Volume 9, Issue 6 (November 2007) 9, 827–834; 10.1111/j.1745-7262.2007.00268.x
Do reproductive hormones explain the association between body mass index and semen quality?
Dan-Dan Qin, Wei Yuan, Wei-Jin Zhou, Yuan-Qi Cui, Jun-Qing Wu and Er-Sheng Gao
1.School of Public Health, Fudan University, Shanghai 200433, China
2.Shanghai Institute of Planned Parenthood Research, Shanghai 200032, China
3.Commission of Population and Family Planning, Shanghai 200002, China
Correspondence: Dr Er-Sheng Gao, Shanghai Institute of Planned Parenthood Research, 2140 Xietu Road, Shanghai 200032, China. Fax: +86-21-6404-3701. E-mail: email@example.com
Received 1 October 2006; Accepted 24 January 2007.
Aim: To examine whether reproductive hormones play a role in the association between body mass index (BMI) and semen quality.
Methods: Semen quality and testosterone (T), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol (E2) were evaluated in 990 fertile males with age 38.9 9.7 (mean SD) years recruited from the Chinese general population in 2001 and 2002.
Results: Semen quality was reduced among underweight (BMI < 18.5) compared with normal (BMI 18.5–24.9) and overweight (BMI 25.0–29.9), but the associations were independent of reproductive hormones. After adjustment for the potential confounders, underweight men had reductions in sperm concentration (22.4 106/mL), total sperm count (52.9 106) and percentage of normal sperm forms (6.9%) compared with men with normal BMI. Being underweight may be a risk factor for low sperm concentration (OR: 4.68, 95% confidence intervals [CI]: 2.01–10.91). Otherwise, being overweight may be a protected factor for low sperm concentration (OR: 0.25; 95% CI: 0.08–0.83) and low total sperm count (OR: 0.37, 95% CI: 0.15–0.87).
Conclusion: Low BMI was associated with reduced semen quality. The associations between BMI and semen quality were found statistically significant even after adjustment for reproductive hormones. Reproductive hormones cannot explain the association between BMI and semen quality.
Keywords: semen quality, reproductive hormones, body mass index
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