The new definition of metabolic syndrome including hyperuricemia improves its prognostic value: results from NHANES database

Abstract

Background Metabolic syndrome (MetS) remains a major health problem worldwide and is strongly associated with an elevated risk of cardiovascular disease (CVD). MetS was proposed to identify more high-risk individuals and facilitate early intervention. Hyperuricemia has not been included in the current definition of MetS yet, despite its strong association with MetS. We aimed at exploring the prognostic value of adding hyperuricemia into the definition of MetS. Methods Data derived from NHANES (1999–2018) was analyzed. The old version of MetS (MetSold) is consistent to NCEP-ATP III criteria, while the new version of MetS (MetSnew) included hyperuricemia as the sixth criterion. Baseline characteristics were compared between participants with and without MetS, and outcomes were assessed by multivariate analyses. Results Of 36,363 participants analyzed, 12,594 (34.6%) and 14,137 (38.9%) met MetSold and MetSnew criteria respectively. Compared to MetSold, MetSnew identified additional 1534 participants with metabolic risk. Both MetSold and MetSnew were significantly associated with long-term all-cause and CVD mortality (all P < 0.001). Furthermore, the additional participants identified by MetSnew displayed the similar risk of all-cause and CVD mortality as participants met MetSold. MetSnew provided a better identification and reclassification ability (all-cause mortality: C-index improvement = 0.06, NRI = 0.03, IDI = 0.55; CVD mortality: C-index improvement = 0.02, NRI = 0.01, IDI = 0.61) when compared with MetSold. Conclusions The inclusion of hyperuricemia in the MetS criteria could identify a greater proportion of people at metabolic risk, thereby allowing for early intervention to prevent long-term adverse events.