Bitter taste receptor gene polymorphisms are an important factor in the development of nicotine dependence in African Americans
Jamie E Mangold 1, Thomas J Payne 2, Jennie Z Ma 1, Guobo Chen 1 and Ming D Li 1*
1 U of VA, United States
2 U of Mississippi Medical Ctr, United States
* To whom correspondence should be addressed. E-mail: ml2km{at}virginia.edu.
Accepted 23 April 2008
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Context: Bitter sensitivity varies among individuals and ethnic groups partly due to polymorphisms in taste receptor genes (TAS2Rs). Although previous psychophysical studies suggest that taste status plays a role in nicotine dependence (ND), genetic evidence is lacking.
Objectives: To determine whether single nucleotide polymorphisms (SNPs) in TAS2R16 and TAS2R38 are associated with ND and if the effects differ by sex and ethnicity.
Design, Setting, and Participants: 2037 individuals from 602 nuclear families of African American (AA) or European American (EA) origin were recruited from the Mid-South States during 1999-2004.
Main Outcome Measure(s): ND was assessed by three measures: indexed Smoking Quantity (SQ), Heaviness of Smoking Index (HSI), and the Fagerström Test for Nicotine Dependence (FTND). Peripheral blood samples were obtained for DNA extraction and genotyping.
Results: The TAS2R38 taster haplotype PAV was inversely associated (P = 0.0165), and the nontaster haplotype AVI was positively associated (P = 0.0120), with SQ in AA smokers. The nontaster haplotype was positively associated with all ND measures in AA female smokers (P = 0.01~0.003). No significant associations were observed in the EA sample.
Conclusions: TAS2R38 polymorphisms are an important factor in determining ND in AAs. Heightened oral sensitivity confers protection against ND. Conversely, decreased sensitivity represents a risk factor for ND, especially in AA females. Together, our findings suggest that taster status plays a role in governing the development of ND and may represent a way to identify individuals at risk for developing ND, particularly in AA smokers.
