Monday, December 22, 2008
Paradoxically, however, it turns out that smoking, at least in teenagers, strongly promotes the development of abdominal obesity – the dangerous fat that leads to diabetes, dysplipidemia and heart disease.
This at least is the observation reported by Suoma Saarni, University of Helsinki, Finland published in the American Journal of Public Health.
Using the FinnTwin16 sample, a prospective, population-based questionnaire study of 5 consecutive and complete birth cohorts of Finnish twins born between 1975 and 1979 (N=4296), studied at four points between the ages of 16 and 27 years, Saarni and colleagues analyzed the effect of adolescent smoking on abdominal obesity and overweight in early hood.
Smoking at least 10 cigarettes daily when aged 16 to 18 years increased the risk of abdominal obesity by around 30% for all participants. However, for women, the risk of becoming overweight after adjustment for possible confounders, including baseline BMI was almost 75% higher.
The authors conclude that teenage smoking is a risk factor for abdominal obesity among both genders but especially in women.
How smoking leads to abdominal obesity is not entirely clear. Are smokers prone to developing metabolic changes like insulin resistance or high sympathetic activity that may lead to abdominal fat? Are smokers more likely to become “addicted” eaters as they grow older (and stop smoking)? Are smokers less physically active than non-smokers, thereby becoming more prone to abdominal fat deposition? Do smokers make poorer food choices (e.g. more transfats)?
It appears that more work needs to be done before we fully understand the link – however, a clear message to those who smoke to control their weight – smoking is unhealthy, period.
Using tobacco to control weight makes no sense – a few pounds gained with smoking cessation are nowhere near the risk posed by continued smoking.
Friday, December 19, 2008
Curiously, however, at least in Canada, overweight and obesity appear to be more common in higher-income middle class men than in those who are less well off.
This at least is the result of a new analysis of the 2004 Canadian Community Health Survey, performed by Stefan Kuhle and Paul J. Veugelers of the University of Alberta for Statistics Canada.
The key finding of this study is, that in contrast to women, where the social gradient holds in that lower SES women tend to have more overweight and obesity, in men, there is a strong inverse relationship between SES in that higher income men are apparently at greater risk for excess weight.
This increased risk for obesity in higher-income men is associated with a greater tendency to eat out as well as a lesser likelihood to be smokers. Eating out has been identified as a strong risk factor for weight gain, while smoking cessation is well-known to be associated with weight gain.
Carly Weeks, who interviewed me about these findings for the Globe & Mail, quoted me as follows:
“That’s likely because men and women tend to have vastly different perceptions of their body image and how they should look, according to Arya Sharma, professor of medicine and chair of obesity research and management at the University of Alberta.”
“[Women] are more likely to be dieting and more likely to be working [out] and doing things about their weight,” said Dr. Sharma, who is also the scientific director of the Canadian Obesity Network. “Men are very cavalier about it.”
For the full Globe & Mail report click here.
The reason this report is alarming is because men (rich or poor) are so much less likely to seek obesity treatments than are women. Indeed, our clinic is dominated by overweight and obese women, rather than by the men, who probably need treatment as much if not more, given their greater propensity for abdominal obesity and risk for complications.
How do we get more men to seek obesity treatments? Look forward to any suggestions on this.
Thursday, December 18, 2008
Anyone, who followed the US elections, may have heard Gov. Palin’s remark on the considerable public money that is being “wasted” on studying the fruit fly (for the YouTube video of her statement click here).
Good thing Gov. Palin did not also mention “worm” research, especially research on the lowly c. elegans, a 1 mm long nematode (round worm), which has been extensively used as a model organism in biomedical research. Because, as it turns out, a genetic mutation found in this worm may hold the key to a novel target for obesity treatments – at least according to a paper by Patrick Narbonne and Richard Roy from McGill University, Montreal, Canada, just published in Nature.
C. elegans, like many other organisms can survive harsh environmental conditions for extended durations by changing their metabolism in ways that essentially allow them to live off their fat stores seemingly forever (a state referred to as “dauer” that can last for six months).
Narbonne and Roy found that C. elegans larvae that lack a certain signaling pathway (the LKB1/AMPK pathway to be precise), which is activated during dauer, quickly downregulate fat mobilization so that lipid reserves are rationed to last the entire duration of the arrest.
In contrast, worms that have a mutation in this pathway enter dauer, but then rapidly burn up their fat stores and die prematurely.
By better understanding how this pathway works and assuming that a similar pathway is present and effective in humans, it may be possible to target this system in order to promote fat mobilization and oxidation in people with overweight and obesity.
Obviously this still is a long stretch and will take a lot more work to understand if and how this system actually works. From there to finding a drug that is safe and effective is of course a whole other venture.
Nevertheless, this work nicely demonstrates how fundamental work in seemingly primitive and irrelevant organisms (like a primitive worm) can perhaps lead to completely new targets that may someday prove to be helpful in finding novel treatments for the biggest health problem of our times.
Wednesday, December 17, 2008
OK, I am not actually on Oprah (yet?) – rather, this post is only about comments I was asked to make about Oprah’s “catastrophic” weight regain by Judith Timson, who interviewed me for her column, which appeared in yesterday’s Globe and Mail.
To read what Judith (and I) had to say – click here
Last week, Yoni blogged about the same topic – for his take on Oprah – click here
I think Oprah has made the same mistake that most people make – they think there somehow must be a “cure”.
Unfortunately, there isn’t – there are only treatments – when you stop the treatment, the weight comes back – ALWAYS!
End of Story!