Type 2 diabetes mellitus is associated with a decrease in heart rate variability (HRV), as well as a decrease in both parasympathetic and sympathetic activity, which results from the harmful effects of altered glucose metabolism and leads to cardiac autonomic neuropathy, according to a systematic review and meta-analysis published in PLOS One.
The review and meta-analysis ultimately included 25 studies with a total of 2932 individuals, 1576 healthy controls and 1356 with type 2 diabetes. Researchers searched the terms “diabetes” AND “HRV” OR “heart rate variability” in Cochrane Library, Embase, PubMed, and Science Direct, finding 3927 articles.
Results were narrowed by eliminating all articles without HRV data measured over 24 hours, a case/control design, or participants with type 2 diabetes. Included studies also had to limit participation to individuals older than 18 years.
The primary findings determined that individuals with type 2 diabetes showed a significant decrease in HRV, along with decreases in both parasympathetic and sympathetic activity compared with healthy controls. The decrease in parasympathetic and sympathetic activity can be explained by the harmful effect of altered blood glucose levels on HRV.
High blood pressure and dyslipidemia were both associated with decreased HRV in individuals with type 2 diabetes, and male gender and age were associated with decreases in both parasympathetic and sympathetic activity.
Investigators conclude that “[the] benefits of an HRV evaluation in assessing and monitoring the severity of [type 2 diabetes] should be further studied, given its potential as a non-invasive, reliable and pain-free measurement.”
Benichou T, Pereira B, Mermillod M, et al. Heart rate variability in type 2 diabetes mellitus: a systematic review and meta–analysis [published online April 2, 2018]. PLoS One. doi: 10.1371/journal.pone.0195166