19 May 2026 : Clinical Research
Association of Novel Oral Appliance Use With Heart Rate Variability in Adolescent Athletes
Jui-Kun Chiang
ACDG 1, Yen-Chang Lin ABD 2, Hsueh-Hsin Kao D 3, Tzu-Ying Hung E 2, Weir-Chiang You DE 3,4*, Yee-Hsin Kao DEF 5
DOI: 10.12659/MSM.952561
Med Sci Monit 2026; 32:e952561
Table 1 Demographic characteristics of the study participants.
| Variablesn | Whole cohort43 | Female athletes20 | Male athletes23 | P value |
|---|---|---|---|---|
| Age, years | 14.8±1.6 | 14.8±1.5 | 14.7±1.7 | 0.903 |
| BMI, kg/m | 21.8±2.5 | 21.2±2.1 | 22.2±2.9 | 0.189 |
| Training time, years | 2.7±1.6 | 3.0±1.6 | 2.5±1.7 | 0.283 |
| RMSSD, milliseconds | ||||
| Test 1 | 69.2±29.6 | 67.4±24.2 | 70.7±34.1 | 0.679 |
| Test 2 | 72.6±35.5 | 68.4±32.8 | 76.3±38.0 | 0.592 |
| Test 3 | 74.7±29.2 | 74.0±26.4 | 75.4±32.1 | 0.626 |
| Test 4 | 81.4±34.6 | 77.4±28.2 | 84.8±39.6 | 0.679 |
| value | 0.002 | 0.226 | 0.006 | |
| p.NN50, % | ||||
| Test 1 | 42.2±19.2 | 41.5±18.5 | 42.8±20.2 | 0.826 |
| Test 2 | 42.9±19.9 | 40.1±20.4 | 45.3±19.6 | 0.399 |
| Test 3 | 47.3±16.2 | 46.8±16.4 | 47.8±16.3 | 0.856 |
| Test 4 | 50.3±15.6 | 48.2±14.3 | 52.1±16.8 | 0.424 |
| value | <0.001 | 0.056 | 0.005 | |
| SDSD, milliseconds | ||||
| Test 1 | 69.2±29.6 | 67.5±24.2 | 70.7±34.1 | 0.691 |
| Test 2 | 72.7±35.5 | 68.4±32.9 | 76.4±38.0 | 0.604 |
| Test 3 | 74.8±29.2 | 74.0±26.4 | 75.4±32.1 | 0.638 |
| Test 4 | 81.5±34.6 | 77.5±28.2 | 85.0±39.6 | 0.691 |
| value | 0.001 | 0.225 | 0.006 | |
| LF/HF ratio | ||||
| Test 1 | 2.3±4.7 | 3.1±6.7 | 1.5±1.7 | 0.808 |
| Test 2 | 2.2±2.7 | 2.3±2.0 | 2.2±3.3 | 0.436 |
| Test 3 | 1.4±1.3 | 1.3±0.9 | 1.5±1.6 | 0.903 |
| Test 4 | 1.8±3.2 | 2.3±4.6 | 1.3±0.8 | 0.643 |
| value | 0.261 | 0.307 | 0.137 | |
| LF power | ||||
| Test 1 | 599.4±491.6 | 720.0±585.3 | 494.6±375.3 | 0.187 |
| Test 2 | 729.6±705.6 | 807.7±820.7 | 661.8±598.8 | 0.782 |
| Test 3 | 526.6±509.4 | 559.3±541.1 | 498.2±490.6 | 0.638 |
| Test 4 | 672.6±706.8 | 819.5±893.0 | 544.9±478.1 | 0.492 |
| value | 0.105 | 0.314 | 0.147 | |
| HF power | ||||
| Test 1 | 555.6±474.6 | 550.1±370.1 | 560.4±558.2 | 0.555 |
| Test 2 | 561.0±520.1 | 532.9±446.0 | 585.4±585.9 | 0.952 |
| Test 3 | 552.1±589.4 | 540.4±380.6 | 562.2±733.4 | 0.433 |
| Test 4 | 605.6±682.8 | 529.6±381.4 | 671.6±868.7 | 0.971 |
| P value | 0.772 | 0.995 | 0.547 | |
| Timing of tests: test 1, before wearing the LOA; test 2, while wearing the LOA; test 3, immediately after removing the LOA; test 4, 10 to 20 minutes after removing the LOA. BMI – body mass index; HF – absolute power of the high-frequency band; LF – absolute power of the low-frequency band; LOA – Lin Oral Appliance; p.NN50 – proportion of adjacent RR intervals differing by more than 50 milliseconds; RMSSD – root mean square of successive heartbeat interval differences; SDSD – standard deviation of differences between adjacent RR intervals. | ||||