Table 2.
Contribution of each variable to seminal quality parameters by β coefficient (significance value, P) from multivariate regression analysis
| Constant | Total number of spermatozoa | Sperm concentration | Total number of motile spermatozoa | Total number of spermatozoa with progressive motility | Total progressive motility | Total sperm motility | Normal morphology (WHO 2010) | Morphology (strict) |
|---|---|---|---|---|---|---|---|---|
| 25(OH)VD3 | 3.231 (0.033*) | 2.103 (<0.001*) | 2.571 (0.015*) | 2.069 (0.003*) | 0.366 (0.015*) | 0.426 (0.013*) | 0.117 (0.053*) | 0.056 (0.006*) |
| Age | −1.439 (0.480) | 0.394 (0.615) | −0.967 (0.499) | −0.536 (0.565) | −0.120 (0.554) | −0.331 (0.152) | 0.007 (0.930) | −0.011 (0.681) |
| BMI | −0.974 (0.522) | 0.195 (0.739) | −0.591 (0.580) | −0.519 (0.455) | −0.014 (0.925) | −0.124 (0.470) | 0.035 (0.569) | 0.015 (0.468) |
| Total testosterone | 0.081 (0.294) | 0.033 (0.262) | 0.069 (0.200) | 0.038 (0.281) | 0.020 (0.009*) | 0.025 (0.004*) | 0.007 (0.021*) | 0.002 (0.058) |
| Total cholesterol | 0.248 (0.439) | 0.139 (0.261) | 0.148 (0.510) | 0.034 (0.817) | −0.025 (0.436) | −0.008 (0.829) | 0.003 (0.840) | −0.002 (0.582) |
| HOMA-IR | −6.558 (0.509) | 3.177 (0.405) | −5.536 (0.427) | −2.170 (0.632) | 0.094 (0.924) | 1.070 (0.341) | 0.363 (0.363) | −0.057 (0.582) |
| Alcohol | −51.649 (0.069) | −20.007 (0.066) | −33.197 (0.095) | −13.701 (0.289) | −1.234 (0.661) | −5.481 (0.087) | 0.685 (0.547) | −0.052 (0.891) |
| Smoking | −0.886 (0.973) | −5.282 (0.605) | −2.210 (0.906) | −5.855 (0.630) | −1.332 (0.615) | −0.700 (0.816) | −0.698 (0.506) | 0.164 (0.638) |
| Varicocele | 62.930 (0.039*) | 16.758 (0.152) | 31.890 (0.135) | 20.889 (0.132) | −2.291 (0.448) | −4.348 (0.206) | −0.593 (0.626) | 0.332 (0.411) |
Predictors (constant): 25(OH)VD3, varicocele, HOMA-IR, age, alcohol, total testosterone, BMI, smoking. Dependent variable: total number of motile spermatozoa, total number of spermatozoa, total number of spermatozoa with progressive motility, total progressive motile, total motile, morphology by WHO, morphology by Kruger. *P≤0.05 is considered statistically significant difference. 25(OH)VD3: 25-hydroxy-vitamin D3; BMI: body mass index; HOMA-IR: homeostatic model assessment insulin resistance; WHO: World Health Organization