Sperm DNA damage-the effect of stress and everyday life factors.

The clinical significance of sperm DNA damage lies in its association with natural conception rates and also might have a serious consequence on developmental outcome of the newborn. The aim of the present study is to determine whether stress and everyday life factors are associated with sperm DNA damage in adult men. The study population consisted of 286 men who attended the infertility clinic for diagnostic purposes and who had normal semen concentration of 20-300 m ml(-1) or with slight oligozoospermia (semen concentration of 15-20 m ml(-1)) (WHO, 1999). Participants were interviewed and provided a semen sample. The sperm chromatin structure assay was assessed using flow cytometry. In the present study, we found evidence for a relationship between sperm DNA damage parameters and everyday life factors. High and medium level of occupational stress and age increase DNA fragmentation index (P=0.03, P=0.004 and P=0.03, respectively). Other lifestyle factors that were positively associated with percentage of immature sperms (high DNA stainability index) included: obesity and cell phone use for more than 10 years (P=0.02 and P=0.04, respectively). Our findings indicate that stress and lifestyle factor may affect sperm DNA damage. Data from the present study showed a significant effect of age, obesity, mobile phone radiation and occupational stress on sperm DNA damage. As DNA fragmentation represents an extremely important parameter indicative of infertility and potential outcome of assisted reproduction treatment, and most of the lifestyle factors are easily modifiable, the information about factors that may affect DNA damage are important.

Occupational, life stress and family functioning: does it affect semen quality?

BACKGROUND AND AIMS: Although psychological stress has been implicated as a cause of idiopathic infertility in both men and women, it has received little scientific attention among males as compared to females. The aim of the study was to examine the association between occupational, life stress, family functioning and semen quality. METHODS AND RESULTS: The study population consisted of 327 men who were attending an infertility clinic for diagnostic purposes. Psychological stress was assessed based on two questionnaires: The Subjective Work Characteristics Questionnaire and the Perceived Stress Scale. The level of satisfaction with family functioning and support was evaluated by means of the APGAR Family Scale. The findings suggest that, on the one hand, exposure to occupational stressors can be negatively associated with semen quality (there was a positive association between stress and the percentage of sperm with DNA damage (p = 0.03) and atypical sperm (p = 0.05)); on the other hand, there was no correlation between the level of life stress and semen quality indicators. Negative associations were found between satisfaction with family functioning and the percentage of motile sperm cells (p = 0.02), VAP (p = 0.05), VSL (p = 0.05) and VCL (p = 0.04). CONCLUSION: The study indicates that occupational stress can affect male semen quality; however, due to limited data on this issue, the obtained results should be confirmed in longitudinal studies.

Effects of noise on cognitive processes of individuals in a laboratory experiment.

The effects of noise on information processing in perceptual and memory tasks, as well as time reaction to perceptual stimuli, were investigated in a laboratory experiment. Performance and heart rate in Information Processing Test, Simple and Choice Reaction Time tests and Stroop's test were evaluated at three levels of noise (silence, 75 dBA, 95 dBA). Individual noise sensitivity and noise-induced temporary threshold shift (NITTS) were also assessed. The results show that neither noise nor individual noise sensitivity, or NITTS, as separate factors have an influence on information processing and time reaction to perceptual stimuli. However, noise effects simple reaction time in interaction with individual noise sensitivity, and information processing--within experimental session duration. Experimental session duration was the one separate factor affecting information processing. Noise as a separate factor does not have an influence on task performance, however, it affects heart rate. The higher increase of noise-induced temporary threshold shift, the smaller the number of heart beats/minute was found.

Psychological tests for measurement of mental functions in individuals exposed to neurotoxicants and noise.

According to Sternberg's additive factors methodology two computer tests have been prepared in the Work Psychology Department of IOM. Several studies which allowed the assessment of effectiveness of experimental factors, manipulation and psychometric tests characteristics have been carried out. As well, effectiveness of experimental factors manipulation as reliability of both tests (IPT-Perception and IPT-Memory) appeared to be satisfactory. So these techniques are good enough to recommend using these tests in psychological examinations.