The relationship between weight and pulmonary outcomes in overweight and obese people with cystic fibrosis: A retrospective observational study

Abstract

Background A major focus in cystic fibrosis (CF) care aims to increase weight gain. Rates of overweight and obese people with CF have gradually increased over the past decade. Obesity could be a risk for restriction of lung volumes and airway obstruction as well as increase rates of pulmonary exacerbations in people with CF. Aim To assess the relationship between weight categories and pulmonary outcomes in children and adults with CF. Methods Patients 6 years of age and older were categorized into weight categories based on the Centers for Disease Control and Prevention (CDC) definitions. A retrospective chart review was conducted to obtain lung function testing and other outcomes. Results One hundred five patients with a median age of 20.6 years were included in this analysis. 8.4%, 64%, 18%, and 10% of patients were underweight, normal/healthy weight, overweight, and obese, respectively. Forced expiratory volume in 1 s (FEV 1 ) and forced vital capacity (FVC) (% predicted) did not differ between patients with weights in the normal range versus patients in the overweight/obese categories. Linear regression analysis showed a direct correlation between body mass index (BMI) and FEV 1 that continued as BMI entered overweight and obese categories in both pediatric and adult patients. Overweight/obese patients did not have increased rates of pulmonary exacerbations compared to those in the normal/healthy weight category. Conclusion As CF therapies continue to improve, an increasing number of people with CF are exceeding the CDC's normal‐weight range. Gaining weight past the normal range does not appear to negatively impact pulmonary health of people with CF. If this trend of increased weight gain continues, it remains to be seen if it will eventually negatively affect lung health.

Cystic fibrosis year in review 2022

“…The effect of being overweight or obese on clinical outcomes was also examined. In Italy and New York, a positive correlation between BMI and FEV1pp was seen 91,92 . The association of BMI based on pancreatic status revealed the loss of positive association above the 85th percentile for BMI in PS PwCF, though it continued to increase through the 99th percentile for PI PwCF 70 .…”

“…The incidence of PwCF who were overweight (BMI 25–29.9 kg/m 2 or 85th to <95th percentile) was reported as 22.1% (71/321) in Italy 19 and 18% in New York, with an overall relative increase in the CFFPR of PwCF categorized as overweight by >300% (8%–17%) 19 . PwCF classified as obese (BMI > 30 kg/m 2 of >95th percentile) was found to be 10% in New York 92 with an overall relative increase by >400% (2%–7%) 19 . All studies revealed individual factors associated with obesity suggesting a milder disease state, 19,90,91 however, the CFFPR found no program‐based factors associated with obesity 19 …”

“…In Italy and New York, a positive correlation between BMI and FEV1pp was seen. 91,92 The association of BMI based on pancreatic status revealed the loss of positive association above the 85th percentile for BMI in PS PwCF, though it continued to increase through the 99th percentile for PI PwCF. 70 Negative associations were seen with more overweight/obese PwCF having CF-related liver disease, elevated cholesterol, and systemic hypertension.…”

Evolving nutritional needs, obesity, and overweight status in cystic fibrosis

“…Previously, correlation between fat-free mass, BMI and increases in lung function have been noted. This was redemonstrated [27] with a study including both children and adults finding significant direct correlation between BMI and FEV1 in children and adults, at all BMI categories [28]. In contrast the association between BMI and FEV1 was less robust in pancreatic sufficient children, compared to pancreatic insufficient.…”

Evolution of nutritional management in children with cystic fibrosis – a narrative review

“…However, a previous review in adults suggested being overweight/obese was associated with an improved prognosis in pwCF, although there was no extra benefit of having a higher BMI on lung function beyond the range of 28–29 kg/m² 60 . The relationship between overweight and obesity and pulmonary and clinical outcomes has been investigated recently in observational studies 61 and published in a systematic review 62 . The authors concluded that long‐term follow‐up studies are necessary to clarify any adverse effects of having a higher BMI or fat mass (FM) in patients with CF 62 .…”