Efficacy of the wen dan decoction, a Chinese herbal formula, for metabolic syndrome

Metabolic syndrome (MS) refers to the clustering of metabolic derangements that include hyperglycemia, dyslipidemia, hypertension, and chronic kidney impairment. Those conditions are well known as being synergistically responsible for morbidity from cardiovascular disease as well as for driving the global epidemic of type 2 diabetes. It is still unknown whether an exact unifying pathogenesis of MS exists.

The meta-analysis intended to analyze the use of Chinese medicine (CM) as a therapeutic tool to explore indirectly the unifying pathogenesis of MS.

PubMed, the Chinese National Knowledge Infrastructure (CNKI), and the Wanfang databases were systematically searched from inception to November 2013 for randomized, controlled trials (RCTs) that compared treatment efficacy for MS patients using the Wen Dan decoction (WDD), a CM formula, versus Western conventional therapeutics.

Measurements included tests of the overall therapeutic efficacy of WDD for hyperglycemia, hypertension, dyslipidemia, and renal functions, and the study also analyzed adverse events. Data were expressed as weighted mean differences (WMDs), with 95% confidence intervals (95% CIs) and the odds ratio (OR).

A total of 31 RCTs were included for meta-analysis, involving 2512 patients and including 1282 participants in the intervention groups. The pooled data favored WDD over the control treatments as follows: (1) hyperglycemia, with a WMD of -0.95 mmol/L (95% CI: -1.19 to -0.71); (2) hypertension, with a WMD of -7.40 mm Hg (95% CI: -9.86 to -4.93); (3) dyslipidemia: (a) total cholesterol (TC), with a WMD of -0.62 mmol/L (95% CI: -0.90 to -0.33); (b) triglycerides (TGs), with a WMD of -0.32 mmol/L (95% CI: -0.52 to -0.13); (c) low-density lipoproteins (LDPs), with a WMD of -0.22 mmol/L (95% CI: -0.41 to -0.02); and (d) high-density lipoproteins (HDPs), with a WMD of 0.10 mmol/L (95% CI: 0.03 to 0.17); and (4) of renal functions: (a) urea, with a WMD of -3.41 mmol/L (95% CI: -5.50 to -1.32) and (b) creatinine, with a WMD of -68.81 μmol/L (95% CI: -132.63 to -4.98). No statistical significance was documented in creatinine clearance between the 2 treatments with a WMD of 15.47 mL/min (95% CI: -7.71 to 38.64). The overall efficacy rate was 91.4% for WDD and 66.9% for the control treatments (OR: 5.33; 95% CI: 4.06 to 6.99). Adverse events were rare and minor.

The consistent improvements found in metabolic profiles by use of the single herbal formula may indirectly imply a common pathogenesis in MS.