Prevalence and predictors of gestational diabetes mellitus: a nationwide multicentre prospective study.

AIM: Prevalence rates of gestational diabetes mellitus (GDM) show considerable variation among different countries and regions of the world. The primary aim of this study was to determine the nationwide prevalence and predictors of GDM in Turkey. METHODS: We conducted prospective nationwide screening among pregnant women. Between August 2016 and November 2017, a total of 2643 pregnant women from 51 centres in 12 different regions were enrolled. A two-step screening method and Carpenter and Coustan criteria were used in the diagnosis of GDM. Clinical and biochemical data were obtained using electronic database software. RESULTS: The national prevalence of GDM was found to be 16.2% [95% confidence intervals (CI) 15.0% to 17.4%] without a significant difference between urban and rural regions. Women with GDM were older (mean age: 32 ± 5 vs. 28 ± 5 years, P < 0.001) and heavier (mean BMI: 27.2 ± 5.1 vs. 24.7 ± 4.7 kg/m2 , P < 0.001) than their counterparts without GDM. The prevalence of GDM tended to increase with age (< 25 years, 6.9%; 26-35 years, 15.6%; and 36-45 years, 32.7%; P < 0.001). Maternal age, maternal BMI, history of previous GDM and family history of diabetes mellitus were independent predictors of developing GDM (P < 0.05 for all). Low-risk women (age < 25 years, BMI < 25 kg/m2 , no family history of diabetes) comprised 10.7% of the total population and the prevalence of GDM in these women was 4.5% (95% CI 2.4% to 7.8%). CONCLUSION: The results of this nationwide study indicate that GDM is very common, affecting one in seven pregnancies in Turkey. Implementation of international guidelines on screening and management of this public health problem is required.

Sucralose enhances GLP-1 release and lowers blood glucose in the presence of carbohydrate in healthy subjects but not in patients with type 2 diabetes.

BACKGROUND/OBJECTIVE: Artificial sweeteners were thought to be metabolically inactive, but after demonstrating that the gustatory mechanism was also localized in the small intestine, suspicions about the metabolic effects of artificial sweeteners have emerged. The objective of this study was to determine the effect of artificial sweeteners (aspartame and sucralose) on blood glucose, insulin, c-peptide and glucagon-like peptide-1 (GLP-1) levels. SUBJECTS/METHODS: Eight newly diagnosed drug-naive type 2 diabetic patients (mean age 51.5±9.2 years; F/M: 4/4) and eight healthy subjects (mean age 45.0±4.1 years; F/M: 4/4) underwent 75 g oral glucose tolerance test (OGTT). During OGTT, glucose, insulin, c-peptide and GLP-1 were measured at 15- min intervals for 120 min. The OGTTs were performed at three settings on different days, where subjects were given 72 mg of aspartame and 24 mg of sucralose in 200 ml of water or 200 ml of water alone 15 min before OGTT in a single-blinded randomized order. RESULTS: In healthy subjects, the total area under the curve (AUC) of glucose was statistically significantly lower in the sucralose setting than in the water setting (P=0.002). There was no difference between the aspartame setting and the water setting (P=0.53). Total AUC of insulin and c-peptide was similar in aspartame, sucralose and water settings. Total AUC of GLP-1 was significantly higher in the sucralose setting than in the water setting (P=0.04). Total AUC values of glucose, insulin, c-peptide and GLP-1 were not statistically different in three settings in type 2 diabetic patients. CONCLUSIONS: Sucralose enhances GLP-1 release and lowers blood glucose in the presence of carbohydrate in healthy subjects but not in newly diagnosed type 2 diabetic patients.

Vitamin D receptor gene ApaI, TaqI, FokI and BsmI polymorphisms in a group of Turkish patients with Hashimoto's thyroiditis.

AIM: Previous studies have suggested an influence of vitamin D receptor polymorphisms on the development of autoimmune thyroid disease in different ethnic populations. We aimed to investigate the distribution of vitamin D receptor (VDR) alleles in a group of Turkish patients with Hashimoto's thyroiditis (HT). METHODS: One hundred and eleven patients (male/female: 5/106, 47.9±12.8 years) and 159 healthy controls (male/female: 21/138, 30.5±6.3 yrs) were included in the study. VDR gene FokI, BsmI, ApaI TaqI polymorphisms were examined using a polymerase chain reaction (PCR) -based restriction analysis. Serum levels of (thyroid-stimulating hormone) TSH, anti-thyroid peroxidase and anti-thyroglobulin levels were determined. RESULTS: The VDR TaqI "TT" (59.5% in patients vs. 27.6% in controls; 95% confidence interval [CI]: 0.14-0.46) and FokI 'FF' genotypes (67.6% in patients vs. 44.6% in controls; 95% CI: 0.46-0.81) occurred more frequently in patients, while VDR "Tt" (56.6% in patients vs. 32.4% in controls 95% CI: 1.22-2.14) and "Ff" genotypes (25.2% in patients vs. 49.1% in controls 95% CI: 1.27-2.18) were more common in controls. There were no differences in the genotype frequencies of the ApaI and BsmI polymorphisms in cases and controls. The most common genotypes were "bbAaTTFF" in the thyroiditis group (12.6% patients vs. 5.6% in controls, P>0.05) and "BbAaTtFf" in the control group (6.3% patients vs. 22.2% in controls, P=0.002). CONCLUSION: VDR gene TaqI TT and FokI FF genotypes are associated with increased risk of HT disease in our group of Turkish patients. BbAaTtFf genotype seems to be protective for HT disease in our population.

Effect of oxidative stress on aorta and tibia osteoprotegerin gene expression in ovariectomized rats.

AIM: Atherosclerosis and osteoporosis share some common pathophysiological pathways. Increase in oxidative stress and activation of cytokines that increase osteoclastogenesis were reported in postmenopausal period. The aim of this study was to determine the link between these two states. METHODS: A total of 32 female adult Wistar albino rats were included in the study. Rats in control group were sham operated, vehicle group were ovariectomized and given 17.5%hydroxypropyl-ß-cyclodextrin. Rats in group III and IV were ovariectomized and given 17ß-estradiol or raloxifene for 12 weeks, respectively. Aorta and tibia bone samples were collected. Tissue oxidative stress was determined via measurement of malondialdehyde levels and osteoprotegerin gene expression with RT-PCR. RESULTS: Ovariectomy increased MDA levels both in bone and aorta compared to sham operated rats. Use of 17ß-estradiol or raloxifene did not create a significant difference compared to ovariectomized rats. Ovariectomy caused a significant decrease in OPG gene expression in the tibia and aorta compared to sham operated rats. Although 17ß-estradiol and raloxifene preserved gene expression in aorta they did not have any effect on bone tissue. OPG mRNA expression was negatively correlated with tissue MDA levels only in ovariectomized rats. CONCLUSION: This study confirms the increase in ovariectomy-induced oxidative stress and association of it to bone and vascular tissue OPG mRNA expression.

Temporal effects of low-dose ACE inhibition on endothelial function in Type 1 diabetic patients.

AIM: Increased asymmetrical dimethylarginine (ADMA) is known to disturb endothelial function. ACE inhibitors decrease plasma ADMA levels in diseases associated with endothelial dysfunction. The effects of ACE inhibition on endothelial function and plasma ADMA levels in Type 1 diabetic patients was evaluated in the study. METHODS: Thirty Type 1 diabetic patients [29+/-6 yr; females (F)/males (M): 18/12] and 29 controls (30+/-6 yr; F/M: 16/13) were recruited. Flow-mediated dilatation (FMD), plasma ADMAand thiobarbituric acid reactive substances (TBARs) were determined at baseline, on day 15 and 90 of 0.5 mg qd trandolapril therapy. RESULTS: Compared to controls, baseline FMD levels were lower (4.7+/-2.0% vs 11.2+/-3.9%) (p<0.001), plasma ADMA (271.1+/-48.1 nmol/l vs 237.5+/-25.1 nmol/l) (p<0.05) and TBARs levels [4517.1+/-2366.9 nmol/malondialdehyde (MDA) vs 1775.9+/-598.7 nmol/MDA] (p<0.001) were higher in diabetic patients. On day 90 of trandolapril treatment, FMD (8.6+/-4.1%) (p<0.01) increased, ADMA levels (229.6+/-42.9 nmol/l) (p<0.001) decreased and TBARs levels (1531.8+/-1036.0 nmol/MDA) (p<0.001) decreased significantly. FMD was negatively correlated with plasma ADMA (r=-0.228, p<0.01), and TBARs levels (r=-0.244, p=0.02), whereas ADMA and TBARs levels were correlated positively (r=0.399, p<0.0001). CONCLUSIONS: In conclusion, endothelial dysfunction is associated with elevated plasma ADMA levels in Type 1 diabetic patients. Low-dose ACE inhibition improves endothelial dysfunction and reduces ADMA levels. The antioxidant action of ACE inhibitors may play role in this process.

QT dispersion in type 2 diabetic patients with altered diurnal blood pressure rhythm.

BACKGROUND: QT dispersion (QTd) is a good prognostic marker in type 2 diabetic patients without previous cardiovascular disease. Diabetic patients with an attenuated decline in nocturnal blood pressure (non-dippers) have been shown to have increased risk of diabetic complications, vascular events and mortality. AIM: The aim of this study was to evaluate the relationship between diurnal blood pressure rhythm, QTd and microvascular complications in type 2 diabetic patients. METHODS: Cardiovascular autonomic function tests, 24-h ambulatory blood pressure monitoring and urinary albumin excretion measurements were performed in healthy controls (n = 25), normoalbuminuric (n = 34) and microalbuminuric (n = 23) type 2 diabetic patients. QTd was assessed manually from 12-lead surface electrocardiograms. RESULTS: Compared with the controls, both normoalbuminuric and microalbuminuric diabetic patients had increased QTd (59.11 +/- 15.86; 60.27 +/- 17.95 vs. 40.48 +/- 10.92, p < 0.001 and p < 0.001, respectively). Similarly, diabetic patients had increased QTd regardless of the presence of autonomic neuropathy. On the other hand, non-dipper diabetic patients had increased QTd compared with the controls and dipper diabetic patients (69.73 +/- 14.50 vs. 40.48 +/- 10.92; 47.84 +/- 9.62 ms, p < 0.001). There was a negative correlation between QTd and diurnal diastolic blood pressure change (r = -0.48, p < 0.0005). CONCLUSION: Patients with type 2 diabetes mellitus were found to have increased QT dispersion irrespective of the presence of diabetic autonomic neuropathy. However, QT dispersion in dipper diabetic patients was similar to the controls. This finding might point out that attenuated decline of nocturnal blood pressure could be a more sensitive marker for autonomic neuropathy.