Improving nutrition is a critical component of CF care, with malnutrition having clear associations with poor outcomes in patients with the disease [4, 5, 10, 11]. Classically, this has been targeted through a combination of increasing caloric intake and supplements, optimizing pancreatic enzyme replacement, and pulmonary/medical management, with general aim of maintaining BMI above CFF goals [5, 14]. Although multidisciplinary nutrition programs are suggested , to this point there is limited knowledge regarding the optimal methods or programs specifically desired by patients. In this study, we describe a patient-centered model that identified specific nutritional concerns and desired programs in a contemporary population of CF adults. The program was popular among participants and identified heterogeneous concerns, nutritional barriers, and desired interventions based on patient-specific factors in our cohort.
There are many barriers to achieving optimal nutrition in patients with CF [5, 9]. In addition to pancreatic exocrine insufficiency, present in at least 85% , CF patients have been shown to have markedly increased basal energy expenditure, a problem related to chronic pulmonary infection which can worsen in more advanced stages of lung disease. Additional medical barriers include dyspnea and mechanical effects of lung hyperinflation, gastrointestinal symptoms, and CFRD. Together with weight loss, lean body mass can also be disproportionately impacted by suboptimal dietary choices and lack of exercise, the latter of which may worsen in those with advanced lung disease [26,27,28,29]. Furthermore, psychosocial obstacles may be more prevalent in CF, including depression, low socioeconomic status, medical knowledge gaps, and issues with adherence to medical/nutritional programs [3, 21, 30,31,32,33,34].
Given the complexity of these barriers, it is natural that poor nutritional status in CF would be a multifaceted problem. Our findings are consistent with this notion. Importantly, in our cohort of CF adults, we found a high prevalence of overweight status. Although more than half met traditional CFF BMI goals, 28.8% were overweight, and 9.1% obese. This finding is consistent with previously demonstrated longitudinal trends in CF , with our percentages even exceeding prior estimates of the prevalence of overweight status [3, 15]. Furthermore, in our study, a significant portion of patients actually desired weight loss, with about 15% of the cohort listing this as their primary nutritional concern, a percentage that approached 40% in patients with a BMI > 25 kg/m2. The problem of CF-associated obesity, on one hand, may reflect improvements in pulmonary management and a general ageing of the CF population, both of which can be considered strong accomplishments in the disease’s history. On the other hand, although general CF nutritional trends have improved with average BMI in adults now above goal, the prevalence of obesity in our study supports the concept that the modern era of CF nutrition has evolved considerably. Recognition of the heterogeneity of nutritional barriers may become even more important as the CF population continues to age and cardiovascular risks increase [35, 36], where personalizing nutrition programs may become integral to improving CF outcomes.
The potential benefits of a patient-centered nutrition program approach are broad. Firstly, it has been demonstrated that CF patients respond well to assuming more control of their treatment plans, including recent data showing effectiveness of online and smartphone-based health-management programs [37, 38]. Secondly, there are studies showing that body image is an important component of well-being for CF children, adolescents, and adults and that improving body satisfaction may increase both adherence and quality of life [22, 39,40,41,42]. Body satisfaction is naturally influenced by subjective medical and psychosocial factors, with optimal satisfaction likely best attained by first identifying the specific barriers at hand [22, 43]. In our cohort we did find an array of nutritional and exercise habits, goals, and desired resources. As with previous reports, we identified gender differences in weight goals, with CF men more often concerned about preventing weight loss, and women more often concerned about preventing weight gain [41, 43]. Online access to CF nutrition and fitness resources was consistently the most sought-after health improvement resource, but many patients preferred other programs including direct education from CF dietitians, recipes via a CF cookbook, or financial assistance. The variety of needs presented in this study support the assertion that individualizing CF nutrition programs may be a valuable means of improving overall nutrition outcomes.
An important consideration in the patient-centered model presented here are financial and psychosocial barriers. Access to insurance coverage and financial limitations pose a challenge to many CF patients, with CFF registry data demonstrating that nearly half of individuals receive some portion of coverage through federal or state-funded programs, and low socioeconomic status having been associated with a variety of adverse outcomes [3, 21, 31, 44]. In our Medicaid cohort, although mean BMI was 23.8 kg/m2, it is noteworthy that nearly 60% fell outside of the “optimal” BMI range of 18.5–25 kg/m2, including roughly 35% overweight or obese, and 22% underweight. More than 1/3 of our cohort was on Medicaid, further suggesting that this may be a CF subset of particular importance when trying to optimize overall nutritional outcomes. In our study, financial assistance and local food resources were commonly desired health-improvement resources even among non-Medicaid patients, lending additional credence to the importance of addressing financial barriers in every patient. Especially considering the expenses and time constraints related to CF care, patient-centered nutrition programs would likely benefit from early assessment of financial concerns, along with education and other psychosocial barriers as they pertain to nutrition and fitness.
There were several limitations of this study, the first of which was a small sample size. The lack of statistically significant differences between subgroups (gender, BMI, socioeconomic status) may have been due to the study being underpowered. Larger studies on the topic are needed, but this exploratory analysis is the first to identify specific, individual nutrition concerns in a modern-day CF adult cohort, and thus represents a foundation on which further patient-centered nutrition programs may be developed. Second, this study used a convenience sample of adults attending our CF clinic with, on average, moderate lung disease. Although identifying nutritional needs may be a valuable tool in all CF cohorts, our specific findings are thus less generalizable to CF children, as well as in adults with very severe lung disease or post-transplant, where specific findings may differ. Likewise, in regards to socioeconomic comparisons, our study necessarily examined CF patients within the United States healthcare system, and while socioeconomic obstacles exist globally, the specific findings may vary in other systems. Finally, this study used an investigator-designed survey tool that has not been validated. Given that (to our knowledge) no similar validated tools exist, we consider it a first step in determining CF patient-specific nutritional needs, but since it was not an interventional study, our data cannot be used to determine the effectiveness of the suggested interventions. Future studies are needed to apply patient-specific interventions in CF using similar tools, while also examining nutritional and overall outcomes.