Rupprecht, Laura
(2017)
THE RELATIONSHIP BETWEEN NICOTINE AND BODY WEIGHT: IMPLICATIONS FOR TOBACCO REGULATORY POLICY FROM RATS & HUMANS.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Smokers weigh less than non-smokers and former smokers, an observation that has been attributed to nicotine in cigarette smoke. Despite the ability of nicotine to suppress weight gain, body mass index is positively associated with smoking intensity. These phenomena suggest a complex relationship between nicotine and body weight: that nicotine impacts body weight, and that body weight may modify nicotine reinforcement. This dissertation tests the hypotheses that self-administered nicotine suppresses body weight and that body weight impacts nicotine reinforcement in rats and human smokers. Experiments tested these hypotheses in a rat model of nicotine self-administration and in human smokers. First, we demonstrated that self-administered nicotine suppressed body weight gain independent of food intake in rats. Acquisition of low dose nicotine self-administration resulted in suppression of weight gain. In contrast, reduction of nicotine dose from a prior higher dose increased weight gain. Experiments using indirect caliorimetry demonstrated that self-administered nicotine in rats suppressed respiratory exchange ratio, indicating increased fat utilization, prior to a nicotine-induced suppression of weight gain. Self-administered nicotine suppressed the proportion of fat mass, but not lean mass. Next, we evaluated weight gain in human smokers randomized to smoke very low nicotine content (VLNC) cigarettes. These data align with the rat self-administration data; smokers compliant with VLNC cigarettes gained weight over 6 weeks of use. As the current environment is obesogenic, the next experiment tested the impact of self-administered nicotine on obesity-prone and obesity-resistant rats and found that nicotine failed to suppress weight gain in obesity-resistant rats. Finally, we tested the ability of body weight and/or diet to impact nicotine self-administration. In obese smokers and rats, smoking/nicotine intake was increased, but decreased per body mass, suggesting that nicotine intake is titrated dependent on body mass. In sum, self-administered nicotine acts to suppress weight gain likely via increased fat utilization, and nicotine consumption is titrated dependent on weight. A potential strategy to reduce the health burden of smoking is a reduction in the nicotine content of cigarettes, which is hypothesized to reduce smoking and promote quitting. Thus, data reported in this dissertation has important implications for tobacco regulatory policy.
Share
| Citation/Export: |
|
| Social Networking: |
|
Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
|
| Date: |
28 September 2017 |
| Date Type: |
Publication |
| Defense Date: |
29 March 2017 |
| Approval Date: |
28 September 2017 |
| Submission Date: |
16 May 2017 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
174 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Neuroscience |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
nicotine, obesity, weight |
| Date Deposited: |
29 Sep 2017 00:12 |
| Last Modified: |
29 Sep 2017 00:12 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/32009 |
Metrics
Monthly Views for the past 3 years
Plum Analytics
Actions (login required)
 |
View Item |
![[feed]](/images/feed-icon-32x32.png){kind=icon}