Date Published: February 12, 2018
Publisher: Public Library of Science
Author(s): Chiara Pavanello, Anna Maria Zanaboni, Sabrina Gaito, Margherita Botta, Giuliana Mombelli, Cesare R. Sirtori, Massimiliano Ruscica, Ying-Mei Feng.
The body variable associated with the diagnosis of Metabolic Syndrome (MetS) is an elevated waist circumference (WC), although a number of other variables have been suggested. Among these, an elevated waist-to-height ratio (WHtR), ie a value higher than 0.5, that may identify abnormality, independently from height. An elevated WHtR provided the best correlation with MetS in a prior study in a large Italian population. In order to assess the validity of this conclusion, a long-term follow-up study re-examined this population, also in order to detect possible associations with cardiovascular (CV) risk.
1,071 subjects with a complete follow-up of over 6 years were evaluated with a comparative assessment of the three anthropometric variables, namely WHtR, WC and body mass index (BMI). WHtR≥ 0.5 had the highest sensitivity for the identification of MetS, both in males and females (94.1% and 86.7% respectively). WHtR was of reduced specificity, occurring, yet less frequently (17.7% in males and 30% in females), in patients without MetS. By contrast, enlarged WC occurred with a lower frequency in male patients who developed MetS (30.2%) whereas in females, frequency was higher than in males (69.3%). Finally, a BMI≥ 25 kg/m2 had intermediate sensitivity and specificity regardless of gender. WC showed the highest odds ratio (2.62, 95%CI: 1.18–5.78) for the prediction of CV occurrence.
The present study confirms WHtR as an excellent screening tool in identifying MetS carriers, but, different from reports in other countries, it shows a lower specificity in our population.
The profile of Metabolic Syndrome (MetS), ie the association of biochemical features (low high-density lipoprotein (HDL) cholesterol, hypertriglyceridemia and hyperglycemia), body variable (i.e. waist circumference (WC) ≥ 102 cm in male and ≥ 88 cm in female) and elevated blood pressure (BP), is widely accepted. There is, however, some variability in the diagnostic criteria, particularly relative to the body variable/s . Further, the assessment of the relative influence of each risk factor on the cardiovascular (CV) risk has led to partially discordant conclusions . Indeed, hypertension is likely to be the most significant MetS variable associated with arterial disease ; while other authors favor low HDL-C , and some others abdominal obesity  or hyperglycemia .
The evaluation of CV risk associated with MetS has become a standard goal in clinical practice. This goal includes the best choice of variables, both biochemical and body structure associated, allowing an optimal diagnosis of MetS, as well as providing a possible marker for CV risk prediction. Body variables associated with MetS have gained considerable interest, also in view of their simplicity of assessment and, in the case of WHtR, of the apparent uniformity of findings in different populations with marked differences in height . In the present report, we evaluated, in a retrospective fashion, a series of over 1,000 patients from the same location and with an over 6-year follow-up with > 95% completeness of data .