Preoperative Yoga Lowers Noradrenaline Levels in Severe Obesity Patients Awaiting Bariatric Surgery
Structured yoga practice during the three months leading up to bariatric surgery is associated with significantly lower plasma noradrenaline levels in patients with severe obesity, according to a prospective observational study published in Frontiers in Public Health. Researchers in Milan, Italy, evaluated 40 adult surgical candidates to determine whether a targeted mind-body intervention could influence stress-related hormones and gene activity before operations, News-Medical reported. While the intervention reduced sympathetic nervous system activation, it did not produce statistically significant changes in DNA methylation across three targeted inflammatory genes.
Study Design and Patient Enrollment in Milan
The research was conducted at a clinical center in Milan, Italy, where investigators initially enrolled 48 adults with severe obesity who met the criteria for bariatric surgery. Out of that initial group, 40 participants completed the protocol and were included in the final analysis. Participants were assigned to either a yoga intervention group of 20 individuals or a standard-care control group of 20 individuals based entirely on their willingness and availability to attend classes.
Participants in the yoga group were offered 36 supervised sessions of the PRANA_it yoga protocol over a three-month preoperative window. This schedule typically required attending three classes per week, with each session lasting between 45 and 60 minutes. Records show that intervention participants attended an average of 26 sessions. The protocol incorporated movement sequences, pranayama breath-control techniques, mantra recitation, and relaxation exercises, with physical modifications made for participants who experienced limited mobility.
Hormonal Findings and Physiological Markers
Following the three-month preoperative intervention and after adjusting for baseline measurements, researchers observed a notable physiological difference between the two groups. Plasma noradrenaline levels were significantly lower in the yoga group than in the control group. Data showed that noradrenaline levels fell modestly on average among yoga participants while rising in the standard-care controls. Investigators noted that this divergence aligns with reduced sympathetic nervous system activation, commonly known as the body’s fight-or-flight stress response.
Despite the hormonal shift, the study detected no statistically significant differences between the groups regarding preoperative weight loss or markers of glucose regulation and insulin resistance.
Targeted Epigenetic Analysis of Inflammatory Genes
The primary outcome of the study focused on DNA methylation changes within the promoter and transcription-start-site regions of three specific inflammatory genes: tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and C-reactive protein (CRP). Using targeted enzymatic methylation sequencing, researchers analyzed blood samples collected at predetermined time points throughout the prehabilitation period.
After accounting for multiple statistical comparisons, the analysis revealed no significant changes in DNA methylation at the targeted sites of these three genes. In unadjusted analyses, circulating TNF-alpha protein levels increased more in the yoga group, but this finding displayed high variability and did not establish an anti-inflammatory benefit.
Psychological Assessments and Physical Functioning
Investigators evaluated psychological health and physical capabilities using three validated questionnaires: the Short Form-36 Health Survey (SF-36), the Beck Depression Inventory-II (BDI-II), and the State-Trait Anxiety Inventory (STAI-Y). Evaluations of physical functioning indicated a greater average decline in self-reported SF-36 physical-functioning scores among yoga participants compared to controls.
Limitations and Future Research Directions
Study authors acknowledged several limitations that restricted broader clinical conclusions. The non-randomized, single-center design left the analysis susceptible to selection bias as well as unmeasured variables such as physical activity levels outside the studio, medication use, and individual lifestyle factors. Furthermore, the short intervention window, small sample size, and exclusive reliance on blood samples may have constrained the ability to detect subtle methylation changes in target tissues.
Although the findings provide preliminary evidence linking structured yoga to lower noradrenaline levels in patients with severe obesity, randomized controlled trials featuring larger cohorts, extended follow-up periods, and comprehensive tissue sampling are required to verify these associations and determine whether hormonal shifts translate into tangible surgical benefits.
Frequently Asked Questions About the Obesity Yoga Study
How many patients participated in the final analysis of the Milan study?
Out of 48 adults initially enrolled at the clinical center in Milan, exactly 40 participants completed the protocol and were included in the final evaluation, divided equally with 20 individuals in the yoga group and 20 in the control group.
What specific yoga protocol was used during the three-month preoperative window?
Intervention participants were offered 36 supervised sessions of the PRANA_it yoga protocol, which included movement sequences, pranayama breath-control techniques, mantra recitation, and relaxation exercises adapted for limited mobility.
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