SIRT1 and metabolic syndrome: Therefore, the aim of the present study was to investigate the association between four single nucleotide polymorphisms (SNPs) in SIRT1 gene (two in the promoter region (rs7895833 A> G and 12049646 T> C), one in intron 4 (rs12413112 G> A) and one in exon 5 (rs2273773 T> C) with LD and MetS phenotypes in PLHIV on regular HAART.