Alternative Medicine for Glycemic Control in Type 2 Diabetes Mellitus: What's the Evidence?

B Y J EANNETTE G OGUEN ,M D This issue of Endocrinology Rounds reviews the best available evidence about the impact of alternative medications on glycemic control. Alternative medicine has been used to treat diabetes mellitus (DM) for thousands of years. For example, there are traditions in China, Tibet, and India (Ayurvedic medicine) that are still in use to this day. Traditional approaches often combine multiple herbs as part of a holistic healing process. These therapies can be classified as "alternative" or "complementary medicine," ie, medicine that does not conform to the standards of the medical community, is not widely taught in North American medical schools, and is not available in North American hospitals.1 Besides historic interest, why is it important for physicians to know about alternative med- ications? Among the reasons - patients often ask questions about alternative medications or they may actually be using them, spending significant amounts of money on them, and having potential drug interactions or side effects from them! Ryan et al discovered that up to 30% of diabetic patients use over-the-counter (OTC) or alternative medications (although the vast majority were not using them for glycemic control).2 An American survey of patients reveals even higher use of alternative medications. Patients with DM were 1.6 times more likely to use alternative medications as those without DM and use correlated positively with older age and higher level of education.3 By not considering the possible efficacy of such compounds, we may be missing an opportu- nity to expand our repertoire of oral agents. The course of DM is typically one of relentless dete- rioration in pancreatic function. In order to advise patients appropriately, it is important to ascertain the level of evidence that is currently available for using alternative medications in DM. A minimum standard for clinical significance was set at lowering glycosylated hemoglobin (HbA1c) by at least 0.5% (absolute) and fasting plasma glucose (FPG) by >1.0 mmol/L (similar to acarbose, the weakest oral hypoglycemic agent that is currently used in conventional medicine). The evidence for alternative medicine in DM Prior to examining the evidence, it is important to recognize that there are challenges in applying the principle of evidence-based medicine to alternative medicine. These challenges include concerns about the underlying philosophy of its practitioners, the quality of the studies of alternative medications, the types of publications, and about the substances them- selves. Each of these will be described below. The underlying paradigm by which practitioners of alternative medicine operate is very different from the "evidence-based approach" currently used in conventional medicine, in which randomized controlled trials (RCTs) are viewed as the gold standard for making thera- peutic decisions. In contrast, practitioners of alternative medicine view illness and healing in the context of the individual and not the population. With the belief that the individual patient may react differently than the "average patient" in large studies, each patient becomes his own study. Because of this, these practitioners are distrustful of the results of negative RCTs, feeling that their patients may react differently than average patients.4 This distrust of science leads to the general lack of RCTs in alternative medicine.