Objective:To analyze the influencing factors of gout patients and explore whether there is an interaction between serum uric acid and diastolic blood pressure affecting the onset of tophi.Methods:A total of 4 798 gout patients were retrospective selected in the outpatient Department of the Gout Clinical Medical Center of the Affiliated Hospital of Qingdao University from September 2016 to May 2020. It was divided into tophi group and non-tophi group to compare the differences in indicators. A logistic regression model was used to analyze the influencing factors of tophi, and an interaction model was constructed to analyze the interactions.Results:Multivariate logistic regression analysis showed significant associations between age, diastolic blood pressure, alcohol consumption history, gout family history, blood uric acid, urea nitrogen, and creatinine clearance and tophi formation. The results of blood uric acid-related interaction analysis showed a significant interaction between blood uric acid and diastolic blood pressure( Pinteraction=0.014), and the risk of developing tophi in low diastolic blood pressure and high diastolic blood pressure group increased by 34.4%( OR=1.344, 95% CI 1.105-1.635, P=0.003) and 95.4%( OR=1.954, 95% CI 1.558-2.450, P<0.001) in the high blood uric acid group compared with the low blood uric acid group. The results of diastolic blood pressure and blood uric acid subgroup analysis showed that there was no statistical difference in the risk of developing tophi in people with low uric acid levels( P=0.238), but in people with high uric acid levels, the risk of developing tophi was 67%( OR=1.670, 95% CI 1.379-2.022, P<0.001) higher than that in the low uric acid group. Conclusion:Age, diastolic blood pressure, combined alcohol consumption history and gout family history, blood uric acid, renal function are related to the occurrence of tophi. High uric acid and high diastolic blood pressure have interaction on the occurrence of tophi. Attention and proactive intervention shall be applied to this group of patients.

Objective:To analyze the clinical characteristics of elderly-onset gouty arthritis and risk factors of tophi.Methods:A total of 1 239 gout patients were retrospective selected in the outpatient department of the Gout Clinical Medical Center of the Affiliated Hospital of Qingdao University from 2016 to 2022. According to age of onset, they were divided into the young and middle-aged group(aged<60) consisted of 826 cases, and the elderly group(aged≥60) consisted of 413 cases. Compare the clinical characteristics of elderly with Young and Middle-aged patients.Results:The systolic blood pressure, fasting blood glucose, creatinine, regular exercise, comorbidities, and tophi in the elderly group was higher than that in the middle-aged and young group. The proportion of diastolic blood pressure, serum triglycerides, eGFR, serum uric acid, alcohol consumption rate, and family history of gout was lower than that of young and middle-aged group( P<0.05); In the elderly-onset group, the initial site of arthritis was commonly observed in the first metatarsophalangeal joint. The proportion of the first attack with the upper limb joint was higher in old age group than in young and middle age group( P<0.05). Renal underexcretion type was the main subtype in the elderly group, and the proportion of overproduction type was higher than that of the young and middle-aged group( P<0.05). The logistic regression analysis showed that age, urea nitrogen, disease duration≥10 years and family history of gout were risk factors for tophi in elderly patients( P<0.05). Conclusion:The elderly-onset gout has unique clinical characteristics, characterized by a higher prevalence of tophi, a higher rate of complications. An initial site of arthritis commonly observed in the first metatarsophalangeal joint and the predominant type of uric acid excretion is renal excretion impairment. Early diagnosis and treatment, control of blood uric acid levels, smoking cessation and alcohol, regular exercise should be applied to prevent or delay the formation of tophi.