**3. Statistical analysis**

The data we obtained were statistically processed using GraphPad Prism (version 6.0 for Windows, GraphPad Software incorporated, San Diego, California,

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**Figure 2.**

*ZDF Rats: A Suitable Model to Study Male Reproductive Dysfunction in Diabetes Mellitus…*

USA, http://www.graphpad.com/). Differences between the compared groups were statistically evaluated by one-way analysis of variance (ANOVA) and the Tukey comparative test. Statistical significance was assessed at levels \*\*\*(P < 0.001),

When we compared the sperm motility of individual groups (**Figure 2**), we found statistically significant differences (P < 0.001) when comparing the experimental group ZDF with the control W group as well as with the ZDN experimental group. Similarly to our results, Ohta et al. [20] reported a reduction in the sperm motility in rats with obesity in comparison with the control group. They tried to demonstrate the potential link between obesity and a reduction of sperm motility, which ultimately affects the fertility of rats. Simas et al. [21] also reported a decrease of morphologically normal spermatozoa in rats with diabetes. The most common abnormalities found were sperm head deformations and flagella deformities. There is a very close connection between the sperm volume and percentage of motile spermatozoa. Both types of diabetes have a serious impact on the sperm quality, and a lot of studies examine the effect of diabetes on the male fertility. Condorelli et al. [22] showed different pathophysiological effects in type 1 and type 2 of diabetes on the sperm function and quality. The aim of their experiment was to compare DM1 and DM2 patients with healthy and fertile subjects. Male patients suffering from diabetes mellitus type 2 have several contraindications. Among these, the most prominent include low sperm volume, higher concentration of mitochondrial superoxide anions, an increased reactive oxygen species production in the seminal fluid, and lipoperoxidation. The study showed that DM2 caused an inflammatory condition and increased the level of oxidative stress which led to an increased sperm DNA fragmentation and a decreased vitality of spermatozoa. In our experiments we also observed several contraindications in the rats which suffered from diabetes mellitus type 2 including a decreased motility and vitality of sperm cells, a lower mitochondrial activity, followed by higher levels of superoxide production and lipid peroxidation. On the other hand, a combination of DM2 and obesity has more serious consequences to male fertility.

*Differences in the sperm motility among the observed groups. W, Wistar rats, control group; ZDN, nonobese ZDF rats with diabetes mellitus type 2; ZDF, ZDF rats with obesity and diabetes mellitus type 2. \*\*\*(P < 0.001).* 

*W, compared to the Wistar group; ZDN, compared to the ZDN group.*

*DOI: http://dx.doi.org/10.5772/intechopen.89939*

\*\*(P < 0.01), and \*(P < 0.05).

**4. Results and discussion**

USA, http://www.graphpad.com/). Differences between the compared groups were statistically evaluated by one-way analysis of variance (ANOVA) and the Tukey comparative test. Statistical significance was assessed at levels \*\*\*(P < 0.001), \*\*(P < 0.01), and \*(P < 0.05).
