Insulin resistance and metabolic syndrome in outpatients with bipolar disorder: [review]

BACKGROUND: Bipolar disorder (BD) is associated with significant morbidity and mortality from metabolic diseases. There is a paucity of data regarding insulin resistance (IR) and its relationship with the metabolic syndrome (MS) in bipolar patients. OBJECTIVE: To evaluate the prevalence of both IR and MS in BD outpatients and to assess clinical criteria associated with IR. METHOD: Cross-sectional study in 65 DSM-IV-TR BD patients consecutively assessed at the Bipolar Disorder Program at Hospital de Clínicas de Porto Alegre , Brazil. IR was diagnosed by the homeostatic model assessment - insulin resistance (HOMA-IR) and MS was diagnosed using three different definitions: National Cholesterol Educational Program - Adult Treatment Panel III (NCEP-ATP III); NCEP-ATP III modified criteria and International Diabetes Federation. RESULTS: IR was present in 43.1 percent of the sample (women 40 percent, men 44.4 percent). The prevalence of MS defined by the NCEP-ATP III criteria was 32.3 percent, NCEP-ATP III modified was 40 percent and IDF was 41.5 percent. NCEP-ATP III modified criteria showed the best trade-off between sensitivity (78.6 percent) and specificity (89.2 percent) to detect insulin resistance. Waist circumference was the clinical parameter most associated with IR. DISCUSSION: Current MS criteria may provide reasonable sensitivity and specificity for the detection of IR in BD patients. Abdominal obesity is closely related to IR in this patient population.