A Prospective Follow-Up of Adipocytokines in Cohort Patients With Gout: Association With Metabolic Syndrome But Not With Clinical Inflammatory Findings: Strobe-Compliant Article

The inflammatory role of silent urate crystal deposition in intercritical gout

OBJECTIVE

To study subclinical inflammation in intercritical gout patients and its relation to the estimated size of monosodium urate crystal deposition and cardiovascular risk factors.

METHODS

We performed a secretome analysis and the quantification of cytokine and adipokine plasma levels (IL-1β, IL-18, IL-6, sIL-6R, TNFα, CXCL5, RANTES, leptin, resistin and adiponectin) to analize subclinical inflammation in intercritical gout patients. Since it is currently not feasible to determinate the whole body deposit of monosodium urate crystals, we created an indirect clinical classification to estimate it. Then, we compared cytokine levels in controls and gout patients, and in patients with different crystal deposition size. We also studied the association between cytokine-levels and the number of cardiovascular risk factors.

RESULTS

Ninety consecutive patients attending a Crystal Arthritis Unit were studied. IL-18, sIL-6R, RANTES, leptin and adiponectin were higher in intercritical gout patients than in controls. An association was observed between IL-18, sIL6-R and RANTES levels and the size of crystal deposition. IL-18, sIL6-R, RANTES and leptin were higher in patients with no cardiovascular risk factors when compared with controls with no risk factors.

CONCLUSION

Our results showed that the levels of some proinflammatory cytokines and metabolic proteins are elevated in intercritical gout patients. The levels of certain cytokines was related to the estimated size of the monosodium urate crystal deposition and to the number of cardiovascular risk factors. These cytokine changes may help to explain the increase of the cardiovascular events in gout patients.

Is There a Nonlinear Relationship between Serum Uric Acid and Lipids in a Hypertensive Population with eGFR ≥30 ml/min/1.73 m2? Findings from the China Hypertension Registry Study

BACKGROUND

Evidence regarding the nonlinear relationship between serum uric acid (SUA) and blood lipids in Chinese population with hypertension is limited. Therefore, the present study aimed to investigate whether there is a nonlinear association between SUA and lipids in Chinese hypertensive population with an estimated glomerular filtration rate (eGFR) ≥30 ml/min/1.73 m².

METHODS

A total of 13,355 hypertensive participants with eGFR ≥30 ml/min/1.73 m² were selected from the Chinese Hypertension Registry Study. Multivariate linear regression was used to examine the linear relationship between SUA and lipids. Smooth curve fitting (penalized spline method) and threshold saturation effects were used to analyze the nonlinear association between SUA and lipids.

RESULTS

In the fully adjusted model, the results showed a positive correlation between SUA and TG (β = 0.15; 95% CI: 0.14, 0.16) and LDL-C (β = 0.06; 95% CI: 0.05, 0.07), respectively. However, the relationship between SUA and HDL-C was nonlinear. The inflection point of SUA was 7.24 mg/dL. On the left side of the inflection point (<7.24 mg/dL), SUA was negatively associated with HDL-C (β = -0.02; 95% CI -0.02, -0.01). On the right side of the inflection point (≥7.24 mg/dL), SUA was not related to HDL-C (β = 0.01; 95% CI -0.01, 0.02).

CONCLUSION

After adjusting for all covariates, SUA was positively associated with TG and LDL-C. The relationship between SUA and HDL-C was nonlinear. The negative correlation between SUA and HDL-C only existed when the SUA was less than 7.24 mg/dL in a hypertensive population with eGFR ≥30 ml/min/1.73 m².