Biol Res Nurs. 2023 Jun 23;10998004231186188. doi: 10.1177/10998004231186188.Online ahead of print.

Li Juen Chen ^1 2, Robert Burr ¹, Kevin Cain ³, Kendra Kamp ¹, Margaret Heitkemper ¹

Author information

¹Department of Biobehavioral Nursing and Health Informatics, School of Nursing, University of Washington, Seattle, WA, USA.

²UW Medicine Valley Medical Center, Renton, WA, USA.

³Center for Biomedical Statistics, University of Washington, Seattle, WA, USA.

Abstract

Background/aims: Patients with irritable bowel syndrome (IBS) often report upper gastrointestinal (GI) (e.g., nausea and heartburn), somatic, and emotional symptoms. This study seeks to examine the relationships among younger and older women with IBS and indicators of autonomic nervous system (ANS) function and daily nausea and heartburn symptoms.

Methods: Women were recruited through clinics and the community. Nocturnal heart rate variability (HRV) was obtained using ambulatory electrocardiogram Holter monitors. Individual symptom severity and frequency were collected using 28-day diaries. All variables were stratified by younger (<46 years) and older (≥46 years) age groups.

Results: Eighty-nine women with IBS were included in this descriptive correlation study (n = 57 younger; n = 32 older). Older women had reduced indices of vagal activity when compared to younger women. In older women, there was an inverse correlation between nausea and vagal measures (Ln RMSSD, r = -.41, p = .026; Ln pNN50, r = -.39, p = .034). Heartburn in older women was associated with sleepiness (r = .59, p < .001) and anger (r = .48, p = .006). Nausea was significantly correlated with anger in the younger group (r = .41, p = .001). There were no significant relationships between HRV indicators and nausea and heartburn in younger women.

Conclusions: Age-related differences in ANS function that are associated with nausea may portend unique opportunities to better understand the vagal dysregulation in women with IBS.