Annual GI Meeting Offers Plenty for Primary Care Docs to Learn From As Well

David A. Johnson, MD


January 11, 2019

Hello, I'm Dr David Johnson, professor of medicine and chief of gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia.

I'm back from the American College of Gastroenterology (ACG) annual scientific meeting, which this year was held in Philadelphia, Pennsylvania. Every year I return from these meetings with a lot of information to share with my gastroenterology colleagues, but I'm also always struck by the sheer number of messages that would benefit my primary care colleagues. This year was no exception, so I'd like to take this opportunity to share take-home messages from my top 5 studies for primary care, with an additional study of interest thrown in for good measure.

Adopting an Aggressive Cancer Screening Approach in Obese Patients

The first study[1] relates to the influence of obesity on increasing cancer incidence. Researchers looked at 2002-2013 data from the Surveillance, Epidemiology, and End Results database. They found that there was a significant correlation between obesity and an increasing risk for cancer, particularly for colon cancer and to a lesser but still significant degree for gastric cancer, in younger adults (18-49 years). Gastric cancer increased by 0.7% per year, whereas colon cancer increased by 1.8% initially and by 0.8% per year thereafter.

The fact that they found the steepest rise for colon cancer in the 18- to 49-yearage group is actually very timely. In 2018, the American Cancer Society recommended earlier colon cancer screening beginning at age 45.[2] And in 2017, the US Multisociety Task Force on Colorectal Cancer joined others in recommending screening begin at age 45 for African Americans.[3]

The take-home message is that cancer can occur in a younger population and that obese patients really need to be looked at very carefully. That makes sense physiologically, because cancer is fed by proinflammatory cytokines, which we know are increased with a number of things associated with obesity—including the adipokines, leptin and adiponectin, and the cytokines, tumor necrosis factor and interleukin 6. There are also some data that suggest that adipocytes, the fatty cells, may promote colon cancer proliferative cells in vitro.

Although it wasn't a part of this particular study, a previous report[4] has shown that the pattern of obesity as it relates to colon cancer risk is also important. It's the abdominal obesity that is more reflective of visceral fat deposition, which is biologically active and associated with insulin resistance and increased insulin growth factor, both of which have been shown to promote the development of colon cancer.

We know these patients are not uncommon. In the United States, the overweight and obese now account for [approximately 70%] of adults.[5] With it now well founded that obesity is associated with increased risk not only for colon cancer but also for adenomas, I would recommend an aggressive screening approach in this population.

Buyer Beware: Gluten-Free Restaurant Foods Often Contain Gluten

The second study[6] looked at gluten contamination in food found at restaurants, which have become quite savvy at understanding the market for gluten sensitivity, particularly as it relates to celiac patients. Researchers collected data from users employing a portable gluten detector over an 18-month period throughout the United States. They then analyzed these data by region, restaurant, food types, and other relevant factors.

Lo and behold, they found that 32% of foods labeled as gluten-free actually contain gluten. This varied by meal, with a little lower rate of mislabeling for breakfast meals and a higher rate for dinner meals. Things varied somewhat related to where you were in the United States, with accurate labeling more likely in the Pacific Northwest than in the Northeast. Gluten-free pizza and pasta were also more likely to contain gluten than other foods.

This is particularly of interest for primary care physicians with celiac or gluten-sensitive patients who don't seem to be doing quite so well. It's worth looking at what they're actually ingesting and warning them that, when it comes to restaurant foods, not all that's labeled gluten-free truly is.

Recommending a Diet That Can Reduce Fecal Incontinence

Fecal incontinence is something that primary care docs may see more than we do in gastroenterology. Although fecal incontinence is rarely reported, I've found that if you ask the right questions, you'll get the right answer. About 15% of patients will have fecal incontinence by the time they're 80 years of age.[7] It's a common complaint that's often associated with urgent diarrhea, but patients will often immeasurably suffer from this in silence. It can be incapacitating in some circumstances, or just troubling with occurrences of fecal leakage and soiling of the underwear.

This third study[8] from researchers at the University of Michigan in Ann Arbor looked at treating fecal incontinence with a low fermentable oligo-, di-, and mono-saccharides, and polyols (FODMAP) diet. I'm sure many of you are familiar with FODMAP, as it has gotten a tremendous amount of attention as it relates to irritable bowel syndrome.

Researchers looked at a group with frequent fecal incontinence, with 35% experiencing it daily and 21.5% weekly. They hypothesized that applying a low-FODMAP diet may lead to a risk reduction due to decreased gas and diarrhea. Indeed, this was borne out by the results, as they found 63% of patients reporting improved symptoms within a short period of time after adopting a low-FODMAP diet.

The caveat, and the reason I bring this up specifically for primary care specialists, is that it's virtually impossible for me as a gastroenterologist to accurately describe to my patients what a low-FODMAP diet entails. So you'll always need to get a dietitian involved.

The axiomatic recommendation I would make is that for fecal incontinence and leakage, this may be something you can apply pretty early that doesn't necessarily require a lot of extra care.

Making Sure Those Flagged for Colonoscopy Actually Undergo One

The fourth study[9] came from a group at the University of California, Los Angeles. They looked at the deficiencies that we see in programmatic screening with the fecal immunohistochemical test (FIT). The relevant guidelines from the American gastrointestinal (GI) societies have all changed to no longer recommend guaiac-based testing, but using FIT instead. This is specific for human hemoglobin, not subject to dietary variation, and in particular detects a lower rather than an upper GI bleed.

They evaluated a group who had at least one positive FIT result, and then assessed how many of them actually got a colonoscopy. A positive FIT should equate to a colonoscopy. In fact, if you're not willing to do a colonoscopy or further testing following [a positive FIT], it's probably recommended that you shouldn't even be doing colon screening.

The cohort was in a tertiary integrated health system, and 62.5% were referred for GI clinic evaluation and 23.5% were referred directly for a colonoscopy. The important finding was that of 77.7% of patients actually evaluated at the GI clinic, only 58.4% completed a colonoscopy. In contrast, 82.9% of those referred directly to a colonoscopy ended up undergoing this procedure.

The reason I bring this study to your attention is to underline the fact that, if you're doing a FIT, you need to have the mitigation strategies and tracking and navigation tools to ensure these patients get to a colonoscopy. That's a marker potentially for colon cancer, and they need to be screened and followed up.

It's Time to Stop Worrying About Dementia and Proton Pump Inhibitors

The fifth study[10] looked at proton pump inhibitors (PPIs) and the risk for dementia, questioning whether this really is much ado about nothing. I reviewed this topic in a video for Medscape, which I recommend you watch as well. That discussion touched upon two individual studies—the Nurses' Health Study[11] and a study from Finland[12]—that I thought were very discriminate against the concept that this was an issue.

However, we must recognize that our patients are very sanguine about this. Approximately 32 million people in the United States suffer from dementia, and that number is expected to double by 2030 and triple by 2050.[13] It is on my patients' minds, as I'm sure it's on yours as well. They ask me about dementia and what it has to do with PPIs. There were some animal data suggesting there is deposition of beta amyloid on the basis of PPI exposure,[14] although it somewhat fell apart in these previously mentioned human trials.[11,12]

This study from a group at the University of Tennessee Health Sciences Center in Memphis performed a systematic literature review to identify nine relevant studies with nearly 200,000 patients. The evidence base for this association unraveled very quickly, with the odds ratio all approaching zero. There was no consistent, significant evidence that patients should be concerned about dementia.

I really think this is important for you to underscore. If your patients don't need to take PPIs, then perhaps they shouldn't. But if they do need them, they should take them, as they're incredibly safe. I think it's time for us to "forget" about the issue of dementia with PPIs, and this abstract presentation at the ACG's annual meeting underscores that point.

Considering a New Diagnosis for Patients With Perplexing Food Aversions

The last study[15] I mention here just as an FYI, because it was a new description for me as a gastroenterologist: avoidant/restrictive food intake disorder (ARFID). This study was conducted by the group at the University of Michigan led by Dr William Chey, an esteemed colleague and good friend of mine. This team looked at the prevalence of ARFID in adults; previously, it was described in younger patients. After screening adult outpatients undergoing endoscopy, they found an ARFID prevalence of approximately 20%, which is quite alarming. ARFID has its own diagnostic criteria in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), and is diagnosed in children in particular. It is characterized as an eating or feeding disturbance, with an apparent lack of interest in eating your food.

When I reflect back, I realize that I have seen a number of these patients. Not knowing what they were dealing with, I would send them back to their primary care doc and say it wasn't a GI condition as far as I could see. As recipients of negative work-ups, you need to be on the lookout for patients in whom no GI disease could be identified but who have weight loss, nutritional deficiencies, and particularly food avoidance, even though they are not anorexic or bulimic. These patients really need to have behavioral evaluations and begin working with a multifaceted team of behavioral therapists, a dietitian, and a good psychiatrist or psychometrician.

Until we recognize this disorder, we're never going to get the diagnosis started. It seems to be more prevalent in patients with autistic spectrum disorder and in those with attention-deficit/hyperactivity disorder. These are populations you might think about this diagnosis in even more.

ARFID is a diagnosis that occurs in adults. To aid that process, here is a link to better understand the criteria involved in diagnosing ARFID.

Clearly, this year's ACG meeting offered a lot of important take-home messages. I will wait to see how these studies mature into articles that give us more facts around these conditions, but in the meantime, I wanted to give you the highlights as it relates to you in primary care. I hope these will be helpful in your discussions with your patients.

I'm Dr David Johnson. Thanks again for listening, and I look forward to seeing you next time.


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