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Smoking and the endocrine system

A new paper includes these paragraphs about smoking and thyroid and other hormones.

Smoking and the endocrine system

Smoking influences hypophyseal, thyroid, adrenal, testicular and ovarian functions, calcium metabolism, and the activity of insulin (Stárka et al. 2005). In addition to nicotine, other toxins from cigarettes mediate the effects on hormonal secretions. For instance thiocyanate acts on the thyroid gland, with the main clinical effect being an increased risk and seriousness of Graves-Basedow toxicity (G-B toxicity) and endocrine orbitopathy, osteoporosis, and infertility. It also contributes to insulin resistance, and thus diabetes type 2. Concerning the influence of smoking on the embryo, there are two important effects: smoking by the mother leads to increased catecholamine production, which causes a lower flow rate in the fetoplacental unit, and the effects of thiocyanate can lead to defects in the size and function of the embryonic thyroid gland (Kapoor and Jones 2005).

Smoking also alters the levels of endogenous steroid hormones. Both acute and chronic smoking increase plasma levels of cortisol, with cortisol levels correlating with the number of cigarettes smoked daily (Kirchbaum et al. 1992). Nicotine immediately activates the hypothalamic -hypophyseal -adrenocorticol axis (HPA). The cessation of smoking first leads to an increase in cortisol, but then a subsequent change in HPA activity and a dramatic decline in cortisol levels (Kirchbaum et al. 1992, Frederick et al. 1998). This decline, and the associated lowered sensitivity to stress, often predicts an imminent relapse. Declines in the ratio of dehydroepiandrostenedione (DHEA) to cortisol during the first eight days of quitting smoking have been associated with relapse in the following weeks (Rasmusson et al. 2006). Interestingly, this study demonstrated that the correlation between hormonal imbalance and relapse is only significant in men. In women, the prediction of relapse has rather been associated with the intensity of withdrawal symptoms (al'Absi 2006).


4 Replies

Interesting for anyone wishing to quit.

1 like

I’ve never smoked and none of my family smoked. Never played a part in my health issues.


I smoked 20 a day for 35 years (from the age of 15) and finally managed to stop just short of 14 years ago. I thought I'd never be able to do so, not even my dad's death of lung cancer stopped me... Then I was given a paperback book by Allen Carr (not either of the comedians) called 'The Easy Way to Stop Smoking'. I read it in a day, smoking all the time I was reading it. When I finished it, I put away all of the smoking paraphernalia and have never smoked another cigarette since.

To be honest, I never felt any inclination to relapse an hour, a day, 8 days or 13 years since then. My cortisol levels aren't brilliant, I will admit, but going back to lighting up has never been an issue. I just wish I'd done it 18 years earlier when my dad died!

So, I'm not entirely sure how accurate this research is... it certainly never applied in my case!


Glad I kicked a 60 a day habit!


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