Lower BMI Increased Risk of C Diff Infection in Elderly Pneumonia Patients

This article was originally published on HCPLive

New research shows lower body weight might be a big risk factor for older patients with pneumonia for clostridium difficile infections (CDI).

A team, led by Risa Suzuki, Department of Health Policy and Informatics, Tokyo medical and Dental University, assessed the associations between body mass index (BMI) and C difficile infection risk for older patients with pneumonia in Japan.

“Obesity is reported to be a risk factor for Clostridioides difficile infection,” the authors wrote. “However, obesity rarely occurs in older Asian patients, and the effects of obesity on health and disease are different in Asian and Western countries.”

The Study

In the retrospective observational cohort study, the investigators assessed data from the nationwide database of acute hospital inpatients’ data in Japan between July 2014 and March 2016.

Each patient included in the analysis was aged at least 65 years and admitted to the hospital with a primary diagnosis of pneumonia. The investigators determined risk factors for CDI using logistic regression analysis, including known risks as covariates.

Overall, there were 221,242 patients with pneumonia in the database, 611 of which developed C difficile infections.

Underweight patients—defined as patients with a BMI less than 18.5 kg/m2—had higher odds for C difficile infections (OR, 1.38; 95% CI, 1.17-1.62; P <0.001) compared to normal weight patients—defined as a BMI between 18.5-24.9 kg/m2. However, overweight patients—defined as having a BMI of at least 25 kg/m2—had lower odds (OR, 0.63; 95% CI, 0.45-0.89; P <0.01).

“Body mass index was associated with C. difficile infection in older pneumonia patients in Japan,” the authors wrote. “Underweight was a risk factor, whereas overweight was a protective factor for C. difficile infection.”

Risk Factors

In recent years, several risk factors have emerged, namely age and the use of certain medications, leading to an increase in CDI.

C difficile infection rates have steadily increased in recent years, leading to more attention paid to identifying and addressing the risk factors associated with the rise in infections. Recently, investigators in Asia found in 51 studies that the proportion of C difficile-associated diarrhea in patients with nosocomial diarrhea was 14.8%, with a mortality rate of 8.9%.

In the case-control study, the investigators examined CDI rates at a tertiary care hospital in Pakistan between June 2020 and March 2021. A total of 200 patients with C difficile-associated diarrhea were included in the study, which was diagnosed based on clinical symptoms and stool enzyme immunoassay. An additional 200 participants without a diagnosis of C difficile-associated diarrhea were included in the study as the control group.

Certain risk factors emerged over the course of the study, particularly in age.

Patients older than 65 had a higher risk of CDI compared to patients younger than 65 15.5% vs. 8.0%; P = 0.02).

There were other factors associated with significantly higher rates of infections, including hospitalization (25.5% vs. 6.0%; P <0.0001), the use of proton pump inhibitors in the last 30 days (23.0% vs. 10.5%; P = 0.001), and the use of antibiotics in the last 30 days (36.0% vs. 10.5%; P <0.0001).

For comorbidities, CDI was linked to increased body mass index (BMI), diabetes, CKD, and malignancy.

The study, “Association of body mass index with Clostridioides difficile infection among older patients with pneumonia in Japan,” was published online in Geriatrics & Gerontology International.