• Cardiometabolic Disorder

Evidence suggests that metabolic syndrome is associated with significantly increased risk of incident cardiovascular disease (CVD) and all-cause and cardiovascular (CV) death [Mottillo S et al. J Am Coll Cardiol 2010]. A clinical priority is to identify patients at risk for stroke and other CV events to enable preventive interventions and promote lifestyle modifications [Timóteo AT et al. J Clin Hyptertens 2012].

Most studies in primary prevention settings have shown a relationship between metabolic syndrome and carotid intima-media thickness (CIMT) [Khan UI et al. Atherosclerosis 2011; Magnussen CG et al. Circulation 2010; Antonini-Canterin F et al. Angiology 2010]. Kenneth Connell, MB, BS, DM (Internal Medicine), The University of the West Indies, Cave Hill, Barbados, presented outcomes from an investigation of the relationship between traditional markers of metabolic syndrome and CIMT. The study also examined ethnic differences in metabolic profiles.

A total of 114 healthy volunteers (84 black, 59 white) recruited from South East London participated in the study. Standard anthropometric measures were collected, along with laboratory tests of lipids and glucose. Ambulatory blood pressure (BP) was monitored for 24 hours. CIMT measurements of the central carotid artery were taken using high-resolution ultrasound and special edge-detection computer software. Other than body mass index (BMI; p<0.0001), 24-hour ambulatory systolic BP (p=0.003), and glucose (p=0.003), there were no significant differences in baseline characteristics.

There were statistically significant ethnic differences in both BMI (26.7 kg/m² black vs 24.1 kg/m² white; p<0.0001) and triglycerides (0.74 black vs 0.92 white; p=0.005), with no significant difference in mean systolic BP (117 mm Hg black vs 121 mm Hg white; p=0.308). Office systolic BP was a significant predictor of CIMT (p=0.009).

The correlation between CIMT and systolic BP was significant (r=0.239; p=0.012), but there was no significant correlation with any lipid subfraction. The ethnic difference in CIMT between blacks and whites (0.477 mm black vs 0.425 mm white; p=0.001) was significant.

The present study showed significant ethnic differences in BMI, 24-hour ambulatory BP (systolic), and fasting glucose when using traditional markers of metabolic syndrome. No significant correlation between any CIMT and lipid subfractions was observed, but there was a statistically significant correlation with office systolic BP. Indeed, office rather than ambulatory BP was the most significant predictor of CIMT.

These data suggest that the main difference observed in CIMT between blacks and whites may not be related to traditional markers of metabolic syndrome. Given the low but statistically significant correlation with BP, there may be additional factors that play a role in the genesis of atherosclerosis in different ethnic groups.

CIMT has been suggested as a surrogate marker for coronary and peripheral artery disease because it is easily obtained by a noninvasive test, and is therefore recommended by guidelines for CV risk stratification, particularly in patients at intermediate risk [Stein JH et al. J Am Soc Echocardiography 2008]. Whether it should replace traditional metabolic syndrome markers in predicting the risk of CVD events and mortality has yet to be determined.

• © 2012 MD Conference Express®