Association between Low-Grade Inflammation and Left Ventricular Diastolic Dysfunction in Patients with Metabolic Syndrome and Hyperuricemia.

BACKGROUND: Hyperuricemia (HUA) induces inflammation and insulin resistance and is reportedly associated with left ventricular hypertrophy (LVH) and possibly with left ventricular diastolic dysfunction (LVDD). OBJECTIVES: To investigate associations among HUA, inflammation, and insulin resistance with LVDD. METHODS: We enrolled patients with metabolic syndrome (MetS) between August 1, 2017, and December 31, 2017. All participants underwent fasting blood tests and transthoracic echocardiography. HUA was defined as an serum uric acid level ≥ 7 mg/dl in men or ≥ 6 mg/dl in women. MetS was defined as at least three of the following Taiwanese criteria: central obesity, prehypertension, fasting glucose impairment, hypertriglyceridemia, and lower values of high-density lipoprotein cholesterol. LVDD was defined according to contemporary guidelines. Prevalence rates of HUA, LVH, LVDD were 40%, 18%, and 10%, respectively. Baseline characteristics were similar between the HUA and normouricemia groups, except that the HUA group had significantly higher serum high-sensitivity interleukin 6 and tumor necrosis factor-alpha (TNF-α) levels. LVDD occurred more frequently in the HUA group (20.0% vs. 2.6%, p = 0.032). HUA was associated with LVDD [crude odds ratio (OR): 9.25, 95% confidence interval (CI): 1.01-84.7, p = 0.049]. In multivariate analysis, the most relevant factor associated with LVDD was TNF-α after adjustments for age, male sex, and body mass index (adjusted OR for TNF-α: 4.1, 95% CI: 1.02-16.5, p = 0.047). CONCLUSIONS: The association between HUA and LVDD partially reflected a low-grade inflammation due to elevated TNF-α rather than increased insulin resistance in MetS patients.