Association of MRI-based adrenal gland volume and impaired glucose metabolism in a population-based cohort study.

OBJECTIVES: The aim of this study was to assess adrenal gland volume by using magnetic resonance imaging (MRI) and to study its role as an indirect marker of impaired glucose metabolism and hypothalamic-pituitary-adrenal (HPA) axis activation in a population-based cohort. METHODS: Asymptomatic participants were enrolled in a nested case-control study and underwent a 3-T MRI, including T1w-VIBE-Dixon sequences. For the assessment of adrenal gland volume, adrenal glands were manually segmented in a blinded fashion. Impaired glucose metabolism was determined using fasting glucose and oral glucose tolerance test. Cardiometabolic risk factors were also obtained. Inter- and intrareader reliability as well as univariate and multivariate associations were derived. RESULTS: Among 375 subjects included in the analysis (58.5% male, 56.1 ± 9.1 years), 25.3% participants had prediabetes and 13.6% had type 2 diabetes (T2DM). Total adrenal gland volume was 11.2 ± 4.2 ml and differed significantly between impaired glucose metabolism and healthy controls with largest total adrenal gland volume in T2DM (healthy controls: 10.0 ± 3.9 ml, prediabetes: 12.5 ± 3.8 ml, T2DM: 13.9 ± 4.6 ml; p < 0.001). In the multivariate analysis, association of T2DM and increased adrenal gland volume was independent of age, sex, hypertension, triglycerides and body mass index (BMI), but was attenuated in subjects with prediabetes after adjustment for BMI. CONCLUSIONS: T2DM is significantly associated with increased adrenal gland volume by MRI in an asymptomatic cohort, independent of age, sex, dyslipidaemia, hypertension and BMI. Adrenal gland volume may represent an indirect marker of impaired glucose metabolism and HPA axis dysfunction.