complete the task, which is influenced by sex but not by age or severity of the disease.