TABLE 1.
Descriptive characteristics of participants.
| Variables | Total sample (n = 107) | Overweight (n = 28, 26%) | Mild-obesity (n = 46, 43%) | Severe/Morbid-obesity (n = 33, 31%) | P value |
| Boys, n (%) | 62 (58) | 16 (57) | 29 (63) | 17 (52) | 0.592 |
| Parents with university degree, n (%) | 0.005∗∗ | ||||
| None of them | 71 (66) | 15 (54) | 27 (59) | 29 (88)a,b | |
| One of them | 19 (18) | 6 (21) | 10 (22) | 3 (9)a,b | |
| Both of them | 17 (16) | 7 (25) | 9 (20) | 1 (3)a,b | |
| Wave, n (%) | 0.905 | ||||
| Wave 1 | 19 (18) | 5 (18) | 8 (17) | 6 (18) | |
| Wave 2 | 43 (40) | 10 (36) | 20 (44) | 13 (39) | |
| Wave 3 | 45 (42) | 13 (46) | 18 (39) | 14 (42) | |
| Age (years) | 10 ± 1 | 10 ± 1 | 10 ± 1 | 9 ± 1a,b | 0.004∗∗ |
| PHV offset (years) | −2.26 ± 0.99 | −2.25 ± 1.01 | −2.06 ± 1.02 | −2.54 ± 0.90 | 0.107 |
| Body composition | |||||
| Weight (kg) | 56 ± 11 | 46 ± 7 | 58 ± 10a | 62 ± 9a | < 0.001** |
| Height (cm) | 144 ± 8 | 142 ± 9 | 147 ± 8a | 142 ± 7b | 0.014∗∗ |
| BMI (kg/m2) | 27 ± 3 | 22 ± 1 | 26 ± 2a | 31 ± 2a,b | < 0.001** |
| WC (cm) | 90 ± 10 | 80 ± 6 | 90 ± 8a | 98 ± 7a,b | < 0.001** |
| WC/Height | 0.62 ± 0.06 | 0.57 ± 0.03 | 0.62 ± 0.04a | 0.69 ± 0.04a,b | < 0.001** |
| DXA FM (Kg) | 25 ± 7 | 18 ± 4 | 25 ± 5a | 30 ± 7a,b | < 0.001** |
| DXA FMI (kg/m2) | 12 ± 3 | 9 ± 1 | 11 ± 2a | 15 ± 2a,b | < 0.001** |
| DXA BFP (%) | 44 ± 6 | 39 ± 4 | 43 ± 4a | 49 ± 4a,b | < 0.001** |
| DXA FFM (Kg) | 31 ± 5 | 28 ± 5 | 32 ± 6a | 31 ± 4a | < 0.001** |
| DXA FFMI (kg/m2) | 15 ± 1 | 14 ± 1 | 15 ± 1a | 15 ± 1a | < 0.001** |
| DXA Total VAT (g)* | 398 ± 115 | 297 ± 73 | 397 ± 97a | 484 ± 99a,b | < 0.001** |
| DXA VAT FMI (g)* | 191 ± 51 | 146 ± 33 | 182 ± 34a | 240 ± 41a,b | < 0.001** |
| Heart rate variability | |||||
| Mean HR (bpm) | 81 ± 10 | 79 ± 10 | 79 ± 9 | 87 ± 8a,b | < 0.001** |
| Mean RR (ms) | 747 ± 91 | 774 ± 101 | 767 ± 87 | 695 ± 63a,b | < 0.001** |
| RMSSD (ms) | 60 [57] | 71 [55] | 72 [83] | 51 [28] | 0.056 |
| pNN50 (%) | 31 [38] | 41 [38] | 37 [43] | 21 [19] | 0.023∗∗ |
| SDNN (ms) | 60 [42] | 68 [44] | 65 [54] | 54 [25] | 0.299 |
| FFT TP (ms2) | 3068 [5405] | 3736 [5609] | 4084 [5997] | 2349 [2339]a | 0.035∗∗ |
| FFT HF (ms2) | 1223 [2642] | 1987 [3212] | 2140 [3731] | 860 [814] | 0.380 |
| FFT LF (ms2) | 1288 [1724] | 1291 [2023] | 1409 [1903] | 1151 [1195] | 0.577 |
| FFT LF/HF | 0.9 [1.2] | 0.8 [1.2] | 0.8 [1.0] | 1.5 [1.5] | 0.061 |
Data presented as mean ± SD, as number and frequency. Median [IQR: Interquartile range] are presented for standard HRV parameters because these variables presented skewed distributions. PHV, peak height velocity; BMI, body mass index; WC, waist circumference; DXA, dual energy X-ray absorptiometry; FM: fat mass; FMI, fat mass index; BFP, body fat percentage; FFM, fat-free mass; FFMI, fat-free mass index; VAT, visceral adipose tissue; HR, heart rate; RR, R–R intervals; RMSSD, The square root of the mean of the sum of the squares of differences between adjacent R–R intervals; pNN50: percentage (%) of the total pairs of R–R intervals that differ by more than 50 ms; SDNN, standard deviation of all normal R–R intervals; FFT, fast fourier transformation; HF, high frequency band (0.15–0.4 Hz) index of parasympathetic activity; LF, low frequency band (0.04–0.15 Hz) mix index of sympathetic and parasympathetic activity. *Indicates that these variables have some missing values, i.e., DXA Total VAT (g): n = 19; DXA VAT FMI (g): n = 19; P value column denotes significant differences among groups. aDenotes significant differences (p < 0.05) respect to the subgroup of children with overweight. bDenotes significant differences (p < 0.05) respect to the subgroup of children with mild obesity. ∗∗p < 0.05.