IBS can be quickly diagnosed with new blood test

Irritable bowel syndrome, the most common gastroenterological disorder in the US, can now be diagnosed with just two simple blood tests, enabling early diagnosis for millions of people affected by the disorder.

Symptoms of IBS include abdominal pain and unpredictable bouts of diarrhea and constipation.

Until now, irritable bowel syndrome (IBS) has only been diagnosed after a long and drawn out process of ruling out other conditions, often involving invasive procedures such as colonoscopies and sigmoidoscopies.

Dr. Mark Pimentel, a gastroenterologist at Cedars-Sinai in Los Angeles, CA, created the tests. He explains that as there have been no definitive tests for IBS, patients have frequently had to go from doctor to doctor, repeating tests before they have been able to get a diagnosis they are confident with.

"Having an early diagnosis means patients can avoid years of invasive tests and visits to specialists that often leave them with more questions than answers," he explains. "With these new blood tests, many patients will now be able to proceed right to therapy for their condition."

Around 10% of the global population is estimated to have IBS, with around 10-15% of the US population affected. The condition is characterized by a variety of symptoms that includes abdominal pain, bloating and bouts of diarrhea and constipation that can cause stress and fatigue.

"Imagine a patient who wakes up in the morning and doesn't know when they're going to have a bowel movement, if it's going to be diarrhea or constipation," says Dr. Pimentel. "Are they going to be at a restaurant with friends? Are they going to be in a meeting? I mean, it's very traumatic because it's unpredictable in terms of the function."

The tests, developed by Dr. Pimentel over the course of 8 years, identify when IBS has developed by recognizing the presence of specific antibodies - anti-Cdtb and anti-vinculin - that react to toxins associated with food poisoning. These toxins, produced by bacteria such as salmonella, damage nerves that are vital to healthy gut functioning.

Tests detect biomarkers with greater than 90% accuracy

To validate the accuracy of the blood tests, Dr. Pimentel and colleagues analyzed nearly 3,000 people aged 18-65, comparing participants with IBS with people with inflammatory bowel disease, celiac disease or no gastrointestinal disease at all.

The researchers found that the blood tests identified anti-Cdtb and anti-vinculin antibodies successfully with greater than 90% accuracy. These antibodies were elevated in participants with IBS compared with participants that did not have IBS.

As a result, the researchers state that these biomarkers may be especially helpful in distinguishing IBS from inflammatory bowel disease in the workup of chronic diarrhea.

The authors acknowledge that the new tests are limited by a lower specificity for identifying IBS compared with celiac disease, though they suggest this problem is easily solved by testing for celiac disease antibodies alongside the IBS tests.

The study is published in PLOS ONE, and Dr. Pimentel presented the findings at Digestive Disease Week 2015 in Washington, DC.

"For the 40 million Americans who have irritable bowel syndrome, they now have a test that says 'You have IBS, it's real, it's an organic disease, it's not a psychological disorder,' and they can go straight to therapy, or at least get an answer," says Dr. Pimentel.

In November, Medical News Today reported on new guidelines published by the American Gastroenterological Association for IBS. The aim of the document is to make it easier for patients and their doctors to select the correct drugs for their particular symptoms.

Metabolic syndrome could increase cardiovascular risks

Metabolic syndrome could be more of a risk to people's health than originally thought, according to new research. A study published in the Journal of Clinical Endocrinology & Metabolism suggests that people with metabolic syndrome are more likely to die from cardiovascular disease than those without the condition. Meanwhile, another new study, published in the Journal of the American Heart Association, suggests that metabolic syndrome may increase cardiovascular risk more in black women than in white women.

Metabolic syndrome is a cluster of risk factors such as abdominal obesity and high blood pressure that can increase the risk of other conditions such as stroke and diabetes.

"It appeared that the cardiovascular disease risk was elevated in black women by the presence of only two or three metabolic abnormalities to a degree that would require four or more metabolic abnormalities among white women," says Dr. Michelle Schmiegelow, author of the Journal of the American Heart Association study and research fellow at University Hospital Gentofte, Denmark.

Metabolic syndrome is a cluster of risk factors that occur together and increase the risk of stroke and diabetes. The risk factors are increased blood pressure, high triglyceride levels, low levels of "good" cholesterol, impaired glucose metabolism and abdominal obesity.

Previous studies have indicated that obesity without metabolic syndrome (defined here as having at least three of the risk factors) is not associated with an increase in cardiovascular disease risk. However, these studies focused predominantly on white participants.

Researchers analyzed a multiethnic group of postmenopausal women aged 50-79 recruited by the Women's Health Initiative, assessing cardiovascular disease risk according to weight and metabolic health status.

Of the 14,364 participants, around 47% were white, 36% were black and 18% were Hispanic. Participants were classified as "overweight" if approximately 10% over their ideal body weight for size and "obese" if around 30 pounds over their ideal weight.

Participants were followed up for 13 years. During this time, 1,101 women had either developed coronary heart disease or had an ischemic stroke for the first time.

The researchers found that, among black women with 2-3 metabolic risk factors, the relative risk of cardiovascular disease increased by 117% in those that were obese and increased by 77% in women who were overweight.

In comparison, white women with 2-3 metabolic risk factors who were obese or overweight experienced cardiovascular events as often as white women with normal weight and without any metabolic disorders.

In the absence of metabolic syndrome, black women who were obese or overweight had a higher risk of cardiovascular disease compared with normal weight black women. In contrast, white women without metabolic syndrome had a similar risk of cardiovascular disease regardless of weight classification.

Dr. Schmiegelow suggests the findings imply that metabolic syndrome may underestimate cardiovascular disease risk in black women and overestimate it in white women, at least in postmenopausal women.

Diabetes and high blood pressure 'elevate the risk of death'

For the other study, published in the Journal of Clinical Endocrinology & Metabolism, researchers assessed the findings of a health screening program at Kangbuk Samsung Hospital in South Korea, in which 155,971 people participated between 2002 and 2009.

Data were collected by conducting questionnaires and measuring the body weight, body mass index, blood pressure, cholesterol and blood sugar of each participant. Death records from the Korea National Statistical Office were also obtained to measure the mortality of the participants.

"Our research found people who had metabolic syndrome had a 1.6-fold-increase in cardiovascular mortality compared to those who did not have the condition," says Prof. Ki-Chul Sung. "Women who have metabolic syndrome faced a greater risk of death from any cause than their counterparts who did not."

A total of 12.6% of the participants had metabolic syndrome when first screened. While the findings indicate that people with metabolic syndrome face a greater risk of death from cardiovascular disease than those with the condition, this difference disappeared when participants with diabetes or high blood pressure were removed from the analysis.

"The analysis tells us diabetes and high blood pressure are significant factors that elevate the risk of death from cardiovascular disease among people with metabolic syndrome," states study author Prof. Eun-Jung Rhee, of Sungkyunkwan University School of Medicine.

"Younger people who have metabolic syndrome should be aware of the risk, particularly those who have diabetes and high blood pressure."

In the US, metabolic syndrome is commonplace. Medical News Today recently reported on a study published in JAMAthat found more than a third of adults in the US have metabolic syndrome, with almost half of adults aged 60 and above affected by the condition.