Evaluate the Effect of Diet on Gastrointestinal Adverse Events in Patients With IPF Treated With Pirfenidone

IPF is a chronic, progressive, irreversible disease that ends in respiratory failure and death. The average survival time is 2-5 years from the onset of the first symptoms. IPF patients are often treated with pirfenidone, and the response is positive, however there are gastrointestinal side effects. The data published about patient adherence to pirfenidone treatment relates to the emergence of gastrointestinal AEs, which is variable and appears to have a lower incidence in the hospitals in the south of Europe, who report fewer serious gastrointestinal AEs than in countries from the north of Europe.

Recent data from the Spanish Registry have reported a prevalence of 6,3% of GI effects with pirfenidone in 270 IPF patients under treatment (IPF-Spanish Registry June 2016), while in Netherlands and Belgium the reported GI effects are around 36%, and associated with treatment discontinuation in 7,9% of patients.

Even though the ingestion of food during the taking of medication and other measures recommended for the prevention of symptoms may have a beneficial effect with respect to gastrointestinal AEs, up to now there have been no studies about the influence of diet on these events. Therefore, it is possible that the differences in the patients' habitual diet, i.e. the composition in quantity and types of fat ingested, may be the source of the variability of the gastrointestinal AEs observed between countries.

Distinct dietary models have been taking shape over the past decades. In countries such as England, central and northern Europe, and a large part of North America, dietary habits characterized by a high consumption of saturated and hydrogenated fats in the form of pastries and pre-cooked products, veal, pork, and lamb (>150 g per day), butter and milk fats, and scant consumption of fruits, greens, vegetables, and whole-grain cereals. It is called the Occidental Diet (OD). Various studies have associated it, as an environmental factor, with diseases such as vascular accidents, diabetes, metabolic syndrome, and various types of cancer.

On the other hand, traditional Mediterranean diets have been associated with low rates of chronic diseases and high life expectancy among the populations that consume them. They are characterized by an abundance of greens, garden produce, fresh fruit, legumes and cereals; a variable quantity, according to the zone, of olive oil, which is the main cooking fat; a moderate consumption of alcohol, mainly in the form of wine; some fish; moderate ingestion of dairy foods, and low consumption of meat.

The main characteristic of the Mediterranean diet is that the ratio of monounsaturated fatty acids (MUFA) to saturated fatty acids (SFA) is much higher than in other zones of Europe and North America due to a high consumption of olive oil as the main cooking oil. Olive oil fills distinct functions in the gastrointestinal tract. Being the fat that provides the best digestibility and whose mechanism of action is based on an inhibition of gastric motility, thus promoting a lower degree of gastroesophageal reflux. That is the reason that it is used extensively among Nutrition professionals when patients present low oral tolerance(22-24). Olive oil, also, has been used to mitigate postoperative nausea and vomiting.

This study will analyze the AEs in IPF patients in 6 countries, who are prescribed pirfenidone. They will be divided into SFA and MUFA arms and the AEs of each arm statistically analyzed.