Impact of excluding hyperglycemia from international diabetes federation metabolic syndrome diagnostic criteria on prevalence of the syndrome and its association with microvascular complications, in adult patients with type 1 diabetes

Background We aimed to determine, in patients with type 1 diabetes (T1DM), the impact of excluding hyperglycemia as a criterion from the International Diabetes Federation (IDF) definition of the metabolic syndrome (MetS), both on its prevalence and on its association with micro and macrovascular complications and markers of subclinical inflammation. Methods A cross-sectional design, including 280 patients with T1DM. We defined MetS by three different models: (i) the standard IDF criteria, (ii) a modification consisting of excluding of hyperglycemia as a criterion (modified IDF criteria) and (iii) a modification consisting in changing the hyperglycemia by insulin resistance (MetS + IR model) defined by the estimated glucose disposal rate. Microvascular complications and cardioautonomic neuropathy were assessed. We measured an inflammatory panel including high sensitivity C reactive protein, erythrocyte sedimentation rate, homocysteine, and fibrinogen concentrations. Results After excluding hyperglycemia, the prevalence of MetS was 6.4% (95%CI: 4.1 to 9.9) compared with 20.7% (95%CI: 16.3 to 25.8) using standard IDF criteria. After adjusting for duration of diabetes, all three MetS definitions increased the odds for having microvascular complications [OR: 6.012 (2.208–16.307) for modified definition; OR: 5.176 (2.555–10.486) for standard definition and [OR: 3.374 (1.649–8.456) for MetS+IR model]. However, the both modified IDF models for MetS showed better predictive performance than standard criteria for suffering from neuropathy, nephropathy, cardiovascular disease and were associated with markers of subclinical inflammation. Conclusions The prevalence of MetS significantly varies as a function whether or not hyperglycemia is included as a diagnostic criterion. The subset of patients fulfilling the modified MetS definitions may reflect better the concept of metabolic syndrome in T1DM. These modified definitions were accompanied by a poorer metabolic control and lipid profile, showing the worse inflammatory biomarker profiles and higher odds for micro- and macrovascular complications. In patients with T1DM, the inclusion of insulin resistance instead of hyperglycemia as a criterion of MetS may be of interest in routine clinical practice.