Lipolysis in smokers during tobacco withdrawal: a pilot study

OBJECTIVE: Nicotine has an influence on several metabolic events, such as lipid metabolism. Habitual smoking increases plasma levels of glycerol as well as noradrenaline, which is the main stimulating hormone of adipose tissue lipolysis. However, the long-term effect of smoking on lipolysis is unclear. We compared nocturnal lipolysis in habitual smokers during short-term tobacco withdrawal with a control group of non-smokers. MATERIAL AND METHODS: Sixteen healthy subjects (9 heavy smokers and 7 non-smokers) were recruited in the study. The smokers were not permitted to smoke for at least 7 h before the test. The microdialysis technique was used to measure glycerol levels, the end-product of lipolysis, in subcutaneous adipose tissue. Variations in adipose tissue blood flow were measured using the ethanol technique. Glycerol, lactate and glucose concentrations as well as ethanol outflow/inflow ratio were measured between 2400 and 0600 h. RESULTS: There were no significant differences in subcutaneous glycerol or glucose concentrations between smokers and non-smokers. Between 0300 and 0600 h, lactate levels in smokers were lower than those in non-smokers. Adipose tissue blood flow did not differ between the groups. CONCLUSIONS: Despite potent acute and direct effects of smoking on lipolysis, we could not find any significant differences in basal lipolysis rate between smokers during short-term tobacco withdrawal and non-smokers.