Effect of a short period of abstinence from smoking on rewarming patterns of the hands following local cooling.

The purpose of the study was to examine the effect of a 12 h period of abstinence from smoking in young and old habitual smokers, on skin rewarming patterns of a hand following local cooling. This was done by comparing changes in peripheral circulation, measured indirectly by monitoring changes in skin surface temperatures of the hand with both infrared (IR) thermography and thermocouples before, during and after immersing the right hand for 2 min in water at 10 degrees C. Included in the study were young male non-smokers (n = 14) and smokers (n = 13), and elderly non-smokers (n = 12) and smokers (n = 14). The results showed no statistically significant difference between young non-smokers and smokers when comparing their response to the local cold challenge. The elderly smokers had a significantly higher hand skin temperature prior to cooling (34.0 +/- 0.2 degrees C) and after 80% rewarming (32.1 +/- 0.2 degrees C) (i.e. when the skin temperature in the "cooled" hand has regained 80% of the cold induced drop in temperature), compared to elderly non-smokers (33.3 +/- 0.2 and 31.3 +/- 0.2 degrees C, respectively). The elderly smoking subjects also had a faster recovery after cooling (9.7 +/- 0.8 min) than the elderly non-smoking subjects (16.7 +/- 2.6 min). A follow-up study with seven elderly smokers, who had smoked as usual until 2 h before the experiment, showed responses lying between the non-smokers and smokers who had had a longer period of abstinence (12 h) from smoking. In conclusion, we have demonstrated using IR-thermal imaging that elderly subjects who have smoked for many years have slightly warmer hand skin temperature when they abstain from smoking. Even a period of abstinence from smoking of a few hours can affect the way in which elderly subjects respond to a local cold challenge, recovering more rapidly then their non-smoking counterparts.