Association of sirtuin 1 rs10997868 and rs730821 polymorphisms with sirtuin 1 and hydroxy-2′-deoxyguanosine levels in healthy smokers: A case–control study

Abstract

Objectives: This case–control study explored the association of sirtuin 1 polymorphisms (rs10997868 and rs730821) with metabolic parameters, smoking duration, sirtuin 1 levels, and the oxidative stress biomarker 8-hydroxy-2′-deoxyguanosine in healthy smokers in Saudi Arabia. Methods: Genomic DNA was isolated from peripheral blood samples, and rs10997868 and rs730821 polymorphism genotyping was performed for 43 healthy smokers and 33 healthy controls using real-time polymerase chain reaction. Plasma sirtuin 1 and 8-hydroxy-2′-deoxyguanosine levels were measured using enzyme-linked immunosorbent assay. Results: Sirtuin 1 levels were significantly higher in healthy smokers than in controls, while 8-hydroxy-2′-deoxyguanosine levels were not significantly lower in healthy smokers. There was no significant association of sirtuin 1 protein expression and 8-hydroxy-2′-deoxyguanosine levels with rs10997868 and rs730821. Our findings showed a significant association between smoking duration and rs10997868 single nucleotide polymorphism, which was highest in those with the C/C genotype and lowest in those with the A/C genotype (p = 0.035). In addition, the serum cholesterol level was highest in the C/C group and lowest in the A/C group (p = 0.029). None of the studied factors (smoking duration, serum cholesterol, fasting blood sugar, or serum triglycerides) was significantly associated with sirtuin 1 rs730821. Conclusions: Our study showed that sirtuin 1 upregulation and polymorphisms are associated with smoking duration and lipid levels in healthy smokers.