Unhealthy Lifestyle Factors Into Idiopathic Pulmonary Fibrosis

— Risk greatest for those at high genetic susceptibility engaged in smoking, other bad habits

by
Elizabeth Short, Staff Writer, MedPage Today
April 13, 2023

Lifestyle habits may contribute to individual risk for idiopathic pulmonary fibrosis (IPF), researchers found in the U.K. Biobank.

In comparison to more “favorable” lifestyles, an “unfavorable” lifestyle was associated with a greater IPF risk (HR 2.271, 95% CI 1.852-2.785), as was an “intermediate” lifestyle (HR 1.384, 95% CI 1.218-1.574), reported Yaohua Tian, PhD, of Tongji Medical College at Huazhong University of Science and Technology in Wuhan, China, and coauthors.

The association between lifestyle and the risk of developing IPF persisted after adjustment for age and sex, as well as education, ethnicity, BMI, employment status, hypertension, diabetes, and hyperlipidemia, according to the population-based study published in CHEST.

When considering the joint effect of lifestyle and genetic susceptibility, patients with both high genetic risk paired with an unfavorable lifestyle saw the greatest risk for IPF (HR 7.796, 95% CI 5.482-11.086).

“In a nationally representative sample from the U.K. Biobank, we found that unfavorable lifestyle and high genetic risk were pronouncedly associated with an increased risk of IPF events,” the group wrote. “At the same time, our study added novel evidence that the association between lifestyle and the risk of incident IPF could be strengthened by the genetic susceptibility to IPF. Therefore, it is necessary to inform and encourage citizens to adhere to a healthy lifestyle, especially for those at high genetic risk.”

These results may provide some insight into the causes of IPF. While IPF is the most common form of pulmonary fibrosis, it can be difficult to diagnose, as it shares many symptoms with chronic obstructive pulmonary disease.

The epidemiological literature suggests a range of modifiable risk factors (including air pollution, industrial dust, tobacco smoking, and viral infection) in causing the development and progression of IPF, Tian and colleagues said. “Nevertheless, to date, only a small number of case-control studies have examined the associations between lifestyle factors and the initiation of IPF.”

For the present study, the investigators relied on self-reported questionnaire data to assign each person a lifestyle score that covers smoking habits, alcohol use, exercise, television habits, and sleep, along with consumption of red meat, oily fish, fruits, and vegetables.

A total of 407,615 U.K. Biobank participants were included in the study (53% women, average age 57 years).

Over 4,837,112 person-years of follow-up, 1,248 incident IPF cases were observed, for an incidence of 25.8 per 100,000 person-years.

Researchers noted that patients who were diagnosed with IPF were more likely to be male participants who were older, white European, and had pre-existing diseases, a lower educational background, and a higher BMI.

Limitations to the study included the use of self-reported questionnaires at a single point in the study, which leaves room for bias, and limits the opportunity to examine lifestyle changes with follow-ups. The authors also noted that not every single lifestyle factor that has the potential to impact risk for IPF could be included in the study.