Background/Purpose:

The metabolic syndrome (MS) is common among gout patients. The metabolic syndrome is diagnosed when a patient has at least 3 of the following 5 conditions: hyperglycemia, hypertension, hypertriglyceridemia, low high-density lipoprotein (HDL) cholesterol, abdominal obesity. Little is known about the relationship between the cumulative effects of all 5 MS conditions and the risk of mortality among adult patients with gout. The MS Severity Score (MSSS) is a validated summary score that accounts for the combined effects of all 5 metabolic features. Our goal was to use the MSSS to examine the overall associations between MS severity and the risk of mortality related to all-causes, cardiovascular disease and diabetes among United States (US) gout patients.

Methods:

We analyzed mortality-linked data for 9,747 adults aged 20 to 74 years who participated in the Third National Health and Nutrition Examination Survey (NHANES III). Data from NHANES III were linked to national mortality records for all participants up to time of death or end of study (i.e. 23 years following initial recruitment). All 5 metabolic features were used to calculate gender-race/ethnicity specific MSSS Z-scores in gout patients. The calculated Z-scores are a continuous representation of all MS conditions while accounting for gender-race/ethnicity disparities. Cox proportional hazard models adjusting for age, marital status, gender, income, education, race, smoking, BMI, insurance, physical activity, alcohol intake and diet, were used to test the associations between MS severity and risk of mortality in gout patients. Complex survey methods with sampling weights, clusters and strata were applied to yield nationally representative prevalence and inference estimates.

Results:

A total of 2,072 deaths were observed, of which 127 had gout. The prevalence amongst adults was 2.40% (95% CI; 1.93%-2.87%). Moderate to high MS severity was significantly prevalent among gout patients (47.33% vs. 21.16 % no gout; P-value <0.0001). The mean MSSS Z-score for gout patients was significantly higher than those without gout (0.71 vs. -0.04 no gout; P-value <0.0001). Among all patients, a one unit increase in MSSS score was associated with a higher risk of mortality in all adjusted models. For gout patients, a one-unit increase in MSSS score was associated with significant increase in the risk of all-cause mortality Adjusted Hazard Ratio (aHR) 1.46 (95% CI; 1.13, 1.87). In a disease-specific survival model, a one-unit increase in MSSS score was associated with 79% and 124% increases in cardiovascular and diabetes mortality risks, aHR 1.79 (95% CI; 1.20, 2.67) and 2.24 (95% CI; 1.21, 4.16), respectively.

Conclusion:

Studies published to date have not accounted for the combined effects of all 5 MS features in gout patients. For gout patients, a one-unit increase in MSSS score was associated with significant increase in the risk of all-cause mortality and 79% and 124% increases in cardiovascular and diabetes mortality risks. The MSSS is a clinically accessible tool for predicting mortality risks in gout patients with the MS.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/the-relationship-between-metabolic-syndrome-severity-and-the-risk-of-mortality-in-gout-patients-a-population-based-study/