Analysis of the relationship between the parameters of the autonomic nervous system and the clinical course of type 2 diabetes mellitus in combination with chronic pancreatitis

Abstract. Currently, the possible relationship between the function of the autonomic nervous system (ANS) and type 2 diabetes mellitus (T2DM) is being actively studied. ANS imbalance is also mentioned by researchers as one of the possible causes of excretory insufficiency of the pancreas, including in chronic pancreatitis (CP). In T2DM, the manifestations of CP symptoms may differ from the typical course, so it was considered advisable to study them in more detail. Purpose: to assess the functional state of some parameters of the autonomic nervous system, to establish the presence and strength of possible interdependencies between ANS parameters and the degree of manifestations of gastrointestinal symptoms according to the values of the GSRS questionnaire scales in patients with DM2 and concomitant CP. Materials and methods: 88 patients with DM2 with concomitant CP were included in the study. The control group consisted of 23 healthy individuals. The state of the ANS was assessed according to the results of determining heart rate variability (HRV) using the diagnostic electrocardiographic complex CARDIO (Ukraine). Among the determined HRV parameters, the following were analyzed in detail: standard deviation of NN, (SDNN) — standard deviation of the values of normalized R-R intervals; total power (TP) — total spectrum power; LF/HF ratio (LF/HF) — the ratio of the value of the low frequency range LF (low frequency band) to the value of the high frequency range HF (high frequency band). The severity of gastrointestinal symptoms over the past week was assessed using the gastrointestinal symptom rating scale (GSRS) questionnaire, resulting in the following scales: abdominal pain (AB), reflux syndrome (RS), diarrhea syndrome (DS), dyspepsia syndrome (SD), constipation syndrome (CS) and total score (SS). Research results and their discussion: an increase in the activation of sympathetic influences of the ANS by 30.19% and a decrease in total HRV by 29.20% were found, based on lower than in the control group values of SDNN and TP. The influence of the parasympathetic component of the ANS was also reduced by 58.12%, according to lower than in the control group values of LF/HF with subsequent increase in relative sympathicotonia in patients with DM2 and CP. The correlation analysis demonstrated the presence of an inverse relationship from weak to significant strength between the degree of manifestation of symptoms of gastrointestinal disorders and signs of activation of sympathetic influences of the ANS and a decrease in total HRV in the form of reduced SDNN and TP, as well as a direct relationship from weak to moderate strength with a sign of a decrease in the parasympathetic component of the ANS in the form of an increased value of the LF/HF coefficient, which is a sign of deepening relative sympathicotonia. Conclusion. The correlation analysis conducted established a statistically significant dependence of clinical manifestations on the depth of HRV impairment: the presence of an inverse relationship from weak to significant strength between the degree of manifestation of symptoms of gastrointestinal disorders and reduced SDNN and TP as signs of activation of sympathetic influences of the ANS and a decrease in total HRV, as well as a direct relationship from weak to moderate strength with an increased value of the LF/HF ratio as a sign of a decrease in the parasympathetic component of the ANS with subsequent increase in relative sympathicotonia.