Individuals with
metabolic syndrome reportedly have an increased risk of
cardiovascular disease, although the association between asymptomatic myocardial damage and
metabolic syndrome has not been sufficiently investigated. The present study investigated possible associations between circulating cardiac
troponin and
metabolic syndrome or related factors. Subjects undergoing their annual health checkups were enrolled in the study (n = 1242). Laboratory measurements included serum high-sensitivity cardiac
troponin I (hs-cTnI) and plasma
B-type natriuretic peptide (BNP). Individual
salt intake was estimated by calculating 24-h urinary
sodium excretion from spot urine. Subjects whose electrocardiograms revealed ST-T segment abnormalities or who had
renal insufficiency or a history of cardiovascular events were excluded. Subjects with
metabolic syndrome had higher hs-cTnI levels than those without, but their BNP levels were equivalent. hs-cTnI levels were significantly associated with the presence and components of
metabolic syndrome. Logistic regression analysis with the endpoint of hs-cTnI levels higher than the median value identified
metabolic syndrome as an independent determinant of increased hs-cTnI levels. Additionally, urinary
salt excretion levels were increased in subjects with
metabolic syndrome or any of its components. Logistic regression analysis with the endpoint of
metabolic syndrome revealed that hs-cTnI levels were independently associated with the presence of
metabolic syndrome. A close association between hs-cTnI levels and the presence of
metabolic syndrome, at least partially mediated by increased
salt intake, was confirmed to exist in the general population. The findings support the idea that patients with
metabolic syndrome develop asymptomatic myocardial damage without obvious ischaemic findings, which leads to increased cardiovascular risk.