Risk Factors for Idiopathic Pulmonary Fibrosis

By Dr. James H. Dauber

Factor	Increase in Risk	Comments
Age	Disease is 3 to 5 times more common in people above the age of 75 versus those younger than 55.	The true date of onset of disease is very difficult to define. Younger patients may have a more severe form of the disease that presents itself earlier in life.
Smoking	70% of individuals are current or former smokers suggesting that smoking increases the risk by 1.5 to 2.5 times.	Symptoms may occur sooner in people who smoke which allows for an earlier diagnosis of disease in smoker vesus nonsmokers.
Sex	Male:Female = 60/40	Males are at increased risk in all age groups. Survival is longer in females than in males.
Metal Dust	Increases risk by 2 to 3 times.	Many years of exposure are required. Steel, brass and lead are most common metals.
Wood Dust	Increases risk by 2 to 3 times.	As with metal dusts, many years of exposure are required.
Stone or Sand Dust	Increases risk by 1.5 to 2.5 times.	Exposure to fine particles of sand can also cause silicosis which is a different form of pulmonary fibrosis than IPF.
Hepatitis C antibodies	Probably no increase.	These patients may develop other forms of interstitial lung disease.
Family History of Pulmonary Fibrosis	Risk is difficult to determine, but 2–5% of all individuals with IPF have familial disease which may skip a generation before showing up again.	Disease tends to occur at an earlier age and be more aggressive but can be present many years before symptoms arise.

View a diagnostic tests table that shows the type study conducted what it involves, when, and why it is done.