The stomach in diabetes: from villain to ally

Association Between Gastric Emptying Time and Incidence of Cardiovascular Diseases in Subjects With Diabetes

Background/Aims

Delayed gastric emptying (GE) is associated with high morbidity and mortality in subjects with diabetes. The aim of this study is to investigate associations between GE time and the major cardiovascular events (coronary heart diseases and ischemic stroke) in diabetic subjects with upper gastrointestinal (UGI) symptoms.

Methods

Among 259 subjects with chronic UGI symptoms who underwent gastric emptying study (GES) over 13 years, 122 diabetic subjects without gastric surgery and/or rapid GE were enrolled in this study. We also gathered data about baseline demographics, clinical characteristics, estimated GE half-time (GE T_½) and incidence of cardiovascular events following GES.

Results

The mean age of subjects was 64.0 ± 17.4 years. There were 86 women and 104 subjects with type 2 diabetes. There were 52 (42.6%) subjects with normal GE, 50 (41.0.%) subjects with mild delayed GE, and 20 (16.4%) subjects with marked delayed GE. During follow-up (median, 207 weeks), cardiovascular events occurred in 7 (13.5%) subjects with normal GE, 4 (8.0%) subjects with mild delayed GE and 7 (35.0%) subjects with marked GE (P = 0.015). Univariate analysis showed that GE T_½ was significantly associated with incidence of cardiovascular events (crude OR, 1.74; 95% CI, 1.12–2.69; P = 0.014). In a multivariate model, association between GE T_½ and incidence of cardiovascular events remained statistically significant after adjustment for baseline characteristics and comorbidities (adjusted OR, 1.94; 95% CI, 1.21–3.12; P = 0.006).

Conclusion

A delay of GE was associated with an increased incidence of cardiovascular events in diabetic subjects with chronic UGI symptoms.

Itopride combined with α-lipoic acid for diabetic gastroparesis: Curative effect and impact on motilin and gastrin

AIM: To observe the efficacy of itopride hydrochloride combined with α-lipoic acid in the treatment of diabetic gastroparesis (DGP) and their effect on motilin and gastrin.

METHODS: Sixty patients with DGP who had gastrointestinal symptoms were treated with α-lipoic acid and itopride (α-lipoic acid 0.6 g + 250 mL 0.9% saline intravenously for 14 d + itopride 50 mg orally before meals, three times a day), and 50 patients were treated with itopride alone (itopride 50 mg orally before meals, three times a day). After two weeks of treatment, clinical symptoms including postprandial abdominal fullness, belching, acid reflux, anorexia, nausea and vomiting were observed, the gastric emptying rate was determined, the efficacy was evaluated, and the changes in the levels of motilin and gastrin were detected.

RESULTS: Improvement of clinical symptoms was observed in both groups, and the total effective rate was 91.6% in the combination therapy group and 78.0% in the monotherapy group. Gastric emptying rate was significantly higher in the combination group than in the monotherapy group (P < 0.05). Motilin and gastrin levels were reduced after treatment in both groups, and the decrease was more significant in the combination group.

CONCLUSION: For patients with DGP, α-lipoic acid and itopride combination therapy can better improve symptoms of gastroparesis, increase gastric emptying, and decrease the levels of motilin and gastrin compared with treatment with itopride alone.

The short-term effects of acupuncture on patients with diabetic gastroparesis: a randomised crossover study

BACKGROUND

Acupuncture may improve gastrointestinal symptoms in patients with various disorders, but its efficacy in diabetic gastroparesis is unclear.

OBJECTIVE

To evaluate the short-term effects of acupuncture on gastric emptying and gastroparesis symptoms in patients with diabetic gastroparesis.

METHODS

In a single-blind controlled crossover trial, 25 patients with diabetic gastroparesis were randomly assigned to undergo 1 week of real acupuncture (RA) treatment followed by 1 week of sham acupuncture (SA) treatment, or vice versa, with a washout of 1 month in between. Before and after each intervention, gastric retention, the Gastroparesis Cardinal Symptom Index (GCSI), fasting blood glucose (FBG) and HbA1c levels were measured.

RESULTS

21 patients completed the study. Compared with SA treatment, RA treatment was associated with significantly greater reductions in gastric retention at 2 h (-11.1±7.0%; 95% CI -13.6% to -6.2%; p<0.01) and at 4 h (-5.0±2.8%; 95% CI -6.0% to -0.2%; p=0.04) and in GCSI score (-8.0±3.4; 95% CI -8.4 to -2.8; p<0.01). There were no significant differences in FBG and HbA1c levels between RA and SA treatments.

CONCLUSIONS

In patients with diabetic gastroparesis, 1 week of short-term manual acupuncture reduces gastric retention and improves gastroparesis symptoms.

Gastric nNOS reduction accompanied by natriuretic peptides signaling pathway upregulation in diabetic mice

AIM

To investigate the relationship between neuronal nitric oxide synthase (nNOS) expression and the natriuretic peptide signaling pathway in the gastric fundus of streptozotocin (STZ)-induced diabetic mice.

METHODS

Diabetic mice were induced by injection of STZ solution. Immunofluorescence labeling of HuC/D, nNOS and natriuretic peptide receptor-A, B, C (NPRs) in the gastric fundus (GF) was used to observe nNOS expression and whether NPRs exist on enteric neurons. The expression levels of nNOS and NPRs in the diabetic GF were examined by western blotting. An isometric force transducer recorded the electric field stimulation (EFS)-induced relaxation and contraction in the diabetic GF. An intracellular recording method assessed EFS-induced inhibitory junction potentials (IJP) on the GF. GF smooth muscles acquired from normal mice were incubated with different concentrations of the NPRs agonist C-type natriuretic peptide (CNP) for 24 h, after which their nNOS expressions were detected by western blotting.

RESULTS

Eight weeks after injection, 43 diabetic mice were obtained from mouse models injected with STZ. Immunofluorescence indicated that the number of NOS neurons was significantly decreased and that nNOS expression was significantly downregulated in the diabetic GF. The results of physiological and electrophysiological assays showed that the EFS-induced relaxation that mainly caused by NO was significantly reduced, while the contraction was enhanced in the diabetic GF. EFS-induced IJP showed that L-NAME sensitive IJP in the diabetic GF was significantly reduced compared with control mice. However, both NPR-A and NPR-B were detected on enteric neurons, and their expression levels were upregulated in the diabetic GF. The nNOS expression level was downregulated dose-dependently in GF smooth muscle tissues exposed to CNP.

CONCLUSION

These findings suggested that upregulation of the NPs signaling pathway may be involved in GF neuropathy caused by diabetes by decreasing nNOS expression.

Chinese herbal medicine banxiaxiexin decoction treating diabetic gastroparesis: a systematic review of randomized controlled trials

Objective. To assess the current clinical evidence of Banxiaxiexin decoction for diabetic gastroparesis (DGP). Methods. Electronic databases were searched until December 2012. No language limitations were applied. We included RCTs using Banxiaxiexin decoction/modified Banxiaxiexin decoction for DGP. No restriction for the control group except acupuncture. Applying clinical effective rate as the main outcome index. Data extraction, analyses and quality assessment were conducted according to the Cochrane review standards. Results. 16 RCTs involving 1302 patients were finally identified, and the methodological quality was evaluated as generally low. The data showed that the effect of Banxiaxiexin decoction (BXXD) for DGP was superior to the control group (n = 1302, RR 1.23, 95% CI 1.17 to 1.29, Z = 8.04, P < 0.00001). Only one trial recorded adverse events, no obvious adverse event occurred. Conclusions. Banxiaxiexin decoction could regain the gastric emptying rate and improve diabetic gastrointestinal symptoms. However, the methodological quality of included studies is low, and long term efficacy and safety are still uncertain, which indicates that the findings above should be read with caution. Thereby, well-designed, large-scale, and high-quality randomized controlled clinical trials with scientific rigor are warranted for stronger evidence in future research.

Diabetes-induced loss of gastric ICC accompanied by up-regulation of natriuretic peptide signaling pathways in STZ-induced diabetic mice

Our previous study demonstrated that natriuretic peptides (NPs) play an inhibitory role in regulation of gastric smooth muscle motility. However, it is not clear whether NPs are involved in diabetics-induced loss of gastric interstitial cell of Cajal (ICC). The present study was designed to investigate the relationship between diabetics-induced loss of gastric ICC and natriuretic peptide signaling pathway in streptozotocin (STZ)-induced diabetic mice. The results showed that the protein expression levels of c-Kit and membrane-bound stem cell factor (mSCF) in gastric smooth muscle layers were decreased in STZ-induced diabetic mice. However, both mRNA and protein expression levels of natriuretic peptide receptor (NPR)-A, B and C were increased in the same place of the diabetic mice. The amplitude of spontaneous contraction in gastric antral smooth muscles was inhibited by C-type natriuretic peptide (CNP) dose-dependently and the inhibitory effect was potentiated in diabetic mice. Pretreatment of the cultured gastric smooth muscle cells (GSMCs) with different concentration of CNP can significantly decrease the mSCF expression level. 8-Bromoguanosine-3',5'-cyclomo-nophosphate (8-Br-cGMP), a membrane permeable cGMP analog, mimicked the effect of CNP but not cANF (a specific NPR-C agonist). Methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay showed that high concentration of cANF (10(-6) mol/L) inhibited cell proliferation in cultured GSMCs. These findings suggest that up-regulation of NPs/NPR-A, B/cGMP and NPs/NPR-C signaling pathways may be involved in diabetes-induced loss of gastric ICC.

Stomach dysfunction in diabetes mellitus: emerging technology and pharmacology

Gastroparesis and other types of gastric dysfunction result in substantial morbidity in diabetes patients. The pathophysiology of these disorders is incompletely understood. This article reviews techniques applicable to the assessment of gastric function in diabetes patients, including the measurement of emptying, accommodation, and contractility. Available treatment options are also reviewed, including novel yet unapproved serotonin 5-HT(4) agonist pharmacological treatments, as well as the role of endoscopic, surgical, and device treatments of gastroparesis.