Influence of the use of functional foods enriched with phytosterols/-stanols on adherence to statin therapy.

Purpose: Subjects using functional foods with approved health claims may be more likely to be non-adherent with prescribed drug therapy. This study aimed to assess the influence of the use of phytosterol/-stanol-enriched functional foods on adherence to statin therapy among patients initiating treatment.
Methods: We used data from the statin intervention research project, a randomized controlled trial aimed at improving adherence to statins. In the trial, new statin users were randomized to receive either usual care or extensive pharmaceutical care consisting of five individual counseling sessions. Customary use of phytosterol/-stanol-enriched products was identified by questionnaires filled out by all participants. Automated pharmacy-dispensing records were used to assess adherence in terms of discontinuation of therapy and the medication possession ratio. Analyses were performed for the overall population, as well as stratified for receiving pharmaceutical or usual care.
Results: The use of functional foods enriched with phytosterols/-stanols was not related to discontinuation of statin therapy, neither in the overall population (overall population adjusted hazard rate ratio (HR(adj)): 0.80 [95%CI: 0.59-1.08]), nor when stratified by randomization arm (pharmaceutical care HR(adj): 0.77 [95%CI: 0.49-1.23]); usual care HR(adj): 0.81 [95%CI: 0.54-1.21]). The median medication possession ratio was significantly lower in users of phytosterols/-stanols in the usual care group, but the difference was not clinically relevant.
Conclusions: Customary use of phytosterol/-stanol-enriched functional foods did not affect adherence to statins in new users that are well informed on the beneficial effects of statin therapy. In daily medical practice, general practitioners and pharmacists should urge subjects not to take phytosterol/-stanol-enriched functional foods as replacement for their prescribed medication.
(Copyright © 2011 John Wiley & Sons, Ltd.)