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Background: The SLC30A8 gene encodes zinc transporter-8 (ZnT8), highly expressed in insulin-secreting pancreatic beta cells, and may contribute to insulin processing and secretion. The SNP 13266634C/T (R325W change) in the SLC30A8 gene has been associated with type 2 diabetes (T2D) development. Genome-wide association studies and subsequent population studies including Europeans and Asians have demonstrated that the rare allele T (Trp325) of SNP 13266634 in the SLC30A8 gene is protective against T2D. Aim: We aimed to investigate whether the SNP rs13266634C/T is associated with T2D and its phenotypes in Turkey, which geographically connects Asia and Europe. Materials and methods: In our study, 650 nonobese individuals (366 T2D and 284 healthy individuals) were enrolled. Target SNP was genotyped by real-time PCR using the LightSNiP Genotyping Assay System. Results: The frequency of the T allele was lower in the T2D group than in the healthy control group (14.6% vs. 24.5%, respectively). The rare variant T of SNP rs13266634 in SLC30A8, located in the last exon of the gene, is associated with an increased c-peptide level, and it was 47.2% protective against type 2 diabetes compared to the C allele (OR = 0.528, 95% CI: 0.399–0.699, p <.001). Conclusions: Our findings indicate consistently with other studies that a rare variant of rs13266634C/T is protective against T2D, as the related first report in the nonobese Turkish population. Comprehensive studies to better understand the envisaged vital molecular role of SLC30A8 in pancreatic beta cells may contribute to developing therapeutic approaches. [ABSTRACT FROM AUTHOR]

Type 2 diabetes (T2D) is a complicated public health problem in Turkey as well as worldwide. Genome-wide approaches have been guiding in very challenging situations, such as the elucidation of genetic variations underlying complex diseases such as T2D. Despite intensive studies worldwide, few studies have determined the genetic susceptibility to T2D in Turkish populations. In this study, we investigated the effect of genes that are strongly associated with T2D in genome-wide association (GWA) studies, including MTNR1B, CDKAL1, THADA, ADAMTS9 and ENPP1, on T2D and its characteristic traits in a Turkish population. In 824 nonobese individuals (454 T2D patients and 370 healthy individuals), prominent variants of these GWA genes were genotyped by real-time PCR using the LightSNiP Genotyping Assay System. The SNP rs1387153 C/T, which is located 28 kb upstream of the MTNR1B gene, was significantly associated with T2D and fasting blood glucose levels (P < 0.05). The intronic SNP rs10830963 C/G in the MTNR1B gene was not associated with T2D, but it was associated with fasting blood glucose, HbA1C and LDL levels (P < 0.05). The other important GWA loci investigated in our study were not found to be associated with T2D or its traits. Only the SNP rs1044498 (A/C variation) in the ENPP1 gene was determined to be related to fasting blood glucose (P < 0.05). Our study suggests, consistent with the literature, that the MTNR1B locus, which has a prominent role in glucose regulation, is associated with T2D development by affecting blood glucose levels in our population. [ABSTRACT FROM AUTHOR]

A correction is presented to the article " Protective effect of the rare variant rs13266634C/T of the SLC30A8 gene in the genetic background of the development of type 2 diabetes in Turkish population " which appeared in the May 09, 2023 issue.

Background: Subclinical hypothyroidism is a situation in which the thyroid-stimulating hormone (TSH) value exceeds the upper limit of normal, but the free triiodothyronine (T3) and thyroxine (T4) values are within the normal range. The etiology is similar to overt hypothyroidism. Case presentation: An 18-year-old female patient was referred to our endocrinology clinic due to elevated TSH levels detected during a routine examination. She was clinically euthyroid and had a normal thyroid ultrasound pattern. The TSH concentration was measured twice independently, giving values of 5.65 μIU/mL and 5.47 μIU/mL. The polyethylene glycol (PEG) method for TSH measurement was used to determine the concentration of macro-TSH (m-TSH), a macromolecule formed between TSH and immunoglobulin (Ig). Using the same blood samples for which the TSH levels were found to be high, the PEG method found TSH levels to be within a normal range, with values of 1.50 μIU/mL (5.65–1.50 μIU/mL measured; a decrease of 75%) and 1.26 μIU/mL (5.47–1.26 μIU/mL measured; a decrease of 77%), respectively. The TSH values determined by the PEG precipitation test were markedly low, with PEG-precipitable TSH ratios greater than 75%. Conclusions: The cause of 55% of subclinical hypothyroidism is chronic autoimmune thyroiditis. However, it is necessary to exclude other TSH-elevated conditions for diagnosis. One of these conditions is m-TSH, which should be kept in mind even though it is rarely seen. m-TSH should be considered especially in patients who have a TSH value above 10 μIU/mL without hypothyroidism symptoms or who require a higher levothyroxine replacement dose than expected to make them euthyroid. [ABSTRACT FROM AUTHOR]

Introduction: Gestational diabetes is defined as various degrees of glucose intolerance diagnosed or detected for the first time during pregnancy and is the most common metabolic complication of pregnancy. Early diagnosis and adequate treatment are important to prevent complications. Preeclampsia, polyhydramnios, fetalmacrosomia, and operative delivery are some of the complications seen in pregnant women diagnosed with Gestational Diabetes Mellitus (GDM). Aim: The present study was designed to determine whether there was an association between Mean Platelet Volume (MPV) in predicting poor fetal outcome, insulin resistance, neonatal Apgar scores and gestational age for women with GDM. Materials and Methods: In this retrospective study, we enrolled 101 pregnant women with GDM together with a group of 138 healthy controls. MPV, insulin and homeostatic model assessment (HOMA-IR) values were measured at 24-28 weeks of the pregnancy. An independent samples t-test was used to compare MPV values. Multivariate linear regression models were used to establish relations between MPV values, HOMAIR, insulin levels and Apgar score. Results: There was a significant positive correlation between MPV values, HOMA-IR and Insulin levels and a negative correlation with Apgar score at 1 min and 5 min in the GDM group (r=0.227, p=0.02; r=0.206, p=0.03; r=-0.485, p<0.001; and r=-0.399, p<0.001, respectively). In the multivariate logistic regression analysis, a high MPV value was most consistently associated with a low Apgar 1 min score (β=-0.387, p=0.003) in the GDM group. An MPV of >8.0 fL had a sensitivity of 82% and a specificity of 75% for the prediction of GDM. Conclusion: We investigated the potential of MPV values in predicting low Apgar scores and insulin resistance in women with GDM. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine whether or not Helicobacter pylori (H. pylori) infection affects the hypothalamic-pituitary-adrenal (HPA) axis and to evaluate the association between vitamin D levels with H. pylori infected and eradicated patients. The glucagon stimulation test (GST) was used to assess the HPA gland axis. An H. pylori infection was diagnosed based on the rapid urease test and histology. All infected patients received triple eradication therapy. Three months after the treatment, 14C urea breath test was reinstituted, and GST was repeated in patients who were negative for H. pylori. Of the 43 patients, 20 (46%) were found to have a lower mean value of peak cortisol than normal responses to the GST in the H. pylori-infected subjects. In 29 subjects, H. pylori infection was successfully eradicated. Twelve (41%) out of 29 subjects were defined as having a blunted GST response and 17 (%59) subjects had normal HPA axis response to GST in the H. pylori-eradicated subjects. A significant correlation between low 25-hydroxyvitamin D3 (25(OH)D3) level and low peak cortisol response to GST was identified in the H. pylori-infected subjects. After H. pylori eradication, the positive correlation between 25(OH)D3 level and high peak cortisol response to GST was also identified. Mean 25(OH)D3 levels were lower in the H. pylori-infected subjects than in the H. pylori-eradicated subjects. Our results indicate an increased prevalence of blunted glucocorticoid response to GST in patients with infected H. pylori. Vitamin D deficiency is also common in the H. pylori-infected subjects and associated with blunted glucocorticoid response. These findings suggest that H. pylori eradication increases the cortisol response to GST. Vitamin D supports adrenal/cortisol production whereby a deficiency can result blunted glucocorticoid response to GST in patients with infected H. pylori. [ABSTRACT FROM AUTHOR]

Objectives: A few studies have investigated the relationship between mean platelet volume (MPV) and gestational diabetes mellitus (GDM), and in these studies the relationship between MPV and insulin resistance has not been analyzed. Our aim in this study was to compare MPV values of the pregnant women with or without GDM and evaluate the relationship between MPV and homeostasis model assessment insulin resistance index (HOMA-IR) in pregnant women. Materials and Methods: One hundred and fourteen with GDM measurements being obtained before any dietary advice or therapy with insulin or hypoglycemic agents were given, and 76 with healthy pregnant women were included the study. Results: In the group with GDM, MPV value was found to be significantly higher than that of the control group (10.2 fl [8.0-12.2] vs. 9.9 fl [5.81-10.9], P = 0.004). HOMA-IR value was detected to be significantly higher in the group with GDM (2.46 [1.5-5.88] vs. 1.30 [0.17-2.92], P < 0.001). A positive correlation between MPV and HOMA-IR was found (r = 0.30, P = 0.002). Conclusion: We have shown that MPV was significantly elevated in GDM patients when compared to healthy pregnant women. Furthermore, we found that there was a positive correlation between MPV and HOMA-IR. [ABSTRACT FROM AUTHOR]

Objective. Diabetes mellitus (DM) is associated with low-grade inflammation. The benefits of regular exercise for the DM are well established, whereas less is known about the impact of aerobic exercise on malondialdehyde (MDA) and tumor necrosis factor-alpha (TNF-α) in the DM. Methods. We randomised 64 participants, who do not exercise regularly, without any diabetic chronic complications in parallel to 12 weeks of aerobic exercise (three times per week, n = 31) and no exercise (control; n = 33). Plasma levels of soluble TNF-α and MDA levels were measured before-after physical training programme and control group. Results. Sixty-four patients with type 2 diabetes mellitus were analysed. When comparing the two groups of patients with age, gender, hemoglobin A1c (HbA1c) levels, lipid profile, waist circumference, body mass index (BMI) and class of treatment for diabetes were not different between groups. While soluble TNF-α remained essentially unaffected by physical training, plasma concentrations of MDA markedly decreased {P < 0.05); physical training also decreased body weight, waist circumference, and blood pressure (P < 0.05). Conclusion. Exercise training favorably affected body weight, waist circumference, and blood pressure. A three-weekly, 12-week, aerobic-training programme, without a concomitant weight loss diet, was associated with significant decrease in MDA levels in type 2 diabetic individuals. [ABSTRACT FROM AUTHOR]

Hypersecretion of PTHrP is a relatively common cause of malignancy-related hypercalcemia. However, there is only one case report of letrozole induced hypercalcemia. A 52-year-old female patient was referred to our clinic because of the recent discovery of hypercalcemia (11.0 mg/dL). The patient had a history of left breast carcinoma. She had started a course of letrozole (aromatase inhibitor; 2.5 mg dose/day) ten months earlier. Patient's parathyroid hormone-related protein levels were normal and a bone scintigram revealed no evidence of skeletal metastasis. Other potential causes of high calcium levels were ruled out. We recognized that, when letrozole was taken at one dose daily (2.5 mg), she had recurrent hypercalcemia. Our experience suggests that letrozole may precipitate hypercalcemia in a patient with breast cancer. [ABSTRACT FROM AUTHOR]

A 71-year-old female patient followed primary immune thrombocytopenia (ITP) was admitted to endocrinology unit with excessive sweating. We started methimazole for Graves' disease. Without any additional immunosuppressive treatment, at week 12 of methimazole therapy, thyroid stimulating hormone (TSH) levels returned to normal, and platelet counts rose to tolerable levels. When her hospital records were analyzed, they revealed that a year ago, when she had been diagnosed with ITP, her TSH values had been suppressed. After immunosuppressive therapy, her platelet values were maintained at normal levels, and during her control visits, her TSH levels were measured twice and were within normal limits. We think that immunosuppressive therapy for ITP without considering thyroid function tests may result in a transient euthyroid state, which potentially masks Graves' disease accompanying immunosuppressive therapy and associated recurrent ITP attacks. [ABSTRACT FROM AUTHOR]