Relationship between nonrestorative sleep and heartburn among a Japanese occupational population

Background Nonrestorative sleep (NRS) is a symptom of insomnia and is clearly more associated with objective indices than other insomnia symptoms. Gastroesophageal reflux disease (GERD) and insomnia are known to be strongly related. However, the link between NRS and heartburn, a main symptom of GERD, is poorly understood. Therefore, the relationships between them were investigated in addition to sleep duration. Methods The results of a single year’s medical examinations were investigated for 29,475 Japanese active office workers who were 20 to 59 years old. NRS and heartburn were investigated in a medical interview using a personal computer. The relationships between NRS and heartburn in addition to sleep duration were also analyzed. Results The subjects were 46.6 ± 8.7 years old (mean ± SD) and 27% and 13% of them had NRS and heartburn, respectively. The presence of NRS together with a sleep duration of ≤ 5, 6, 7 or ≥ 8 hours was an independent comorbid factor for heartburn compared with the absence of NRS together with a sleep duration of seven hours (reference; odds ratio [OR], 2.38; 95% confidence interval [CI], 2.11–2.69, OR, 2.44; 95% CI, 2.16–2.76, OR, 2.33; 95% CI, 1.94–2.79; and OR, 1.72; 95% CI, 1.14–2.52). The absence of NRS together with a sleep duration of ≤ 5 hours was also an independent comorbid factor for heartburn compared with the reference (OR, 1.20; 95% CI, 1.05–1.37). Conclusions NRS in active workers may contribute to heartburn comorbidity despite the sleep duration as in other workers without NRS.