Affiliation:
1. Cardiovascular Research Institute University of California, San Francisco CA USA
2. Center for Tobacco Control Research and Education University of California, San Francisco CA USA
3. Department of Physiological Nursing University of California, San Francisco CA USA
4. Department of Epidemiology and Biostatistics University of California, San Francisco CA USA
5. Department of Medicine University of California, San Francisco CA USA
6. Department of Biochemistry and Biophysics University of California, San Francisco CA USA
Abstract
Background
African American smokers have 2.5 times higher risk for stroke compared with nonsmokers (higher than other races). About 50% of the African American population carry 1 or 2 genetic variants (G1 and G2; rare in other races) of the apolipoprotein L1 gene (
APOL1
). Studies showed these variants may be associated with stroke. However, the role of the
APOL1
risk variants in tobacco‐related stroke is unknown.
Methods and Results
In a cross‐sectional study, we examined whether
APOL1
risk variants modified the relationship between tobacco smoking and stroke prevalence in 513 African American adults recruited at University of California, San Francisco. Using DNA, plasma, and questionnaires we determined
APOL1
variants, smoking status, and stroke prevalence. Using logistic regression models, we examined the association between smoking (
ever
versus
never
smokers) and stroke overall, and among carriers of
APOL1
risk variants (1 or 2 risk alleles), and noncarriers, separately. Among participants, 41% were
ever
(
current
and
past
) smokers, 54% were carriers of the
APOL1
risk variants, and 41 had a history of stroke. The association between smoking and stroke differed by
APOL1
genotype (
P
interaction term
=0.014). Among carriers,
ever
versus
never
smokers had odds ratio (OR) 2.46 (95% CI, 1.08–5.59) for stroke (
P
=0.034); OR 2.00 (95% CI, 0.81–4.96) among carriers of 1 risk allele, and OR 4.72 (95% CI, 0.62–36.02) for 2 risk alleles. Among noncarriers, smoking was not associated with a stroke.
Conclusions
Current and past smokers who carry
APOL1
G1 and/or G2 risk variants may be more susceptible to stroke among the African American population.
Publisher
Ovid Technologies (Wolters Kluwer Health)
Subject
Cardiology and Cardiovascular Medicine