There are several limitations to our study. Given the data limitations for examining long duration of illness mentioned above, we lack a more nuanced understanding of the association between those with, for example, over 10�C15 years of disease exposure and glycemic control. We were also unable to consider smoking status, given incomplete data on this variable among those over age 75. Consequently, we did not include the variable in the analyses which could potentially yield an omitted variable bias, thereby over or under-estimating the effects of the other factors in the model. Additionally, while the study was intended to focus on type 2 diabetes, our database does not distinguish between type 1 and type 2 diabetes; however, by restricting the study sample to adult diabetes patients taking OAMs, we eliminated the majority of the individuals with type diabetes from the sample. Lastly, a limitation of our weighted measure of adherence relates to the dosage/time details of the prescription. In CHS, the standard prescriptions for chronic medications are issued for a 30-day supply. The MWA is based on this standard; therefore, to the extent that prescriptions are written to cover more than a 30-day supply, there will be discrepancies between written and filled prescriptions over periods of time that are tabulated as reduced adherence. In summary, we have tested, in a large-scale population-based study, the association between poor adherence to diabetes medications and poor glucose control among several subgroups of adults with diabetes. Poor medication adherence was a key mechanism in explaining why younger adults with diabetes have poor glycemic control, with adherence making up a highest attributable fraction of poor control in this sub-segment. This suggests that interventions for addressing medication adherence may prove to be particularly beneficial in helping younger diabetes patients achieve RN486 greater glucose control. Diabetes has been increasing in the world, especially in Asian countries including China. It predisposes to increased risk of microvascular and Benzoylhypacoitine macrovascular diseases and cancer. Hypertension occurs in up to 30�C40% of patients with type 2 diabetes and itself is a risk factor for cardiovascular disease and renal disease in both general population and diabetic population.