['To investigate the association between the presence of Porphyromonas\xa0gingivalis-induced immunoglobulin G antibodies and the high-density lipoprotein (HDL) level.', 'A total of 108 individuals were examined. The presence of P.\xa0gingivalis was detected using primers designed to target the 16S rRNA gene sequence. Peripheral blood was collected from each subject to determine the levels of P.\xa0gingivalis-induced IgG1 and IgG2 serum antibodies. The HDL levels were determined using fully enzymatic methods.', 'A higher proportion of periodontitis patients had high levels of P.\xa0gingivalis-induced IgG1 and IgG2, and the proportion of subjects with a HDL level of <\xa035\xa0md/dL was higher in the group of chronic periodontitis patients. In the unadjusted regression model, the presence of high levels of P.\xa0gingivalis-induced IgG2 was associated with a HDL level of <\xa035\xa0md/dL. The adjusted model indicated that periodontitis patients with high levels of P.\xa0gingivalis-induced IgG2 showed 3.2 more chances of having pathological HDL levels (odds ratio\xa0=\xa03.2, 95% confidence interval\xa0=\xa01.2-9.8).'] Are high levels of Porphyromonas gingivalis-induced immunoglobulin G2 associated with lower high-density lipoprotein levels in chronic periodontitis?