Cancer diagnosis affects adherence to diabetes drugs

A diagnosis of cancer is linked with lower adherence to taking prescribed diabetes drugs and the effect is more pronounced with later stage cancers.
The study, carried out by researchers from Eindhove, Netherlands and Edmonto, Canada, reviewed out-patient data to investigate patients’ adherence to medication. From 52,228 patients taking glucose lowering drugs (GLDs), 3,281 people with cancer and 12,891 people without cancer were chosen.
Adherence to taking diabetes drugs was measured using the Medication Possession Ratio (MPR). A drop in the MPR represents that adherence to medication has dropped.
The study showed that there were no important declines in medication adherence following diagnosis of prostate or breast cancers whereas the largest drops in MPR were observed after diagnoses of liver, pancreas, stomach and oesophageal cancers. Large drops in adherence were also recognised in people with later stage cancers.
The study did not investigate the reasons why medication adherence reduced but the researchers suggest that the effects of a serious cancer diagnosis could lead to patients relegating the importance of taking their diabetes medication. It is also noted that hypoglycemia could be a factor in reducing adherence. Cancer treatment can lead to a loss of appetite which could increase the risk of hypos in patients on insulin stimulating drugs such as sulphonylureas.