Metabolic and cardiovascular features of the course of type 2 diabetes mellitus in men with hypogonadism

Introduction. Androgenic deficiency is an important pathogenetic element in the development of metabolic syndrome and cardiovascular diseases in men. It has been proven that in male patients with type 2 diabetes, hypogonadism develops much more often. Objective – to study the metabolic and cardiovascular features of the course of type 2 diabetes mellitus (T2DM) in men with androgen deficiency.Materials and methods. The study included 124 men with type 2 diabetes. To diagnose hypogonadism, the levels of total testosterone (T), sex hormone binding globulin (SHBG), albumin and luteinizing hormone (LH) were measured. Free testosterone (free T) levels were calculated using a calculator from Ghent University Hospital, Belgium. A retrospective analysis of case histories was carried out (spectrum of late complications, the presence of heart attacks and strokes, laboratory data – total cholesterol (CS), triglycerides (TG), fasting blood plasma glucose, basal insulin level, glycated hemoglobin (HbA1c)). The HOMA-IR index was used to determine the degree of insulin resistance.Results. The average age of men was 57.39 ± 9.41 years. The incidence of laboratory-confirmed hypogonadism is 50.81%. An average positive correlation was found between androgen deficiency and the incidence of non-fatal cardiovascular events (r = 0.45, p < 0.05). There was no statistically significant relationship between the presence of hypogonadism and the incidence and degree of late complications of T2DM. Patients with low T levels tended to have higher HOMA-IR values compared to patients with normal T levels (p < 0.05). At the same time, the indicators of carbohydrate and lipid metabolism did not differ significantly in these groups (p > 0.05).Conclusions. The revealed incidence of hypogonadism in men with T2DM corresponds to the data of international studies. The presence of a significant correlation between low testosterone levels and cardiovascular events in patients with T2DM suggests that hypogonadism can be used as an additional criterion for cardiovascular risk. Testosterone deficiency exacerbates insulin resistance, which can lead to weight gain and impair carbohydrate metabolism

Surface properties of AlInGaN/GaN heterostructure

Surface structural, electronic and electrical properties of the quaternary alloy AlInGaN/GaN heterostructures are investigated. Surface termination, atomic arrangement, electronic and electrical properties of the (0001) surface and (10-11) V-defect facets have been experimentally analyzed using various surface sensitive techniques including spectroscopy and microscopy. Moreover, the effect of sub-band gap (of the barrier layer) illumination on contact potential difference (VCPD) and the role of oxygen chemisorption have been studied

Multicharacterization approach for studying InAl(Ga)N/Al(Ga)N/GaN heterostructures for high electron mobility transistors

We report on our multi–pronged approach to understand the structural and electrical properties of an InAl(Ga)N(33nm barrier)/Al(Ga)N(1nm interlayer)/GaN(3μm)/AlN(100nm)/Al2O3 high electron mobility transistor (HEMT) heterostructure grown by metal organic vapor phase epitaxy (MOVPE). In particular we reveal and discuss the role of unintentional Ga incorporation in the barrier and also in the interlayer. The observation of unintentional Ga incorporation by using energy dispersive X–ray spectroscopy analysis in a scanning transmission electron microscope is supported with results obtained for samples with a range of AlN interlayer thicknesses grown under both the showerhead as well as the horizontal type MOVPE reactors. Poisson–Schrödinger simulations show that for high Ga incorporation in the Al(Ga)N interlayer, an additional triangular well with very small depth may be exhibited in parallel to the main 2–DEG channel. The presence of this additional channel may cause parasitic conduction and severe issues in device characteristics and processing. Producing a HEMT structure with InAlGaN as the barrier and AlGaN as the interlayer with appropriate alloy composition may be a possible route to optimization, as it might be difficult to avoid Ga incorporation while continuously depositing the layers using the MOVPE growth method. Our present work shows the necessity of a multicharacterization approach to correlate structural and electrical properties to understand device structures and their performance

Influence of androgen deprivation therapy on glucose metabolism and ambulatory glucose profile

Introduction. Androgen deprivation, used to treat prostate cancer, leads to metabolic disorders, including glucose metabolism disorders. The timing of development and the characteristics of these changes have not been sufficiently studied. The expansion of the possibilities for assessing glycemia makes it possible to obtain changes in glucose.Objective. To study the dynamics of the effect of long-term androgen-deprivation therapy with gonadotropin-releasing hormone agonists (GnRH agonists) on the parameters of glucose metabolism and ambulatory glucose profile in patients with locally advanced prostate cancer (La PCa).Materials and methods. The study included 99 patients with La PCa receiving androgendeprivation therapy (ADT) with (GnRH agonists) for at least 12 months. The study of fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) levels was performed at baseline, after 3, 6 and 12 months of ADT, and constant self-monitoring of glycemia was recommended using portable glucometers. Flash glucose monitoring systems (FreeStyle Libre) were installed in ten patients with a detected increase in glycemia on the background of ADT, allowing them to obtain data on the ambulatory glucose profile (AGP).Results and discussion. Long-term ADT in patients with La PCa, regardless of baseline age, BMI, WC, was accompanied by an early, progressive deterioration in parameters of glucose metabolism. The proportion of patients with prediabetic FPG values after 12 months becames 66% according ADA criteria. We found that 12-month ADT changes the AGP: an increase area under the curve and postprandial glycemic levels, an increase in blood glucose variability with an increase in the CONGA index to 6.817 (p < 0.001).Conclusion. ADT by GnRH agonists in patients with La PCa is accompanied by a predisposition to early disorders of glucose metabolism with a high risk of rapid development of prediabetes regardless of baseline age, BMI, and WC. The AGP of patients is characterized by an increase in the total glycemic load, and glycemic variability