Cardiac autonomic dysfunctions in type 2 diabetes mellitus: an investigative study with heart rate variability measures

Anu Panackal Purackal John; Kaviraja Udupa; Santhosh Avangapur; Magadi Umeshchandra Sujan; Ganagarajan Inbaraj; Prathyusha Parthipulli Vasuki; Anita Mahadevan; Rudramunisetty Anilkumar; Mysore AnkeGowda Shekar; Talakad Narasappa Sathyaprabha

Cardiac autonomic dysfunctions in type 2 diabetes mellitus: an investigative study with heart rate variability measures

Am J Cardiovasc Dis. 2022 Aug 15;12(4):224-232. eCollection 2022.

Affiliations

¹ Department of Neurophysiology, National Institute of Mental Health and Neurosciences Bangalore, India.
² Current affiliations: Department of Yoga, JSS Academy of Higher Education & Research, Mysuru (Deemed to be University) India.
³ Department of Biostatistics, National Institute of Mental Health and Neurosciences Bangalore, India.
⁴ Department of Neuropathology, National Institute of Mental Health and Neurosciences Bangalore, India.
⁵ Karnataka Institute of Endocrinology and Research (KIER), Diabetology Bangalore, India.

PMID: 36147784
PMCID: PMC9490161

Abstract

Cardiac autonomic neuropathy (CAN) is a common yet underdiagnosed complication of Type 2 diabetes mellitus (T2DM). Heart rate variability (HRV), a sensitive diagnostic marker of cardiovascular risk, could help detect CAN at its earliest stage. However, the progression of CAN based on age and disease duration in T2DM is lacking. In this study, we propose to explore the occurrence of CAN in patients with varying stages and duration of T2DM. This cross-sectional study involves participants with T2DM (n = 160) and healthy volunteers (n = 40) with an age range of 30-60 years of both genders. Patients in the T2DM group were further subdivided into four subgroups based on their disease duration [Prediabetes, disease duration <5 yrs (D1), 5-10 yrs (D2), and >10 yrs (D3)]. All participants underwent short-term HRV recording for 20 minutes and analyzed for both time and frequency domain measures. The study results showed a significant increase in Heart Rate (HR) in D1 (P = 0.031) and D3 (P = 0.001) groups compared to healthy controls. The time-domain measures of HRV were significantly reduced in the T2DM group compared to the healthy controls. Furthermore, this reduction is more intense in the D3 group than in D2 and D1. Correspondingly, in frequency domain parameters: total power, high-frequency power, and low-frequency power were significantly reduced in all the T2DM groups compared to healthy controls. The study concludes that the overall HRV (as determined by total power), sympathetic activity (low frequency power) and parasympathetic activity (time domain measures and high frequency power) were significantly reduced in all the diabetic subgroups except prediabetes as compared to the healthy controls, implying that both sympathetic and parasympathetic limbs are symmetrically affected in T2DM patients even in the earliest stages (<5 yrs) implying subclinical cardiac autonomic dysfunction in the earliest stages.

Keywords: Autonomic nervous system; cardiac autonomic neuropathy; heart rate; heart rate variability; sympathetic and parasympathetic activity; type 2 diabetes mellitus.