The relationship between diet and glycemic response and inflammatory markers in children with cystic fibrosis

The aim of this study was to determine the relationship between the diets of children with cystic fibrosis, their glycemic responses and some inflammatory markers. Twenty-four children with cystic fibrosis (75,0% girls) aged 6-18 years, who were known to have normal glucose tolerance and whose mean age was 10,4±3,3 years, were included in the study. With the questionnaire form, information about the children's age at diagnosis of cystic fibrosis, cystic fibrosis transmembrane regulator (CFTR) mutation, pancreatic enzyme replacement therapy dose, child's eating habits, physical activity levels and their families were obtained. Routinely evaluated biochemical results of the patients whose anthropometric measurements were taken, some inflammation marker levels (C-reactive protein, malondialdehyde, interleukin-1-beta, tumor necrosis factor-alpha, interleukin-6, interferon-gamma), respiratory function tests and data obtained from the continuous glucose monitoring sensor (CGMS) were recorded. Healthy Eating Index 2015 version (HEI-15) and dietary inflammatory index (DII) were calculated with food record data obtained from three consecutive days between the days when the continuous glucose monitoring sensor was worn. Adequate energy intake levels of the patients were evaluated at 110%. The data were evaluated with appropriate statistical methods using SPSS 25.0 and Prism 9.0 programs. The most common mutation type was delF508 (37,5%) and the majority of patients (83,3%) apply pancreatic enzyme replacement therapy (PERT). The average body mass index (BMI) Z scores of female patients was -0,6±1,2, while that of males was -1,0±1,3; hand grip strength percentages were found to be 71,2±15,9 and 56,6±20,4 in girls and boys, respectively. When the relationship between mean forced vital capacity (FVC) and the forced expiratory volume in one second (FEV1) with anthropometric measurements was examined, neck circumference was statistically positively related to FVC (r=0,442), upper middle arm circumference was statistically positively related to FVC and FEV1 (r=0,478, r=0,640, respectively) and hand grip strength were found to have a statistically significant positive relationship with FEV1 (p<0,05). There was no statistically significant relationship between respiratory function tests and continuous glucose monitoring sensor data (p>0,05). When the diets of the patients were evaluated according to their HEI-15 scores, it was determined that the majority (83,3%) were in the diet quality group that needed improvement and their mean DII score was 1,4±3,5. It was found that the average blood glucose values of the participants had a positive relationship with carbohydrates (g) (r=0,460), n-6 fatty acids (r=0,515), glycemic index (r=0,670), glycemic load (r=0,655) and a negative significant relationship with DII scores (r=-0,452) (p<0,05). Similarly, glucose management indicator values were determined to have a positive significant relationship with energy (r=0,685), carbohydrate (r=0,696), protein (r=0,520), n-6 fatty acid (r=0,613), glycemic index (r=0,792), glycemic load (r=0,830) and a negative significant relationship with DII scores (r=-0,516) (p<0,05). In addition, a statistically significant relationship was found between the patients' HEI-15 components, dark green leaves and fresh legumes (r=-0,520), fatty acids (r=-0,486), and the increase in the total HEI score (r=-0,458) and the decrease in the inflammatory burden of the diet (p<0,05). It was determined that C-reactive protein (CRP), one of the inflammatory markers that play a role in the etiology of cystic fibrosis-related diabetes, was significantly associated with both blood glucose fluctuation (r=0,575) and DII scores (r=0,478) (p<0,05). As a result, the amount of dietary energy and macronutrients, carbohydrate type, glycemic index and load, DII and HEI scores were correlated with plasma cytokine levels and glycemic response in patients with cystic fibrosis. Regulating and closely monitoring nutritional habits in childhood will have an important role in preventing diabetes, which increases in prevalence with the extension of life expectancy, and in maintaining a healthy life.