Review Article
Leptin Levels in Serum or Semen and Its Association with Male Infertility: A Meta-Analysis with 1138 Cases
Table 1
The characteristics of 12 eligible studies providing serum leptin concentration.
| | Year | Country | Control | Case | Language | Method | | Total (n) | Leptin (ug/L) | Age (y) | BMI | Sperm concentration (106/mL) | Sperm progressive motility (%) | Total (n) | Leptin (ug/L) | Age (y) | BMI | Sperm concentration (106/mL) | Sperm progressive motility (%) |
| | 2014 | China | 77 | 9.22 ± 1.15 | 31.1 ± 2.7 | 24.32 ± 2.14 | 41.84 ± 11.39 | 48.73 ± 7.27 | 79 | 9.48 ± 0.98 | 30.9 ± 2.7 | 24.15 ± 2.13 | 33.47 ± 11.08 | 20.42 ± 5.78 | English | ELISA | | 2001 | Israel | 35 | 5 ± 0.4 | 31.6 ± 1.4 | <25 | ≥20 | ≥50 | 36 | 7.6 ± 0.8 | 36.6 ± 1.3 | <25 | ≤8.5 ± 6.7 | ≤16 ± 5.5 | English | RIA | | 2007 | Egypt | 30 | 6.88 ± 8.65 | 30.9 ± 8.8 | 27.3 ± 6.4 | 71.35 ± 35.7 | N/A | 50 | 16.3 ± 13.98 | 30.1 ± 7.3 | 28.15 ± 4.4 | 8.09 ± 4.8 | N/A | English | RIA | | 2003 | Germany | 21 | 5.62 ± 3.72 | 33 ± 4 | 23 ± 3 | 88.31 ± 41.81 | ≥50 | 13 | 5.12 ± 2.93 | 33 ± 4 | 23 ± 3 | 0 | 0 | English | RIA | | 2016 | Iran | 95 | 7.69 ± 6.9 | 34.12 ± 5.3 | 24.15 ± 3.8 | 27.6 ± 16.5 | 22.98 ± 18.9 | 98 | 6.1 ± 5.8 | 34.14 ± 6.2 | 24.17 ± 4.42 | 9.45 ± 8 | 22.51 ± 11.64 | English | ELISA | | 2002 | Germany | 28 | 2.9 ± 0.6 | N/A | 25.45 ± 2.45 | 86.3 ± 15.2 | 31.9 ± 2.6 | 36 | 4.5 ± 0.5 | N/A | 25.60 ± 2.46 | 23.6 ± 4.1 | 18.1 ± 1.9 | English | RIA | | 2007 | Slovenia | 85 | 8.2 ± 0.6 | 34.6 ± 0.4 | 25.54 ± 0.31 | ≥20 | ≥50 | 68 | 12.4 ± 1.6 | 34.6 ± 0.4 | 26.22 ± 0.47 | 0 | 0 | English | ELISA | | 2011 | China | 30 | 5.61 ± 0.43 | 29.8 ± 0.57 | 21.83 ± 1.36 | ≥20 | ≥32 | 45 | 13.29 ± 1.56 | 29.56 ± 0.77 | 23.45 ± 0.57 | 0 | 0 | Chinese | RIA | | 2012 | China | 40 | 7.88 ± 2.63 | 30.42 ± 6.22 | N/A | 24.58 ± 4.13 | 43.97 ± 4.89 | 42 | 16.32 ± 3.86 | 29.14 ± 6.01 | N/A | 18.56 ± 3.24 | 27.90 ± 5.03 | Chinese | RIA | | 2014 | South Africa | 19 | 4.1 ± 2.4 | 35.1 ± 5.9 | 25.5 ± 2.4 | 35.3 ± 16.7 | 33.8 ± 16.2 | 23 | 8.8 ± 8.5 | 37.9 ± 7.3 | 35.8 ± 4.3 | 23.7 ± 13.6 | 24.5 ± 19.1 | English | ELISA | | 2009 | China | 48 | 3.86 ± 1.56 | 32 ± 5.24 | 18.56 ± 2.32 | 60.38 ± 8.62 | 75.80 ± 4.38 | 52 | 16.82 ± 11.46 | 32 ± 5.24 | 30.21 ± 2.9 | 22.90 ± 2.15 | 28.12 ± 4.14 | Chinese | ELISA | | 2014 | China | 10 | 4.22 ± 0.76 | 31.1 ± 4.38 | 22.74 ± 1.43 | 40.49 ± 12.02 | 31.28 ± 9.41 | 30 | 7.63 ± 1.68 | 29.6 ± 3.21 | 26.79 ± 1.28 | 15.54 ± 3.45 | 12.54 ± 8.36 | Chinese | ELISA |
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ELISA: enzyme-linked immunosorbent assay; RIA: radioimmunoassay; N/A: negative.
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