Table 3.
General characteristics of the study population according to tertiles of leukocyte telomere length.
| Leukocyte telomere length (T/S ratio) |
||||
|---|---|---|---|---|
| T1 | T2 | T3 | ||
| (n = 65) | (n = 65) | (n = 64) | P-value | |
| Age (years) | 29 [24–33] | 29 [24–31] | 28 [23–33] | 0.878 |
| Anthropometric measurements | ||||
| Weight (kg) | 76 [73–83.5] | 75.2 [68.5–81.7] | 75.8 [68.3–81.1] | 0.251 |
| Waist circumference (cm) | 83 [78.3–89.4] | 81 [77–84.5] | 81.7 [76.8–87.3] | 0.139 |
| BMI (kg/m²) | 25.2 (3.5) | 23.9 (2.9) | 24 (2.9) | 0.298 |
| Energy intake (kcal/day) | 2566.8 (646.1) | 2656.2 (621.3) | 2699.3 (623.6) | 0.477 |
| Leisure-time physical activity (METs—min/week) | 3729.1 [1965–5137.5] | 3615.4 [1864.8–5757.6] | 3128.7 [1521.7–5311.2] | 0.509 |
| Educational level, n (%) | 0.244 | |||
| High school or less | 20 (30.8) | 21 (32.3) | 28 (43.8) | |
| College or high education | 45 (69.2) | 44 (67.3) | 36 (56.2) | |
| Smoking status, n (%) | 0.571 | |||
| Current | 7 (10.8) | 7 (10.8) | 9 (14.1) | |
| Former | 11 (16.9) | 9 (13.9) | 5 (7.8) | |
| Never | 43 (66.1) | 47 (72.3) | 44 (68.8) | |
| Not reported | 4 (6.2) | 2 (3.1) | 6 (9.4) | |
| Seminogram parameters | ||||
| Sexual abstinence (days) | 3 [3–5] | 4 [3–5] | 4 [3–5] | 0.189 |
| Semen volume (ml) | 3.2 [2.3–4] | 3.5 [2.7–5] | 3.7 [2.8–4.5] | 0.100 |
| Sperm concentration (×106/ml) | 42 [21.5–74.2] | 43.5 [25.4–65.7] | 63.7 [37.6–111.8] | 0.001 |
| Total sperm count (×106) | 130.1 [64.3–230.1] | 141.9 [83.8–232.7] | 243.9 [137.9–350.7] | <0.001 |
| Motility | ||||
| Total motility (%) | 59.1 (17.5) | 58.8 (16.5) | 62.5 (15.3) | 0.562 |
| No motility (%) | 40.8 (17.6) | 40.9 (16.1) | 37 (15.1) | 0.486 |
| Vitality (%) | 80.8 [73–87.8] | 85.5 [76–91] | 80.8 [75.8–85.8] | 0.112 |
| Normal sperm morphology (%) | 8 [4.5–15] | 10 [5–16.5] | 9.5 [5.5–14.5] | 0.841 |
| Sperm TL (T/S ratio) | 2.2 [1.4–3.1] | 3.2 [2.3–4.5] | 4.2 [3.2–5.6] | <0.001 |
Data are expressed as mean and SD or median and [25th–75th] percentile for continuous variables and number and percentage for categorical variables. Differences across tertiles of leukocyte TL were analyzed by one-way ANOVA or Kruskal–Wallis test according to normal or skewed distributions, respectively. To compare categorical variables across TL tertiles, the chi-squared test was used.
BMI, body mass index; MET, metabolic equivalent of task; T, tertile; TL, telomere length; T/S, telomere to single-copy gene.