Diet-induced obesity in rats leads to a decrease in sperm motility

Abstract

BackgroundObesity is rapidly becoming a worldwide epidemic that affects children and adults. Some studies have shown a relationship between obesity and infertility, but until now it remains controversial. Thus, the aim of the present study was to investigate the effect of high-fat diet-induced obesity on male reproductive parameters.MethodsIn a first experiment, male Wistar rats were fed a high-fat diet (HFD) or standard chow (SD) for 15, 30 or 45 weeks, after which they were evaluated by adiposity index, serum leptin levels, reproductive organ weights and sperm counts. In a second experiment, rats received HFD or SD only for 15 weeks, long enough to cause obesity. Sexual hormones and sexual behavior were evaluated in these animals, as well as fertility after natural mating. Another group of rats was submitted to motility analysis and fertility evaluation after in utero insemination.ResultsAfter 15, 30 or 45 weeks, HFD-fed animals presented significant increases in obesity index and serum leptin levels. Reproductive organ weights and sperm counts in the testis and epididymis were similar between the two groups at all timepoints studied. Sexual behavior was not altered by the diet regimen, and HFD fertility after natural mating was also similar to SD-fed animals. Intergroup testosterone levels were also comparable, but estradiol levels were increased in HFD rats. Furthermore, sperm quality was reduced in HFD animals as evidenced by their decreased percentage of sperm with progressive movement. This altered motility parameter was followed by a trend toward reduction in fertility potential after artificial in utero insemination.ConclusionsThe results reported herein showed that obesity can affect sperm quality, by reducing sperm motility, without affecting other sperm parameters. The low sperm quality caused a slight reduction in fertility potential, showing that obesity may lead to impairment in male fertility.

Energy restriction ameliorates metabolic syndrome-induced cavernous tissue structural modifications in aged rats

“…Onwards, WAT refers to the sum of epididymal, mesenteric, and retroperitoneal fat pads. In order to assess the effects of the diet on body fat content, adiposity index (AI) was calculated by WAT · BW −1 · 100 and expressed as adiposity percentage (Fernandez et al 2011).…”

“…To further understand the effect of HF diet and ER on body adiposity, AI was determined as described by Fernandez et al (2011). As summarized in Table 2, HFD animals presented the highest AI when compared either with C (P00.001, P<0.001, and P00.001, for 6, 12, and 18 months, respectively) or ER rats (P00.003, P 00.001, and P 0 0.333, for 6, 12, and 18 months, respectively).…”

Impairment on sperm quality and fertility of adult rats after antiandrogen exposure during prepuberty

“…The following parameters were observed for 40 min: latency to the first mount, intromission, and ejaculation; number of intromissions until the first ejaculation; latency of the first post-ejaculatory intromission; number of post-ejaculatory intromissions; and total number of ejaculations [18][19][20][21][22]. Males that did not mount in the initial 10 min were considered sexually inactive.…”

Endocrine disrupting chemicals

“…Reduced interaction of leptin with Leydig or germ cells would lead to the reduction in the expression of steroidogenic enzymes 156,157 and the impairment of sperm mobility. 155,[158][159][160] In gestational exposure of EDCs (i.e., phthalate), plasma leptin level was reduced and was accompanied by the reduction of anogenital distance and the expression levels of several steroidogenic enzymes such as steroidogenic acute regulatory protein (StAR), CYP11A, CYP17 in fetal male rats. 156 Leptin synthesis was also found to be inhibited in cadmium exposure.…”