Chinese herbal medicines for hypercholesterolemia

Background Hypercholesterolemia is an important key contributory factor for ischemic heart disease and is associated with age, high blood pressure, a family history of hypercholesterolemia, and diabetes. Chinese herbal medicines have been used for a long time as lipid-lowering agents. Objectives To assess the effects of Chinese herbal medicines on hypercholesterolemia. Search strategy We searched the following databases: The Cochrane Library (issue 8, 2010), MEDLINE (until July 2010), EMBASE (until July 2010), Chinese BioMedical Database (until July 2010), Traditional Chinese Medical Literature Analysis and Retrieval System (until July 2010), China National Knowledge Infrastructure (until July 2010), Chinese VIP Information (until July 2010), Chinese Academic Conference Papers Database and Chinese Dissertation Database (until July 2010), and Allied and Complementary Medicine Database (until July 2010). Selection criteria We considered randomized controlled clinical trials in hypercholesterolemic participants comparing Chinese herbal medicines with placebo, no treatment, and pharmacological or non-pharmacological interventions. Data collection and analysis Two review authors independently extracted data and assessed the risk of bias. We resolved any disagreements with this assessment through discussion and a decision was achieved based by consensus. We assessed trials for the risk of bias against key criteria: random sequence generation, allocation concealment, blinding of participants, incomplete outcome data, selective outcome reporting and other sources of bias. Main results We included 22 randomized trials (2130 participants). The mean treatment duration was 2.3 +/- 1.3 months (ranging from one to six months). Twenty trials were conducted in China and 18 trials were published in Chinese. Overall, the risk of bias of included trials was high or unclear. Five different herbal medicines were evaluated in the included trials, which compared herbs with conventional medicine in six comparisons (20 trials), or placebo (two trials). There were no outcome data in any of the trials on cardiovascular events and death from any cause. One trial each reported well-being (no significant differences) and economic costs. No serious adverse events were observed. Xuezhikang was the most commonly used herbal formula investigated. A significant effect on total cholesterol (two trial, 254 participants) was shown in favor of Xuezhikang when compared with inositol nicotinate (mean difference (MD) -0.90 mmol/L, 95% confidence interval (CI) -1.13 to -0.68). Authors' conclusions Some herbal medicines may have cholesterol-lowering effects. Our findings have to be interpreted with caution due to high or unclear risk of bias of the included trials.