The progression of idiopathic pulmonary fibrosis (IPF) depends on the gender and smoking habits of patients, according to researchers.
IPF-specific mortality was higher in female patients, whereas male patients were more likely to die from comorbidities associated with IPF. Female patients and non-smokers were less likely to succumb to pneumonia, a comorbidity known to trigger acute exacerbations of IPF.
The research with those findings, developed at the Kuopio University Hospital, in Finland, was published in the journal BMC Pulmonary Medicine. The study is titled “Underlying and immediate causes of death in patients with idiopathic pulmonary fibrosis.”
The major cause of death among IPF patients is the disease itself, followed by cardiac diseases and lung cancer. Pulmonary embolism, infections, accumulation of free air in the chest cavity (pneumothorax), and heart failure are known as major causes of lung deterioration in IPF patients.
The global mortality rate of IPF is increasing, and males are reported to have a higher mortality than females. Mortality rates also vary between countries and seem to depend on the definition and diagnosis criteria used.
The highest IPF mortality rates in the European Union between 2011 and 2013 were registered in the U.K.; the lowest rates were reported in Lithuania.
Despite the reported differences in IPF mortality rates between genders and countries, no previous studies had explored differences among genders, smoking status, and disease progression.
Now, in this retrospective study, researchers collected data from the Kuopio University Hospital registry, as well as death certificates from a Finnish national database of IPF patients. Mortality rates were determined for 117 PF-related deaths, from 1998 to 2015.
Researchers found that the PF mortality rate in Finland increased — 2.6 PF deaths per 100,000 inhabitants in 1998 vs 5.1 per 100,000 in 2015.
The major underlying causes of death were the disease itself (67.5 percent), followed by heart diseases (14.8 percent).
Mortality rates differed between genders, being higher in males. Of the 117 deaths analyzed, 73.5 percent occurred in males, versus 26.5 percent in females.
However, IPF-specific mortality was higher in females (87.1 percent, compared to 60.5 percent in males), while males died more often from comorbidities (39.5 percent vs 12.9 percent in females).
Pneumonia, a frequently associated comorbidity in IPF patients, more often was the underlying cause of death in males (27.9 percent) than in females (3.2 percent). The same trend was observed for ex-smokers (32.7 percent) compared to non-smokers (9.3 percent).
Based on the findings, researchers suggested that pneumonia-related deaths may be associated with gender and smoking habits, with females and non-smokers being less likely to succumb to this disease.
“The mortality determined in this study population reflects the demographics of IPF since there has been a year-on-year increase in the numbers of males and smokers with IPF dying from this disease,” researchers concluded.
Taken together, the team concluded: “Even though the overall mortality was higher in males with IPF, the disease-specific mortality for IPF was higher in females, i.e. in males, comorbidities were more often the underlying causes of death.”
The researchers suggest that in IPF patients “disease progression at the end of life may vary depending on smoking habits and gender.”