The Effects of Nicotine on the Metabolic and Hormonal Responses during Acute Cold Exposure

Abstract

0902 PURPOSE: To examine the effects of nicotine on the metabolic and hormonal responses during acute cold exposure. METHODS: Six males and five females between the ages of 19 and 25 years participated in this study. All subjects were active, apparently healthy smokers. Each subject performed two cold air trials (CATs) consisting of a 30 minute baseline period (BASE) and a 120 min exposure to 10°C air. One CAT was performed following a nicotine dosing using a 21 mg transdermal patch (NIC) while the other trial was performed after a placebo treatment (PL). Blood samples were obtained at the end of BASE and immediately following the cold exposure. RESULTS: For males, norepinephrine tended to be higher during PL compared to NIC (4.73 ± 3.02 and 3.62 ± 2.44 nmol×L−1; P = 0.066). There was no difference in epinephrine between PL and NIC. The decrease in cortisol from BASE to 120 min of the CAT tended to be greater during PL compared to NIC (PL: −20%; NIC: −12%; P = 0.077). Glucose concentration tended to be lower during PL compared to NIC (5.1 ± 0.8 and 5.6 ± 1.1 mmol×L−1), however the decrease in glucose concentration from BASE to 120 min of the CAT tended to be less during PL compared to NIC (PL: −18%; NIC: −25%; P = 0.078). There was no difference in glycerol between PL and NIC. At BASE, non-esterified fatty acid concentration (NEFA) was lower during PL compared to NIC (0.45 ± 0.31 and 0.71 ± 0.20 mmol×L−1; P = 0.021), however at 120 min of the CAT, NEFA was greater during PL compared to NIC (1.21 ± 0.46 and 0.98 ± 0.32 mmol×L−1; P = 0.035) CONCLUSION: During 120 min of cold exposure, NIC resulted in alterations in the responses of norepinephrine, cortisol, glucose, and NEFA compared to PL, while epinephrine and glycerol were unaffected. Supported by the Wilderness Medical Society.