Vitamin D Deficiency in Type 2 Diabetic Patients with Hypogonadism

Factors Defining the Association Between Vitamin D and Testosterone in Males With Type 2 Diabetes and Hypogonadism

OBJECTIVE

This study aimed to evaluate Serum 25-hydroxyvitamin D (25[OH]D) levels in diabetic men with and without hypogonadism and figured out the potential factors influencing the connection between vitamin D and testosterone.

METHODS

A total of 367 men with type 2 diabetes mellitus (T2DM) were investigated, including 254 men with normal gonadal function (Group 1) and 113 men with hypogonadism (Group 2). Men with hypogonadism were classified as either hypogonadotropic hypogonadism (Group 2a) or hypergonadotropic hypogonadism (Group 2b). Serum 25(OH)D levels were detected by liquid chromatography-tandem mass spectrometry in all cases. Morning total testosterone (TT), estradiol (E), dehydroepiandrosterone (DHEA), prolactin (PRL), sex hormone-binding globulin (SHBG), luteinizing hormone (LH), follicle-stimulating hormone (FSH), thyroid function, parathyroid and adrenal hormones, fasting blood glucose (FBG), fasting insulin (Fins) and hemoglobin A1c (HbA1c) were also assessed.

RESULTS

The prevalence of hypovitaminosis D in men with T2DM was up to 96.46%. Serum 25(OH)D levels were significantly lower in men with hypogonadism than those with eugonadism (16.65 ± 6.44 ng/mL vs. 18.17 ± 6.17 ng/mL, P=0.033). The lowest 25(OH)D level was observed in Group 2a (16.22 ± 6.52 ng/mL). After adjustment for the selected factors, serum 25(OH)D concentrations were shown to be positively correlated with TT concentrations (r=0.137, P=0.032). The relationship between 25(OH)D and testosterone was altered by age, duration of T2DM, body mass index, and HbA1c. Serum 25(OH)D level was positively associated with serum TT level in men with age <60 years (r=0.180, P=0.003), or with duration≥5 years (r=0.186, P=0.013), or with body mass index (BMI)≥28kg/m² (r=0.431, P=0.000), or with HbA1c≥9% (r=0.145, P=0.031).

CONCLUSIONS

These findings indicate that type 2 diabetes patients with hypogonadism have lower 25(OH)D levels than those without hypogonadism. There seems to be a positive association between the serum 25(OH)D and TT levels, which affected by age, duration, BMI, and HbA1c.

New insights into vitamin D regulation: is there a role for alkaline phosphatase?

PURPOSE

The diagnosis of vitamin D deficiency is based on the determination of total plasma 25-hydroxyvitamin D (25-OHD) concentrations, but the regulation of vitamin D 25-hydroxylation is not a major consideration and very little information is available on this activity. To check what factors could interfere with the activity of vitamin D-25-hydroxylase and thus alter the 25-OHD concentrations, we looked for potential correlations between 25-OHD and results of liver function tests in healthy adults.

METHODS

This single-centre study was retrospective and consisted of evaluating the correlations between 25-OHD and the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), and bone alkaline phosphatase (BALP) in 349 healthy subjects aged from 18 to 65 years. In particular, in Group 1 (n = 119), we looked for correlations between 25OHD and all liver function tests and in Group 2 (n = 230) the correlation between 25OHD and BALP.

RESULTS

In Group 1, we found no correlation between 25OHD and AST (r =  - 0.03; p = 0.8), ALT (r =  - 0.02; p = 0.91), GGT (r =  - 0.08; p = 0.68), direct bilirubin (r =  - 0.02; p = 0.89), indirect bilirubin (r =  - 0.24; p = 0.21), and total bilirubin (r =  - 0.24; p = 0.21) but one between 25OHD and ALP (r =  - 0.2; p = 0.007); in Group 2, we found a significant negative correlation between 25-OHD and BALP (r =  - 0.2; p = 0.0008).

CONCLUSIONS

The correlations that we found suggest that ALP and BALP might be involved in the regulation of vitamin D-25-hydroxylase activity, but further studies are mandatory to confirm our assumptions.

Uptake of Vitamins D2, D3, D4, D5, D6, and D7 Solubilized in Mixed Micelles by Human Intestinal Cells, Caco-2, an Enhancing Effect of Lysophosphatidylcholine on the Cellular Uptake, and Estimation of Vitamins D' Biological Activities

Vitamins D have various biological activities, as well as intestinal calcium absorption. There has been recent concern about insufficient vitamin D intake. In addition to vitamins D₂ and D₃, there are lesser-known vitamins D₄–D₇. We synthesized vitamins D₅–D₇, which are not commercially available, and then evaluated and compared the mixed micelles-solubilized vitamins D uptake by Caco-2 cells. Except for vitamin D₅, the uptake amounts of vitamins D₄–D₇ by differentiated Caco-2 cells were similar to those of vitamins D₂ and D₃. The facilitative diffusion rate in the ezetimibe inhibited pathway was approximately 20% for each vitamin D type, suggesting that they would pass through the pathway at a similar rate. Lysophosphatidylcholine enhanced each vitamin D uptake by approximately 2.5-fold. Lysophosphatidylcholine showed an enhancing effect on vitamin D uptake by reducing the intercellular barrier formation of Caco-2 cells by reducing cellular cholesterol, suggesting that increasing the uptakes of vitamins D and/or co-ingesting them with lysophosphatidylcholine, would improve vitamin D insufficiency. The various biological activities in the activated form of vitamins D₄–D₇ were estimated by Prediction of Activity Spectra for Substances (PASS) online simulation. These may have some biological activities, supporting the potential as nutritional components.

Seasonal fluctuation of erectile dysfunction: A cross-sectional study from a tertiary university hospital across 10 years

Erectile dysfunction (ED) shares several risk factors with diabetes mellitus (DM), hypertension (HT) and coronary vascular disease (CVD), which were well-associated with seasonal fluctuation with the highest peak in winter. In this study, we aimed to determine whether ED demonstrates seasonal fluctuations with the above-mentioned systemic diseases. Database from a tertiary university hospital between 2010 and 2020 was deciphered to retrieve patients diagnosed with ED. Patients with primary bladder tumour and post-procedural ED constituted the negative control groups from the same study period. International index of erectile function questionnaire (IIEF-15) was used to segregate included patients into mild/moderate and severe ED groups. The probability of detecting DM, HT and CVD in patients with severe ED was significantly higher than that of with mild/moderate ED (p < 0.05). More ED symptoms emerged and were diagnosed in the winter seasons even though no statistical significance was observed between patients with mild/moderate and severe ED (p = 0.946, Cramer's V coefficient = 0.19). The seasonal variation of patients with bladder tumour and post-procedural ED groups showed no significant difference (p > 0.05, both). ED admissions are associated with higher peaks in the winter seasons. This may help in daily clinical practice to warrant better clinical and epidemiological interpretation of ED.

Novel predictive risk factor of erectile dysfunction: Serum 25-hydroxy vitamin D

The present study aimed to investigate the association between the severity of erectile dysfunction (ED) and serum 25-hydroxy vitamin D. It also sought to determine the cut-off level of serum 25-hydroxy vitamin D for ED. This study included 130 men who had ED between 2018 and 2019. Patients were divided into three groups according to their scores on the international index of erectile function-5 (IIEF-5) Turkish validated short form questionnaire. The serum 25-hydroxy vitamin D results were compared between the groups. The mean age of the patients was 49.28 ± 13.62 years. Groups 1, 2 and 3 included 44 (33.8%) patients with severe ED, 56 (43.1%) patients with moderate ED and 30 (23.1%) patients with mild ED, respectively. Statistical significance was observed between the groups and serum 25-hydroxy vitamin D levels. A positive correlation was detected between the IIEF-5 scores, serum testosterone and serum 25-hydroxy vitamin D levels. A cut-off level for serum 25-hydroxy vitamin D was calculated as 27.32 ng/ml. During multivariate analysis, we found that serum 25-hydroxy vitamin D levels were independent prognostic risk factors for decreased IIEF-5 scores. Decreased serum 25-hydroxy vitamin D levels were associated with decreased IIEF-5 scores. Therefore, vitamin D replacement therapy may improve symptoms.

Is There an Association Between Vitamin D Deficiency and Erectile Dysfunction? A Systematic Review and Meta-Analysis

Erectile dysfunction (ED) is found very frequently in the male population, in particular in its arteriogenic form, which also represents an important predictor of cardiovascular diseases (CVDs). Some evidence suggests that vitamin D could play a role in cardiovascular risk prevention thanks to its ability to reduce endothelial damage, oxidative stress, the production of inflammatory cytokines, and dyslipidemia. Since ED and CVDs have pathogenic mechanisms in common, numerous studies have evaluated a possible association between vitamin D deficiency (blood concentrations of 25-hydroxyvitamin D < 20 ng/mL) and ED, but with conflicting results. This meta-analysis was therefore performed to clarify the discrepancy of the data so far published. To achieve this, articles have been searched extensively in the Pubmed, MEDLINE, Cochrane, Academic One Files, Google Scholar, and Scopus databases from the first day they were created until January 2020. The search strategy included pertinent Medical Subjects Headings (MeSH) terms. Of the 431 items retrieved, only eight observational studies were included, resulting in a total sample size of 4055 patients. It was found that 25-hydroxyvitaminD (25(OH)D) levels did not show any significant difference between patients with and without ED. However, when patients with vitamin D deficiency only were taken into account, the international index of erectile function (IIEF) score for erectile dysfunction was significantly worse than in controls. This association remained significant even when eugonadal-only patients were considered. Finally, we found that eugonadal patients with severe ED have lower 25(OH)D₃ levels than patients with mild ED. In conclusion, this meta-analysis suggests an association between vitamin D deficiency and the presence of severe forms of ED, independent of testicular function.

The effect of low vitamin D status on sexual functioning and depressive symptoms in apparently healthy men: a pilot study

Hypovitaminosis D is associated with sexual dysfunction in apparently healthy women and with erectile dysfunction in men with the presence of concomitant disorders. This study was aimed at investigating sexual functioning and depressive symptoms in young men with low vitamin D status. The study included 15 apparently healthy men (18-40 years old) with vitamin D deficiency (group A), 16 subjects with vitamin D insufficiency (group B), and 16 men with normal vitamin D status (group C). All participants of the study completed questionnaires investigating their sexual function (the International Index of Sexual Function-15-IIEF-15 for heterosexual men), as well as the presence and severity of depressive symptoms (Beck Depression Inventory-Second Edition-BDI-II). Compared with healthy men, subjects with vitamin D deficiency obtained lower scores for erectile function, orgasmic function, and sexual desire, while individuals with vitamin D insufficiency lower scores only for erectile function. Erectile dysfunction was more prominent in group A than group B. The total BDI-II score was higher in group A than in the other study groups. The results of the study suggest that low vitamin D status impairs male sexual functioning and severity of sexual dysfunction correlates with the degree of hypovitaminosis D.

Occurrence, patterns & predictors of hypogonadism in patients with HIV infection in India

Background & objectives:

Data on hypogonadism among human immunodeficiency virus (HIV)-infected Indians are not available. This study was aimed to evaluate the occurrence, pattern and predictors of hypogonadism in HIV-infected Indians.

Methods:

Consecutive stable HIV-infected patients, 18-70 yr age, without any severe comorbid state, having at least one year follow up data at the antiretroviral therapy clinic, underwent clinical assessment and hormone assays.

Results:

From initially screened 527 patients, 359 patients (225 males; 134 females), having disease duration of 61.44±39.42 months, 88.58 per cent on highly active antiretroviral therapy (HAART), 40.67 per cent having tuberculosis history and 89.69 per cent with vitamin D insufficiency were analyzed. Testosterone <300 ng/dl was documented in 39.11 per cent males. Primary, hypogonadotropic hypogonadism (HypoH) and compensated hypogonadism were observed in 7.56, 31.56 and 12.44 per cent males, respectively. Males with hypogonadism were significantly older (P=0.009), and had higher opportunistic infections (P<0.001) with longer disease duration (P=0.05). Menstrual abnormalities were observed in 40.3 per cent females, who were significantly older (P<0.001), had lower CD4 count (P=0.038) and higher tuberculosis history (P=0.005). Nearly 46.3, 16.2 and 13 per cent women with menstrual abnormalities were in peri-/post-menopausal state, premature ovarian insufficiency (POI) and HypoH, respectively. Age, CD4 count at diagnosis and 25(OH)D were best predictors of male hypogonadism. Age and CD4 count increment in first 6-12 months following HAART were the best predictors of POI.

Interpretation & conclusions:

Hypogonadism was observed to be a significant problem in HIV-infected men and women in India, affecting 39 and 29 per cent patients, respectively. HypoH was the most common form in males whereas ovarian failure being the most common cause in females.

Vitamin D and Male Sexual Function: A Transversal and Longitudinal Study

BACKGROUND

The effects of vitamin D on sexual function are very unclear. Therefore, we aimed at evaluating the possible association between vitamin D and sexual function and at assessing the influence of vitamin D administration on sexual function.

METHODS

We retrospectively studied 114 men by evaluating clinical, biochemical, and sexual parameters. A subsample (n = 41) was also studied longitudinally before and after vitamin D replacement therapy.

RESULTS

In the whole sample, after performing logistic regression models, higher levels of 25(OH) vitamin D were significantly associated with high values of total testosterone and of all the International Index of Erectile Function (IIEF) questionnaire parameters. On the other hand, higher levels of total testosterone were positively and significantly associated with high levels of erectile function and IIEF total score. After vitamin D replacement therapy, total and free testosterone increased and erectile function improved, whereas other sexual parameters did not change significantly. At logistic regression analysis, higher levels of vitamin D increase (Δ-) were significantly associated with high values of Δ-erectile function after adjustment for Δ-testosterone.

CONCLUSIONS

Vitamin D is important for the wellness of male sexual function, and vitamin D administration improves sexual function.

Strengths, weaknesses and future challenges of biosimilars' development. An opinion on how to improve the knowledge and use of biosimilars in clinical practice

Biosimilars started receiving the marketing authorization by European Medicine Agency since 2006. The development of biosimilars follows a well-defined step-wise approach, the so-called comparability exercise, which aims to compare non-clinical (mainly quality features and biological activity) and clinical (efficacy and safety profiles) features of new biosimilars with their respective reference products. Despite the undeniable advantages of such procedure, some concerns (such as the absence of switching studies or the evaluation of efficacy and safety in all therapeutic indications) still exist about its. In particular, the European regulatory framework on biosimilars approval does not include the conduction of switching studies demonstrating the interchangeability to be carried out before marketing authorization. This is one of the main aspects that negatively affects healthcare professionals' clinical decisions on switch. In order to achieve a better knowledge on safety and efficacy of biosimilar drugs, real world data should be collected and post-marketing efficacy and safety clinical studies (including those evaluating specific endpoints, therapeutic regimens and patients population), should be planned. also the conduction of well-designed switching studies is highly advisable, especially in the case of biosimilar drugs used in oncology settings. Lastly, considering the critical role of antidrug antibodies on efficacy/safety profile of biologic drugs, studies based on therapeutic drug monitoring would be useful in order to achieve treatment optimization. Implementing the above strategies could be helpful to fill the gap in knowledge observed in the present European biosimilar regulatory framework.

Vitamin D and diabetes mellitus: Causal or casual association?

The incidence of both type 2 and type 1 diabetes mellitus has been increasing worldwide. Vitamin D deficiency, or the awareness of its prevalence, has also been increasing. Vitamin D may have a role in the pathogenic mechanisms predisposing to type 2 diabetes by modulating insulin resistance and/or pancreatic β-cell function. Vitamin D status or elements involved in its activation or transport may also be involved in the development of type 1 diabetes mellitus through immunomodulatory role . Based on these observations a potential association between vitamin D and diabetes has been hypothesized. In this review we discuss up to date evidence linking vitamin D with the development of diabetes. Moreover, the role of vitamin D supplementation in the prevention of both types of diabetes is analysed together with its role in improving glycemic control in diabetic patients. We also address the potential role of vitamin D deficiency in the development of macro- and microvascular complications in diabetes. Finally, we provide recommendation for Vitamin D therapy in diabetes in view of current evidence and highlight areas for potential future research in this area.

Is there a role for vitamin D in human reproduction?

Vitamin D is a steroid hormone with canonical roles in calcium metabolism and bone modeling. However, in recent years there has been a growing body of literature presenting associations between vitamin D levels and a variety of disease processes, including metabolic disorders such as diabetes and prediabetes and autoimmune conditions such as thyroid disease. This review focuses on the potential role of vitamin D in both male and female reproductive function. The vitamin D receptor (VDR) is expressed throughout central and peripheral organs of reproduction. VDR is often co-localized with its metabolizing enzymes, suggesting the importance of tissue specific modulation of active vitamin D levels. Both animal and human studies in males links vitamin D deficiency with hypogonadism and decreased fertility. In females, there is evidence for its role in polycystic ovary syndrome (PCOS), endometriosis, leiomyomas, in-vitro fertilization, and pregnancy outcomes. Studies evaluating the effects of replacing vitamin D have shown variable results. There remains some concern that the effects of vitamin D on reproduction are not direct, but rather secondary to the accompanying hypocalcemia or estrogen dysregulation.

Vitamin D and chronic diseases: the current state of the art

The objective was to provide the current state of the art regarding the role of vitamin D in chronic diseases (osteoporosis, cancer, cardiovascular diseases, dementia, autism, type 1 and type 2 diabetes mellitus, male and female fertility). The document was drawn up by panelists that provided their contribution according to their own scientific expertise. Each scientific expert supplied a first draft manuscript on a specific aspect of the document's topic that was subjected to voting by all experts as "yes" (agreement with the content and/or wording) or "no" (disagreement). The adopted rule was that statements supported by ≥75 % of votes would be immediately accepted, while those with <25 % would be rejected outright. Others would be subjected to further discussion and subsequent voting, where ≥67 % support or, in an eventual third round, a majority of ≥50 % would be needed. This document finds that the current evidence support a role for vitamin D in bone health but not in other health conditions. However, subjects with vitamin D deficiency have been found to be at high risk of developing chronic diseases. Therefore, although at the present time there is not sufficient evidence to recommend vitamin D supplementation as treatment of chronic diseases, the treatment of vitamin D deficiency should be desiderable in order to reduce the risk of developing chronic diseases.

Serum vitamin D levels and hypogonadism in men

There is inconsistent evidence on a possible association of vitamin D and androgen levels in men. We therefore aim to investigate the association of 25-hydroxyvitamin D (25(OH)D) with androgen levels in a cohort of middle-aged men. This cross-sectional study included 225 men with a median (interquartile range) age of 35 (30-41) years. We measured 25(OH)D, total testosterone (TT) and SHBG concentrations. Hypogonadism was defined as TT <10.4 nmol/L. We found no significant correlation of 25(OH)D and androgen levels. Furthermore, androgen levels were not significantly different across 25(OH)D quintiles. The overall prevalence of hypogonadism was 21.5% and lowest in men within 25(OH)D quintile 4 (82-102 nmol/L). We found a significantly increased risk of hypogonadism in men within the highest 25(OH)D quintile (>102 nmol/L) compared to men in quintile 4 (reference) in crude (OR 5.10, 1.51-17.24, p = 0.009) as well as in multivariate adjusted analysis (OR 9.21, 2.27-37.35, p = 0.002). We found a trend towards increased risk of hypogonadism in men within the lowest 25(OH)D quintile (≤43.9 nmol/L). In conclusion, our data suggest that men with very high 25(OH)D levels (>102 nmol/L) might be at an increased risk of hypogonadism. Furthermore, we observed a trend towards increased risk of hypogonadism in men with very low vitamin D levels indicating a U-shaped association of vitamin D levels and hypogonadism. With respect to risk of male hypogonadism, our results suggest optimal serum 25(OH)D concentrations of 82-102 nmol/L.

Age-associated (cardio)metabolic diseases and cross-talk between adipose tissue and skeleton: endocrine aspects

Aged individuals continue to increase in number, and it is important to understand the pathophysiological mechanisms of age-related changes in order to develop interventions that could contribute to “successful aging”. Metabolic and hormonal factors, age-related changes in body composition, and a decline in physical activity are all involved in the tendency to lose muscle mass, to gain fat mass, and, also, to experience bone loss. Obesity, sarcopenia, and osteoporosis are important widespread health problems that lead to high prevalence of both mortality and morbidity. Indeed, during the last decades, obesity and osteoporosis have become a major health threat around the world. Aging increases the risk of developing obesity, sarcopenia, osteoporosis, and, also, cardiovascular diseases. A reduction of both bone and muscle mass with a corresponding increase of fat mass and inflammation and hormonal imbalance in the elderly lead to and may synergistically increase cardiovascular diseases. This review will focus on the relationship among these different medical situations, trying to clarify the cellular and molecular mechanisms.