The normal-weight type 2 diabetes phenotype revisited

Abstract Background Type 2 diabetes (T2DM) is associated with obesity, insulin resistance and the metabolic syndrome (MetS). In non-diabetic populations, features of metabolic obesity (MO) are observed in a minority of normal-weight (NW) subjects. The cardiometabolic status of metabolically obese but normal-weight (MONW) individuals has not yet been phenotyped in T2DM. Patients and methods Prevalence and features of MONW were analyzed in 1244 T2DM patients, in whom MONW was identified as a BMI n  = 262; 21%), those without MetS ( n  = 152; NW-MetS[−]) were compared to NW-MetS[+] ( n  = 110; i.e. 42% of NW and 9% of all T2DM). Results There were no differences between groups in age; gender; diabetes duration; smoking; BP; and LDL-C. NW-MetS[+] had higher BMI; waist; fat mass; visceral fat; liver steatosis and HbA 1c , and lower insulin sensitivity. Non-right-handedness was twice-higher (18%) in NW-MetS[−]. NW-MetS[+] had higher apoB 100 and triglycerides, and lower HDL-C and LDL size. Macroangiopathy was present in 39% of NW-MetS[+] vs. 22% of NW-MetS[−], as coronary (23% vs. 14%) or peripheral artery disease (14% vs. 5%) and TIA/stroke (15% vs. 7%). Microangiopathy was present in 54% of NW-MetS[+] vs. 32% of NW-MetS[−], as retinopathy (25% vs. 13%); neuropathy (29% vs. 18%); and albuminuria (39% vs. 20%). Conclusions MONW among T2DM represents a significant minority (about 1 in 10). Their cardiometabolic phenotype deserves attention due to multiple comorbidities, including a twice-higher prevalence of micro-/macrovascular damage in patients wrongly perceived at lower risk due to normal BMI. Unexpectedly, non-right-handedness was over-represented among metabolically healthy patients.