written by Jess G. Fiedorowicz, Editor-in-Chief, Journal of Psychosomatic Research, May 2019
Psychological Stress and Proteinuria in Children with Nephrotic Syndrome
I’m excited to announce a small but novel study as Editor’s Choice for this quarter’s newsletter of the European Association of Psychosomatic Medicine. Of the many deserving papers that were considered, “A longitudinal study on the effects of psychological stress on proteinuria in childhood steroid-sensitive nephrotic syndrome” by Lianne Bakkum, Agnes Maresa Willemen, Lydia Zoetebier, and Antonio Bouts best piqued my interest with their unique study design and findings that discerned temporal relations between stress and proteinuria in children with nephrotic syndrome . These collaborators from Cambridge UK and Amsterdam, The Netherlands concisely summarize their findings as follows:
Steroid-sensitive nephrotic syndrome (SSNS) in children is often complicated by relapses, as manifested by proteinuria. Besides health-related triggers, stress might be associated with relapse. In a longitudinal study, we examined the relation between children’s subjective stress, stressful events, and proteinuria. Using online diaries (for an average of 124 days), 16 children with SSNS reported daily proteinuria and subjective stress. Stressful days were determined at the start of the study. Perceived stress significantly predicted higher proteinuria; even five days later, and proteinuria was higher on stressful days. While preliminary, our findings suggest that stress may trigger proteinuria in childhood SSNS.
This study was unique in identifying stressful days in advance, mitigating any bias from reporting stressful days after the fact, perhaps influenced by urine results. The study used a high intensity follow-up with daily diaries and proteinuria measures over an average of 124 days to discern the temporal relation between stress and proteinuria. Identified stressful days could include negative or positive events, such as a birthday. Using lagged analyses, they found significant elevations in proteinuria beginning a day before and extending up to five days after stressful events. Moderate effects were observed on the same day and the day following these events with smaller but still significant effects for the day before and from two to five days later. Interestingly, the emotional valence of the stress did not bear on the results. As I noted in a recent editorial, “This innovative study design provided important information on the temporal relationships between stress and proteinuria in this condition, highlighting a role for anticipatory anxiety while also confirming the relevance of both positive (e.g., birthdays) and negative stress .”
The innovative work of Bakkum et al. was also discussed in an editorial by Federica Picariello, Joseph Chilcot, and Joanna Hudson of King’s College London . They identified this study as the first to proactively assess the relation between stress and SSNS using an intensive prospective design. They also highlighted the focus on children, which introduces several challenges, and kidney disease, which is relatively underrepresented in the stress literature. Picariello et al. cite a definition of stress as “any stimulus or situation that disrupts homeostatic balance.” This can include positive events, such as birthdays, which were included in the analysis of Bakkum et al. Elucidating the timeline for the effects of stress, which includes stress related to anticipatory anxiety, can allow for targeted stress-management interventions for those with SSNS. While the editorial was largely laudatory, the writers did note issues related to missing data and parental reporting. They identify opportunities for future studies using a related designs to address these gaps.
The Journal of Psychosomatic Research is very interested in any such longitudinal studies. We even have a special issue on “Intensive longitudinal research methods in psychosomatic research” led by guest editors Eva Ceulemans and Judith Rosmalen. This special issue will focus on novel measurement approaches in daily life, including ecological momentary assessments, and innovative analytical methodologies, such as time series analyses and network models. For more information on this special issue, please visit https://www.journals.elsevier.com/journal-of-psychosomatic-research/call-for-papers/special-issue-call-for-papers-time-series-methods.
References: L. Bakkum, A.M. Willemen, L. Zoetebier, A.H. Bouts, A longitudinal study on the effects of psychological stress on proteinuria in childhood steroid-sensitive nephrotic syndrome, J Psychosom Res (2019).  J.G. Fiedorowicz, Integrating psychosomatic care across settings and specialties, J Psychosom Res (2019).  F. Picariello, J. Chilcot, J.L. Hudson, Re: Bakkum et al. “Effects of psychological stress on proteinuria in childhood steroid-sensitive nephrotic syndrome”, J Psychosom Res (2019).