Ravages of Diabetes on Gastrointestinal Sensory-Motor Function: Implications for Pathophysiology and Treatment. Curr Gastroenterol Rep. 2016;18:6. [PMID: 26768896 DOI: 10.1007/s11894-015-0481-x]

Association between jejunal remodeling in fasting rats and hypersensitivity of intestinal afferent nerves to mechanical stimulation

Remodeling of Intestinal properties and hypersensitivity of intestinal afferents to mechanical stimulation were previously demonstrated in a fasting rat model. Other studies investigated the association between mechanical and histological remodeling during fasting. This study aimed to further explore the relationship between the jejunal remodeling and intestinal afferent hypersensitivity by combining afferent nerve recordings with histological and mechanical data. Eight male Sprague Dawley rats had no access to food for 7 days (Fasting group). Seven male rats served as controls (Control group). Jejunal segments were studied in vitro in an organ bath for analysis of afferent signaling and for analysis of mechanical and histomorphological parameters. Correlation analyses were done to analyze association between nerve activity (spike rate increase ratio, SRIR) at distension levels of 20, 40 and 80 cmH2O and mechanical stress and histomorphological changes of the jejunal segments. Compared with the Control group, the main findings in jejunal segments in the Fasting group were (1) Most histomorphometry parameters were reduced (P < 0.05-P < 0.001), (2) SRIR values were higher (P < 0.001), (3) The relative numbers of intermuscular and submucosal neurons were increased (P < 0.05-P < 0.01), and (4) SRIR was negatively correlated with intestinal wall thickness, circumferential muscle layer thickness and positively correlated with the inner residual strain, the number of neurons, and the mechanical stress. In conclusion, the fasting-induced histomorphological remodeling (reduced wall thickness and increased relative number of neurons) and biomechanical remodeling (residual strain changes and high stress level) of the intestine in fasting rats were associated with hypersensitivity of intestinal afferents. Afferent hypersensitivity appears to be dependent on stress rather than on strain.

The Composite Autonomic Symptom Score 31 Questionnaire: A Sensitive Test to Detect Risk for Autonomic Neuropathy

Background and Aims

Autonomic neuropathy is a common but often neglected complication of diabetes, prediabetes, and even in individuals with an elevated risk of diabetes. The Composite Autonomic Symptom Score (COMPASS) 31 is a validated and easy-to-use questionnaire regarding autonomic symptoms. We aimed to use a digitally, Norwegian version of the COMPASS 31 in people with different durations of diabetes and healthy controls to consider feasibility and to investigate if scores could discriminate between positive and negative outcomes for established tests for diabetic neuropathy, including cardiovascular autonomic neuropathy (CAN) and a novel method of examining the gastrointestinal visceral sensitivity.

Method

We included 21 participants with longstanding type 2 diabetes, 15 with early type 2 diabetes, and 30 matched controls. The mean age for all groups was 69 years. Participants were phenotyped by cardiovascular autonomic reflex tests, electrical skin conductance, sural nerve electrophysiology, and the monofilament test. As a proxy for gastrointestinal visceral and autonomic nerve function, evoked potentials were measured following rapid rectal balloon distention.

Results

Participants with longstanding diabetes scored a median (IQR) of 14.9 (10.8-28.7) points, early diabetes of 7.3 (1.6-15.2), and matched controls of 8.6 (4.1-21.6), p = 0.04. Women and men scored 14.4 (5.5-28.7) and 7.8 (3.6-14.6) points, respectively, p = 0.01. Participants with definite or borderline CAN scored 14.3 (10.4-31.9) points, compared to participants with no CAN, 8.3 (3.2-21.5), p = 0.04. Lowering the diagnostic cut-off from 16 to 10 points increased the sensitivity from 0.33 to 0.83, with a decreased specificity from 0.68 to 0.55.

Conclusion

We successfully used COMPASS 31 in Norwegian. Thus, following the guidelines, we suggest clinical implementation for the assessment of autonomic neuropathy. Participants with longstanding diabetes had an increased likelihood of symptoms and signs of autonomic neuropathy. For screening purposes, the sensitivity was improved by lowering the cut-off to 10 points, with a lower score nearly excluding the diagnosis.

Molecular mechanism of Sishen pills in the treatment of diarrheal diabetic enteropathy based on network pharmacology

This study aimed to explore the effectiveness and safety of Sishen pills for the treatment of diarrheal diabetic enteropathy (DDE). The Traditional Chinese Medicine (TCM) Systems Pharmacology and BATMAN-TCM databases were used to determine the chemical composition of Sishen pills and thus predict information on protein targets. We searched for potential targets of DDE in the GeneCards, DrugBank, Therapeutic Target (TTD), and DisGeNET databases. Using the intersection of the drug and disease targets, protein-protein interaction (PPI) networks and molecular interaction modules were constructed, and key targets were screened. The intersecting gene targets were imported into the Metascape database to conduct Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. The core targets and active ingredients were then docked at the molecular level. Sishen pills contain 70 active ingredients, 463 targets, and 566 disease targets. A module analysis of the targets revealed that the module was mainly related to adrenergic receptor activity, the adenosine phosphate kinase signaling pathway, and the G protein-coupled receptor signaling pathway. The GO and KEGG pathway enrichment results indicated that the protein genes regulated by Sishen pills were mainly enriched in the response to lipopolysaccharides, the AMPK signaling pathway, the JAK-STAT signaling pathway, and other signaling pathways. The molecular docking results showed that the core active compounds exhibited good binding activity with the predicted targets. Sishen pills can regulate the immune function of the body through anti-inflammatory and antibacterial effects for the treatment of DDE.

The day-night pattern of colonic contractility is not impaired in type 1 diabetes and distal symmetric polyneuropathy

Colonic contractility normally shows circadian variability regulated by sleep and especially food intake. However, individuals with type 1 diabetes have a reduced or even absent gastrocolic response to a meal, indicating that colonic contractility may be affected by the disease. We hypothesized that individuals with type 1 diabetes and distal symmetric polyneuropathy (DSPN) have decreased motility (expressed as the motility index) and contractility of the colon and a reduced increase in motility index from night to morning compared to healthy controls and individuals with type 1 diabetes without DSPN. Cohorts of 35 individuals with type 1 diabetes and DSPN, 40 individuals with type 1 diabetes without DSPN, and 28 healthy controls were included in this post-hoc, cross-sectional analysis. We investigated, using a wireless motility capsule that measures pH, temperature, and pressure throughout the gastrointestinal tract, whether individuals with type 1 diabetes with and without DSPN, compared to healthy controls, exhibit altered colonic contractility in the evening, night, and morning. Max amplitude, mean peak amplitude, mean contraction, and motility index of the colon were calculated at the afore-designated times. Motility index of the colon tended to be higher in individuals with type 1 diabetes and DSPN compared to controls in the evening (P = .064), but the effect size was small (1.74%). There was no difference in motility index between the groups in the morning or evening. Furthermore, there was no difference in max amplitude, mean peak amplitude, or mean contraction between groups in the morning, evening, and night. As expected, overall contractility increased from night to morning in all groups, but there was no difference between groups in the increase in contractility from night to morning. Colonic contractility generally peaked in the morning, decreased in the evening, and was almost absent at night. Type 1 diabetes and/or DSPN did not impair contractility of the colon at any time point. Contractility and motility increased from morning to night unaffected by type 1 diabetes and/or DSPN.

The Prevalence of Enteropathy Symptoms from the Lower Gastrointestinal Tract and the Evaluation of Anorectal Function in Diabetes Mellitus Patients

Complications affecting the gastrointestinal tract often occur in the course of diabetes mellitus (DM). The aim of this study was to evaluate enteropathy symptoms and anorectal function using high-resolution anorectal manometry (HRAM). Fifty DM patients and 20 non-DM controls were enrolled into the study. Clinical data and laboratory tests were collected, physical examination and HRAM were performed. Symptoms in the lower gastrointestinal tract were reported by 72% of patients. DM patients with a long disease duration reported anal region discomfort (p = 0.028) and a sensation of incomplete evacuation (p = 0.036) more often than patients with shorter diabetes duration. Overall, DM patients had a lower maximal squeeze pressure (MSP) (p = 0.001) and a higher mean threshold of minimal rectal sensation (p < 0.01) than control subjects. They presented with enhanced features of dyssynergic defection than the control group. MSP and maximal resting pressure (MRP) were significantly lower in the group of long-term diabetes (p = 0.024; p = 0.026 respectively) than in patients with a short-term diabetes. The same observation was noted for patients with enteropathy symptoms that control for MSP (p < 0.01; p < 0.01; p = 0.03) and MRP (p < 0.001; p = 0.0036; p = 0.0046), respectively, for incontinence, constipation, and diarrhea. Symptoms in the lower gastrointestinal tract are often reported by DM patients. All DM patients have impaired function of the external anal sphincter and present enhanced features of dyssynergic defecation and also impaired visceral sensation. Patients with long-standing DM and patients with enteropathy symptoms have severely impaired function of both anal sphincters.

Factors associated with diabetic gastrointestinal dysfunction

AIM: To compare the data of diabetic patients with diabetic gastrointestinal dysfunction and those without to identify factors associated with gastrointestinal dysfunction in patients with diabetes mellitus.

METHODS: One hundred and eighty diabetes mellitus patients treated from 2006 to 2015 at the Second Affiliated Hospital of Kunming Medical University were included, including 80 with diabetic gastrointestinal dysfunction as a case group, and 100 without diabetic gastrointestinal dysfunction as a control group. The two groups were compared with regard to gender, age, medical history, islet function (C-peptide release test), glycosylated hemoglobin, fasting blood-glucose, 2 h postprandial blood glucose, diabetic complications (diabetic nephropathy, diabetic eye disease, coronary heart disease, diabetic ketosis and cerebral artery elasticity, peripheral vascular atherosclerosis, and diabetic peripheral neuropathy) and other related paramters.

RESULTS: There was no significant difference in sex distribution between the two groups (P = 0.083). C-peptide levels at 0, 1, and 2 h were significantly lower in the case group than in the control group (1.79 ng/mL ± 1.54 ng/mL vs 1.98 ng/mL ± 1.20 ng/mL, P = 0.367; 2.86 ng/mL ± 2.33 ng/mL vs 3.97 ng/mL ± 2.77 ng/mL, P = 0.05; 3.33 ng/mL ± 2.58 ng/mL vs 8.44 ng/mL ± 3.62 ng/mL, P < 0.001). Fasting blood glucose was lower in the case group than in the control group (8.53 mmol/L ± 3.61 mmol/L vs 9.10 mmol/L ± 3.70 mmol/L, P = 0.30). The proportions of patients with peripheral atherosclerosis and those with coronary heart disease in the case group were significantly higher than those in the control group (25% vs 7%, P = 0.01; 26.25% vs 24%, P = 0.73). The proportions of diabetic nephropathy, diabetes, eye diseases, diabetic ketosis, and peripheral neuropathy were also significantly higher in the case group than in the control group (37.5% vs 16%, P = 0.02; 45% vs 15%, P < 0.001; 22.5% vs 20%, P = 0.72; 51.25% vs 21%, P < 0.001).

CONCLUSION: The occurrence of diabetic gastrointestinal dysfunction is associated with islet function, history, coronary heart disease, diabetic nephropathy, diabetic eye disease, and peripheral neuropathy. Patients with poor islet function, long history of disease, complications like coronary heart disease, diabetic nephropathy, diabetic eye disease, and peripheral neuropathy are more likely to develop diabetic gastrointestinal disorders. However, diabetic gastrointestinal dysfunction has no significant correlation with age, glycosylated hemoglobin, fasting blood glucose, 2 h postprandial blood glucose, diabetes ketosis, or peripheral vascular atherosclerosis.

Pathogenesis of diabetic gastrointestinal dysfunction

Diabetic gastrointestinal dysfunction is a common complication in patients with diabetes mellitus. Most of the symptoms are related to impaired gastrointestinal function. The pathogenesis and etiology of diabetic gastroenteropathy are complex, involving the parasympathetic and sympathetic nervous systems, enteric neurons, smooth muscle cells, the network of interstitial cells of Cajal, cholinergic receptors and neuronal nitric oxide synthase. This article reviews the pathogenesis of diabetic gastrointestinal dysfunction.