Smoking and thyroid. Thyroid and smoking. The inter-relation between smoking, very likely largely due to nicotine, and thyroid has been discussed here and elsewhere many times. The place it does NOT get mentioned is anywhere concerned with giving up smoking. You can get nicotine patches, anti-depressents such as Welbutrin, and several other interventions - but not once have I ever seen even a suggestion that a thyroid test might be sensible.
Well, have a read of these three recent abstracts.
Nicotine Tob Res. 2015 Jun;17(6):690-6. doi: 10.1093/ntr/ntu229. Epub 2014 Oct 30.
Withdrawal From Chronic Nicotine Reduces Thyroid Hormone Levels and Levothyroxine Treatment Ameliorates Nicotine Withdrawal-Induced Deficits in Hippocampus-Dependent Learning in C57BL/6J Mice.
Leach PT1, Holliday E1, Kutlu MG1, Gould TJ2.
Author information
1Temple University Department of Psychology, Neuroscience Program, Temple University, Philadelphia, PA.
2Temple University Department of Psychology, Neuroscience Program, Temple University, Philadelphia, PA tgould@temple.edu.
Abstract
INTRODUCTION:
Cigarette smoking alters a variety of endocrine systems including thyroid hormones. Altered thyroid hormone signaling may lead to a subclinical or overt hypothyroid condition that could contribute to nicotine withdrawal-related symptoms, such as cognitive deficits. Thus, normalizing thyroid hormone levels may represent a novel therapeutic target for ameliorating nicotine withdrawal-associated cognitive deficits.
METHODS:
The current studies conducted an analysis of serum thyroid hormone levels after chronic and withdrawal from chronic nicotine treatment in C57BL/6J mice using an enzyme-linked immunosorbent assay. The present studies also evaluated the effect of synthetic thyroid hormone (levothyroxine) on contextual and cued memory.
RESULTS:
The current studies found that nicotine withdrawal reduces secreted thyroid hormone levels by 9% in C57BL/6J mice. Further, supplemental thyroid hormone not only enhanced memory in naïve animals, but also ameliorated deficits in hippocampus-dependent learning associated with nicotine withdrawal.
CONCLUSIONS:
These results suggest that smokers attempting to quit should be monitored closely for changes in thyroid function. If successfully treated, normalization of thyroid hormone levels may ameliorate some deficits associated with nicotine withdrawal and this may lead to higher rates of successful abstinence.
© The Author 2014. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
PMID:
25358661
[PubMed - in process]
PMCID:
PMC4481724
[Available on 2016-06-01]
And...
Neurosci Biobehav Rev. 2015 Sep 4. pii: S0149-7634(15)00236-5. doi: 10.1016/j.neubiorev.2015.09.001. [Epub ahead of print]
Thyroid Hormone Signaling: Contribution to Neural Function, Cognition, and Relationship to Nicotine.
Leach PT1, Gould TJ2.
Author information
1Temple University Department of Psychology, Neuroscience Program, Temple University, Philadelphia, PA 19122.
2Temple University Department of Psychology, Neuroscience Program, Temple University, Philadelphia, PA 19122. Electronic address: tgould@temple.edu.
Abstract
Cigarette smoking is common despite its adverse effects on health, such as cardiovascular disease and stroke. Understanding the mechanisms that contribute to the addictive properties of nicotine makes it possible to target them to prevent the initiation of smoking behavior and/or increase the chance of successful quit attempts. While highly addictive, nicotine is not generally considered to be as reinforcing as other drugs of abuse. There are likely other mechanisms at work that contribute to the addictive liability of nicotine. Nicotine modulates aspects of the endocrine system, including the thyroid, which is critical for normal cognitive functioning. It is possible that nicotine's effects on thyroid function may alter learning and memory, and this may underlie some of its addictive potential. Here, we review the literature on thyroid function and cognition, with a focus on how nicotine alters thyroid hormone signaling and the potential impact on cognition. Changes in cognition are a major symptom of nicotine addiction. Current anti-smoking therapies have modest success at best. If some of the cognitive effects of nicotine are mediated through the thyroid hormone system, then thyroid hormone agonists may be novel treatments for smoking cessation therapies. The content of this review is important because it clarifies the relationship between smoking and thyroid function, which has been ill-defined in the past. This review is timely because the reduction in smoking rates we have seen in recent decades, due to public awareness campaigns and public smoking bans, has leveled off in recent years. Therefore, novel treatment approaches are needed to help reduce smoking rates further.
Copyright © 2015. Published by Elsevier Ltd.
PMID:
26344666
[PubMed - as supplied by publisher]
And...
Neuropharmacology. 2015 Jun;93:155-63. doi: 10.1016/j.neuropharm.2015.01.026. Epub 2015 Feb 7.
Thyroid receptor β involvement in the effects of acute nicotine on hippocampus-dependent memory.
Leach PT1, Kenney JW1, Connor DA1, Gould TJ2.
Author information
1Department of Psychology, Neuroscience Program, Temple University, Philadelphia, PA 19122, USA.
2Department of Psychology, Neuroscience Program, Temple University, Philadelphia, PA 19122, USA. Electronic address: tgould@temple.edu.
Abstract
Cigarette smoking is common despite adverse health effects. Nicotine's effects on learning may contribute to addiction by enhancing drug-context associations. Effects of nicotine on learning could be direct or could occur by altering systems that modulate cognition. Because thyroid signaling can alter cognition and nicotine/smoking may change thyroid function, nicotine could affect learning through changes in thyroid signaling. These studies investigate the functional contributions of thyroid receptor (TR) subtypes β and α1 to nicotine-enhanced learning and characterize the effects of acute nicotine and learning on thyroid hormone levels. We conducted a high throughput screen of transcription factor activity to identify novel targets that may contribute to the effects of nicotine on learning. Based on these results, which showed that combined nicotine and learning uniquely acted to increase TR activation, we identified TRs as potential targets of nicotine. Further analyses were conducted to determine the individual and combined effects of nicotine and learning on thyroid hormone levels, but no changes were seen. Next, to determine the role of TRβ and TRα1 in the effects of nicotine on learning, mice lacking the TRβ or TRα1 gene and wildtype littermates were administered acute nicotine prior to fear conditioning. Nicotine enhanced contextual fear conditioning in TRα1 knockout mice and wildtypes from both lines but TRβ knockout mice did not show nicotine-enhanced learning. This finding supports involvement of TRβ signaling in the effect of acute nicotine on hippocampus-dependent memory. Acute nicotine enhances learning and these effects may involve processes regulated by the transcription factor TRβ.
Copyright © 2015 Elsevier Ltd. All rights reserved.
KEYWORDS:
Acetylcholine; Fear conditioning; Gene; Learning and memory; Nicotine; Thyroid; Thyroid receptor
PMID:
25666034
[PubMed - in process]
PMCID:
PMC4387063
[Available on 2016-06-01]
OK folks - how many of you gave up smoking shortly before starting to suffer thyroid issues, or saw them worsen?