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World J Gastroenterol. Jan 21, 2007; 13(3): 403-407
Published online Jan 21, 2007. doi: 10.3748/wjg.v13.i3.403
Environmental noise alters gastric myoelectrical activity: Effect of age
James S Castle, Jin-Hong Xing, Mark R Warner, Mark A Korsten
James S Castle, Jin-Hong Xing, Mark R Warner, Mark A Korsten, Medical Program and Audiology Service, James J Peters VA Medical Center, Bronx, NY and Mount Sinai School of Medicine, New York, United States
Author contributions: All authors contributed equally to the work.
Correspondence to: Mark A Korsten, MD, James J Peters VA Medical Center, 130 W. Kingsbridge Road, Bronx, New York 10468, United States. mark.korsten@med.va.gov
Telephone: +1-718-5849000-6753 Fax: +1-718-7414233
Received: October 20, 2006
Revised: November 5, 2006
Accepted: December 11, 2006
Published online: January 21, 2007
Abstract

AIM: To evaluate the effect of age and acoustic stress on gastric myoelectrical activity (GMA) and autonomic nervous system function.

METHODS: Twenty-one male subjects (age range 22-71 years, mean 44 years) were recruited and exposed, in random order, to three auditory stimuli (Hospital noise, conversation babble and traffic noise) after a 20-min baseline. All periods lasted 20 min and were interspersed with a 10 min of recovery. GMA was obtained using a Synectics Microdigitrapper. Autonomic nerve function was assessed by monitoring blood pressure and heart rate using an automatic recording device.

RESULTS: Dominant power tended to decrease with increase of age (P < 0.05). The overall percentage of three cycle per minute (CPM) activity decreased during exposure to hospital noise (12.0%, P < 0.05), traffic noise (13.9%, P < 0.05), and conversation babble (7.1%). The subjects in the younger group (< 50 years) showed a consistent reduction in the percentage of 3 CPM activity during hospital noise (22.9%, P < 0.05), traffic noise (19.0%, P < 0.05), and conversation babble (15.5%). These observations were accompanied by a significant increase in bradygastria: hospital noise (P < 0.05) and traffic noise (P < 0.05). In contrast, the subjects over 50 years of age did not exhibit a significant decrease in 3 CPM activity. Regardless of age, noise did not alter blood pressure or heart rate.

CONCLUSION: GMA changes with age. Loud noise can alter GMA, especially in younger individuals. Our data indicate that even short-term exposure to noise may alter the contractility of the stomach.

Keywords: Noise; Acoustic stress; Gastric myoelectrical activity; Electrogastrogram; Autonomic nervous system