Children With Autism Spectrum Disorder May Have Increased Rates of Gastrointestinal Symptoms

Children with autistic spectrum disorder experience gastrointestinal symptoms of diarrhea, constipation, and abdominal pain more often than other children. Image: JAMA, ©AMA

Children with autism spectrum disorder experience gastrointestinal symptoms of diarrhea, constipation, and abdominal pain more often than other children. Image: JAMA, ©AMA

Rates of diarrhea, constipation, abdominal pain, and general gastrointestinal concerns appear to be higher in children with autism spectrum disorder compared with children without the disorder, according to a study released in Pediatrics today.

Gastrointestinal problems are frequently noted among children with autism spectrum disorder, the prevalence of which has increased substantially in recent years. Estimates from the US Centers for Disease Control and Prevention’s Autism and Developmental Disabilities Monitoring Network indicate that among 8-year-old American children, about 1 in 68 have a diagnosis of autism spectrum disorder.

In the new study, researchers from Emory University in Atlanta performed a meta-analysis of 15 studies on autism spectrum disorder and gastrointestinal symptoms from 1980 through 2012 and found that among a total pooled population of 2215 children, those with autism spectrum disorder had a greater than 3-fold prevalence of diarrhea and constipation, a greater than 2-fold prevalence of abdominal pain, and a greater than 5-fold prevalence of “general gastrointestinal concerns” compared with a control population. However, the study does not specify the actual rates of these symptoms in the autism spectrum disorder versus control populations, and therefore it is unclear what the absolute magnitudes of these differences are, which may affect the clinical importance of these findings.

This is the first quantitative study to support the expert consensus released in 2010 based on qualitative observations that there was a link between autism spectrum disorder and gastrointestinal symptoms.

Although these numbers may be useful for parents and pediatricians, the underlying reason for the increased rates of gastrointestinal symptoms remain unknown. The problem could be “functional;” that is, children with autism spectrum disorder may have behaviors such as suboptimal eating and toileting habits, such as extreme food selectivity (often a preference for starches and snack foods and an aversion towards fruits and vegetables) or ineffective toileting routines. Alternatively, the problem could be “organic,” that is, related to biological factors. Preliminary research has provided some support for such biological factors as an altered population of intestinal microbes, altered patterns of intestinal contractions, or increased risks of gluten sensitivity, lactose intolerance, food allergies, or gastroesophageal reflux disease in children with autism spectrum disorder.

The authors stated that this general topic of gastrointestinal disease in autism spectrum disorder has been understudied—perhaps because the gastrointestinal system was implicated as part of a causal pathway in the disease in a highly controversial and now-retracted study published in 1998 that suggested a potential link between autism and the measles-mumps-rubella (MMR) vaccine. The bottom line, they wrote, is that “additional research is needed to elucidate the etiology, prevalence, topography, and remediation” of gastrointestinal problems in autism spectrum disorder.

Author Insights: Less Aggressive Treatment May Be Warranted for Many Cases of Diverticulitis

Arden M. Morris, MD, MPH, an associate professor of surgery, University of Michigan Health System, Ann Arbor, and colleagues found in a systematic review that less aggressive strategies for treating diverticulitis may be appropriate for many patients. (Image: Michigan MultiMedia)

Arden M. Morris, MD, MPH, an associate professor of surgery, University of Michigan Health System, Ann Arbor, and colleagues found in a systematic review that less aggressive strategies for treating diverticulitis may be appropriate for many patients. (Image: Michigan MultiMedia)

Recent research suggests that recommendations offered in current national clinical guidelines for treating patients with sigmoid diverticulitis may overstate the need for aggressive antibiotic and surgical interventions. This finding comes from a systematic review published today in JAMA.

Diverticulitis is a common digestive disease caused by inflammation of small pouches called diverticula that can form anywhere in the digestive system but are most often found in the sigmoid colon, the part of the large intestine that attaches to the rectum. Most cases of uncomplicated diverticulitis resolve without the need for any treatment; if diverticulitis remains, antibiotics may be prescribed. If a patient experiences recurring acute attacks, the treating physician may order a computed tomography (CT) scan to distinguish uncomplicated diverticulitis from complicated diverticulitis, a condition involving such complications as ruptured diverticula or abscess that may require surgery.

The JAMA researchers analyzed 80 articles regarding the diagnosis and management of diverticulitis published between January 1, 2000, and March 31, 2013. They found, contrary to previous thought, that the risk of septic peritonitis is reduced rather than increased with each recurrence of diverticulitis. Their analysis also found that treatment with antibiotics and fiber consumption were not as beneficial as previously thought and that surgery for chronic disease is not always warranted.

Lead author, Arden M. Morris, MD, MPH, associate professor of surgery at the University of Michigan Health System in Ann Arbor, discusses her team’s findings.

news@JAMA: Why did you do this review?

Dr Morris: The knowledge we have about diverticulitis has changed very extensively in the last 10 years. But the dissemination of knowledge has been traditionally extremely slow, and the guidelines have not necessarily kept up with these changes.

news@JAMA: What has brought about these changes in knowledge?

Dr Morris: In the past we made clinical decisions not necessarily by imaging the patient, but by basing it on the physical exam and history and then opening up the belly. CT scans are of substantially higher quality than they were 10 years ago, allowing us to make decisions without the need for opening up the patient. Secondly, we now have these fantastic clinical databases we can mine to guide our decision-making processes and not base our decisions just on the protocols at our own institutions or through discussions with our colleagues.

news@JAMA: Are the primary care physicians who refer patients to you for the treatment of diverticulitis aware of these changes in the knowledge surrounding the condition?

Dr Morris: I have a very busy surgery practice and most of the patients we see come in quoting information from their primary care physicians that is outdated. So we need forums like JAMA and others to disseminate this information.

news@JAMA: You found that for many cases of diverticulitis, less aggressive treatment strategies may be warranted than were used in the past. But that doesn’t hold true for all patients presenting with this condition, does it?

Dr Morris: Some people really do need an operation for their diverticulitis—some are truly sick or don’t improve with medical therapy—and it can be a very serious situation.

FDA Issues Safety Warning About Over-the-Counter Sodium Phosphate Laxatives

FDA issues new safety warning about sodium phosphate laxatives sold over the counter. Image: istockphoto.com/ruigsantos

FDA issues new safety warning about overuse of over-the-counter sodium phosphate laxatives. Image: istock.com/ruigsantos

The US Food and Drug Administration (FDA) has issued a new warning this week about the safety of sodium phosphate laxatives available over the counter (OTC) when taken in higher doses than recommended.

Occasional use of OTC laxatives and stool softeners to treat constipation is widespread among both adults and children. Sodium phosphate laxatives work by drawing water into the gastrointestinal tract to help promote a bowel movement. When used in excess, potentially large fluid shifts can occur and cause serious health problems, such as dehydration, disturbances in electrolyte levels (particularly with calcium, potassium, and phosphate), kidney failure requiring dialysis, heart arrhythmias, and even death.

Sodium phosphate laxatives are sold as both oral and rectal preparations (enemas) and are marketed under the brand name Fleet or as store/generic brands (labeled as saline, sodium phosphate, or sodium biphosphate laxatives).

The FDA reviewed data from their Adverse Event Reporting System from 1969-2012 as well as medical literature from 1957-2013 and found 54 cases of serious adverse events in both adults and children, all related to the above complications.

Individuals at highest risk for these serious adverse events were children younger than 5 years, adults older than 55 years, and individuals who have underlying kidney disease or who are taking other medications that may affect kidney function, such as diuretics, certain blood pressure medications, and nonsteroidal antiinflammatory drugs. Furthermore, most adverse events occurred in individuals who took more than the maximum recommended dose of the medication—either more frequently than recommended or in greater amounts than recommended at one time.

The FDA issued the following recommendations to decrease the risk of adverse events related to OTC sodium phosphate laxatives:

  • Do not use more than 1 dose in 24 hours, either rectally or orally; if a bowel movement does not occur after a single dose, do not take another dose
  • Avoid simultaneous use with any other type of laxative
  • Ensure adequate hydration before use
  • Do not give rectal products to children younger than 2 years
  • Do not give oral products to children younger than 5 years without first talking to a health care professional
  • Do not use these products without first talking to a health care professional if you are older than 55 years, have kidney disease or bowel inflammation or obstruction, or take certain medications that may affect kidney function

Prescription versions of sodium phosphate laxatives are also available for precolonoscopy bowel preparation (OsmoPrep or Visicol), and the FDA has previously issued a warning about the higher doses used for this purpose.

Rotavirus Vaccine May Prevent Infection-Related Seizures

Vaccination against rotavirus may prevent related seizures that require hospitalization or emergency care, according to a new study. (Image: CDC)

Vaccination against rotavirus may prevent related seizures that require hospitalization or emergency care, according to a new study. (Image: CDC)

New research shows that vaccinating children against rotavirus may prevent more than intestinal illness. Immunization significantly reduced the risk of severe rotavirus-related seizures that required hospitalization or emergency department care.

Researchers from the Centers for Disease Control and Prevention and several other institutions analyzed records of some 250 000 US children born between March 2006 and November 2009. About three-fourths were fully immunized against rotavirus. All were enrolled in the Vaccine Safety Datalink, a national initiative that collects information for vaccine safety research.

Overall, 2244 of the children had at least 1 seizure. The researchers calculated that children who were fully vaccinated against rotavirus had a first seizure at a rate of 1145 per 100 000 person-years compared with 1212 per 100 000 person-years among children who hadn’t received any doses of rotavirus vaccine. For all seizures, the rate among vaccinated children was 1383 per 100 000 person-years and 1502 per 100 000 person-years among unvaccinated children.

Further analysis showed that compared with unvaccinated children, those who were fully vaccinated had a statistically significant 20% reduced risk of having a seizure that required emergency department care or hospitalization.

The study authors noted that the degree of risk reduction they found could help prevent about 1000 hospitalizations and 5000 emergency department visits annually for seizures among young children. The cost savings from preventing rotavirus-related seizures could reach $7 million or more per year, they added. Their findings were published today in the journal Clinical Infectious Diseases.

Rotavirus infection causes gastroenteritis but also may result in complications involving the central nervous system. Previous research in Canada estimated that about 7% of children infected with rotavirus have a seizure. A study in a single US hospital showed that 18% of children with a rotavirus-related seizure spent at least 1 day in an intensive care unit and 59% had a lumbar puncture.

A pentavalent rotavirus vaccine became available in 2006 and a monovalent formulation was introduced in 2008. In an accompanying editorial, Geoffrey Weinberg, MD, of the University of Rochester School of Medicine in New York, noted that the vaccines have been “extraordinarily successful.” A study published earlier this year showed that positive results from laboratory testing for rotavirus infection have decreased by at least 74% since the vaccines became available.

“Work such as this not only is interesting scientifically, but provides yet another reason to strongly promote universal rotavirus immunization,” Weinberg wrote. “Sometimes, unexpected effects of vaccination… are a cause for celebration rather than the more commonly publicized concern for unexpected adverse effects.”

Use of Antacids for Heartburn Linked With Reduced Cancer Risk

Antacid use for treating heartburn was linked in a new study with a 41% reduced risk of throat and vocal cord cancers. (Image: skhoward/iStockphoto.com)

Antacid use for treating heartburn was linked in a new study with a 41% reduced risk of throat and vocal cord cancers. (Image: skhoward/iStockphoto.com)

Antacids may provide more than soothing relief for heartburn. A new study suggests that stomach acid neutralizers may decrease the risk of throat or vocal cord cancers in people with frequent heartburn who don’t smoke or drink alcohol.

The study’s aim was to clarify the relationship between gastric reflux, the backflow of stomach acid into the esophagus that causes heartburn, and cancers of the throat and vocal cords. “Previous studies have generated mixed results,” lead author Scott Langevin, PhD, of Brown University in Providence, RI, said in a statement.

Langevin and his colleagues compared 631 patients with throat or vocal cord cancers with 1234 matched controls. All completed questionnaires about their history of cancer and heartburn and use of medications. The questionnaire also asked about smoking, alcohol consumption, and exposure to human papillomavirus 16, which are known risk factors for throat and vocal cord cancers.

Among study participants who didn’t smoke or drink heavily, a history of frequent heartburn was linked with a 78% increased risk of developing throat or vocal cord cancer. But those who took over-the-counter antacids for heartburn relief had a 41% reduced risk for these cancers. Taking other types of medications used to treat heartburn—proton pump inhibitors or histamine H2 receptor antagonists—was associated with an increased but nonsignificant risk of throat or vocal cord cancer.

“It is biologically plausible that antacid use confers anticancer protection by neutralizing the pH of the reflux reaching the upper aerodigestive tract, leading to a decrease in inflammation and reducing DNA damage stemming from increased levels of cellular acidity,” the investigators wrote.

Langevin said finding a potential protective effect of antacids could have important future clinical implications, but the result needs to be repeated in other studies before definitive conclusions can be reached about their benefits.

“The finding that acid reflux is a risk factor for throat and vocal cord cancers… is now better established with the addition of our large, well-controlled study,” he noted. “Our hope is that this type of information can be used clinically to predict risk for these cancers.”

Vaccinating Infants Against Rotavirus May Also Protect Adults

The rotavirus vaccine given to infants also appears to indirectly protect adults. (Image: CDC)

The rotavirus vaccine given to infants also appears to indirectly protect adults. (Image: CDC)

Vaccinating young children to protect them from rotavirus also appears to give indirect protection to adults, say researchers whose findings appeared today in Clinical Infectious Diseases.

Symptoms of rotavirus infection, the most common cause of severe gastroenteritis in infants and young children, include vomiting and diarrhea, which can cause severe and potentially fatal dehydration. Before the introduction of the pediatric rotavirus vaccine in 2006 in the United States, rotavirus was responsible for more than 400 000 annual doctor visits, 200 000 emergency room visits, up to 70 000 hospitalizations, and up to 60 deaths in children younger than 5 years. Worldwide before the vaccine’s introduction, rotavirus infection caused an estimated 2.4 million hospitalizations and more than 450 000 deaths in young children. Continue reading

A Bitter Pill May Be Just the Thing for Weight Loss

Bitter tastes trigger a cascade of events in the gut, a phenomenon that suggests new approaches in obesity treatment and prevention. (Image: Niilo Tippler/iStockphoto.com)

Bitter tastes trigger a cascade of events in the gut, a phenomenon that suggests new approaches in obesity treatment and prevention. (Image: Niilo Tippler/iStockphoto.com)

Does weight loss really have to be the proverbial bitter pill? Researchers in Belgium who’ve studied how receptors in the gut respond to sweet, salty, bitter, sour, and umami taste sensations say the answer may be yes—literally.

In a review article published online today in Trends in Endocrinology and Metabolism, investigators at the Catholic University of Leuven suggest that the gut’s bitter taste receptors could be high-quality targets for potential drugs aimed at preventing or controlling obesity.

The gut’s ability to detect bitter tastes probably plays a role in limiting the absorption of toxins. It may seem counterintuitive, but the investigators said bitter tastes also boost secretion of the appetite-stimulating hormone ghrelin. Eating a meal then slows ghrelin production. Subsequently, the stomach muscle relaxes and the stomach empties more slowly, so a tempting dessert doesn’t seem quite so inviting. Continue reading