Endocrine Abstracts

This systematic review examined slow breathing as a non-pharmacological adjuvant intervention to improve autonomic function in individuals with Type 1 and Type 2 Diabetes Mellitus. We searched 6 databases (MEDLINE, PsychINFO, CINAHL, EMBASE, Web of Science, Scopus) up to October 9th 2024. Eligible studies included RCTs, non-randomised controlled trials (NRCT), before-and-after time series, and case-control studies involving adults with type 1 or type 2 diabetes undergoing slow breathing interventions (<10 breaths/minute) with or without HRV biofeedback. Extracted data covered intervention characteristics, population, comparator and outcomes. Methodological quality was assessed using Cochrane and JBI risk-of-bias tools. A systematic search identified 6,641 articles, of which 125 underwent full-text review and 7 reported autonomic outcomes. 2 studies evaluated patients with T1DM, 4 focused on T2DM, and 1 included both. Interventions ranged from single-session experiments (4) to programmes with long-term interventions up to 8 weeks (3). Across single session interventions, heart rate variability (HRV) and baroreceptor sensitivity (BRS) consistently improved during slow breathing, attenuating baseline differences vs. healthy controls. While these findings suggest autonomic dysfunction may be temporarily reversible, blunted responses in a subgroup with diabetic kidney disease, suggest limited reversibility with advanced disease. Among the three longitudinal studies, two demonstrated a significant increase in ≥ 1 HRV metric vs. standard care. The third, involving individuals with diabetic polyneuropathy, found no change, suggesting reduced responsiveness at advanced disease stages. These findings support the short-term autonomic benefits of slow breathing in uncomplicated diabetes; however, whether such modulation leads to long-term adaptation remains unclear.