Reduced Heart Rate Variability in Patients With Medically Unexplained Physical Symptoms: A Meta-Analysis of HF-HRV and RMSSD

Psychosomatic Medicine, vol. 83, pp. 2–15

Abstract

OBJECTIVE: Medically unexplained physical symptoms (MUPS) and related syndromes are common and place a substantial burden on both patients and society. Chronic psychological distress and dysregulation of the autonomic nervous system may be common factors associated with MUPS, although previous studies have reported mixed results. The aims of this meta-analysis are to provide an updated synthesis of studies investigating heart rate variability (HRV) indices associated with autonomic nervous system functioning in three common MUPS syndromes and to explain inconsistencies in previous study findings. METHODS: Literature search yielded 58 studies comparing HRV indices of reduced parasympathetic activity of healthy individuals with those of patients with chronic fatigue syndrome (npatients = 271), irritable bowel syndrome (npatients = 1005), and fibromyalgia (npatients = 534). Separate random-effects meta-analyses were conducted on studies measuring root mean square of successive differences (RMSSD) and high-frequency HRV (HF-HRV). RESULTS: Regardless of syndrome type, patients had significantly lower RMSSD (k = 22, Hedges g = -0.37 [-0.53 to -0.21], p < .001) and HF-HRV (k = 52, Hedges g = -0.69 [-1.03 to -0.36], p < .001) than did healthy individuals. Sample age and publication year explained a substantial variation in RMSSD, whereas controlling for confounders in statistical analyses explained variation in HF-HRV. CONCLUSIONS: Lower RMSSD and HF-HRV in patients with MUPS versus healthy controls indicates that autonomic nervous system dysregulation, particularly lower parasympathetic activity, may play a role in patients with these conditions. This conclusion may have important implications for the underlying mechanisms and treatment of MUPS and related syndromes.

Authors 3

1. Sarah R. Vreijling corresponding Aachen Dept of Health and Medical Psychology Institute of Psychology, Leiden University

   Leiden University · Amsterdam University Medical Centers

   Affiliation as printed

   From the Department of Health and Medical Psychology, Institute of Psychology, Leiden University, the Netherlands

   Supplemental Content

   [email protected]

   the Department of Health and Medical Psychology, Institute of Psychology, Leiden University, the Netherlands

   to Sarah R. Vreijling, Msc, Department of Psychiatry, Amsterdam UMC/VUmc, Oldenaller 1, 1081 HJ, Amsterdam, the Netherlands. E-mail: [email protected]

2. Yael Troudart Aachen Dept of Health and Medical Psychology Institute of Psychology, Leiden University

   Leiden University

   Affiliation as printed

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   the Department of Health and Medical Psychology, Institute of Psychology, Leiden University, the Netherlands

3. JOS F. BROSSCHOT Aachen Dept of Health and Medical Psychology Institute of Psychology, Leiden University

   Leiden University

   Affiliation as printed

   Supplemental Content

   the Department of Health and Medical Psychology, Institute of Psychology, Leiden University, the Netherlands