Fatty liver largely explains associations of subclinical hypothyroidism with insulin resistance, metabolic syndrome, and subclinical coronary atherosclerosis

• Published in: European journal of endocrinology Vol. 171; no. 3; pp. 319 - 325
• Main Authors: Posadas-Romero, Carlos, Jorge-Galarza, Esteban, Posadas-Sánchez, Rosalinda, Acuña-Valerio, Jorge, Juárez-Rojas, Juan G, Kimura-Hayama, Eric, Medina-Urrutia, Aida, Cardoso-Saldaña, Guillermo C
• Format: Journal Article
• Language: English
• Published: Bristol Bioscientifica Ltd 01.09.2014; BioScientifica
• Subjects: Adult; Aged; Biological and medical sciences; Clinical Study; Coronary Artery Disease - blood; Coronary Artery Disease - diagnosis; Coronary Artery Disease - epidemiology; Cross-Sectional Studies; Endocrinopathies; Fatty Liver - blood; Fatty Liver - diagnosis; Fatty Liver - epidemiology; Female; Fundamental and applied biological sciences. Psychology; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Hypothyroidism - blood; Hypothyroidism - diagnosis; Hypothyroidism - epidemiology; Insulin Resistance - physiology; Liver. Biliary tract. Portal circulation. Exocrine pancreas; Male; Medical sciences; Metabolic Syndrome - blood; Metabolic Syndrome - diagnosis; Metabolic Syndrome - epidemiology; Middle Aged; Non tumoral diseases. Target tissue resistance. Benign neoplasms; Other diseases. Semiology; Thyroid. Thyroid axis (diseases); Vertebrates: endocrinology; Endocrinopathy; Pancreatic hormone; Thyroid diseases; Coronary artery; Metabolic diseases; Cardiovascular disease; Hepatic disease; Hypothyroidism; Metabolic syndrome; Coronary heart disease; Insulin; Vascular disease; Target tissue resistance; Association; Fatty liver; Atherosclerosis; Digestive diseases; Insulin resistance; Endocrinology
• ISSN: 0804-4643; 1479-683X
• DOI: 10.1530/EJE-14-0150

BackgroundThe association of subclinical hypothyroidism (SCH) with insulin resistance, metabolic syndrome (MS), and coronary atherosclerosis is uncertain.ObjectiveTo investigate the role of increased intrahepatic fat in the association of SCH with insulin resistance, MS, and coronary atherosclerosis.Design, patients, and methodsWe conducted a cross-sectional study in a sample of 753 subjects (46% males) aged 35–70 years with no history of diabetes, renal, hepatic, thyroid, or coronary heart disease, and were participants of the Genetics of Atherosclerotic Disease study. SCH was defined as a high serum TSH level with normal free thyroxine concentration. Fatty liver (FL), coronary artery calcification (CAC), and abdominal visceral adipose tissue were assessed by computed tomography. Cross-sectional associations of SCH with and without FL, with MS, insulin resistance, and subclinical atherosclerosis defined as a CAC score >0, were examined in logistic regression models.ResultsSCH was observed in 17.7% of the population studied. The prevalence of FL was similar in both euthyroid and SCH subjects (31.8 vs 27.8%, P=0.371). SCH plus FL subjects were heavier and had more metabolic abnormalities compared with SCH plus normal liver subjects. In multivariate-adjusted logistic regression analyses, SCH plus FL was associated with MS (odds ratio (OR): 2.73, 95% CI: 1.26–5.92), insulin resistance (OR: 4.91, 95% CI: 1.63–14.75), and CAC score >0 (OR: 3.05, 95% CI: 1.20–7.76). SCH without FL showed no associations.ConclusionSCH with FL is associated with increased odds of MS, insulin resistance, and CAC, independent of potential confounders.