Sleep apnea and gastroesophageal reflux: a study with esophageal pH monitoring and polysomnography

SLEEP APNEA AND GASTROESOPHAGEAL REFLUX: A STUDY WITH ESOPHAGEAL pH MONITORING AND POLYSOMNOGRAPHY (ABSTRACT)^*. THESIS. PORTO ALEGRE, 1999.

JOSÉ VICENTE NORONHA SPOLIDORO^**

Objective: To access the association between gastroesofageal reflux (GER) and sleep apnea of infancy.

Patients and Methods: Study 1 ¾ Infants (1 to 6 months old) were studied by esophageal pH monitoring and divided in 3 groups: APNEA (n=39) with history of sleep apnea of infancy; RESPIRATORY (n=59) with respiratory symptoms without history of sleep apnea of infancy; DIGESTIVE (n=14) without history of respiratory symptoms or sleep apnea of infancy. In the next step, the groups RESPIRATORY and DIGESTIVE were combined to compare esophageal pH monitoring between infants with and without sleep apnea of infancy. Study 2 ¾ 23 infants from the APNEA group undertook polysomnography simultaneously with esophageal pH monitoring. They were divided in 2 groups by the ZMD index (G1 <4.4 min/episode and G2 >4.4 min/episode). The ZMD index is the total time with esophageal pH below 4.0 during sleep time in late post-prandial time (more than two hours after feeding) divided by the number of reflux episodes during this same period of time, which means the average duration of reflux episodes during sleep at late post-prandial time. Tuttle test was done to see whether gastric acid stimulation could differentiate those infants with sleep apnea of infancy associated to the GER. The Tuttle test is the 3 hours of esophageal pH monitoring post gastric injection of 300 cc/1,73m² of 0.1N hydrochloric acid by nasogastric tube.

Results: Study 1 ¾ The esophageal pH monitoring study of patients from the APNEA group had higher ZMD (p=0.011), reflux index (p=0.003) and number of episodes >5 minutes (p=0.001) than the RESPIRATORY group. As the DIGESTIVE group had few patients and the results were very similar to the RESPIRATORY group, they were put together, and became the NON-APNEA group. Comparing infants from the APNEA and NON-APNEA groups, their median (P25-P75) were respectively: ZMD 4.3 min/episode (1.1-7.1) vs 1.25 min/episode (0.5-2.75), p=0.003; reflux index 9,.2% (5.2-14.8) vs 4.1% (2.2-7,7), p=0.001; number of episodes >5 minutes 31 (15-49) vs 10 (6-21), p=0.001. Multivariate analysis showed that infants with ZMD index >4.4 had 4.5 times more chance to develop sleep apnea (p=0.002), independent of age in months. Study 2 ¾ G1 8.98 apneas/h (5.45-14.86) vs13.08 apneas/h (7.92-21.43), p=0.085. The number of obstructive, mixed and central apneas were similar between the two groups. Apnea index (AI) (number of apneas/hour) was higher before Tuttle test (10.7 apneas/h [6.4-16.4]) than after (9.8 apnéias/h [4.4-14.0]), p=0.101. Comparing Tuttle test with esophageal pH study of 18-24h, the Pearson coeficient for reflux index was not significant (p=0.647).

Conclusion: 1) Infants with sleep apnea had more gastroesophageal reflux at sleep time (ZMD), higher reflux index and higher number of episodes longer than 5 minutes, than infants without history of sleep apnea. 2) Infants with long episodes of reflux during sleep time had 4.5 times more chance to have sleep apnea. 3) Apnea index was higher in infants with higher ZMD, what was clinically relevant but not statistically significant. 4) Tuttle test did not help to identify infants with association of sleep apnea of infancy and gastroesophageal reflux.

KEYWORDS: sleep apnea of infancy, gastroesophageal reflux, esophageal pH monitoring, polysomnography, ZMD, Tuttle test, infant.

** Address: Centro Clínico da PUCRS, Avenida Ipiranga 6690 / 715, 90610-000 Porto Alegre RS, Brasil.

*

Apnéia do sono e refluxo gastroesofágico: avaliação por pHmetria esofágica e polissonografia (Resumo). Dissertação/Tese de Mestrado, Faculdade de Medicina da PUCRS - Pontifícia Universidade Católica do Rio Grande do Sul (Área: Pediatria). Orientador: Jaderson Costa da Costa.

Publication Dates

• Publication in this collection
  03 Apr 2000
• Date of issue
  Dec 1999