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. 2019 Mar 4;9:3389. doi: 10.1038/s41598-019-39826-7

Table 1.

Baseline characteristics of the study population according to tertiles of Mediterranean diet adherence.

Variables 1st Tertile n = 30 MD score ≤3 2nd Tertile n = 49 MD score 4–5 3rd Tertile n = 27 MD score ≥6 P-value
MD score*; median [Pc25-Pc75] 3 [2–3]a 4 [4–5]b 6 [6–7]c <0.001
Demographic parameters
Age (years); mean (±SD) 24.1 (±4.5) 24.1 (±4.6) 26.3 (±4.8) 0.100
Energy (kcal); mean (±SD) 2418 (±701)a 2860 (±836)b,c 3192 (±720)c 0.001
BMI (kg/m2); mean (±SD) 22.5 (±2.3)a 24.3 (±3.7)b,c 24.4 (±2.5)c 0.021
Waist circumference (cm); mean (±SD) 78.4 (±5.6)a 81.5 (±9.3)a,b 84.6 (±6.8)b 0.014
Systolic blood pressure (mmHg); mean (±SD) 126.3 (±11.4) 129.0 (±9.3) 127.0 (±11.0) 0.571
Diastolic blood pressure(mmHg); mean (±SD) 72.6 (±7.0) 72.1 (±9.1) 72.7 (±7.7) 0.946
Blood parameters
Plasma glucose (mg/dl); mean (±SD) 88.0 (±9.3) 87.1 (±7.2) 88.5 (±9.1) 0.759
Total cholesterol (mg/dl); median [Pc25-Pc75] 170.8 [150.8–182.3] 170.8 [147.5–192.0] 169.0 [149.0–188.0] 0.878
HDL-c (mg/dl); median [Pc25-Pc75] 57.7 [54.8–66.3] 56.0 [47.5–66.0] 56.0 [48.0–59.0] 0.467
LDL-c (mg/dl); median [Pc25-Pc75] 96.7 [76.8–105.5] 96.7 [73.5–106.0] 93.0 [79.0–108.0] 0.911
VLDL-c (mg/dl); median [Pc25-Pc75] 14.1 [11.0–16.3] 15.0 [9.5–19.5] 13.0 [12.0–18.0] 0.827
Triglycerides (mg/dl); median [Pc25-Pc75] 75.0 [56.5–81.6] 76.0 [48.5–99.0] 66.0 [59.0–88.0] 0.739
Plasma insulin (mcUI/ml); mean (±SD) 6.1 (±3.7) 6.8 (±5.5) 6.2 (±5.7) 0.794
C-reactive protein (mg/dl); median [Pc25-Pc75] 0.2 [0.2–0.2] 0.2 [0.2–0.2] 0.2 [0.2–0.2] 0.985
Folate (ng/ml); median [Pc25-Pc75] 6.6 [5.7–8.9] 6.3 [4.7–6.9] 6.2 [4.6–8.1] 0.150
Semen/sperm parameters
pH; median [Pc25-Pc75] 8.0 [8.0–8.5]a 8.0 [8.0–8.5]a,b 8.5 [8.0–8.5]a,c 0.023
Volume (ml); median [Pc25-Pc75] 2.8 [1.9–4.5] 3.0 [1.9–4.6] 3.3 [2.1–4.4] 0.852
Volume <1.5 ml; n (%) 3 (10) 8 (16.3) 4 (14.8) 0.731
Total sperm count (x106); median [Pc25-Pc75] 76.6 [30.8–139.5] 65.0 [24.8–126.0] 79.0 [43.5–101.0] 0.675
Total sperm count <39 × 106 spz; n (%) 9 (30) 19 (38.8) 6 (22.2) 0.321
Sperm concentration (x106); median [Pc25-Pc75] 27.6 [9.1–53.7] 23.6 [10.0–38.1] 25.2 [16.1–35.6] 0.669
Sperm concentration <15 × 106 spz/ml; n (%) 11 (36.7) 19 (38.8) 5 (18.5) 0.175
Vitality (%); median [Pc25-Pc75] 79.2 [69.4–82.2] 79.3 [72.7–84.2] 78.9 [72.7–87.9] 0.662
Vitality <58%; n (%) 3 (10) 2 (4.1) 3 (11.1) 0.451
Total motility (%); median [Pc25-Pc75] 54.5 [38.8–72.4]a 64.4 [43.8–72.7]a,b 73.2 [64.7–82.2]c 0.009
Total motility <40% motile; n (%) 8 (26.7) 7 (14.3) 2 (7.4) 0.127
Progressive motility (%); median [Pc25-Pc75] 40.8 [20.9–58.8]a 41.8 [25.9–53.5]a,b 52.2 [43.3–62.3]c 0.013
Progressive motility <32% motile; n (%) 10 (33.3) 17 (34.7) 4 (14.8) 0.160
Non-progressive motility (%); median [Pc25-Pc75] 11.1 [6.3–14.4] 12.1 [8.6–16.1] 12.1 [7.9–15.3] 0.674
Immotility (%); median [Pc25-Pc75] 34.3 [25.6–53.0]a 35.6 [27.3–56.2]a,b 29.0 [20.1–35.9]a,c 0.045
Morphology (%); median [Pc25-Pc75] 6.4 [4.4–8.0] 6.5 [5.6–7.9] 6.3 [5.0–8.0] 0.762
Morphology <4% normal; n (%) 5 (16.7) 5 (10.2) 2 (7.4) 0.515
Seminogram abnormality; n (%) 19 (63.3) 32 (65.3) 11 (40.7) 0.094

Abbreviations. BMI: Body-mass-index, HDL-c: High-density lipoprotein cholesterol, LDL-c: Low-density lipoprotein cholesterol, MD: Mediterranean diet, n: number of subjects, Pc: percentile, spz: spermatozoa, VLDL-c: very-low-density lipoprotein cholesterol, SD: standard deviation.

*MD score (Trichopoulou et al.)18.

Continuous variables were presented as means (±SD) or medians [25th-75th percentiles (Pc)] and categorical variables are presented as number (n) and percentages (%). Differences in variables across tertiles of MD adherence were tested using ANOVA test or Kruskal–Wallis test for continuous variables. Same superscripts in different columns denote non-significant differences, while different superscript letters denote statistically significant differences in a paired comparison (after multiple comparison post-hoc Bonferroni test). Pearson chi-squared test (Fisher’s exact test) was used to compare categorical variables.