Table 3.
Subgroup analysis of the effects of metabolic syndrome on semen quality and circulating sex hormones according to the ethnicity and study area.
| Variables | Caucasian cohort/developed area | Non-Caucasian cohort/developing area | ||
|---|---|---|---|---|
| SMD (95% CI) | No. | SMD (95% CI) | No. | |
| Semen volume | −0.60 (−3.28 to 2.09) | 6 | −0.25 (−0.69 to 0.18) | 4 |
| Sperm total count | −0.95 (−1.79 to −0.11) | 3 | −0.96 (−1.42 to −0.50) | 2 |
| Sperm concentration | −0.56 (−1.82 to 0.70) | 6 | −1.94 (−3.10 to −0.78) | 5 |
| Sperm normal morphology | −0.93 (−1.66 to −0.19) | 6 | −0.10 (−0.17 to −0.04) | 3 |
| Sperm total motility | −0.54 (−2.16 to 1.08) | 2 | −0.75 (−1.47 to −0.02) | 4 |
| Sperm progressive motility | 0.02 (−0.25 to 0.28) | 4 | −1.32 (−2.34 to −0.30) | 5 |
| Sperm vitality | – | – | −0.83 (−1.11 to −0.54) | 3 |
| DNA fragmentation | – | – | 0.76 (0.45 to 1.06) | 3 |
| Mitochondrial membrane potential (MMP) | – | – | 0.89 (0.49 to 1.28) | 2 |
| Follicle-stimulating hormone (FSH) | −0.03 (−0.29 to 0.23) | 5 | −13.87 (−16.12 to −11.62) | 1 |
| Testosterone | −5.61 (−10.90 to −0.31) | 5 | −6.41 (−12.81 to −0.02) | 1 |
| Luteinizing hormone (LH) | −0.36 (−3.24 to 2.52) | 5 | – | – |
| estradiol | 1.04 (−2.05 to 4.12) | 4 | – | – |
| Prolactin | 0.04 (−0.11 to 0.20) | 3 | – | – |
| Inhibin B | −0.59 (−1.28 to 0.10) | 2 | −6.31 (−7.41 to −5.21) | 1 |
| Anti-Müllerian hormone (AMH) | −0.92 (−2.06 to 0.22) | 2 | – | – |
SMD, standardized mean differences; CI, confidence interval; No., number of included studies.