The role of the digestive tract in the regulation of hunger hormone (ghrelin) concentration in patients nourished parenterally and enterally

Introduction : Ghrelin is a peptide hormone secreted mostly in the stomach. Its concentration increases at the time of hunger and decreases after eating.

Aim : To evaluate the influence of nutrition through the alimentary canal and intravenously on the ghrelin concentration in blood serum and to evaluate the effect of anthropometric and biochemical parameters and caloric supply on the concentration of the above-mentioned hormone.

Material and methods : The research involved 124 patients hospitalized in Bydgoszcz at University Hospital no. 1, nourished parenterally (group I; n = 78) or intestinally (group II; n = 46). The patients were weighed and the following were determined: body mass index (BMI), ideal body weight (IBW), energetic demand by means of the Harris-Benedict method both for the present weight and for IBW, caloric supply, the ratio of caloric supply to the assessed demand, supply of glucose, lipid and protein as well as the present level of glucose, triglycerides and albumin in blood serum. The level of ghrelin was measured by means of the Elisa test.

Results : Average concentration of ghrelin in group I was 194.277 pg/dl (median 159.776 pg/dl, range 12.1–925.310 pg/dl). In group II the average concentration was 219.978 pg/dl (median 272.19 pg/dl, range 35.0–790.8 pg/dl). The differences were not statistically significant (p = 0.5547). A statistically significant inverse dependence of ghrelin concentration on glucose supply and concentration of triglycerides and protein in blood serum was found. However, the correlations compared to the caloric supply, protein and lipid supply and glucose concentration in blood serum were not evaluated.

Conclusions : Nutrition by means of the alimentary canal and intravenously causes analogical stimulation of ghrelin secretion in the digestive tract. The concentration of ghrelin in blood serum correlates negatively with body weight and BMI. Decreased ghrelin concentration (a feeling of satiety) correlates with glucose supply and high protein and lipid concentration in blood serum; however, there is a lack of dependence of hormone concentration on the caloric supply.