The association of rs1051730 genotype on adherence to and consumption of prescribed nicotine replacement therapy dose during a smoking cessation attempt

INTRODUCTION: While nicotine replacement therapy (NRT) is an effective pharmacological smoking cessation treatment, its efficacy is influenced by adherence to and consumption of the prescribed dose. The genetic variant rs1051730 in the nicotinic receptor gene cluster CHRNA5-A3-B4 influences smoking quantity. The aim of this study was to explore the impact of rs1051730 genotype on adherence to and consumption of NRT prescription following a smoking cessation attempt.

METHODS: Secondary analysis of data from a pharmacogenetic smoking cessation trial. Participants (n=448) were prescribed a daily dose of NRT for four weeks post quit attempt, and monitored during weekly clinic visits. Outcome measures were NRT prescription adherence rate (%) and average daily NRT consumption (mg) at 7- and 28-days after the quit attempt.

RESULTS: An association between rs1051730 genotype and both outcome measures was observed at 7-days after the quit date. Each copy of the minor allele corresponded to a 2.9% decrease in adherence to prescribed NRT dose (P=0.044), and a 1.0mg decrease in daily NRT consumption (P=0.026). Adjusting for number of cigarettes smoked during this period only slightly attenuated these associations. There was no clear statistical evidence of an association between genotype and adherence or consumption at 28-days.

CONCLUSIONS: This is the first study to evaluate the impact of rs1051730 genotype on consumption of and adherence to NRT prescription during a smoking cessation attempt. We observed an association between this variant and both outcome measures at 7-days; however, this was only moderate. These findings require replication in an independent sample.