Study identifies predictors of fibromyalgia and chronic fatigue in IBS patients

Results of a recent study have drawn attention to the increased prevalence of medical comorbidities in patients with irritable bowel syndrome (IBS), highlighting the increased incidence of fibromyalgia and chronic fatigue syndrome in this group.

Results from a retrospective cohort study identified several factors, including increasing age, female gender, Caucasian race, obesity, smoking, and hyperlipidemia, as predictors of concurrent diagnosis of fibromyalgia and chronic fatigue syndrome in patients with IBS.¹

“To our knowledge, this is the first published study to utilize a large national general population database in the United States to assess fibromyalgia and chronic fatigue syndrome in individuals diagnosed with irritable bowel syndrome,” the researchers wrote. )burden.”¹

IBS is a gastrointestinal disorder that affects the digestive system, affecting approximately 10-15% of the adult population in the United States. It is the most common disease diagnosed by gastroenterologists and is often accompanied by other comorbid diseases or conditions. The International Foundation for Gastrointestinal Diseases estimates that 50% of patients seen in primary care or a gastroenterologist have at least 1 comorbidity, but the exact incidence and pathology of these overlaps are unknown.^{twenty three}

To assess the prevalence and predictors of fibromyalgia and chronic fatigue syndrome in patients with IBS, Zahid Ijaz Tarar, MD, clinical instructor at the University of Missouri School of Medicine, and colleagues collected hospitalization data from patients with a primary or secondary admission to the hospital diagnosed with IBS. Fibromyalgia and chronic fatigue syndrome co-diagnosis in the US National Inpatient Sample. The study population was selected using ICD-10-CM codes: IBS with diarrhea (K58.0), IBS with constipation (K58.1), mixed IBS (K58.2), other IBS (K58.3), IBS without diarrhea ( K58.9), fibromyalgia (M79.7) and chronic fatigue syndrome (R53.82). Patients under 18 years of age were excluded from the study.¹

The researchers identified a total of 1,256,325 patients admitted to hospital with a primary or secondary diagnosis of IBS, of whom 134,890 (10.73%) had fibromyalgia and 5220 (0.42%) had chronic fatigue syndrome. The prevalence and predictors of fibromyalgia and chronic fatigue syndrome in a population with IBS were assessed and compared with those without IBS.¹

We conducted univariable and multivariable regression analyzes to determine the unadjusted and adjusted odds of a comorbid diagnosis of fibromyalgia or chronic fatigue syndrome in patients with IBS. Results were adjusted for patient demographics, hospital characteristics, and comorbidities, including hypertension, diabetes, dyslipidemia, coronary artery disease, congestive heart failure, chronic kidney disease, cerebrovascular accident, smoking, malnutrition, alcohol abuse, and malignancy.¹

On analysis, the prevalence of fibromyalgia and chronic fatigue syndrome was significantly higher in patients with IBS (adjusted odds ratio (aOR), 5.33; 95% confidence interval (CI), 5.24-5.41; ask

< .001 and aOR, 5.40; 95% CI, 5.04-5.78; ask < .001, respectively, compared with the general adult population without IBS. IBS-D, IBS-C, and IBS mixed types are independently associated with increased incidence of fibromyalgia and chronic fatigue syndrome.¹

Researchers noted that IBS patients with fibromyalgia and/or chronic fatigue syndrome were younger compared with patients without fibromyalgia (58.7 years vs. 62 years) and chronic fatigue syndrome (59.9 years vs. 61.6 years) . 45.6% of fibromyalgia patients and 42.6% of chronic fatigue syndrome patients had hypertension, and 25.7% of fibromyalgia patients and 21.1% of chronic fatigue syndrome patients were obese. Other comorbidities in patients with fibromyalgia and chronic fatigue syndrome included dyslipidemia (36.2% and 36.1%), diabetes (25.1% and 19.9%), and coronary artery disease (13.8% and 13%).¹

The researchers conducted multivariable regression analyzes and identified the following factors as independent predictors of increased incidence of fibromyalgia and chronic fatigue syndrome:

• increasing age (aOR, 1.02; 95% CI, 1.01-1.04; ask < .003 Fibromyalgia and aOR, 1.02; 95% CI, 1.01-1.03; ask < .001 (Chronic Fatigue Syndrome)
• women (aOR, 11.2; 95% CI, 11.1-11.4; ask < .001 Fibromyalgia and aOR, 1.86; 95% CI, 1.78-1.93; ask < .001 (Chronic Fatigue Syndrome)
• Whites (aOR, 2.04; 95% CI, 1.95-2.12; ask < .001 Fibromyalgia and aOR, 1.69; 95% CI, 1.34-2.13; ask < .001 (Chronic Fatigue Syndrome)

“Early identification of comorbidities in IBS patients will be valuable as they can be managed with better treatment strategies. In current clinical practice, the risk of overlooking multi-syndromal patients is high,” the researchers concluded.¹

“As clinicians, we should incorporate regular screening for other medical conditions in the IBS population into our practice and determine whether consultation with other specialties such as rheumatology and psychiatry is needed to improve overall health outcomes for patients with IBS.”

refer to:

1. Tarar ZI, Farooq U, Nawaz A, et al. Prevalence of fibromyalgia and chronic fatigue syndrome in patients with irritable bowel syndrome: analysis of the National Inpatient Sample database. biomedicine. 2023;11(10):2594. Published on September 22, 2023. doi:10.3390/biomedicines11102594
2. Cleveland Clinic. Irritable bowel syndrome (IBS). Diseases and Conditions. September 24, 2020. Accessed 31 October 2023. https://my.clevelandclinic.org/health/diseases/4342-irritable-bowel-syndrome-ibs
3. IFFGD. Conditions that overlap with IBS. Irritable bowel syndrome and other conditions. Accessed: October 31, 2023. https://aboutibs.org/what-is-ibs/ibs-and-other-disorders/overlapping-condition-with-irritable-bowel-syndrome/