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    Öğe
    Contemporary surface wind climatology of Turkey
    (Springer Wien, 2013) Sahin, Sinan; Turkes, Murat
    The aim of this study was to examine the climatological characteristics of boundary layer gradient winds in Turkey in detail. In the study, monthly average wind speed (V (m)) data measured at 267 stations for the 16 directions, prevailing wind direction (V (p)), and station pressure (P (s)) data measured at 174 stations during the period 1970-2008 by the Turkish Meteorological Service (TMS) were used. The data were provided by the TMS. To attain the aim of the study, wind patterns of midseason months representing the seasonal wind distributions were used, and surface wind formations were examined through calculation of divergent and rotational components of the average wind rate. Besides, it was aimed at explaining the relationships between sea level pressure (SLP) patterns and wind formations. The patterns of midseason months were examined via the Principal Component Analysis (PCA). In accordance with V (m) data, it is seen that air flows in Turkey generally tend to orientate radially from west to east. Climatologically, the strongest prevailing winds in Turkey blow during the summer months, while the weakest winds blow during the autumn months. V (m) and V (p) distributions show a parallelism (i.e., wind gradient) in the months during which temperature differences between land and sea are high due to the differences in their specific heat values. The distributions of V (m) and V (p) values vary considerably in spring and autumn months during which temperature differences are relatively lower. According to the PCA results, the first two components represent the strong wind areas in Turkey. These components presumably explain the existence of coherent wind formation areas, which display different characteristics due to regional physical geographical factors and processes (e.g., orography, altitude, exposure, land-sea distribution, surface mechanical and thermodynamic modifications of the air masses and air flows, etc.) in addition to the direct effect of different synoptic-scale pressure and circulation conditions.
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    Öğe
    Evaluation of epicardial fat tissue thickness in patients with Hashimoto thyroiditis
    (Wiley-Blackwell, 2013) Asik, Mehmet; Sahin, Sinan; Ozkul, Faruk; Anaforoglu, Inan; Ayhan, Semiha; Karagol, Sukriye; Gunes, Fahri
    Objective Hypothyroidism, whether overt or subclinical, has multiple effects on the cardiovascular system. Epicardial fat tissue (EFT) is closely related to cardiovascular disorders and atherosclerosis. Our study aimed to assess EFT thickness and carotid artery intima-media thickness (CIMT) in patients with Hashimoto's thyroiditis (HT) displaying overt and subclinical hypothyroidism (SCH). Design and patients The study included 33 patients with SCH and 24 patients with overt hypothyroidism (OH) with HT as well as 32 healthy controls. EFT thickness, CIMT, thyroid hormone levels and lipid parameters were measured in all subjects. Correlation analysis and linear regression analysis were performed for EFT thickness. Results Mean EFT thickness was 2.89 +/- 0.38, 3.53 +/- 0.92 and 4.56 +/- 1.61mm in control, SCH and OH groups, respectively (P < 0.001). EFT thickness of OH patients was high compared with SCH and control subjects (P < 0.01 and < 0.001, respectively). CIMT of OH patients was high compared with SCH and control subjects (P < 0.01 and < 0.001, respectively). In addition, EFT was significantly thicker in SCH patients than in controls (P < 0.05). Correlation analysis showed that EFT thickness was significantly positively correlated with CIMT, age, body mass index, systolic blood pressure, thyroid-stimulating hormone, total and LDL cholesterol and triglyceride and negatively correlated with free T4. In the regression analysis, EFT thickness retained its independent and positive association with CIMT, patient group (particularly OH) and systolic blood pressure. Conclusions Epicardial fat tissue thickness may be a useful indicator of early atherosclerosis in SCH and OH patients with HT.
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    Öğe
    EVALUATION OF EPICARDIAL FAT TISSUE THICKNESS IN PATIENTS WITH PRIMARY HYPERPARATHYROIDISM
    (Amer Assoc Clinical Endocrinologists, 2014) Asik, Mehmet; Sahin, Sinan; Temiz, Ahmet; Ozkaya, Mesut; Ozkul, Faruk; Sen, Hacer; Binnetoglu, Emine
    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 intimamedia thickness (CIMT), serum levels of parathormone (PTH) and calcium, and blood chemistry profiles 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 significantly greater in the pHPT group than the control group (P<.001 for both). Correlation analysis showed that EFT thickness was significantly correlated 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 atherosclerosis in patients with pHPT. Furthermore, the increase in EFT thickness appears to be due to hypercalcemia.