Follow me on

Is Asthma Overdiagnosed in Obesity?

Exertional dyspnoe, including puffing and wheezing suggestive of asthma, is not uncommon in patients with overweight and obesity.

But how much of this is really asthma?

This question was addressed by Shawn Aaron and other members of the Canadian Respiratory Consortium in a study published last week in CMAJ.

Aaron and colleagues conducted a longitudinal study of 242 obese (BMI >30) individuals with physician-diagnosed asthma, identified by random dialing in 8 Canadian cities. A diagnosis of current asthma was excluded in those who did not have evidence of acute worsening of asthma symptoms, reversible airflow obstruction or bronchial hyperresponsiveness, despite being weaned off asthma medications.

Asthma was ultimately excluded in 31.8% of obese patients, of whom 65% did not need to take asthma medications or seek health care for asthma symptoms during a 6-month follow-up period.

This study shows that only 2 in 3 obese patients treated for asthma actually have asthma.

Now if anyone thinks that asthma is only overdiagnosed in obese patients, it is worth pointing out that the rate of overdiagnosis of asthma was virtually identical (28.7%) in the 254 non-obese (BMI 20-25) individuals also examined in the same study.

Thus, the really surprising finding of this study for me is that overdiagnosis of asthma is NOT more likely in obese patients than in non-obese patients. This is certainly unexpected, given the fact that exertional dyspnoe, which is indeed more common in obese individuals, can indeed mimic asthma.

The alarming piece in this finding though, as pointed out in an accompanying editorial by Matthew Stanbrook and Alan Kaplan, is that

“Asthma misdiagnosis in patients with persistent or recurrent symptoms has important and potentially serious consequences to both patients and the health care system. Symptoms assumed to be due to asthma may instead signify another medical condition that thereby goes undiagnosed and untreated. Asthma … can only be reliably distinguished with objective testing. Because asthma is a chronic disease, the consequences of misdiagnosis may extend for many years.” 

The bottom line is that suspected asthma should always be confirmed with spirometry – especially in obese patients, where restriction and/or simply the increased oxygen cost of breathing can cause breathlessness, which is easily misdiagnosed as asthma.

Edmonton, Alberta
p.s. don’t forget to vote for your favourite Health Blog by clicking here!


Pregnancy and Fertility after Bariatric Surgery

Today I am presenting a talk on obesity at the 54th Annual Meeting of the Canadian Fertility and Andrology Society, being held in Calgary, Alberta. The reason that I’ve been invited, is because, as many of you know, excess weight has a significant negative effect on fertility rates. Indeed, obesity may today be by far the most frequent cause of failure to conceive.

While my talk is on the general approach to obesity diagnosis and management, it is timely that in this week’s issue of JAMA, Melinda Maggard et al. from the University of California, Los Angeles, CA, publish a systematic review on pregnancy and fertility following bariatric surgery.

For their review, Maggard and colleagues searched the Nationwide Inpatient Sample (1998-2005) and multiple electronic databases to identify articles published between 1985 and February 2008 on bariatric surgery among women of reproductive age. Of 260 screened articles, 75 were included. Women aged 18 to 45 years accounted for 49% of all patients undergoing bariatric surgery (>50,000 cases annually for the 3 most recent years).

Matched cohort studies showed lower maternal complication rates after bariatric surgery than in obese women without bariatric surgery, or rates approaching those of nonobese controls. Rates of gestational diabetes (0% vs 22.1%, P < .05) and preeclampsia (0% vs 3.1%, P < .05) were lower in the bariatric surgery patients. These findings were supported by 13 other bariatric cohort studies.

Neonatal outcomes were similar or better after surgery compared with obese women without laparoscopic adjustable gastric band surgery (7.7% vs 7.1% for premature delivery; 7.7% vs 10.6% for low birth weight, P < .05; 7.7% vs 14.6% for macrosomia, P < .05).

Unfortunately, studies regarding nutrition, fertility, cesarean delivery, and contraception were limited.

For e.g. on the issue of fertility, the authors identified 6 studies generally showing improved fertility, although due to lack of a denominator (the number of women actually trying to get pregnant), the impact of surgery is hard to determine. Nevertheless, data clearly shows improvements to complete disappearance of polycystic syndrome and normalization of hormonal patterns and return of normal menstrual cycles.

On the issue of contraception there are isolated reports of failure of contraception following bypass surgery – systematic or controlled trial are lacking.

In summary, the authors concluded that the rates of many adverse maternal and neonatal outcomes may be lower in women who become pregnant after having had bariatric surgery compared with rates in pregnant women who are obese; however, as almost always in this rapidly evolving field of medicine, further data are needed from rigorously designed studies.

Clearly, the good news is that bariatric surgery is not a barrier to having healthy babies – babies, which, as we know from other studies, may in fact have a far lower risk for future obesity, than babies from severely obese mothers, who have not undergone bariatric surgery before pregnancy.

Edmonton, Alberta

p.s. don’t forget to vote for your favourite Health Blog by clicking here!


Obesity Epidemic Hits India

Yesterday, the Indian Ministry of Health and Family Welfare proposed new obesity guidelines, which reduce the BMI criteria for the diagnosis of overweight and obesity to 23 and 25 respectively.

Likewise, the abdominal circumference cutoffs for abdominal obesity have been reduced to 90 cm for men and less than 80 cm for women, i.e. 12 cm and 8 cm, respectively, lower than the cutoff for abdominal obesity in the West.

According to these guidelines, people with BMI of 25 and above will be considered for initiating drug therapy, eligibility for bariatric surgery requires a BMI of 32.5.

These lower cutoff levels are fully in line with the greater metabolic risk posed by excess weight in people of South Asian origin – currently already home to the largest number of patients with diabetes anywhere in the world. The current load of diabetes in India (41 million) is expected to increase by 170% in the next 20 years.

This new definition of obesity, means that currently 15% of the Indian population have obesity – not too far behind Canada, where the population prevalence of obesity is only 3% points higher. Remarkable statistics for a country, where a significant proportion of the population still performs hard manual labour and has modest access to nutritious foods.

According to my good friend and colleague Dr. Anoop Misra, director and head, department of diabetes and metabolic diseases, Fortis Hospitals, New Delhi and Noida, “The guidelines – with revised statistics – will benefit the additional 15-20 per cent (60-80 million) of the Indian population who can now be clinically termed obese under the revised measurement.”

How India will cope with the treatment of obesity at a population level is unclear. Knowing that so far no society has succeeded in preventing or managing the obesity epidemic (e.g. it is hard to imagine how we will actually deliver obesity treatments to the 600,000 Albertans who need it), it will be interesting to see how a country like India, with its limited health care resources, will even begin to cope.

It is perhaps most timely that I have been invited to speak and chair sessions at the forthcoming 5th Asia-Oceania Obesity Conference to be held in Mumbai in February 2009 – I certainly look forward to some interesting discussions with my Indian colleagues.

Edmonton, Alberta

p.s. don’t forget to vote for your favourite Health Blog by clicking here!


Nominated for Best Canadian Health Blog

Thanks to my friend Yoni, I found out that I have been nominated for the Best Health Blog Category in the Canadian Blog Awards!

There are two rounds to voting: the first round began a couple of days ago and ends Nov. 30th.

The other health blogs nominated include:

  • Ottawa Street Dental
  • Medical Education Blog
  • Breast Reloaded
  • Canadian Medicine
  • Prostate Reloaded
  • Fibromyalgia and Exercise
  • ZXC
  • Marijke: Nurse turned writer
  • Facing Autism in New Brunswick
  • My Journey With AIDS
  • Salted Lithium
  • Baby will you love me when i’m bald?
  • Weighty Matters
  • Feel free to take a look at all of these great blogs including my friend and colleague Yoni’s.

    When you’re ready to vote just click here!

    To see all the other categories click here!

    Edmonton, Alberta


    Severe Obesity is Not a Choice!

    Last week, the Supreme Court of Canada passed a ruling that would entitle severely handicapped individuals to be accommodated on airlines and specifically extended this ruling to include individuals, who were severely handicapped because of excess weight. This ruling resulted in a flood of raves and rants on why the Supreme Court would promote obesity by accommodating rather than punishing obese people for their laziness and indulgence. The Globe & Mail commentator went as far as to imply that by extending the ruling to obese individuals, the Supreme Court was in fact undermining the case for people with “real disabilities”.

    In light of this ridiculous and discriminating accusation, I could not help but write the following letter to the Globe & Mail:

    As Medical Director of one of the largest medical obesity programs in the country, I am appalled at the notion that including obesity in the recent Supreme Court judgement on accommodation of disabled people on airline flights, should be considered by the Globe & Mail commentator as anything but fair. To be clear, this ruling does not provide free rides for anyone with a few pounds excess weight – this ruling is specific in that it addresses the issues of individuals, who suffer from a condition so disabling that they require help with even the most basic functions. The idea that someone with such severe disabling obesity, has gained that amount of weight (often several hundred excess pounds) simply by lack of willpower or sheer laziness rather than some underlying genetic, mental heath or medical issue is not only naïve but also reflects the prevailing negative stereotyping, prejudice and discrimination toward obese individuals, that appears to be perfectly acceptable even to otherwise compassionate and reflective individuals. But that is not even the point.

    The point is that the Globe & Mail commentator, unlike the Supreme Court, uses causality as a criterium for judging which disability is deserving of special accommodation and which is not. By those standards, it would be fair to ask if the person claiming disability due to a spinal cord or brain injury from a motor vehicle accident was in fact observing the speed limit at the time of the accident or if the person who suffered a disabling stroke always religiously took her blood pressure medications and passed on the salt. Singling out individuals disabled by severe obesity as the only group undeserving of special accommodation is blatant discrimination and belies even a remote understanding of the complex and heterogeneous nature of this unfortunate condition that today befalls so many in our society. Individuals disabled by severe obesity are neither more nor less deserving of accommodation than are folks who loose their eyesight to diabetes, their limbs to smoking, their kidneys to analgesic abuse or their mobility to a reckless sporting injury.

    Arya M. Sharma, MD
    Professor of Medicine and Medical Director of the Alberta Health Services (Edmonton Area) Weight Wise Program, Edmonton Alberta.

    Obviously, I have no idea whether or not the G&M will chose to print or respond to this letter.

    For anyone interested in the issue of Weight Bias, this is the topic of a whole supplement to this month’s issue of OBESITY, which includes 14 research articles on the “New Science of Weight Bias: a Significant Social Problem“.

    Edmonton, Alberta


    Bariatric Surgery for Pediatric Obesity

    It’s sad but true – the number of kids requiring surgery for severe obesity is alarmingly on the rise and this once rare and drastic treatment is now often the only viable option.

    But how safe is obesity surgery in kids and what are the outcomes?

    This question was now addressed by Jonathan Tradwell and colleagues from the Evidence-Based Practice Center and Health Technology Assessment Information Service, Plymouth Meeting, PA, who performed a systematic review and meta-analysis of bariatric surgery for pediatric obesity just published in the Annals of Sugery.

    Based on a systematic search of MEDLINE, EMBASE, 13 other databases, and article bibliographies to identify relevant evidence for studies reporting outcome data for three or more patients younger than 21 years of age or representing more than 50% of pediatric patients enrolled at that center with a minimum 1-year follow-up for weight and body mass index (BMI), the authors identified 8 studies of laparoscopic adjustable gastric banding (LAGB) reporting data on 352 patients (mean BMI 45.8), 6 studies of Roux-en-Y gastric bypass (RYGB) including 131 patients (mean BMI 51.8), and 5 studies of other surgical procedures including 158 patients (mean BMI 48.8). Average patient age was 16.8 years (range, 9-21).

    Meta-analyses of BMI reductions at longest follow-up indicated sustained and clinically significant BMI reductions for both LAGB and RYGB patients. Comorbidity resolution was sparsely reported, but surgery did appear to resolve some medical conditions including diabetes and hypertension.

    For LAGB patients, band slippage and micronutrient deficiency were the most frequently reported complications, with sporadic cases of band erosion, port/tube dysfunction, hiatal hernia, wound infection, and pouch dilation.

    For RYGB patients, more severe complications were documented, including pulmonary embolism, shock, intestinal obstruction, postoperative bleeding, staple line leak, and severe malnutrition.

    The authors conclude that Bariatric surgery in pediatric patients results in sustained and clinically significant weight loss, but also has the potential for serious complications.

    Based on these data, I would guess that for most pediatric patients, LABG may be the best option – but no matter which operation is used, indications have to be tight and surgery on this vulnerable and special population is perhaps best left to the most experienced and specialized centres.

    Edmonton, Alberta