Darren R. Brenner, Paul Arora, Bibiana Garcia-Bailo, Howard Morrison, Ahmed El-Sohemy, Mohamed Karmali and Alaa Badawi
Background: The metabolic syndrome (MetS) is a well-established risk factor for cardiometabolic disease. However, the association between MetS, and its components, with the metabolic phenotypes and inflammatory markers that are risk factor for cardiometabolic disease has not been explored in the general population. The present study examines this association among Canadian adults and explores the changes in the profile of a number of metabolic and inflammatory markers associated with cardiometabolic disease at various MetS stages.
Methods: Serum levels of apolipoprotein A1 and B (Apo-A1, -B), total:HDL-cholesterol (HDL-C) ratio, C-reactive protein (CRP), fibrinogen, glycosylated haemoglobin (HbA1c) and homocysteine were determined in 1,818 non-diabetic adults (16-79 years of age) from the Canadian Health Measures Survey (CHMS). The definition of MetS components was based on the National Cholesterol Education Program, Adult Treatment Panel III criteria. Taylor-series expansion methods for complex survey data were used to estimate variances. Generalized linear models adjusted for age, sex, physical activity, smoking status, use of medications and ethnicity were used to quantify the relationship between the metabolic phenotypes and inflammatory markers associated with risk to cardiometabolic disease and the number of MetS components.
Results: The prevalence of the MetS (i.e., with three or more MetS components) among the study subjects was 8.9%, with 31.8% having at least one component. As expected, metabolic markers such as total: HDL-C, Apo-B and HbA1c were all significantly increased as the number of MetS components increased whereas Apo-A was decreased. We also observed a significant association between the number of MetS components and the serum levels of inflammatory biomarkers such as CRP and fibrinogen, but not homocysteine. Mean serum levels of these markers were significantly elevated as the numbers of MetS components increased. Strong correlations were noted between CRP, fibrinogen, and homocysteine and the individual components of the MetS.
Conclusions: There is an apparent profile of metabolic phenotypes and inflammatory biomarkers, known to be related to the cardiometabolic disease risk, that emerges as MetS manifests with increasing the number of its components. These findings may permit proposing a metabolic trait that predisposes to MetS and may permit developing an effective approach for early risk prediction and intervention.