Attenuated fast heart rate recovery suggests delayed parasympathetic reactivation after cessation of exercise in uncomplicated type 1 diabetes patients

• Published in: Scientific reports Vol. 15; no. 1; pp. 24136 - 8
• Main Authors: Hyrylä, Vesa V., Eronen, Timo, Kupari, Saana, Venojärvi, Mika, Tikkanen, Heikki O., Tarvainen, Mika P.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 06.07.2025; Nature Publishing Group; Nature Portfolio
• Subjects: 639/166/985; 692/163/2743/137/1418; Adolescent; Adult; Blood pressure; Case-Control Studies; Chronic illnesses; CPET; Diabetes; Diabetes mellitus (insulin dependent); Diabetes Mellitus, Type 1 - physiopathology; Exercise - physiology; Exercise Test; Female; Glucose; Heart rate; Heart Rate - physiology; Heart rate recovery; Humanities and Social Sciences; Humans; Hypertension; Male; Maximum oxygen consumption; multidisciplinary; Nervous system; Neuropathy; Parasympathetic nervous system; Parasympathetic Nervous System - physiopathology; Parasympathetic reactivation; Science; Science (multidisciplinary); T30HRR; Vagus nerve; Young Adult; Germany; T30; CPET; Diabetes; Heart rate recovery; Neuropathy; Parasympathetic reactivation; T30HRR
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-025-09287-2

Heart rate recovery (HRR) and fast HRR, believed to reflect parasympathetic reactivation, have been recognized as powerful predictors of all-cause mortality. In this study we propose a modified fast HRR parameter T30 HRR and investigate if otherwise healthy subjects with type 1 diabetes (T1D) have attenuated HRR. Eighteen T1D subjects (T1D = 15 ± 7 years, HbA1c = 58 ± 0.8 mmol/mol) and thirty-five healthy matched control subjects underwent maximal cardiopulmonary exercise test. After cessation of exercise T30, T30 HRR and monoexponential decay as well as HRR at 10, 20, 30, 60, 120 and 300 s were assessed. The T1D subjects had diminished HRR described by T30 HRR (12.6 ± 3.9 bpm vs. 16.4 ± 4.3 bpm, p  = 0.013), T30 (520 ± 263 s vs. 361 ± 133 s, p  = 0.022), HRR 20 (9.2 ± 3.5 vs. 11.6 ± 3.1 bpm, p  = 0.046), HRR 30 (13.0 ± 4.5 bpm vs. 16.3 ± 4.2 bpm, p  = 0.035) and HRR 60 (23.0 ± 6.8 bpm vs. 28.4 ± 7.1 bpm, p  = 0.041) when compared to the control subjects. Subjects with T1D exhibited attenuated fast HRR suggesting that vagal reactivation may be diminished, and exercise may unmask subclinical symptoms in otherwise healthy T1D subjects.