Kahn (1) pointed out that metabolic syndrome is associated with many uncertainties and inconsistencies, which could easily misdirect care, mislead patients, and lead to unnecessary health care costs. The risk of cardiovascular disease (CVD) associated with the syndrome is no greater than that explained by the presence of its components, and it is possible to create an almost infinite number of scenarios in which individuals who do not meet the diagnostic criteria for metabolic syndrome would be at greater risk of CVD than would those who do, as noted by Reaven (2).
What if, among the diagnostic components of metabolic syndrome, waist circumference, which is one of the anthropometric markers of obesity, was substituted by high-sensitivity C-reactive protein (CRP)? CRP is a sensitive marker of subclinical systemic inflammation and positively relates to leptin (3) and insulin resistance (4) and negatively relates to adiponectin (5), even in people with normal BMI (excluding those with diabetes). Reaven (2) pointed out that only about one-third of the most insulin-resistant individuals were actually obese, and the degree of correlation between insulin-mediated glucose uptake and BMI, waist circumference, and visceral obesity were almost equal. Neither abdominal obesity nor metabolic syndrome, as defined by the National Cholesterol Education Program Adult Treatment Panel III criteria, were a significant independent risk factor for CVD in multiple regression analyses (6,7), while very low levels of CRP were useful for risk prediction among women with calculated 10-year Framingham risks <10% (8). Previously, we propose a CRP value of 0.65 mg/l as the cut point for metabolic syndrome (9) instead of ethnic-specific controversial cut points of waist circumference. Whether the new clothes fit the emperor should be revealed by reanalyses of existing epidemiological studies including CRP data.
