Meal-Specific Fiber Intake and Self-Reported Pain of Individuals with Sickle Cell Disease
Samuel M Degenhard, Stephaine Wildridge, Ashley Buscetta, Li Yang, Samuel Zamora, Djaina-Shae Dervil, Danetta Hooks, Rebecca M Metellus, Shanna Yang, Sara Turner, Allison Brichacek, Vence Bonham, Nicole FarmerAbstract
Background
Specific dietary recommendations tailored to individuals with sickle cell disease (SCD) remain limited. Current clinical guidelines emphasize adequate fiber intake to help manage the side effects of common SCD medications. Earlier work has indicated that only a small proportion of individuals with SCD consume adequate dietary fiber despite clinical guidance and the importance of fiber for other health outcomes such as cardiovascular disease and all-cause mortality. Soluble fiber, in particular, is fermented by colonic bacteria, creating short-chain fatty acid metabolites that reduce inflammation. The benefit of fiber intake may also be related to timing of consumption as meal timing has been linked to health outcomes such as sleep and all-cause mortality. However, it is unclear how fiber intake and timing are related to SCD symptoms such as pain. Therefore, this secondary analysis aimed to investigate the relationship of fiber consumption, fiber intake timing, and self-reported pain of adults with SCD.
Methods
Participants were enrolled in an observational study investigating the role of nutrition and dietary behaviors in adults living with SCD. Demographic, dietary, and clinical data were collected from a sample of adults with SCD in steady-state living in the United States. Nutrient intake data were obtained from two unannounced 24-hour recall interviews conducted over the phone. Nutrient intakes were averaged between the two days and categorized by the time of day they were consumed: breakfast (7:00–10:00), lunch (12:00–15:00), dinner (17:00–21:00), after-dinner snack (21:00–5:00), and snack (any eating occasion outside of these time ranges). Eating occasion categories were based on analysis of national data of the most common mealtimes in the U.S., but the associated labels may be inaccurate for shift workers or participants with atypical schedules. SCD pain was measured using Adult Sickle Cell Quality of Life Measure (ASCQ-Me) pain frequency, pain severity, and pain impact scores. General linear models were controlled for energy intake (kcal) and serum c-reactive protein (CRP) levels.
Results
Across the sample (n = 64), the mean age was 42.7 (± 1.5) years, 71.9% of participants were female, 54.2% were overweight or obese, and the median household income was $60,000–69,999. SCD genotypes were SS (n = 43; 67.2%), SC (n = 16; 25.0%), and beta thalassemia (n = 5; 7.90%). Daily total mean energy intake was (1829 kcal; SD = 673 kcal), mean total fiber intake (17.7g; SD = 8.9 g; range:4.61g–38.52g), mean soluble fiber intake (4.98 g; SD = 2.9; range:1.06g–16.99g), and mean insoluble fiber intake (12.6g; SD = 6.8g; range:2.45g–36.61) were calculated from the two dietary recalls. In unadjusted models, total fiber intake (R2=0.057; β=-0.133; p = 0.03) and soluble fiber intake (R2=0.110; β=-0.530; p = 0.005) were significantly, negatively associated with SCD pain impact scores. After controlling for energy intake and CRP levels, only soluble fiber intake was significantly negatively correlated with pain impact scores (R2=0.211; β=-0.535; p = 0.03). Insoluble fiber intake was not significantly related to pain frequency, pain severity, nor pain impact, and total and soluble dietary fiber intakes were not significantly correlated with pain frequency nor severity. More specifically, total fiber intake at dinner (R2=0.156; β=-0.370; p = 0.002) and snack (R2=0.094; β=-0.259; p = 0.023) were significantly associated with pain impact scores in unadjusted models. Similarly, soluble fiber intake at dinner (R2=0.109; β=-0.787; p = 0.012) and snack (R2=0.128; β=-0.667; p = 0.007) were significantly related to pain impact scores. These relationships did not remain statistically significant in adjusted models, suggesting that caloric intake and inflammation may have a role in relationship between fiber and pain.
Conclusions
These results demonstrate that dietary fiber, particularly soluble fiber, is an important nutritional factor in the symptomology and management of SCD. Additionally, our findings indicate that the timing of fiber consumption throughout the day may play a role in SCD pain management. Despite this, average total fiber consumption in our sample of individuals with SCD was well below recommended intakes. Although further investigation is warranted to understand mechanistic underpinnings of this relationship, our findings suggest that inflammation may be one such pathway. Eventually, understanding the role of fiber and timing of fiber consumption may inform nutritional guidance for the management of SCD complications such as pain.