Arya M. Sharma, MD

Indigenous populations in most Westernised countries are well known to be particularly susceptible to obesity - the same can be certainly be said for Canada’s high Arctic Inuit population.

In a study just published online this week in the International Journal of Circumpolar Health, Tracey Galloway and colleagues from the University of Toronto and Montreal’s McGill University present results from the Nunavut Inuit Child Health Survey, a study in preschool-aged Canadian Inuit children.

As part of a larger study of population health across the Canadian High Arctic, the survey collected growth and nutrition data on 388 children aged 3 to 5 years.

While mean height-for-age was comparable, body mass index z-scores were significantly greater than a standard US reference population for all age and sex categories.

The overall prevalence of overweight was 50.8%, with significantly more boys (57.1%) than girls (45.2%) in the overweight category.

Although, the researchers could not find a definite explanation for the increased obesity risk in any of the biological, socio-economic and dietary factors, including birth weight, breastfeeding, day care attendance, traditional and market food consumption and sweetened beverage consumption in this population, they concede that their sample size may have been too small to detect such associations.

Nevertheless, a recent separate report from this survey, published in CMAJ, shows a high degree of food insecurity and a high prevalence of poverty indicators, both of which have been related to obesity in other populations.

In fact, the data on food insecurity are shocking: nearly 70% of Inuit preschoolers resided in households rated as food insecure. Children from severely food-insecure households experienced times in the past year when they skipped meals (75.8%), went hungry (90.4%) or did not eat for a whole day (60.1%).

In households in which children were moderately food insecure, primary caregivers reported experiencing times in the past year when they worried food would run out (85.1%), when they fed their children less expensive food (95.1%) and when their children did not eat enough because there was no money for food (64.3%).

Whatever the drivers of the childhood obesity epidemic, these new numbers certainly do not spell out a healthy future for Canada’s Northern-most inhabitants.

AMS
Edmonton, Alberta

Arab Food Pyramid

When we think of the global obesity epidemic, we tend to conjour up images of of US-Americans, literally hefting along excess pounds as they go about their lives across America. We may also recall that Canada and most other Western countries have a problem.

But, interestingly, nowhere is the obesity problem as big as in the countries of the Gulf Region and the Middle East (exceeded perhaps only by populations on remote Oceanic islands).

According to the United Arab Emirates global school-based student health survey (GSHS) 2005 fact sheet, over 30% of 13-15 year olds exceed the 85th percentile for body weights. The adult population (though it is hard to find accurate statistics) apparently does not fare much better.

Why, you may wonder, am I interested in this?

Because tonight I am heading out from Munich to speak on Saturday at the 1st International Abu Dhabi Diabetes Conference, in the United Arab Emirates.

Although the conference focusses on diabetes, it is obvious that the prime driver of the diabetes epidemic in that region of the world (as elsewhere) is the obesity crisis.

It is therefore not surprising that the organisers have opted to include sessions on obesity assessment and management (although most of the conference of course focusses on diabetes management, which I have often described as “palliative care”).

As should be obvious to anyone who has recently visited the UAE, population-based prevention measures in a society that spends most of its time indoors (I would too when it’s 40-50 degrees C outside) and enjoys food as one of the only officially endorsed “vices” (there are tough restrictions on alcohol, gambling and other worldly “pleasures”), is lilkely to be challenging if not simply impossible.

Given that the Arab susceptibility to obesity appears similar to other Asians in that they appear more prone to abdominal obesity with all its dire metabolic consequences, diabetes may in fact be the least of their worries.

I look forward to attending the meeting and learning more about the Arab “diabesity” epidemic from my friends and colleagues in the Emirates.

AMS
Munich, Germany

Today, I am speaking at the XII Congreso Internacional Avances en Medicina 2010 hosted by the Hospital Civil de Guadalajara (Thank you Juan Ricardo Lopez y Taylor for the kind invitation!).

There is indeed no denying that Mexico, as does everyone else in North America, has a substantial obesity problem.

As recently pointed out by Dudley Althaus, who writes for the Houston Chronicle:

“Though still afflicted by large pockets of the malnourished poor, Mexico is fat and quickly getting fatter, its children gaining weight faster than anyone else in the country.

About 70 percent of Mexican adults are now overweight, according to government estimates, more than triple the number of three decades ago. Also, about a third of the country’s schoolchildren and teenagers are overweight, making Mexicans the second-heaviest people on the planet, gaining quickly on their American neighbors.

With more people living in urban areas, and some with more money, Mexicans are eating more and exercising less. Forgoing the beans, tortillas, fruit and vegetables their grandparents ate, people flock to U.S.-style fast food.

Also, calorie-laden Mexican dishes once reserved for special occasions have become routine fare. Anything fried, packaged pastries, soft drinks and candy are widely available.”

Not surprisingly, last month, Mexican President Felipe Calderon launched a national campaign against obesity (beating the US Obama initiative by a few weeks) and called on parents, teachers and the food industry to guide people to more healthful living.

Whether or not this appeal will indeed have any noticeable impact on the obesity epidemic remains to be seen.  From my conversations with fellow delegates, at least the interest and concerns amongst health professionals seems considerable - but so does their sense of helplessness.

To read more by Dudley Althaus on the obesity problem in Mexico click here.

AMS
Guadalajara, Mexico

Despite the wide-spread concern about the health impact of the childhood obesity epidemic, there is actually not much data that directly shows how this excess weight may affect mortality.

Such data is now available at least for native American kids, from a study by Paul Franks (National Institutes of Health, Phoenix, AZ) and colleagues, just published in the New England Journal of Medicine.

The researchers analysed data from a cohort of 4857 American Indian (Pima or Tohono O’odham Indian) children without diabetes (mean age, 11.3 years) born between 1945 and 1984.

During a median follow-up period of around 24 years, death rates from endogenous causes among children in the highest quartile of BMI were more than double those among children in the lowest BMI quartile.

Similarly, rates of death from endogenous causes among children in the highest quartile of glucose intolerance were 73% higher than those among children in the lowest quartile and childhood hypertension was significantly associated with a 60% increased risk of premature death from endogenous causes.

Thus, at least in native Americans, childhood obesity is a significant risk factor for premature death - certainly a warning for those who believe that early obesity is something you can simply grow out of.

Given the raging epidemic of childhood obesity amongst the First Nations, Inuit, and Métis populations in Canada, these data should certainly prompt decisive action to address obesity amongst its native peoples.

AMS
Edmonton, Alberta

Yesterday, the Heart and Stroke Foundation of Canada released a report titled “A Perfect Storm” in which they present an alarming increase in hypertension and other cardiovascular risk factors in young adults.

According to this report, currently over 160,000 Canadians aged 20-30 and over 340,000 Canadians aged 35-44 are hypertensive.

This should really not come as a surprise, as the same report states that currently 40.5% or 2,5 million 20-30 year olds and 51.5% or another 2.4 million 35-44 year olds are overweight or obese.

Why, given these obesity numbers, does this increase in hypertension not surprise me in the least?

Because, as someone who has extensively worked on the relationship between excess weight and blood pressure, I am only all too familiar with the profound effect that overweight and obesity can have on blood pressure - especially in the young!

Thus, as we reported in a paper that was published back in 2004 in the American Journal of Hypertension, overweight and obesity are indeed the primary drivers of hypertension in the young.

In this cross-sectional study of 45,125 unselected consecutive primary care attendees in a representative nationwide sample of 1912 primary care physicians in Germany, we not only found that blood pressure levels were consistently higher in obese patients (increasing from 34.3% in normal weight to 60.6% in overweight, and well over 70% in obese individuals), but that this increase was also associated with markedly poorer blood pressure control rates (odds-ratio for good blood pressure control in diagnosed and treated patients was 0.8 in overweight and as low as 0.5 in obese patients).

However, even more relevant to yesterday’s report, was the clear finding that the younger the patients, the greater the impact of excess weight on their blood pressure.

As seen in the figure (click figure to enlarge), while in patients older than 60 years, there was little impact of BMI class on hypertension prevalence, in younger patients, there was a steep and consistent increase in hypertension rates with increasing BMI.

This is not surprising, when we look at the pathophysiology of hypertension, which in older individuals is driven almost entirely by stiffening of arteries and an increase in peripheral resistance (or in other words “aging”), while in younger individuals hypertension is driven mainly by the increased sympathetic activity, volume expansion, and increased cardiac output typically associated with excess weight.

Let us not forget that the prevalence of diabetes in the young (over 66,000 in 20-30 year olds and over 130,000 in 35-44 year olds according to the report) is also virtually entirely driven by overweight and obesity.

If all of this is not enough to get us to focus all our efforts on preventing and treating overweight and obesity, I don’t know what is.

If we want to prevent hypertension and diabetes in the young, we need to prevent overweight and obesity.

If we want to treat hypertension and diabetes in the young, we need to treat overweight and obesity.

It is that simple!

AMS
Edmonton, Alberta.