Objective: We examined whether the association of the metabolic syndrome (MetS) and subclinical atherosclerosis is independent of insulin resistance in a Chinese community sample with no history of type 2 diabetes.
Methods: Five hundred and ninety-six men and 526 women from a substudy of the Guangzhou Biobank Cohort Study (GBCS-CVD) had carotid intimal-medial thickness (IMT) measured by B-mode ultrasonography, and brachial-ankle pulse wave velocity (PWV) and ankle-brachial systolic blood pressure index (ABI) measured simultaneously by a noninvasive automatic waveform analyser.
Results: Fourteen percentage had MetS as defined by the International Diabetes Federation. Obesity indices, systolic and diastolic blood pressure and pulse pressure, lipids, fasting and postload glucose and insulin, homeostatic model assessment of insulin resistance, glycosylated haemoglobin A1c, leptin, high-sensitivity C-reactive protein, IMT and PWV increased and high-density lipoprotein-cholesterol, adiponectin and ABI decreased significantly with increasing number of MetS components after adjusting for age and sex (P for trend from 0.004 to <0.001). After adjusting for traditional cardiovascular risk factors and insulin resistance, the odds ratios [OR (95% CI)] of thicker IMT (> or =1.0 mm), higher PWV (> or =14.0 m/s) and low ABI (< or =1.0) for MetS were significantly increased [2.28 (1.19-4.38), 2.17 (1.36-3.46) and 1.72 (1.14-2.59), respectively, all P < 0.01] but were lower than the adjusted OR for those with three or more MetS components.
Conclusion: MetS was associated with subclinical atherosclerosis independent of insulin resistance. The presence of increasing number of MetS risk factors appeared to be more important than the diagnosis of MetS in predicting subclinical atherosclerosis. Early screening for MetS risk factors might identify those at greater cardiovascular risk.