Relationship between lipoprotein(a), metabolic syndrome, and carotid atherosclerosis in older Japanese people.

BACKGROUND Lipoprotein(a) [Lp(a)] or metabolic syndrome (MS) is individually considered an atherosclerotic factor. Serum Lp(a) may reportedly show the additive effects on atherosclerosis under certain particular pathologies. We do not know the association between serum Lp(a) and carotid artery intima-media thickness (CIMT) with relation to MS in older people. OBJECTIVE The present study aims at investigating the relationship between Lp(a) and CIMT levels in relation to MS among older subjects. METHODS We studied 182 Japanese subjects of >or=60 years (mean 72.5 years), free of cardiovascular/cerebrovascular disease. MS was based on the NCEP-ATPIII criteria with a minor modification for Japanese. The CIMT was ultrasonographically measured. RESULTS The CIMT levels were significantly greater in the MS group (n = 60, 1.03 +/- 0.22 mm) than the non-MS group (n = 122, 0.96 +/- 0.22 mm). Multivariate analysis, using Lp(a) levels or the product term for interaction between Lp(a) and MS, showed that age significantly and independently correlated to CIMT, along with male gender. DISCUSSION Even when Lp(a) and MS were simultaneously considered, age was the best determinant of CIMT in this population. The mechanism of our results including weak additive effects of Lp(a) and MS among older subjects may be partly throughout aging.