Chinese herbal medicine for impaired glucose tolerance: a randomized placebo controlled trial

Abstract

BackgroundDiabetes remains a major health problem worldwide. Low-risk low-cost alternatives to pharmaceutical interventions are needed where lifestyle modifications have failed. We conducted a double-blind randomised placebo controlled trial to investigate the efficacy of a Chinese herbal formula, Jiangtang Xiaozhi, in treating impaired glucose control and insulin resistance in persons with prediabetes and controlled diabetes.MethodsSeventy-one patients with prediabetes or ‘controlled’ diabetes were randomised to receive 3 capsules of Jiangtang Xiaozhi (n = 39) or placebo (n = 32) three times daily for 16 weeks with a follow up eight weeks later (week 24). The primary outcome was change in glycaemic control as evidenced by fasting blood glucose (FBG), post-prandial plasma glucose and glycosylated haemoglobin (HbA1c). Other measures included change in fasting insulin, insulin resistance and sensitivity, lipids, C-reactive protein (CRP), body mass index (BMI), waist girth, blood pressure (BP), health related quality of life (HRQoL) and safety. Analysis of covariance (ANCOVA) was used to model outcomes at 16 weeks, by treatment group corrected for baseline level of the outcome variable.ResultsIn patients receiving Jiangtang Xiaozhi, FBG was not significantly different (p = 0.73) compared to placebo after 16 weeks of treatment (6.3 ± 1.1 mmol/L vs 6.7 ± 1.3 mmol/L). There was a significant difference (p = 0.04) in the mean levels of fasting insulin between the treatment group (11.6 ± 5.5 mmol/L) and the placebo group (22.1 ± 25.9 mmol/L). Insulin resistance slightly decreased in the treatment group (1.58 ± 0.74) compared to that of the placebo group (2.43 ± 1.59) but this change did not reach statistical significance (p = 0.06). Patients taking Jiangtang Xiaozhi had a significant improvement in high-density lipoprotein (HDL) level compared to the placebo group at week 16 (p = 0.03). Mean levels of cholesterol, triglycerides, BMI, waist-girth, HRQoL, BP, CRP and insulin sensitivity were not significantly different between the two groups. The herbal medicine was well tolerated.ConclusionsIn the current study, the 16 week Jiangtang Xiaozhi treatment did not lower fasting blood glucose, but it improved serum insulin and HDL cholesterol in a Western population with prediabetes or controlled diabetes. Our trial may have been underpowered. Dosage needs to be considered before commencing a longer adequately powered trial.Trial registrationAustralian New Zealand Clinical Trials Registry ACTRN12612000128897; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=362005

Insulin combined with Chinese medicine improves glycemic outcome through multiple pathways in patients with type 2 diabetes mellitus

“…Thus, a high HOMA%B might not always mean better β-cell functioning, perhaps the opposite. This was consistent with the recent study by Grant et al 31. Although it is unclear why insulin secretion decreases when insulin sensitivity increases, a possible explanation is that β-cells do not have to produce more insulin when insulin sensitivity is improved28.…”

“…Theoretically, while insulin sensitivity is improved, b-cell function (HOMA%B) is also improved. A HOMA%B value near to 100% is associated with better b-cell function 31 . However, in the SQF+Ins group, the level of insulin secretion did not increase, even though b-cell function (HOMA%B) and insulin sensitivity appeared to improve.…”

“…Although it is unclear why insulin secretion decreases when insulin sensitivity increases, a possible explanation is that β-cells do not have to produce more insulin when insulin sensitivity is improved28. Decreased β-cell function as represented by HOMA%B does not seem to predict the development of diabetes31, and low insulin secretion might be adequate for an insulin-sensitive patient32.…”

Antidiabetic Properties of Curcumin II: Evidence from In Vivo Studies

“…However, glucose levels were not affected by this treatment. In addition, patients administered Jiangtang Xiaozhi had increased serum HDL level, while total cholesterol, triglyceride and LDL levels were similar [78]. These data suggest that administration of Jiangtang Xiaozhi reduces insulin resistance and improves lipid homeostasis in cases of prediabetes and controlled diabetes.…”

“…In a randomized, double-blind, placebo-controlled trial, prediabetic (fasting plasma glucose ≥126 mg/dL) and controlled (diet and exercise) diabetic individuals were administered Jiangtang Xiaozhi (3.79 g/thrice/day; containing 13% curcumin) for 16 weeks. Jiangtang Xiaozhi administration resulted in a significantly reduced serum insulin level and HOMA-IR index score, indicating reduced insulin resistance [78]. However, glucose levels were not affected by this treatment.…”