Inter and Intra-Rater Reliability of Short-Term Measurement of Heart Rate Variability on Rest in Diabetic Type 2 Patients.

Heart rate variability (HRV) among other methods can be used to assess diabetic cardiac autonomic neuropathy by cardiac intervals were recorded. However, the amount of error depending on this measurement methodology is unclear. To evaluate the intra- and inter-rater reliability to calculate HRV indices, comparing different times and by different trained examiners in patients with type 2 diabetes mellitus (T2DM). Thirty individuals of both genders, aged between 18 and 45 years, with T2DM. The RR interval (RRi) were recorded during a 10 min period on supine position using a portable heart rate monitor (Polar® S810i model). HRV indices were calculated by the software Kubios® HRV analysis (version 2.2). Linear (Mean RRi; STD RR; Mean HR; rMSSD; RR Tri; TINN LF; HF; total power) and non-linear (SD1; SD2; DFα1; DFα2, ApEn and, SampEn) indices were calculated by two examiners with an interval of one week between them. Substantial to excellent was found for reliability of the intra-examiner, with intraclass correlation coefficient (ICC) values ranging from 0.79 to 0.99, standard error of measurement (SEM) between 0.02 and 123.49 (in percentage: 1.83 and 16.67), and minimum detectable change (MDC) between 0.07 and 342.30. Regarding the inter-examiner reliability, substantial to excellent reliability was found, with ICC values ranging from 0.73 to 0.97, SEM between 0.04 and 178.13 (in percentage: 3.26 and 24.18), and MDC between 0.11 and 493.77. The use of the portable heart rate monitor to measure HRV showed acceptable intra and inter reliability in individuals with T2DM, supporting the use of this method of evaluation in research and clinical practice.