Dr. Sharma's Obesity Notes: August 2008

Monday, August 25, 2008

Another Obesity Drug for Obesity?

Dear Readers,

As of Aug 11, my blog has moved to my home page - you can read today's post here.

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Should you experience any problem cancelling your subscription to the old site, please do not hesitate to contact me at amsharm@ualberta.ca

Looking forward to your continuing interest, comments and support,

AMS
Edmonton, Alberta

Friday, August 22, 2008

Could Obesity Cost Canadians $95 Billion in 2008?

Thursday, August 21, 2008

Pros and Cons of Video Games

Wednesday, August 20, 2008

Obesity is Unfair to Women

Monday, August 18, 2008

Obesity is a Sign, Overeating is a Symptom

Sunday, August 17, 2008

Obesity Needs Treatment Forever

Friday, August 15, 2008

Drugs Don’t Work in Patients who Don’t Take Them

Thursday, August 14, 2008

Intragastric Balloons for Obesity

Wednesday, August 13, 2008

Does Regular Weighing Help Control Weight?

Tuesday, August 12, 2008

Do Pedometers work?

Dear Readers,

As of Aug 11, my blog has moved to my home page - you can read today's post here.

- If you subscribe by email, you will need to update your email subscribtion here!

- If you subscribe by RSS, your feed should redirect automatically.

- Please change your bookmarks (and any web links) to point to drsharma.ca!

- Old posts have already been transfered to the new location and soon the content at this location will no longer be updated.

Looking forward to your continuing interest, comments and support,

AMS
Edmonton, Ablerta

p.s. if you have already subscribed to the "new blog" and are still receiving this message - please remember to unsubscribe to this message. If you experience any difficulty (or are confused), simply e-mail me at amsharm@ualberta.ca

Monday, August 11, 2008

Dr. Sharma's Obesity Blog Has Moved

Dear Readers,

As of today, my blog has moved to my home page - you can read today's post here.

- If you subscribe by email, you will need to update your email subscribtion here!

- If you subscribe by RSS, your feed should redirect automatically.

- Please change your bookmarks (and any web links) to point to drsharma.ca!

- Old posts have already been transfered to the new location and soon the content at this location will no longer be updated.

Looking forward to your continuing interest, comments and support,

AMS
Edmonton, Ablerta

Friday, August 8, 2008

Does Obesity Kill Kidneys?

Kidneys are exquisitely sensitive to many risk factors that can also accelerate atherosclerosis and heart disease. Thus, high blood pressure and diabetes are well-established risk factors for chronic kidney disease (CKD).

Because both hypertension and diabetes are in turn linked to obesity, the question is: does obesity increase the risk for CKD?

This questions was now addressed by Meredith Foster and colleagues from the National Heart, Lung, and Blood Institute, Framingham, MA, USA, who studied the relationship between Stage 3 CKD (= moderately reduced kidney function) and BMI in the Framingham Offspring participants (n = 2,676; 52% women; mean age, 43 years) free of stage 3 CKD at baseline who participated in examination cycles 2 (1978-1981) and 7 (1998-2001). (Am J Kidney Dis)

While there was no increased risk of kindey disease in overweight participants, obese individuals had a 68% increased odds of developing Stage 3 CKD (estimated glomerular filtration rate < 59 mL/min/1.73 m(2) for women and < 64 mL/min/1.73 m(2) for men).

However, this relationship became non-significant when data was adjusted for diabetes, systolic blood pressure, hypertension treatment, current smoking status, and high-density lipoprotein cholesterol level.

The authors rightly conclude that the link between obesity and CKD is largely explained by the effect of obesity on other cardiovascular risk factors like hypertension or diabetes.

Clearly, if your excess weight is raising your blood pressure and/or making you diabetic, you may need to start worrying about your kidneys.

AMS
Edmonton, Alberta

Thursday, August 7, 2008

Adolescent Obesity Kills Middle-Aged Adults

Yes, there's a childhood and adolescent obesity epidemic out there. The word on the street now is that "this is the first generation of kids, who will not outlive their parents".

But is this really true? Where is the data showing that childhood obesity is really a risk factor for early death?

This question is now answered by perhaps the largest study on this issue to date published by Tone Bjørge and colleagues from the University of Bergen, Norway, in the American Journal of Epidemiology.

Bjørge and colleagues studied the relationship between BMI (measured height and weight) and mortality in 227,000 adolescents (aged 14-19 years) recruited in Norwegian health surveys in 1963-1975. During follow-up (8 million person-years), 9,650 deaths were observed. Cause-specific mortality was compared among individuals whose baseline BMI was below the 25th percentile, between the 75th and 84th percentiles, and above the 85th percentile in a US reference population with that of individuals whose BMI was between the 25th and 75th percentiles.

Risk of death from endocrine, nutritional, and metabolic diseases and from circulatory system diseases was increased in the two highest BMI categories for both sexes. Relative risks of ischemic heart disease death were 2.9 for males and 3.7 for females in the highest BMI category compared with the reference. There was also increased risk of death from colon cancer (males: 2.1; females: 2.0), respiratory system diseases (males: 2.7; females: 2.5), and sudden death (males: 2.2; females: 2.7).

The authors conclude that adolescent obesity is related to increased mortality in middle age from several important causes.

Clearly not a good sign for what awaits our sons and daughters unless we get a hold on the obesity crisis.

AMS
Edmonton, Alberta

Wednesday, August 6, 2008

Sibutramine Lowers Blood Pressure in High-Risk Patients

Sibutramine (Meridia) is a serotonin and norepinephrine reuptake inhibitor (SNRI) licensed as a prescription drug for obesity treatment.

Although sibutramine has been available for around a decade in over 70 countries and has been shown to reduce weight and improve comorbidities and risk factors in patients with obesity, its potential to increase blood pressure in some patients has remained an important barrier to its widespread use.

In the most recent issue of Diabetes Obesity and Metabolism, together with other colleagues from the Executive Steering Committee, we now publish an analysis of blood pressure changes associated with sibutramine during the 6-week lead-in period of the sibutramine cardiovascular outcomes trial (SCOUT), an ongoing, double-blind, randomized, placebo-controlled trial in over 10,000 overweight/obese patients at high risk of a cardiovascular event.

During the 6-week lead-in period, 10,742 patients received sibutramine and weight management. At entry, approximately 50% of patients were hypertensive and 26% were high-normal.

In hypertensive patients, blood pressure decreased by median of -6.5 mmHg systolic and -2.0 mmHg diastolic (p < 0.001). Even hypertensive patients with no weight loss or with weight gain had median decreases of -3.5 mmHg systolic and -1.5 mmHg diastolic (p < 0.001). Approximately 43% of patients initially categorized as hypertensive had a lower blood pressure category at end-point.

On the other hand, normotensive patients had median increases of 1.5 mmHg systolic and 1.0 mmHg diastolic (p < 0.001) which was attenuated with increasing weight loss.

As expected, pulse rates were uniformly elevated (median 1-4 bpm, p < 0.001) across blood pressure and weight change categories.

Although it must be remembered, that all patients received sibutramine during the lead-in period and therefore some decrease in blood pressure may be due to regression to the mean, the data confirm that even in patients at high risk for cardiovascular events, the vast majority of patients (especially if hypertensive) will experience a reduction in blood pressure.

Whether or not treatment with sibutramine will also reduce cardiovascular mortality of course remains to be seen when the study finishes sometime next year.

In the meantime, these data reinforce the notion that sibutramine can indeed be used in the vast majority of patients with controlled hypertension without having to fear an increase in blood pressure.

Obviously, in the few patients who do happen to experience an increase in blood pressure, adjustments in antihypertensive medications or discontinuation of sibutramine should be considered.

AMS
Edmonton, Alberta

Conflict of Interest: I am on the Executive Steering Committee of the SCOUT trial and am reimbursed for my time and effort by Abbott Laboratories, the maker of sibutramine

Tuesday, August 5, 2008

Obesity Treatment is Prevention!

In the August 4 issue of the Globe and Mail, the science journalist Andre Picard puts forth the argument (as discussed at the International AIDS conference) that AIDS treatment is prevention because treated patients are less likely to transmit the disease.

The same, if not more, could be said about treating obesity. Not only is obesity a major driver of a laundry list of mental and physical health issues, including type 2 diabetes, osteoarthritis, and cancer – its treatment has been well documented to help prevent, and in some instances, even cure these conditions. Thus, for example, obesity treatment not only prevents type 2 diabetes, but can often reverse it to the point of cure. Obesity surgery also reduces cancer deaths by 60%.

But obesity treatment is perhaps also the most effective prevention for obesity itself. There is now accumulating evidence that genetic modifications that occur in the womb and during the first months of life in the offspring of overweight and obese mothers, essentially programs their kids for obesity later in life. Perhaps the best example of how aggressive obesity treatment in women can prevent obesity in their kids comes from a Laval University study where the children of obese women, who had undergone obesity surgery, were far less likely to become obese than expected.

Many experts now believe that perhaps our best handle on the childhood obesity epidemic is to also aggressively target the parents for obesity treatments – indeed, there is little evidence that treating the kids without doing the same for the parents is likely to be successful in the long term.

Furthermore, the recent observation that obesity may be “contagious” amongst peers, has also prompted serious discussions about whether targeting obese individuals would prevent the spread of this disorder to friends and family.

Thus, while we wait for policy makers and individuals to make important inroads into obesity prevention by changing our obesogenic environment and lifestyles, we need to also seriously step up our investments in obesity treatments – not only for the sake of the individuals who struggle with this condition – but also for the sake of their families and friends.

AMS
Edmonton, Alberta

Monday, August 4, 2008

Another Successful Obesity Boot Camp

I spent all of last week at the 2008 Obesity Boot Camp co-organized by the Canadian Obesity Network (CON) and the Merck-Frosst/CIHR Obesity Chair at the University of Laval, QC.

As in the two previous camps, this year's camp once again brought together some of the best and brightest students and new professionals from across Canada for over 100 hours of education and social activities (including the Tree Top Adventure, Kayaking, tour of Quebec City and the obligatory late night excursions to DD).

Overall I have no doubts that, as in previous camps, some friendships have been forged for life - both personal and professional.

For my part, I again learnt a lot from listening and interacting with the students and faculty. While there continue to be no easy solutions to obesity in sight, there certainly are reasons for optimism, seeing the enthusiasm with which the students are preparing to face the challenge of solving one of the greatest global health problem of our times.

The Canadian Obesity Network is grateful to all of the faculty and supporters who made this camp possible.

Personally, I look forward to continuing interactions with the Boot Camp Alumni over the coming months and years.

AMS
Edmonton, Alberta

Friday, August 1, 2008

Exercise in a Pill

Physical activity has numerous beneficial effects on mental and physical health. With the reduced need for physical activity to ensure our basic needs (utilitarian activity), it is increasingly up to the individual to compensate by consciously engaging in recreational (non-utilitarian) activity, generally referred to as exercise.

Numerous barriers exist to engaging in exercise, including time limitations, lack of motivation, and pain or injury. Researchers have therefore pursued the idea of being able to mimic the beneficial effects of exercise with the help of drugs that induce the same gene-expression patterns and metabolic changes seen with exercise.

In yesterday's issue of CELL, Vihang Narkar and colleagues from the Salk Institute, La Jolla, CA report on their findings that the combination of an orally active AMPK agonist with a PPARβ/δ agonist can induce metabolic genes and dramatically enhance running endurance in sedentary mice. Furthermore, the PPARβ/δ agonist in combination with exercise synergistically induced fatigue-resistant type I fibers and mitochondrial biogenesis, ultimately enhancing physical performance

These results demonstrate that AMPK-PPARδ pathway can be targeted by orally active drugs to enhance training adaptation or even to increase endurance without exercise.

Obviously, treatments that work in mice may not be as effective or safe in humans. Furthermore, the researchers did not actually demonstrate that the induction of metabolic genes and increased endurance actually improves the health of the mice.

But the results are promising and certainly a major step towards developing a pharmacological alternative to exercise.

In the meantime, however, there is no alternative to being as physically as you can. As Angelo Tremblay, presenting today to the students at the CON Obesity Boot Camp emphasized, increased participation in physical activity is a key characteristic of individuals who lose weight and manage to keep it off.

AMS
Duschesnay, Quebec

Clip art licensed from the Clip Art Gallery on DiscoverySchool.com