Introduction & Objectives: In recent studies, the negative effects of smoking on different parts of body have been cleared. Nevertheless other negative effects of smoking are being investigated. One of those effects is central and peripheral nervous system problem. The aim of this investigation was comparison of Hoffmann (H) reflex latency of tibial nerve in male smokers and non smokers between 20-40 y/o. In addition, correlation between height and H-reflex latency was investigated.

Materials & Methods: In this case - control study, samples included 65 males (32 smokers and 33 non-smokers) 20-40y/o. After assuring of desired conditions H-reflex latency was measured. In smokers, H-reflex test was done at least one hour after cigarette consumption. Before measuring H-reflex latency distal lower extremity skin temperature was measured and the study was done at 33 °C skin temperature.

Results: The average of H-reflex latency in smokers was 29.9±1.5 ms and the average of H-reflex latency in non-smokers was 29.25±1.3 ms. The results showed that there is no significant difference between H-reflex latency in male smokers and non-smokers (p>0.05).

Conclusion: Therefore, cigarette consumption does not have any effect on H-reflex latency in males between 20-40y/o. Also, correlation test indicate that there is significant relationship between height and H-reflex latency.