26 ENDOCRINE PRACTICE Vol 20 No. 1 January 2014 Original Article Mehmet Asik, MD 1 ; Sinan Sahin, MD 2 ; Ahmet Temiz, MD 3 ; Mesut Ozkaya, MD 4 ; Faruk Ozkul, MD 5 ; Hacer Sen, MD 6 ; Emine Binnetoglu, MD 6 ; Fahri Gunes, MD 6 ; Neslihan Bozkurt, MD 6 ; Mustafa Sahin, MD 7 ; Kubilay Ukinc, MD 1 Submitted for publication April 2, 2013 Accepted for publication July 1, 2013 From the 1 Department of Endocrinology and Metabolism, Faculty of Medicine, Çanakkale Onsekiz Mart University, Çanakkale, Turkey, 2 Department of Cardiology, Bergama Government Hospital, Izmir, Turkey, Department of Cardiology 3 , Faculty of Medicine, Çanakkale Onsekiz Mart University, Çanakkale, Turkey, 4 Department of Endocrinology and Metabolism, Faculty of Medicine, Gaziantep University, Gaziantep, Turkey, 5 Department of General Surgery, Faculty of Medicine, Çanakkale Onsekiz Mart University, Çanakkale, Turkey, and 6 Department of General Medicine, Faculty of Medicine, Çanakkale Onsekiz Mart University, Çanakkale, Turkey, and 7 Department of Endocrinology and Metabolism, Faculty of Medicine, Ankara University, Ankara, Turkey. Address correspondence to Dr. Mehmet Aşık, Department of Endocrinology and Metabolism, Faculty of Medicine, Çanakkale Onsekiz Mart University, Kepez, Çanakkale, Turkey. E-mail: mehmetzu@yahoo.com. Published as a Rapid Electronic Article in Press at http://www.endocrine practice.org on September 6, 2013. DOI:10.4158/EP13140.OR To purchase reprints of this article, please visit: www.aace.com/reprints. Copyright © 2014 AACE. ABSTRACT Objective: Primary hyperparathyroidism (pHPT) affects the cardiovascular system, and epicardial fat tissue (EFT) thickness is closely associated with cardiovascular diseases and atherosclerosis. Despite this, the association between EFT thickness and pHPT has not been studied in a clinical setting. This study aimed to assess EFT thickness in patients with pHPT. Methods: The study included 38 patients with pHPT and 40 healthy controls. EFT thickness, carotid intima- media thickness (CIMT), serum levels of parathormone (PTH) and calcium, and blood chemistry profles were determined in all subjects. Correlation and regression analyses were performed with EFT thickness and CIMT as dependent variables and age; systolic and diastolic blood pressure; body mass index (BMI); presence of diabetes mellitus; and free plasma glucose (FPG), PTH, and serum calcium (Ca) levels as independent variables. Results: Both the mean EFT thickness and the mean CIMT were signifcantly greater in the pHPT group than the control group (P<.001 for both). Correlation analy- sis showed that EFT thickness was signifcantly corre- lated with CIMT, age, systolic blood pressure, and PTH and serum Ca levels. Furthermore, the regression analysis revealed that EFT thickness retained its independent and positive association with FPG and serum Ca levels. Conclusions: The results of this study indicate that EFT thickness may be a useful marker of early athero- sclerosis in patients with pHPT. Furthermore, the increase in EFT thickness appears to be due to hypercalcemia. (Endocr Pract. 2014;20:26-32) Abbreviations BMI = body mass index; Ca = calcium; CIMT = carotid intima-media thickness; EFT = epicardial fat tissue; FPG = fasting plasma glucose; HDL = high-density lipoprotein cholesterol; LDL = low-density lipoprotein cholesterol; pHPT = primary hyperparathyroidism; PTH = parathormone; TC = total cholesterol; TG = triglycerides INTRODUCTION Primary hyperparathyroidism (pHPT) is characterized by recurrent renal stones; osteoporosis; and symptoms of hypercalcemia, such as constipation, fatigue, and weak- ness. It has also been recently reported that patients with pHPT have increased mortality, which appears to be mainly due to cardiovascular death (1). pHPT has been reported to be associated with cardiac dysfunction, including hyper- tension, cardiac arrhythmia, left ventricular hypertrophy, and carotid intima-media thickening (CIMT) (2), as well as metabolic syndrome including insulin resistance and dyslipidemia (2). However, no particular measurement has been demonstrated to be the best parameter for predicting the risk of cardiovascular mortality among patients with pHPT.