ABSTRACTObjective:We aimed to identify metabolic dysfunction in non-functioning adrenal adenomas (NFAAs) and Visceral Adiposity Index (VAI) predictability in the practical estimation of metabolic syndrome (MetS) in NFAAs.Subjects and methods:134 NFAA patients and 68 control subjects matched for age, sex, and body mass index (BMI) were included in the study. After physical, biochemical, and endocrine evaluation, IDF and NCEP ATP III criteria were used to determine MetS. HOMA-IR and VAI were calculated for both study group subjects.Results:MetS was significantly higher in the NFAA patients. The incidence of MetS by IDF and NCEP criteria was 52.9%,48.5% in the NFAI and 32.3%,30.8% in the control group (p < 0.01, p = 0.02). The risk of MetS was increased in NFAA (75.6vs.24.4%, p = 0.017, OR = 1.34, 95% CI = 1.06-1.68). Glucose, HOMA IR, hypertension, and VAI were significantly increased in NFAA patients. The risk of MetS was independently associated with high VAI (79.2vs.20.8%, p = 0.001, OR = 2.22; 95% CI = 1.70-2.91).Conclusion:MetS, insulin resistance, and VAI are more prevalant in NFAA patients than in healthy individuals. VAI can be used with high specificity to estimate MetS in NFAA patients.