The relationship between vitamin D and adolescents' parathyroid hormone and bone mineral density

Introduction

To detect the relationship between 25-hydroxy vitamin D (25(OH)D) and adolescents' parathyroid hormone (PTH) and bone mineral density (BMD).

Material and methods

Two hundred adolescent girls were recruited for this cross-sectional comparative study. After detailed evaluation, a pelvic sonography was performed for the studied adolescents to rule out any pelvic pathology. Adolescents' blood samples were collected to measure the thyroid stimulating hormone, prolactin, glycosylated haemoglobin (HbA1C), PTH, and 25(OH)D. The studied adolescents' BMD and the T-score were evaluated at 2 anatomical sites. The studied adolescents were classified according to their serum 25(OH)D into 2 groups: a 25(OH)D-deficient group (study group; 25(OH)D < 20 ng/ml) and normal controls (25(OH)D > 30 ng/ml). Student's t-test was used for analysis of the studied adolescents' variables, and correlation analysis (Pearson`s correlation) was used to detect the relationship between 25(OH)D and adolescents' PTH and BMD.

Results

The parathyroid hormone was statistically higher in the 25(OH)D-deficient group than in the normal controls (41.3 ±3.4 pg/ml vs. 21.1 ±2.8) (p = 0.02), and the BMD was statistically lower in the 25(OH)D-deficient group than in the normal controls (-1.25 ±0.5 vs. 0.3 ±0.4) (p = 0.01). The 25(OH)D had a significant negative correlation with the adolescents' PTH (r = -0.9175; p < 0.00001) and a significant positive correlation with the adolescents' BMD (r = 0.756; p < 0.00001). The parathyroid hormone had a significant negative correlation with the adolescents' BMD (r = -0.7006; p < 0.00001).

Conclusions

The parathyroid hormone in this study had significant negative correlations with both 25(OH)D and BMD. The 25(OH)D had a significant positive correlation with the studied adolescents' BMD.

Genetic regulation of testosterone level in overweight males from the Kazakh population and its association with hypogonadism

Male hypogonadism and erectile dysfunction in different populations are associated with excess body weight. A key aspect in most studies is the metabolism of sexual hormones, primarily testosterone. At the same time, the binding protein sex hormone binding globulin (SHBG) can play a large role, as it determines the ratio of total and bioavailable testosterone in blood, i.e. both the hormone content and level of its production. Recent research has identified common mutations that affect SHBG levels, such as the rs727428 polymorphic locus, which is associated with alterations in histone protein function, affecting the regulation of ribonucleic acid (RNA) protein SHBG synthesis. Similar relationships have been observed for prevalent mutations, including rs5934505 and rs10822184, in diverse populations. This study involved 300 individuals of Kazakh nationality from the Eastern Kazakhstan region, examining three polymorphic variants of the SHBG gene (rs727428, rs5934505, and rs10822184). The participants were categorized into three groups: individuals with hypogonadism and obesity (group 1, n=85), those with excess body weight but no hypogonadism (group 2, n=70), and individuals with neither excess body weight nor hypogonadism (group 3, n=145). The frequency of mutant gene alleles impacting GPS (SHBG) synthesis in the Kazakh population was notably high, comparable to European and South-East Asian populations. However, the association between excess body weight and these mutations exhibited varying patterns. Hypogonadism was linked to decreased GPS levels, strongly correlating with total testosterone but not bioavailable testosterone. The retention of sexual functions in overweight men was not always directly related to BMI levels and GPS concentrations.

Correction to: The levels of oxidative stress in a combination of stress factors

This corrects the article on p. 927 in vol. 15, PMID: 36188645.

The levels of oxidative stress in a combination of stress factors

We studied the effect of the combined action of ionizing radiation and induced immobilization stress on the lipid peroxidation process and antioxidant protection of organs (mesenteric lymph nodes, spleen, adrenal glands, thymus, and liver) and immune cels - the blood lymphocytes. Results were obtained on the role of free-radical oxidation in combination with exposure to ionizing radiation and immobilization stress at an early stage in the experiment. Gamma radiation in the acute period resulted in significant changes in lipoperoxidation and antioxidant systems. The first period of immobilization stress was marked by the imbalance of LPO-AOS systems disturbance with an accumulation of toxic compounds in tissues which had affected their function. The combined sublethal gamma radiation and immobilization stress disturbed the functional activity of adaptive systems of the body in the early stage of adaptation syndrome. Furthermore, the results show the dominant role of ionizing radiation in it.

Effect of SHBG Polymorphism on the Levels of Bioavailable Testosterone and Lipid Metabolism in Older Men of the Kazakh Population

This study is aimed at investigating the effect of SHBG (rs727428; rs10822184) and LPL (rs754493647) single nucleotide polymorphisms on the concentration of the bioavailable fraction of testosterone in older men. Materials and methods To study gene mutations, 417 residents of the East Kazakhstan region of Kazakh nationality were examined. The main group included 135 men with signs of hypogonadism (AMS 37-49), and the control group consisted of 282 healthy men (AMS 17-26) of the corresponding age (p = 0.5). Single nucleotide polymorphisms rs 727428 [C / T]; rs10822184 [T / C]; rs754493647 [T / C], was determined by the TaqMan method. Results Analysis of the rs727428 polymorphism has revealed that the TT allele (rs727428) has a lower level of albumin (p = 0.03), bioavailable testosterone (p = 0.04), and free testosterone (p = 0.6) than in carriers of the CC and CT genotypes. Also, it has shown a decrease in total testosterone (p = 0.001) and an increase in SHBG levels (p = 0.07) in men with the TT genotype of the rs727428 gene polymorphism. The rs10822184 polymorphism demonstrated an increase in triglyceride and LDL levels in TT genotype (p ≤ 0.04), in comparison with CC and CT genotypes. Conclusion It has been proven that rs727428 (p = 0.001) is associated with testosterone levels and therefore can determine the concentration of bioavailable testosterone. Decreased levels of bioavailable testosterone are a sign of male hypogonadism. This study confirms the effect of rs10822184 on LDL (p = 0.01) and triglyceride (p = 0.04) levels, but its association with androgen levels has not been proven. Our results may be of interest for understanding the etiology of early development of hypogonadism and lipid metabolism disorders in men. To confirm the conclusions, a more detailed study with a large sample of men from the Kazakh population may be required.