Hypoglycemic effects and mechanisms of electroacupuncture on insulin resistance

Electro-acupuncture for central obesity: a patient-assessor blinded, randomized sham-controlled clinical trial

BACKGROUND

Central obesity is considered as a significant health threat to individuals. Scientific research has demonstrated that intra-abdominal fat accumulation is associated with higher metabolic and cardiovascular disease risks independent of Body Mass Index (BMI). This study aimed to evaluate the efficacy and safety of electro-acupuncture in treating central obesity compared with sham acupuncture.

METHOD

This was a patient-assessor blinded, randomized, sham-controlled clinical trial. One hundred sixty eight participants aged between 18 and 65 years old with BMI ≥ 25 kg/m2 and waist circumference (WC) of men ≥ 90 cm / women ≥ 80 cm were enrolled and allocated to the acupuncture or sham acupuncture group equally. For the acupuncture group, disposable acupuncture needles were inserted into eight body acupoints, including Tianshu (ST-25), Daheng (SP-15), Daimai (GB-26), Qihai (CV-6), Zhongwan (CV-12), Zusanli (ST-36), Fenglong (ST-40), and Sanyinjiao (SP-6) with electrical stimulation. For the control group, Streitberger's non-invasive acupuncture needles were utilized at the same acupoints with identical stimulation modalities. The treatment duration was 8 weeks with 2 sessions per week and the follow-up period was 8 weeks. The primary outcome was the change in WC before and after the treatment. The secondary outcomes were the changes in hip circumference, waist-to-hip circumference ratio, BMI, and body fat percentage during the treatment and follow-up period.

RESULTS

The acupuncture group displayed a significant change in WC compared to the sham group both treatment and follow-up period (MD = -1.1 cm, 95% CI = -2.8 to 4.1). Significant change in body fat percentage was recorded for both groups after treatment but no significance was observed during the follow-up period (MD = -0.1%, 95% CI = -1.9 to 2.2). The changes in hip circumference were also significant both treatment and follow-up period for the acupuncture group (MD = -2.0 cm, 95% CI = -3.7 to -1.7). Compared with sham acupuncture, the body weight (MD = -1 kg, 95% CI = -3.3 to 5.3), BMI (MD = -0.5, 95% CI = -0.7 to 1.9) also decreased significantly within and between groups. The incidence of adverse events was similar in the two groups.

CONCLUSION

This study provided evidence that electro-acupuncture could be effective in treating central obesity by reducing WC, hip circumference, body weight, BMI, and waist-to-hip circumference ratio.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03815253, Registered 24 Jan 2019.

Ultrasound Stimulation Potentiates Management of Diabetic Hyperglycemia

OBJECTIVE

Glucose homeostasis is the only way to manage diabetic progression as all medications used do not cure diabetes. This study was aimed at verifying the feasibility of lowering glucose with non-invasive ultrasonic stimulation.

METHODS

The ultrasonic device was homemade and controlled via a mobile application on the smartphone. Diabetes was induced in Sprague-Dawley rats through high-fat diets followed by streptozotocin injection. The treated acupoint CV12 was at the middle of the xiphoid and umbilicus of the diabetic rats. Parameters of ultrasonic stimulation were an operating frequency of 1 MHz, pulse repetition frequency of 15 Hz, duty cycle of 10% and sonication time of 30 min for a single treatment.

DISCUSSION

The diabetic rats exhibited a significant decrease of 11.5% ± 3.6% in blood glucose in 5 min of ultrasonic stimulation (p < 0.001). After the single treatment on the first day, third day and fifth day in the first week, the treated diabetic rats had a significantly small area under the curve of the glucose tolerance test (p < 0.05) compared with the untreated diabetic rats in the sixth week. Hematological analyses indicated that the serum concentrations of β-endorphin were significantly increased by 58% ± 71.9% (p < 0.05) and the insulin level was increased by 56% ± 88.2% (p = 0.15) without statistical significance after a single treatment.

CONCLUSION

Therefore, non-invasive ultrasound stimulation at an appropriate dose can produce a hypoglycemic effect and improve glucose tolerance for glucose homeostasis and may play a role as adjuvant therapy with diabetic medications in the future.

Acupuncture for patients with type 2 diabetes mellitus with dry eye: protocol for a systematic review and meta-analysis

INTRODUCTION

The global incidence of patients with type 2 diabetes mellitus (T2DM) with dry eye is increasing annually, which imposes additional healthcare costs and financial burden on families and societies. In clinical practice, artificial tears are often used for symptomatic treatment, but these can only relieve the symptoms of discomfort. Acupuncture is a widely used alternative therapy. Indeed, randomised trials have found that acupuncture confers a definite therapeutic effect on patients with T2DM with dry eye. However, systematic reviews on the effectiveness and safety of acupuncture are lacking, therefore this systematic review aims to evaluate the effectiveness and safety of acupuncture for T2DM with dry eye.

METHODS AND ANALYSIS

Four English databases (PubMed, Cochrane Library, Embase and Ovid), three Chinese databases (China National Knowledge Infrastructure, Wanfang, Chonqing VIP Information), three Japanese databases (Japan Science, Technology Agency and Japan Medical Abstracts Society) and three Korean databases (Korean Medical database, Oriental Medicine Advanced Searching Integrated System and Research Information Service System) will be searched for reports published between 1 January 2007 and 1 October 2021. Only randomised controlled trials will be included, and language or publication dates will not be restricted. Two researchers will independently extract, manage and analyse data. The primary outcomes will include Schirmer's I test, breakup time, corneal fluorescein staining and ocular surface disease index scores. Secondary results will include visual analogue scale scores for ocular symptoms and any adverse events related to acupuncture. We will use Review Manager V.5.4 for the meta-analysis. The risk of bias will be independently assessed using Cochrane's 'risk of bias' tool.

ETHICS AND DISSEMINATION

Ethical approval will not be required since raw data will not be collected or generated. Our findings will be disseminated through peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42021271891.

Underlying mechanisms of acupuncture therapy on polycystic ovary syndrome: Evidences from animal and clinical studies

Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder among women of reproductive age. Current standard treatment includes lifestyle change, oral pharmacological agents, and surgical modalities. However, the efficacy of current therapies is less than satisfactory. Clinical evidence has shown that acupuncture is effective for regulating hormone levels, promoting ovulation, and attenuating insulin resistance in patients with PCOS. Acupuncture may affect the production of β-endorphin, which may lead to gonadotropin-releasing hormone secretion and then affect ovulation, menstrual cycle, and fertility. The mechanism of acupuncture for patients with PCOS has not been comprehensively reviewed so far. Better understanding of the mechanisms of acupuncture would help popularize the use of acupuncture therapy for patients with PCOS. In this narrative review, we aimed to overview the potential mechanisms and evidence-based data of acupuncture on PCOS, and analyze the most frequently used acupoints based on animal and clinical studies. The results of this study will contribute to a better understanding of the current situation in this field.

Hypoglycemic Effect of Electroacupuncture at ST25 Through Neural Regulation of the Pancreatic Intrinsic Nervous System

Electroacupuncture (EA) is considered to have potential antidiabetic effects; however, the role of the pancreatic intrinsic nervous system (PINS) in EA-induced amelioration of type 2 diabetes (T2DM) remains unclear. Therefore, we investigated whether EA at ST25 exerts any beneficial effects on insulin resistance (IR), inflammation severity, and pancreatic β cell function via the PINS in a rat model of a high-fat diet-streptozotocin (HFD/STZ)-induced diabetes. To this end, Sprague Dawley rats were fed with HFD to induce IR, followed by STZ (35 mg/kg, i.p.) injection to establish the T2DM model. After hyperglycemia was confirmed as fasting glucose level > 16.7 mmol/L, the rats were treated with EA (2 mA, 2/15 Hz) for the next 28 days. Model rats showed increased serum glucose, insulin, IR, and TNF-α levels with a concomitant decrease in β cell function. Microscopy examination of the pancreas revealed pathological changes in islets, which reverted to near-normal levels after EA at ST25. EA improved islet cell morphology by increasing islet area and reducing vacuolation. EA at ST25 decreased transient receptor potential vanilloid 1 (TRPV1) and increased substance P (SP) and calcitonin gene-related peptide (CGRP) expression. Subsequently, insulin secretion decreased and impaired pancreatic endocrine function was restored through the TRPV1 channel (SP/CGRP)-insulin circuit. EA increased choline acetyltransferase and neuropeptide Y expression and controlled inflammation. It also enhanced the cocaine and amphetamine-regulated transcript prepropeptide expression and promoted glucagon-like peptide-1 secretion. Additionally, the electrophysiological activity of PINS during acupuncture (2.71 ± 1.72 Hz) was significantly increased compared to the pre-acupuncture frequency (0.32 ± 0.37 Hz, P < 0.05). Thus, our study demonstrated the beneficial effect of EA on β cell dysfunction via the PINS in rat models of HFD-STZ-induced T2DM.

A prospective pilot study of the effect of acupuncture on insulin sensitivity in women with polycystic ovary syndrome and insulin resistance

OBJECTIVE

To test the hypothesis that acupuncture improves insulin sensitivity in women with polycystic ovary syndrome (PCOS) and insulin resistance (IR).

DESIGN

Prospective pilot study.

SETTING

Guangzhou, China, 2014-2016.

PARTICIPANTS

Eighty women with PCOS aged 18-40 years with body mass index (BMI) above 18.5 kg/m² and with homeostatic model assessment for insulin resistance (HOMA-IR) index ⩾2.14.

INTERVENTIONS

Subjects received acupuncture with combined manual and low-frequency electrical stimulation of the needles three times per week for 6 months.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the change in HOMA-IR after 6 months of acupuncture relative to baseline. Secondary outcomes included changes after 6 months of acupuncture and at 3 months of follow-up (both relative to baseline) in oral glucose tolerance test (OGTT) parameters (glucose and insulin levels), anthropometric measurements, and circulating metabolic and endocrine variables.

RESULTS

HOMA-IR and fasting plasma glucose and insulin levels were significantly decreased after 6 months of acupuncture, and both HOMA-IR and fasting insulin remained significantly decreased at 3 months of follow-up. In a subgroup analysis of normal-weight and overweight/obese women, HOMA-IR was reduced after 6 months of acupuncture in both subgroups, but there was no significant difference between the two groups.

CONCLUSIONS

Acupuncture treatment in Chinese women with PCOS and IR was associated with an encouraging improvement in insulin sensitivity. Further randomized controlled studies are required to confirm the efficacy of acupuncture for this indication.

Hypoglycemic Effects of Intestinal Electrical Stimulation by Enhancing Nutrient-Stimulated Secretion of GLP-1 in Rats

PURPOSE

To find out the best location for intestinal electrical stimulation (IES) to decrease hyperglycemia, and mechanisms involving intraluminal nutrients and plasma glucagon-like peptide-1 (GLP-1) MATERIALS AND METHODS: Eight rats had electrodes implanted at the duodenum and ileums for IES. The oral glucose tolerance test (OGTT) was performed with IES and sham-IES and with/without GLP-1 antagonist, exendin. To study the role of intraluminal nutrients, the experiment was repeated using intraperitoneal glucose tolerance test (IPGTT). Glucagon was administrated in the OGTT/IPGTT to induce temporary hyperglycemia.

RESULTS

(1) In the OGTT, IES at the duodenum reduced blood glucose from 30 to 120 min after oral glucose (P < 0.05, vs. sham-IES) and the hypoglycemic effect was more potent than IES at the ileum. (2) The hypoglycemic effect of IES was absent in IPGTT experiment, suggesting the important role of intraluminal nutrients. (3) An increase in GLP-1 was noted in the OGTT with IES at the duodenum in comparison with sham-IES. Moreover, the blocking effect of exendin suggested the role of GLP-1 in the hypoglycemic effect of IES.

CONCLUSIONS

The best stimulation location for IES to decrease hyperglycemia is in the duodenum. The hypoglycemic effect of IES is attributed to the enhancement in nutrient-stimulated release of GLP-1.

Electroacupuncture treatments for gut motility disorders

Functional gastrointestinal (GI) diseases are common and there are patients who are refractory to medical therapies as not all treatments work in all patients. Consequently, a large number of patients with functional GI diseases use complementary and alternative medicine, such as acupuncture or electroacupuncture (EA). In this issue, Zheng et al. reported interesting results of a multi-center placebo-controlled clinical study on the use of EA for treating refractory functional dyspepsia; another study reported a multi-center clinical trial on EA for chronic functional constipation; Liang et al. studied mechanisms of EA involving enteric nervous system and neurotransmitters in treating constipation in rats. While controversial reports are available in the literature, EA with appropriate methodologies as shown in these recent studies is believed to be effective in treating certain functional GI diseases. In this mini-review, a number of clinical studies, including those included in this issue on the use of EA for treating gastro-esophageal reflux, functional dyspepsia, irritable bowel syndrome, and constipation are reviewed. Some critically important issues, such as the choice of stimulation parameters for EA, the administration frequency of the therapy, and the appropriate choice of placebo for clinical research are also discussed. Mechanisms of action involved in the therapeutic effects of EA for gut dysmotility and future research directions are also presented.

Comparison of acupuncture pretreatment followed by letrozole versus letrozole alone on live birth in anovulatory infertile women with polycystic ovary syndrome: a study protocol for a randomised controlled trial

INTRODUCTION

The high prevalence of insulin resistance in women with polycystic ovary syndrome (PCOS) is considered to be one of the major pathophysiological changes in PCOS that leads to anovulatory infertility. We hypothesise that electroacupuncture pretreatment improves insulin sensitivity and leads to a higher ovulation rate and greater chances of live birth after the induction of ovulation. The effect of electroacupuncture pretreatment followed by ovulation induction in women with anovulatory PCOS has not been investigated before, and we present here a randomised controlled trial to test this hypothesis by comparing electroacupuncture pretreatment followed by letrozole versus letrozole alone in anovulatory women with PCOS.

METHODS/ANALYSIS

This is a multicentre, randomised,and controlled trial. A total of 384 patients will be enrolled in this study and will be randomly allocated by a central randomisation system to the treatment group or the control group in a 1:1 ratio. The treatment group will undergo 16 weeks of electroacupuncture pretreatment followed by 4 cycles of letrozole, and the control group will only undergo 4 cycles of letrozole. The primary outcome will be the live birth rate. All statistical analyses will be performed using the SPSS program V.21.0 (SPSS, Chicago, Illinois, USA), and a p value <0.05 will be considered statistically significant.

ETHICS/DISSEMINATION

This study has been approved by the ethics committees of each participating centre. Written consent will be obtained from each patient and her husband before any study procedure is performed. Adverse events will be categorised, and the percentage of patients experiencing adverse events or serious adverse events during the treatment period will be documented. The results of this trial will be disseminated in peer-reviewed journals and presented at international meetings.

TRIAL REGISTRATION NUMBER

NCT02491320.

15 hz Electroacupuncture at St36 Improves Insulin Sensitivity and Reduces Free Fatty Acid Levels in Rats with Chronic Dexamethasone-Induced Insulin Resistance

Objective

To evaluate the effect of electroacupuncture (EA) in a rat model of chronic steroid-induced insulin resistance (SIIR).

Methods

An SIIR rat model was created using daily intraperitoneal injections of clinically relevant doses of dexamethasone (1 mg/kg) for 5 days to induce chronic insulin resistance. Thirty-six SIIR rats were randomly divided into the SIIR+EA group (n=18), which received 15 Hz EA at ST36 for 60 min, and the SIIR group (n=18), which remained untreated. Plasma glucose and free fatty acid (FFA) levels were measured in serial blood samples taken without further manipulation (n=6 per group) and during insulin challenge test (ICT, n=6 per group) and intravenous glucose tolerance test (ivGTT, n=6 per group). Insulin receptor substrate (IRS)-1 and glucose transporter (GLUT)-4 were measured using Western blotting and expressed relative to β-actin.

Results

Following EA, area-under-the-curve (AUC) for glucose was reduced (7340±291 vs 10 705±1474 mg/dL/min, p=0.049) and FFA levels significantly lower at 30/60 min in the SIIR+EA versus SIIR groups. Similar effects on glucose AUC were seen during the ICT (5568±275 vs 7136±594 mg/dL/min, p<0.05) and igVTT (11 498±1398 vs 16 652±1217 mg/dL/min, p<0.01). FFA levels were lower at 30 and/or 60 min in SIIR+EA versus SIIR groups (p<0.01). Relative expression of IRS-1 and GLUT4 were significantly increased by EA (p<0.01).

Conclusions

EA decreased the FFA level and increased insulin sensitivity in SIIR rats. Further clinical studies are needed to determine whether EA is an effective alternative treatment for the reduction of insulin resistance in patients requiring chronic use of dexamethasone.

A Targeted Metabolomics MRM-MS Study on Identifying Potential Hypertension Biomarkers in Human Plasma and Evaluating Acupuncture Effects

The critical role of metabolic abnormality in hypertension is increasingly recognized, but its biomarkers are not clearly identified. In this study, 47 chemical compounds recorded by literature were employed as target metabolites of essential hypertension (EH). We detected their content in the plasma of EH patients and healthy subjects by using the Multiple Reaction Monitoring-Mass Spectrometry (MRM-MS). After screening the most altered compounds, acupuncture was used to treat patients for 3 months and these plasma metabolites were tested again. The results showed that oleic acid (OA) and myoinositol (MI) were the most important differential metabolites between the hypertensive plasma and the healthy plasma. They were also closely correlated with 24-hour blood pressure and nocturnal dipping. Moreover, plasma OA and MI could be restored to normal levels by acupuncture, accompanying with reduction of 24-hour systolic and diastolic blood pressure [from 145.10 ± 9.28 mm Hg to 140.70 ± 9.59 mm Hg (P < 0.0001), and 88.35 ± 7.92 mm Hg to 85.86 ± 7.95 mm Hg (P = 0.0024), respectively] and improvement of circadian blood pressure rhythm. This study demonstrated that plasma OA and MI were potential hypertension biomarkers and they could be used to preliminarily assess the treating effects such as acupuncture.

Differential Effect of Electroacupuncture on Inflammatory Adipokines in Two Rat Models of Obesity

Chronic inflammation is known to be associated with visceral obesity and insulin resistance which are characterized by altered levels of production of pro- and anti-inflammatory adipokines. The dysregulation of the production of inflammatory adipokines and their functions in obese individuals leads to a state of chronic low-grade inflammation and may promote obesity-linked metabolic disorders and cardiovascular diseases such as insulin resistance, metabolic syndrome, and atherosclerosis. Electroacupuncture (EA) was tested to see if there was a difference in its effect on pro- and anti-inflammatory adipokine levels in the blood serum and the white adipose tissue of obese Zucker fatty rats and high-fat diet-induced obese Long Evans rats. In the two rat models of obesity, on Day 12 of treatment, repeated applications of EA were seen to have had a significant differential effect for serum tumor necrosis factor-α, adiponectin, the adiponectin:leptin ratio, and blood glucose. For the adipose tissue, there was a differential effect for adiponectin that was on the borderline of significance. To explore these changes further and how they might affect insulin resistance would require a modification to the research design to use larger group sizes for the two models or to give a greater number of EA treatments.