Body mass index and sperm quality: effects of overweight and underweight.

MARTINI AC; TISSERA AD; VINCENTI LM; ESTOFÁN D; BELTRAMONE F; SAD J; RUIZ RD; FIOL DE CUNEO M; MOLINA R

Sevilla

Congreso; V Congreso Internacional de Medicina Reproductiva; 2013

We previously reported a negative association between body mass index (BMI) and sperm motility and seminal alpha-glucosidase concentration (NAG), suggesting that epididymis may be a target organ for weight-linked alterations. In this study, we analyzed the possible association between BMI and semen quality in 4876 patients, including morbidly-obese and underweight patients, with no genitourinary diseases, alcohol or cigarette consumption or toxin exposure. We performed multivariate regression analysis (using BMI, age and abstinence as independent variables) and demonstrated that BMI was inversely and significantly associated with semen volume, total sperm count, motility and NAG (slopes: -0.01, -1.33, -0.18, -0.75; p<0.05); in addition, we found a significant negative association between BMI and viability, morphology and HOST. Furthermore, we randomly selected a similar number of patients/group and evaluated the seminal characteristics of underweight (UW=BMI<20, n=45), normal (N=20≤BMI<25, n=50), overweight (OW=25≤BMI<30, n=50), obese (O=30≤BMI<40, n=50) and morbidly-obese (MO=BMI>40, n=57) patients, performing MANCOVA with age and abstinence as co-variables. We found that not only MO, but also UW patients had spermogram impairments, reaching statistical significance in sperm concentration (UW=42.7±6.0sperm/ml, N=54.7±5.5, OW=59.1±7.5, O=54.4±6.1, MO=37.9±4.9; p<0.05 OW and O vs UW and MO; p<0.05 N vs MO) and total sperm count (UW=103.3±11.4sperm/ejaculate, N=161.3±19.0, OW=166.5±20.0, O=149.1±17.2, MO=121.5±20.6; p<0.05 N, OW and O vs UW; p<0.05 OW vs MO). In conclusion, although the increase of BMI is negatively associated with semen quality, underweight also constitutes a risk factor for infertility. Since sperm density, motility and NAG are signs of the epididymal function, these new results support our original hypothesis.