Oral calorie supplements for cystic fibrosis

Poor nutrition occurs frequently in children and adults with cystic fibrosis and is associated with a number of other adverse outcomes. Oral calorie supplements are used to try and increase total daily calorie intake and improve weight gain. However, they are expensive and there are concerns that they may lead to a reduction in the amount of food eaten and no overall improvement in energy intake.

To examine the evidence that in patients with cystic fibrosis, oral calorie supplements increase daily calorie intake, improve overall nutritional intake, nutritional indices, lung function, survival and quality of life. To assess possible adverse effects associated with use of oral calorie supplements.

The Cochrane Cystic Fibrosis and Genetic Disorders Group specialist trials register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and handsearching abstract books of conference proceedings. The companies which market oral calorie supplements were also contacted. Date of the most recent search of the Group's specialised register: November 1999.

All randomised or quasi-randomised controlled trials comparing use of oral calorie supplements for at least one month to increase calorie intake with no specific intervention or additional nutritional advice in patients with cystic fibrosis.

The following outcomes were assessed: indices of nutrition and growth, anthropometric measures of body composition, calorie intake (total, from oral calorie supplements and from food), nutrient intake, eating behaviour, quality of life, specific adverse effects, lung function and mortality.

Two trials which reported results from a total of 29 patients were suitable for inclusion in the review. From the data provided in the published reports only one item (change in weight) could be extracted from one trial for inclusion in the review. This showed no difference between intervention and comparison group.

Oral calorie supplements are very widely used around the world in an attempt to improve nutritional status in patients with cystic fibrosis, at some considerable cost. It is therefore very disappointing that their effectiveness has not been assessed by adequate clinical trials. No conclusions can be made about the use of oral calorie supplements in cystic fibrosis from the information currently available and clinicians must balance potential benefits against possible adverse effects of treatment in making decisions about individual patients. This systematic review has clearly identified the need for a well designed, adequately-powered, multicentre, randomised controlled trial assessing the effectiveness and possible adverse effects of oral calorie supplements in cystic fibrosis.