Puffy belly

Question

Hello, I am a 43 year-old patient with CF. I am now on the waiting list for two new lungs. My lung function fluctuates around 30 %. I do not have liver problems, and in the screening, no complications were found. The only thing I have problems with lately is a very puffy belly. In the evening there is so much tension on the belly that it seems as if I am pregnant. I’ve heard this complaint from other patients with CF and I have also heard that when you have bad lungs, your abdominal cavity is more filled with lungs because they are “elongated” to compensate the lack of oxygen. My BMI is alright, but it seems there is more fat around my abdomen than elsewhere. I also have diabetes and use insulin. Can you tell me if it is common that the abdominal circumference of CF patients increases, although the BMI is average? Thank you for your reply.

Answer

Dear questioner,

Thank you for your interesting question. However, we can only answer this question ‘in general’. For specific advice, please consult your doctor.

A ‘distended’ belly can have several causes. The most obvious in patients with cystic fibrosis is poor digestion. Nutrients such as fat, proteins and carbohydrates need enzymes to be digested and absorbed. These enzymes are produced in the pancreas and are transported to the small intestine. In about 85 % of the CF patients, this process is disturbed. Therefore digestive enzymes need to be taken orally with every meal. When these enzymes are taken incorrectly, the digestive problems worsen. The pancreatic enzymes need to be taken in the correct dose at each meal, snack or drink containing fat and / or protein. When high doses are needed they are best divided over the meal.
Patients with CF are also prone to develop constipation or a more severe form: DIOS (=Distal Intestinal Obstruction Syndrome). In DIOS an accumulation of mucus, stool, and undigested food occurs at the site of transition from small to large intestine. This can lead to a partial or total gut obstruction. When digestion is very poor (e.g. poor intake of pancreatic enzymes) excess fat in the intestine can further slow down the gut mobility and lead to DIOS. In case of DIOS patients can feel bloating, and the abdominal circumference can increase.
Feeling bloated could also result from a lot of gas in the gut. Gas can originate from carbonated beverages or certain vegetables (f.e. cabbage, onion, peppers,... ). But gas can also come from for swallowing air during breathing or from the use of BiPAP (device to support breathing).
Other factors that can cause abdominal bloating are: delayed gastric emptying (which gives more trouble a few hours after the meals and in the evening), use of gastric acid inhibitors (PPI (=protone pump inhibitors) such as omeprazole).
Liver disease can increase the abdominal circumference, especially when there are complications. Finally, long-term use of corticosteroids can impact on the body composition: abdominal fat deposition is stimulated.
Hyperinflation (secondary to airway obstruction) will make the chest bigger, because the lungs take up more space. This is however at the level of the chest and is constant, not at certain times of the day. It is most likely not the cause of feeling bloated in the evening.
Physical examination (and if needed extra tests) is usually sufficient to find the cause of bloating.

Best regards,
Prof. K. de Boeck

02.06.2014