ObjectiveTo explore the relationship between interleukin-6 (IL-6) single nucleotide polymorphisms and paroxysmal atrial fibrillation (PAF) in elderly patients with primary hypertension.Methods279 elderly patients with primary hypertension admitted to our hospital from January 2020 to January 2023 were selected as the study subjects. The polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method was used to detect the single nucleotide polymorphisms at the-174G/C and-572C/G sites of the IL-6 gene, and the Hardy Weinberg (H-W) genetic balance test was performed. All patients were followed up until January 2024 and divided into PAF group and non-PAF group according to whether they had concurrent PAF. The general clinical data and IL-6 gene single nucleotide polymorphisms of the two groups were analyzed and compared. Serum IL-6 level was measured by blood samples collected from two groups. The influencing factors of elderly primary hypertension and PAF were analyzed by univariate and multivariate Logistic regression analysis.ResultsThe incidence of PAF in elderly patients with primary hypertension was 19.70% (52/264). The age of patients, the proportion of smoking history, the proportion of hypertension grade Ⅲ, the proportion of GG, GC genotypes, and the frequencies of G alleles at the IL-6-572C/G site in the PAF group were higher than those in the non PAF group (P<0.05). The serum IL-6 level of patients in the PAF group was higher than that in the non PAF group (P<0.05), and the serum IL-6 level of patients with the IL-6-572C/G site GC genotype and GG genotype were higher than those of patients with the IL-6-572C/G site CC genotype (P<0.05). The results of multivariate Logistic analysis showed that age [odds ratio (OR) =1.952, 95% confidence interval (95% CI): 1.281－2.975], smoking history (OR=1.619, 95% CI: 1.145－2.291), hypertension grade Ⅲ (OR=1.752, 95% CI: 1.205－2.548), IL-6-572C/G site GC genotype (OR=1.694, 95% CI: 1.228－2.336), IL-6-572C/G site GG genotype (OR=1.846, 95% CI: 1.176－2.897) were independent risk factors for elderly primary hypertension with PAF (P<0.05).ConclusionSingle nucleotide polymorphisms at the IL-6-572C/G site is associated with elderly primary hypertension with PAF. Age, smoking history, hypertension grade Ⅲ, and IL-6-572C/G site GC and GG genotype are independent risk factors for elderly primary hypertension with PAF.