This blog post was written by Christina Hunt, BS, RRT, Director of Bronchiectasis and NTM Research and Education.

Bronchiectasis is a lung disease characterized with enlarged airways that are thickened and/or dilated. Individuals that have bronchiectasis typically have a cough that is usually productive with mucus. Recurrent lung infections or exacerbations can plague those with bronchiectasis. Recently, there has been more awareness of bronchiectasis likely from improved testing techniques which have allowed physicians to recognize and diagnose those with the condition. Interesting data shows that individuals with bronchiectasis live all over the world, are diverse in age groups, and other demographics. This has made studying bronchiectasis to find new therapies and treatments a challenge.

One way to classify bronchiectasis is by severity. The Bronchiectasis Severity Index (BSI) uses information about individuals with bronchiectasis like body mass index (BMI) to predict patient risk of hospitalization and prognosis. BMI is a measure of body fat based on height and weight that applies to men and women. It is an inexpensive, easy method for categorizing weight – underweight, normal/healthy weight, overweight, and obese. There have been several studies that suggest that if an individual with bronchiectasis is underweight or suffers from malnutrition, they have a higher rate of exacerbations, hospitalization, and mortality.^1-3 Thus, better nutrition may be beneficial for managing and coping with the diagnosis. Therefore, if poor nutrition is associated with poor outcomes, improving nutrition of bronchiectasis patients might help to improve or prolong the progression of bronchiectasis lung disease.

Researchers at the University of North Carolina in Chapel Hill recently conducted a study using data from the U.S. Bronchiectasis and NTM Research Registry (BRR). The goal of the study was to assess the relationship between nutritional status of non-CF bronchiectasis patients enrolled in the BRR and other markers of bronchiectasis severity. The study took place using patient data from the BRR over a span of 5 years. Patients were categorized based on their BMI into four groups: underweight, normal/healthy weight, overweight, and obese. The data analyzed for each group included: number of exacerbations and hospitalizations over two years, PFT results, history of hemoptysis (coughing up blood), and history of lung resection (surgery to remove part of a lung or an entire lung). Other patient information like age, gender, race/ethnicity, infection with pseudomonas aeruginosa and/or NTM, smoking status, underlying causes of bronchiectasis, as well as coexisting conditions were also evaluated.

The final study included 496 patients. A majority of the patients were female (83.3%) and the average age was 65 years old. White patients comprised 92% of the patient population, while the second largest race represented was Asian patients (5.4%). Only 13 patients (2.6%) identified as black, and only 12 patients (2.4%) identified as other race (including multiple races). At baseline, 12.3% were underweight, about 64% were normal weight, 17.3% were overweight, and 6.5% were obese. A larger proportion of men were represented in the overweight and obese categories compared to the underweight and normal weight categories. Patients in the underweight group had significantly lower lung function than the other weight groups. There was no significant difference in exacerbation frequency, hospitalization, or lung resections between the groups. The study revealed that most of the patients maintained their BMI over the five-year period. Researchers found it interesting and surprising that fewer patients than expected were underweight, and that the majority of patients in the study had a normal BMI.

Nutrition has been associated with outcomes for individuals with bronchiectasis. Specifically, if a person with bronchiectasis is underweight it can lead to worsening lung function. Despite this association, based on this study, lower BMI did not seem to be associated with other markers of disease severity such as hospitalization rates or frequency of exacerbations. The study also concluded that most patients with bronchiectasis within the United States are of normal BMI. As the bronchiectasis community continues to learn more about the diagnosis, further research on the disease and its relationship to gender, weight, race/ethnicity, and comorbidities may be required in order to develop new therapies.

The results of this study were published in the Journal of the COPD Foundation and can be accessed here.

References:

1. Cano NJ PC, Roth H, Court-Fortuné I, et al; Clinical Research Group of the Société Francophone de Nutrition Entérale et Parentérale. C-reactive protein and body mass index predict outcome in end-stage respiratory failure. Chest. 2004;126(2):540-546. doi: https://doi.org/10.1378/chest.126.2.540
2. Qi Q, Li T, Li JC, Li Y. Association of body mass index with disease severity and prognosis in patients with non-cystic fibrosis bronchiectasis. Braz J Med Biol Res. 2015;48(8):715-724. doi: https://doi.org/10.1590/1414-431x20154135
3. Onen ZP, Gulbay BE, Sen E, et al. Analysis of the factors related to mortality in patients with bronchiectasis. Respir Med. 2007;101(7):1390-1397. doi: https://doi.org/10.1016/j.rmed.2007.02.002