Objective:
The metabolic syndrome (MetS) and subclinical CVD measures are associated with a higher risk of future cardiovascular disease (CVD) events. Furthermore, individuals with MetS have a greater burden of subclinical CVD, such as the presence of carotid plaque (CP) and larger adventitial diameter (AD). Midlife women proceeding through the menopausal transition are vulnerable to developing MetS and are also at greater risk of CVD, a risk that varies by race/ethnicity. We hypothesized that there are racial/ethnic differences in the association between MetS and measures of subclinical atherosclerosis.
Methods:
Participants from 6 sites of the Study of Women’s Health Across the Nation (SWAN) were analyzed if they were free of clinical CVD and had measures of CP and AD at the 12th annual visit. Women were identified as having MetS if they met the criteria defined by the International Diabetes Federation (IDF). Multivariable logistic and linear regression models were used to investigate the relationship of MetS with CP and AD overall and separately within each race/ethnicity group. Study site, age, height, LDL-C, smoking status, menopausal status, hormone use, and education level were included as covariates. Further analysis adjusted for inflammatory and metabolic biomarkers.
Results:
The 1454 women were, on average, 59.6 years old 43.5% had evidence of MetS, and 85.8% were postmenopausal. The race/ethnicity breakdown was 51.1% White, 30.3% Black, 12.7% Chinese, and 5.8% Hispanic. Overall, MetS was associated with the presence of CP and higher AD after adjusting for covariates (OR (95%): 1.65 (1.31, 2.08); β (SE): 0.344(0.035) mm, p< .0001, respectively). In race-specific models, MetS was significantly associated with AD in White, Black, Hispanic, and Chinese participants, adjusting for covariates (β (SE): 0.305 (0.043) p<.0001; 0.401(0.077) p<.0001; 0.466 (0.147) p= 0.0023; 0.291 (0.098) p = 0.0035; respectively). MetS was significantly associated with CP in White participants only (OR (95%): 1.89 (1.39, 2.57)). When high-sensitivity C-reactive protein and insulin resistance were included in the model, MetS remained significantly associated with AD in Black (0.327(0.86), p = 0.0002) and White (0.212(0.051) p<.0001) participants, and MetS remained significantly associated with CP in Whites participants (1.55 (1.08, 2.23)).
Conclusion:
MetS is associated with subclinical atherosclerosis, and the association varies by race/ethnicity in midlife women. This variation may help explain differences in incidence rates of CVD events between racial/ethnic groups.