Early, Rapid BMI Increase May Affect Overall Growth of CF Children, Study Suggests

Rapid weight gain early in life may have a long-term negative impact on the growth of children with cystic fibrosis (CF), a study has found.

This finding suggests that nutritional interventions aimed at supporting the child’s normal growth should be implemented early on, taking into consideration their weight and overall body mass index.

The study, “Rapid early increase in BMI is associated with impaired longitudinal growth in children with cystic fibrosis,” was published in the journal Pediatric Pulmonology.

Many patients with CF struggle with low body weight due to poor nutrient absorption related to their disease. To overcome this, high-fat, high-protein diets are often recommended for patients, in addition to enzyme replacement therapies to help the digestive process.

Low body weight can also have a negative impact on overall health, particularly in children, potentially affecting their normal growth and development. This is particularly important in the CF population, as previous studies have suggested that short stature is associated with a lower life expectancy.

Researchers from the University Medical Center Utrecht in the Netherlands conducted a long-term prospective study to better understand the impact of body weight changes on the development of children with CF.

The study included 57 infants diagnosed with CF, who were born between 1997 and 2001. In this group, 30 were boys, and most had severe CF.

Results showed that before diagnosis, the infants’ height was already substantially lower than the general population of the same age.

In boys, a slight improvement in height was seen between the ages of 12.5 and 14 years. Still, their final height at 18 years old was on average 4 centimeters (about 1.6 inches) shorter than Dutch reference values.

A similar pattern was also observed in girls with CF, who, from an early age, were also smaller compared with the national height average. At age 11, their linear growth seemed to improve and catch up to the normal trend. Their final height was 1.4 centimeters (about 0.6 inches) shorter, but this difference was not significantly different from the Dutch average.

An analysis of the children’s body mass index (BMI) — a measure of body fat based on weight and height — revealed that BMI values for both CF boys and girls were lower during the first year of life. However, these rapidly increased to closer to normal values for their respective ages in early childhood.

Researchers also found that rapid BMI increase between the ages of 1 and 6 was associated with a smaller final height.

In contrast, the children’s respiratory function and development of complications (namely CF-related diabetes) were not found to have a significant effect on their final height.

These findings demonstrate that “in boys and girls, early BMI increase was associated with impaired final height,” the researchers wrote, especially in boys.

Based on these data, the team believes that early childhood may serve “as a ‘window’ in which nutritional variations may program subsequent growth.” Better nutritional strategies and a more detailed recognition of the role of BMI in long-term development may therefore help improve the outcome of CF children.