Abstract

The aim of this study was to compare three methods for estimating biological age (BA) based on heart rate variability (HRV) indices recorded in the supine position: multiple linear regression (MLR), MLR corrected for regression-to-the-mean bias using the Dubina method (1984), and the Klemera-Doubal Method (KDM, 2006). A total of 343 subjects were examined (193 women and 150 men aged 20-90 years); nine time- and frequency-domain HRV indices were analyzed (NN, lnSDNN, lnRMSSD, lnVLF, lnLF, lnHF, VLF%, LF%, HF%). The association between HRV indices and chronological age was substantially in women and men (p<0.01). KDM produced the lowest estimation error (MAE=4.34 years in women, 3.67 years in men), whereas uncorrected MLR produced the largest error (MAE=6.57 and 7.47 years, respectively); the Dubina correction substantially improved MLR accuracy (MAE=4.22 and 4.82 years) but relied directly on actual chronological age, which limits its independent diagnostic value. The strengths and limitations of each method and recommendations for their application are discussed. Keywords: biological age, heart rate variability, Klemera-Doubal method, multiple linear regression.