Abstract

Obesity rates doubled from 1980 to 2014 and is an epidemic today. Obesity is linked with various health issues but its effects on reproduction remain unsolved. Leptin is a hormone secreted by fat tissue and helps to control a number of body processes. Leptin and leptin receptor deficiency lead to obesity and may be related to impaired fertility parameters. In this study, male c57, ob/ob, (leptin deficient) and db/db (leptin receptor deficient) mice were raised to 8 and 16 weeks when tissues were collected and evaluated. Obesity was evident in both the ob/ob and db/db groups since body weight was grossly larger than c57 mice. The number of elongated spermatids, sperm/mg of testis and daily sperm production were reduced in the ob/ob group compared to controls suggesting that lack of leptin reduces sperm production. Interestingly, testicular sperm parameters of db/db mice were similar to controls suggesting that leptin receptor deficiency does not have the same effect as leptin hormone deficiency in the testis. Total sperm in the epididymis of both obese groups was significantly reduced at 16 weeks compared to control mice. Collectively, these data suggest that leptin deficient and leptin receptor deficient obese mice have impaired fertility parameters but that different mechanisms are responsible for reduced fertility in these males.