Background: Malnutrition in cystic fibrosis (CF) patients is associated with worse pulmonary function and increased morbidity and mortality. Nutritional intervention and introduction of modulator therapy has led to increase in overweight (body mass index [BMI]=25-29.9) and obesity (BMI >30) in CF patients, however advantage and impact of higher BMI remains understudied. We aim to study the association of higher BMI in CF patients on clinical outcomes.
Methods: We conducted a retrospective cross-sectional study of CF patients, age 18 years and older, who follow with the Mountain State CF center. Demographic variables, BMI, lung function (percent predicted FEV1) and number of exacerbations from January 1, 2020, to December 31, 2020, were collected from the CF Registry, as well as number of reported exacerbations from January 1, 2015-Dec 31, 2019. Outcomes between the underweight/normal (BMI =/< 24.9) and overweight/obese (BMI >24.9) were compared.
Results: A total of 86 patients were included in the study with 41.8% (36 patients) being overweight or obese. Mean age of the total cohort was 33.3 (SD ±13.3) years with a mean BMI of 25.1 (±6.5). Percent predicted FEV1 was higher in the overweight/obese group [78.5% (±26.7)] compared to those with underweight/normal BMI [67.4% (±25.8)]. Of the total cohort, 60 (69.8%) patients were on modulator therapy with half of these being on triple modulator therapy (Trikafta), while 25 patients (69.4%) of the overweight/obese group and 35 (70%) patients in the underweight/normal BMI group were on modulator therapy. Pulmonary complications (asthma, ABPA, bronchiectasis) were similar in both groups [8 (16%) vs 8 (22.2%); p-value=0.5]. Hyperlipidemia was more common in the overweight/obese group compared to underweight/normal BMI group (p-value 0.04). All other co-morbidities including hypertension, diabetes, cardiovascular events were similar (p-value >0.05). CF exacerbations in 2020 were similar in the two groups (p-value >0.05) while exacerbation between 2015-2019 were fewer in the overweight/obese group although this was not statistically significant.
Conclusions: Higher BMI may be associated with a decrease in CF exacerbations. It may however also increase risk of cardiovascular co-morbidities. Therefore, the risks and benefits of a higher BMI in CF patients needs to be studied in further detail.
