Alterations of NIS expression in functioning thyroid nodules.

OBJECTIVES: This study aimed to analyze both the level and the cell site of the sodium-iodide symporter (NIS) protein expression in autonomously functioning thyroid nodules (AFTNs) and extranodular thyroid tissues. In addition, this study sought to compare the clinical results of patients with the levels of human NIS (hNIS) protein expression. PATIENTS AND METHODS: The histological slides consisted of 36 AFTNs and 31 extranodular thyroid tissues from 28 patients (5 males, 23 females; mean age 54.5±11.0 years; range 37 to 72 years) who underwent surgery for toxic multinodular goitre. The expression of NIS protein was investigated by immunohistochemistry in paraffin-embedded tissue sections using anti-hNIS monoclonal antibody by the labeled streptavidin-biotin method. RESULTS: The percentage of hNIS positive follicular cells was significantly higher in the AFTNs (13.33±12.09) than in the extranodular thyroid tissues (1.35±3.03). Staining for hNIS was mostly confined to the cell membrane in the AFTNs (88.9%) and in the extranodular thyroid tissues (54.5%). The clinical parameters and nodule volume did not establish any correlation with hNIS immunoreactivity. CONCLUSION: Our data indicate that functioning nodules express higher amounts of NIS protein than the extranodular thyroid tissue, but the level of hNIS immunoreactivity was lower than had been reported in the previous literature. This result may be due to interindividual variability between different populations, and iodine status. Furthermore, the localization of the NIS protein might not give an indication of its functional status.

Myasthenia gravis and autoimmune Addison disease in a patient with thymoma.

The association of thymoma with myasthenia gravis has been well documented. However, the relationship between these two syndromes and Addison disease are very rarely encountered in clinical practice. We report on a 32-year-old man who underwent a resection for thymoma 48 months ago. The diagnosis of Addison disease was made followed by a diagnosis of myasthenia gravis on the basis of a high titer of acetylcholine receptor levels. The treatment of oral prednisolone 7.5 mg/day and oral prostigmine 180 mg/day was initiated. His symptoms and physical signs were improved after this treatment. To our knowledge, this is the fourth reported case of thymoma synchronously associated with myasthenia gravis and Addison disease.

A new silent germline mutation of the TSH receptor: coexpression in a hyperthyroid family member with a second activating somatic mutation.

BACKGROUND: Up to date, three thyroid-stimulating hormone receptor (TSHR) germline variants have been reported for which no functional consequences have been detected by in vitro characterizations. However, familial nonautoimmune hyperthyroidism and hot nodules are clearly associated with constitutively activating TSHR germline mutations. We describe a family with a new TSHR germline mutation that is associated with euthyroidism in 13 family members and hyperthyroidism in 1 family member. METHODS: Mutation analysis of the TSHR gene was performed by denaturing gradient gel electrophoresis. TSHR constructs were characterized by determination of cell surface expression, 3'-5'-cyclic adenosine monophosphate (cAMP) accumulation, and constitutive cAMP activity. RESULTS: A novel TSHR germline mutation (N372T) was found in a man who presented with thyrotoxicosis. The mutation was also detected in 13 family members, all of whom were euthyroid. Interestingly, an additional constitutively active somatic mutation (S281N) was identified on the second parental TSHR allele of the hyperthyroid index patient. Linear regression analysis showed a lack of constitutive activity for N372T. Moreover, coexpression studies of N372T with S281N did not reveal any evidence for a functional influence of N372T on the constitutively active mutation (CAM). CONCLUSIONS: N372T is unlikely to cause altered thyroid function. This is consistent with the finding that only the index patient with the additional somatic mutation S281N was hyperthyroid.

Assessment of health-related quality of life (HRQoL) of patients with type 2 diabetes in Turkey.

We measured the health-related quality of life (HRQoL) in a sample of 376 type 2 diabetes patients in Turkey using the Diabetes Quality of Life (DQOL) instrument and examined which patient socio-demographic and diabetes-related clinical characteristics are associated with better quality of life (QoL). The influence of patient socio-demographic and clinical characteristics on QoL was examined using independent sample t-tests and one-way analysis of variance. Diabetes significantly affected the HRQoL of patients included in this study. The mean score of the total DQOL measure was higher among patients who were less than 40 years of age, male, married, had less than 8 years of education, lived with their family and had no family history of diabetes (p<0.05). Similarly, patients with less than 5 years of disease duration, no complications or prior hospitalization, receive insulin, and with HbA(1)c<7 reported significantly better overall HRQoL (p<0.05). Patients with BMI<24 had higher levels of satisfaction with diabetes than those with BMI>or=24 (p<0.05). Diabetes-related HRQoL information is clearly of supreme importance to family physicians and policy makers to identify and implement appropriate interventions for achieving better management of diabetes and ultimately improving the QoL of diabetes patients.

Translation, cultural adaptation, cross-validation of the Turkish diabetes quality-of-life (DQOL) measure.

OBJECTIVE: The aim of this study was to test the validity and reliability of the Turkish version of the diabetes quality of life (DQOL) questionnaire for use with patients with diabetes. METHODS: Turkish version of the generic quality of life (QoL) scale 15D and DQOL, socio-demographics and clinical parameter characteristics were administered to 150 patients with type 2 diabetes. Study participants were randomly sampled from the Endocrinology and Diabetes Outpatient Department of Dr. Lutfi Kirdar Kartal Education and Research Hospital in Istanbul, Turkey. RESULTS: The Cronbach alpha coefficient of the overall DQOL scale was 0.89; the Cronbach alpha coefficient ranged from 0.80 to 0.94 for subscales. Distress, discomfort and its symptoms, depression, mobility, usual activities, and vitality on the 15 D scale had statistically significant correlations with social/vocational worry and diabetes-related worry on the DQOL scale indicating good convergent validity. Factor analysis identified four subscales: satisfaction", impact", "diabetes-related worry", and "social/vocational worry". CONCLUSION: Statistical analyses showed that the Turkish version of the DQOL is a valid and reliable instrument to measure disease related QoL in patients with diabetes. It is a simple and quick screening tool with about 15 +/- 5.8 min administration time for measuring QoL in this population.

Similar prevalence of somatic TSH receptor and Gsalpha mutations in toxic thyroid nodules in geographical regions with different iodine supply in Turkey.

OBJECTIVE: Differences in iodine intake could account for the variable prevalences reported for somatic TSH receptor (TSHR) mutations in toxic thyroid nodules (TTNs). However, this question has not been settled, since no study has yet determined the TSHR mutation prevalence in regions with different iodine supplies in the same population using the same methodology. Therefore, we studied the prevalence of somatic TSHR mutations in TTNs from patients living in iodine-deficient or -sufficient regions in Turkey. DESIGN AND METHODS: We screened 74 TTNs for somatic TSHR mutations. Exons 9 and 10 of the TSHR and 7 and 8 of the Gsalpha were screened by denaturing gradient gel electrophoresis. Determination of X-chromosome inactivation was used for clonality analysis. RESULTS: TSHR mutations were identified in 52 (70.2%) of 74 TTNs. A Gsalpha mutation was identified in one TTN. Three new TSHR mutations were detected (A627V, I640K, I486N). No significant difference between frequencies of TSHR mutations in iodine deficient/sufficient regions was found. The frequency of non-random X-chromosome inactivation was similar in iodine-sufficient or -deficient regions and in TSHR mutation positive or negative hot nodules. CONCLUSIONS: These findings suggest that TTNs in iodine deficient/sufficient areas predominantly arise from aberrant growth of a single cell. Our results suggest that neither the prevalence of TSHR mutations nor that of monoclonal TTNs is related to iodine supply.

A case of McCune-Albright syndrome associated with Gs alpha mutation in the bone tissue.

The syndrome of McCune-Albright syndrome (MAS) is clasically defined as a triad presentation with the findings of polyostotic fibrous dysplasia, café-au-lait spots, and sexual precocity. However, not all patients present with complete symptoms. A 52-year-old man was diagnosed as having a variant of McCune-Albright syndrome with the following findings: polyostotic fibrous dysplasia, acromegaly due to pituitary tumor and subclinical hyperthyroidism due to toxic multinodular goiter. Sexual precocity and café-au-lait spots were not noted. Acromegaly was confirmed by laboratory examination (IGF-1, glucose suppression test and TRH stimulation test). Long acting somatostatin analogue was used as treatment. Although the pituitary tumor could not be removed due to technical problems, mass lesions on the cranium were removed subtotally. Histopathological evaluation demonstrated that the lesion complied with fibrous dysplasia. Genomic DNAs were isolated from the craniofacial bones and peripheral leucocytes of the patient. After amplifying the related regions, Gs alpha (Gs alpha) gene was analysed by automatic DNA sequence analysis. An activating mutation of the Gs alpha gene (Arg 201 Cys) was found in the genomic DNA isolated from the bone tissue of the patient, but not in the genomic DNA isolated from the blood. We described a case of MAS associated with Gs alpha mutation in the bone tissue, presenting with polyostotic fibrous dysplasia, subclinical hyperthyroidism and acromegaly.

Is adiponectin level a predictor of nonalcoholic fatty liver disease in nondiabetic male patients?

AIM: Adiponectin is a hepatic insulin sensitizer and also an inhibitor of tumor necrosis factor. We studied its levels in nondiabetic patients with nonalcoholic fatty liver disease (NAFLD) and compared with control group. METHODS: Thirty-five patients who had elevated serum aminotransferase levels with bright liver and 34 healthy volunteers without liver disease were evaluated. Age, gender and body mass index (BMI) were recorded. Fasting plasma glucose, insulin, adiponectin, proinsulin and lipid profile were measured. A standard oral glucose tolerance test (OGTT) with insulin response was performed and the index of insulin resistance was calculated according to the homeostasis model assessment (HOMA) method. RESULTS: According to the OGTT results, none of the participants had diabetes. Serum adiponectin levels were statistically significantly lower in patients with NAFLD than in control group (8.14+/-3.4 microg/mL vs 12.4+/-9.4 microg/mL, respectively, P<0.01). A statistically significant correlation was found between adiponectin and BMI (r : -0.33, P<0.01), HOMA (r : -0.26, P<0.05), proinsulin (r : -0.32, P<0.01), AST (r : -0.25, P<0.05), ALT (r : -0.26, P<0.05) or GGT (r : -0.22, P<0.05). In multiple regression analysis models, adiponectin levels were the only predictor of NAFLD in males, whereas in female group it was the BMI. CONCLUSION: Low adiponectin level might be a predictor of NAFLD especially in male nondiabetics.

The effect of defective early phase insulin secretion on postload glucose intolerance in impaired fasting glucose.

Impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) are two risk groups for type 2 diabetes. Type 2 diabetes is characterized by both impaired insulin secretion and insulin resistance but their relative contribution to the development of hyperglycemia may differ due to heterogeneity of the disease. Combined glucose intolerance (CGI), on the other hand, seems to represent a more advanced stage of prediabetes that bears a distinctly higher risk of progression to diabetes and its comorbidities. This study has the aim to compare isolated IFG and CGI categories with respect to the degree of early phase insulin secretion abnormalities and insulin resistance. Subjects who had IFG (fasting glucose: 110-126 mg/dl) were included in the study. A 75-g oral glucose tolerance test (OGTT) with insulin response was done and subjects were classified according to the WHO criteria. Six subjects were excluded because they had diabetic glucose tolerance. A total of 66 patients (53.4 +/- 11.1 years, female/male: 48/18) were divided into two groups according to their glucose tolerance in OGGT (Group 1: isolated IFG and group 2: CGI). Early phase insulin secretion was measured by intravenous glucose tolerance test (IVGTT) and OGTT. Insulin resistance was assessed by the R value of the homeostasis model assessment (HOMA). We did not find any statistically significant difference between groups according to age, gender, body mass index (BMI), fasting glucose, fasting insulin, insulin-AUC (0-180 min) and HOMA-R values. In OGGT there was no statistically significant difference between 0', 30', 60' and 90' insulin levels of the groups; only 120' and 180' insulin levels were higher in CGI than in IFG group (p<0.05). In IVGTT, there was no statistically significant difference between glucose levels of the groups. Furthermore, insulin response to intravenous glucose was higher in IFG than in CGI (p<0.05). Our data demonstrate that isolated IFG and CGI are similar with respect to the degree of insulin resistance, and that subjects with CGI had a more prominent deficit in early phases of insulin secretion.

The evaluation of left ventricular hypertrophy in hypertensive patients with subclinical hyperthyroidism.

The aim of this prospective cross-sectional study was to investigate the hypertrophic effects of endogenous subclinical hyperthyroidism on myocardium and early development of left ventricular hypertrophy (LVH) in essential hypertensive patients accompanied by endogenous subclinical hyperthyroidism. A total of 31 consecutive patients with stage I hypertension were included in the study. Sixteen of them also had endogenous subclinical hyperthyroidism that they were unaware before. The patients and the controls formed out of ten healthy subjects all underwent an investigation of thyroid functions and cardiologic evaluation. The mean wall thickness of the left ventricle in the stage I hypertensive group with endogenous subclinical hyperthyroidism (group I) was significantly increased as compared with both hypertensive patients without thyroid disease (group II) and the control subjects. The mean left ventricle mass was also significantly higher in group I than group II. Both of the patients' groups had an increased prevalence of LVH as compared with the controls. In this study, hypertensive patients with subclinical hyperthyroidism presented more increase in left ventricular mass, suggesting that subclinical hyperthyroidism may contribute to left ventricular hypertrophy forming a natural progression to hypertension. The hypertensive population should always be screened for endogenous subclinical hyperthyroidism, and should be examined for the criteria of left ventricular hypertrophy by echocardiography in early stages.

The prevalence of silent ischemia in Turkish patients with type 2 diabetes mellitus.

Cardiovascular disease (CVD) is the major cause of death in patients with type 2 diabetes mellitus. However, the diagnosis of CVD is delayed due to concealment of antecedent symptoms by factors such as autonomic neuropathy. In this study, we aimed to investigate the frequency of silent ischemia by using exercise electrocardiogram (ECG). The present study included 500 Turkish patients with type 2 diabetes (male/female: 222/278), who showed no evidence of CAD and angina pectoris or no sign(s) of ischemic changes in resting ECGs. All patients underwent treadmill exercise test according to Bruce protocol, and 62 cases (12.4%) exhibited abnormal changes. These patients identified by exercise ECG consisted of 28 males (28/222, [12.6%]) and 34 females (34/278, [12.2%]) and were then examined by coronary angiography. CAD was diagnosed in 53 individuals by coronary angiography. The abnormalities of exercise test are associated with the age of the patients or the duration of diabetes (p < 0.05). There is no significant difference in the severity of coronary disease or in the prevalence of silent ischemia between male and female patients. However, among the patients identified by exercise ECG females have higher body mass index than males, suggesting that obesity may represent the risk factor of CAD in women with type 2 diabetes.

Addition of rosiglitazone to glimepirid and metformin combination therapy in type 2 diabetes.

The study was planned to determine the efficacy and safety of adding rosiglitazone to a combination of glimepiride and metformin therapy with insufficiently controlled type 2 diabetes. This was an open-label study with a follow-up period of 26 weeks. Thirty patients were taking 3 mg glimepiride two times and 850 mg metformin two times per day. Patients were told to take one rosiglitazone 4 mg tablet before breakfast additionally. The primary efficacy measure was the mean change in HbA1c from baseline to the end of the study. Secondary efficacy parameters included the mean changes from baseline to the end of the study in fasting plasma glucose (FPG) and insulin levels, as well as total cholesterol, HDL-C, LDL-C, triglycerides, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Mean HbA1c levels decreased significantly from 7.54 +/- 0.9% to 6.57 +/- 0.7% (p < 0.001) at 26th week. FPG levels fell from 169.39 +/- 37.8 mg/dl to 135.69 +/- 28.0 mg/dl (p < 0.001), respectively. Insulin levels decreased from 19.60 +/- 9.8 U/L to 14.66 +/- 11.6 U/L (p = 0.026) at 26th week. No one experienced elevations of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels greater than 2.5 times the upper limit of the reference range. This study confirms that the addition of rosiglitazone (4 mg/day) to sulphonylurea and metformin treatment for patients with type 2 diabetes improves glycemic control, is safe, and generally well tolerated.

Prevalence of peripheral neuropathy in type 2 diabetic patients attending a diabetes center in Turkey.

The aim of this study was to determine the prevalence and risk factors for neuropathy in type 2 diabetic patients attending a major Turkish diabetes center. Eight hundred and sixty-six consecutive type 2 diabetic patients were included in the study. A single observer performed biothesiometry studies on these patients. The presence of diabetic neuropathy was investigated using neurological symptom scale (NSS) and neurological disability score (NDS) performed. Neuropathy was determined with standardized neurological examinations and defined as the presence of abnormal NSS and NDS together with abnormal sensory or motor signs and symptoms as well as decreased great toe vibration perception. Overall, 60% (n = 520) of the patients were diagnosed as having neuropathy. The prevalence of neuropathy increased with age (p < 0.001) and duration of diabetes (p < 0.001). Multiple logistic regression analysis revealed the duration of diabetes (p < 0.001) and HbA1c levels (p < 0.001) as the risk factors for neuropathy. The overall prevalence of neuropathy in Turkish type 2 diabetic population was 60%. Age, duration of diabetes, and poor glycemic control were considered to be the risk factors for neuropathy.

Association of nonalcoholic fatty liver disease with insulin resistance: is OGTT indicated in nonalcoholic fatty liver disease?

Nonalcoholic fatty liver disease (NAFLD) is frequently associated with type 2 diabetes mellitus, obesity, and dyslipidemia. We tested the hypothesis that there may be an association between NAFLD and insulin resistance (IR); and its correlation with glucose tolerance status of subjects who aren't known patients with diabetes. One hundred and seventy-six consecutive patients with elevated serum aminotransferase levels and bright liver were evaluated. Sixty-two patients were excluded from the study. Age, gender, height, weight, body mass index, waist circumferences, and family history of diabetes were recorded. Fasting plasma glucose, insulin, lipid profile were measured. A standard oral glucose tolerance test (OGTT) was performed and the index of IR was calculated according to the HOMA method. Patients with a normal glucose tolerance formed group 1 (64 patients) and patients with impaired or diabetic glucose tolerance group 2 (50 patients). Age, female sex, family history of type 2 diabetes, fasting insulin, fasting plasma glucose and HOMA-R index were statistically significantly different between the groups. Although the subjects in the study are not known patients with diabetes, the prevalence of impaired or diabetic glucose tolerance was prominent. In conclusion, performing OGTT in cases with nonalcoholic fatty liver disease may be useful for early screening of diabetes mellitus.

Comparison of lunch and bedtime NPH insulin plus mealtime insulin Lispro therapy with premeal regular insulin plus bedtime NPH insulin therapy in type 2 diabetes.

AIM: Nonfasting plasma glucose is claimed to be a better marker of diabetic control than fasting plasma glucose in type 2 diabetes. In this study we compared the efficacy and safety profile of two different intensive insulin treatment strategies in patients with uncontrolled type 2 diabetes despite using a twice-daily insulin regimen. METHODS: We studied 60 insulin-treated patients who had uncontrolled type 2 diabetes. The study was a 6-month, open-label, randomised, parallel clinical trial conducted in two diabetes centres. The main end-points for analysis were weekly self-monitored blood glucose readings, HbA1c levels, total daily insulin dose, weight gain and the number of hypoglycaemic episodes. RESULTS: The breakfast 2-h, lunch 2-h and dinner 2-h postprandial glucose values and pre-dinner glucose values were significantly lower in the Lispro group than the regular insulin group. The HbA1c value at the end of the study was significantly lower in the Lispro group (7.3 +/- 0.7%) compared with the regular insulin group (7.7 +/- 0.7%; P<0.05). Mean insulin doses were similar in the treatment groups initially and at the end. There was a statistically significant increase in insulin dose in both groups from baseline to the end of the study (P<0.05). Overall hypoglycaemia rates were comparably low and similar in both groups during the study. CONCLUSIONS: We have shown that mealtime insulin Lispro plus additional lunch and bedtime NPH insulin is superior to premeal regular insulin plus bedtime NPH insulin for overall glycaemic regulation with similar weight gain and comparable rates of hypoglycaemia.