Cardiovascular Complications in Patients with Klinefelter's Syndrome

Testosterone replacement therapy and vascular thromboembolic events: a systematic review and meta-analysis

To evaluate the relationship between testosterone replacement therapy (TRT) and arterial and/or venous thrombosis in patients with pre-treatment total testosterone (TT) <12 nmol l -1 , we performed a meta-analysis following the Population Intervention Comparison Outcome model. Population: men with TT <12 nmol l -1 or clear mention of hypogonadism in the inclusion criteria of patients; intervention: TRT; comparison: placebo or no therapy; outcomes: arterial thrombotic events (stroke, myocardial infarction [MI], upper limbs, and lower limbs), VTE (deep vein thrombosis [DVT], portal vein thrombosis, splenic thrombosis, and pulmonary embolism), and mortality. A total of 2423 abstracts were assessed for eligibility. Twenty-four studies, including 14 randomized controlled trials (RCTs), were finally included, with a total of 4027 and 310 288 hypotestosteronemic male patients, from RCTs and from observational studies, respectively. Based on RCT-derived data, TRT did not influence the risk of arterial thrombosis (odds ratio [OR] = 1.27, 95% confidence interval [CI]: 0.47-3.43, P = 0.64), stroke (OR = 1.34, 95% CI: 0.09-18.97, P = 0.83), MI (OR = 0.51, 95% CI: 0.11-2.31, P = 0.39), VTE (OR = 1.42, 95% CI: 0.22-9.03, P = 0.71), pulmonary embolism (OR = 1.38, 95% CI: 0.27-7.04, P = 0.70), and mortality (OR = 0.70, 95% CI: 0.20-2.38, P = 0.56). Meanwhile, when only observational studies are considered, a significant reduction in the risk of developing arterial thrombotic events, MI, venous thromboembolism, and mortality was observed. The risk for DVT remains uncertain, due to the paucity of RCT-based data. TRT in men with TT <12 nmol l -1 is safe from the risk of adverse cardiovascular events. Further studies specifically assessing the risk of DVT in men on TRT are needed.

Serum Lipocalin-2 Levels as a Biomarker in Pre- and Post-Pubertal Klinefelter Syndrome Patients: A Pilot Study

Klinefelter syndrome (KS) is a male genetic disease caused by the presence of an extra X chromosome, causing endocrine disorders mainly responsible for a high rate of infertility and metabolic disorders in adulthood. Scientific research is interested in identifying new biomarkers that can be predictive or prognostic of alterations strictly connected to KS. Lipocalin-2 (LCN-2, also known as NGAL) is a small protein initially identified within neutrophils as a protein related to innate immunity. Serum LCN-2 estimation seems to be a useful tool in predicting the metabolic complications caused by several pathological conditions. However, little is known about its potential role in infertility conditions. The present pilot study aims to investigate the presence of LCN-2 in the serum of a group of pre-pubertal and post-pubertal children affected by KS, compared to healthy controls. We demonstrated for the first time the presence of elevated levels of LCN-2 in the serum of KS patients, compared to controls. This increase was accompanied, in pre-pubertal KS patients, by the loss of correlation with LH and HDL, which instead was present in the healthy individuals. Moreover, in all KS individuals, a positive correlation between LCN-2 and inhibin B serum concentration was found. Despite the limited size of the sample analyzed, our preliminary data encourage further studies to confirm the findings and to extend the study to KS adult patients, to verify the predictive/prognostic value of LCN-2 as new biomarker for metabolic diseases and infertility associated with the pathology.

Altered Thyroid Feedback Loop in Klinefelter Syndrome: From Infancy Through the Transition to Adulthood

CONTEXT

It has been claimed that thyroid dysfunction contributes to the spectrum of Klinefelter syndrome (KS); however, studies are scarce.

OBJECTIVE

In a retrospective longitudinal study, we aimed at describing the hypothalamic-pituitary-thyroid (HPT) axis and thyroid ultrasonographic (US) appearance in patients with KS throughout the life span.

METHODS

A total of 254 patients with KS (25.9 ± 16.1 years) were classified according to their pubertal and gonadal status and compared with different groups of non-KS age-matched individuals with normal thyroid function, treated and untreated hypogonadism, or chronic lymphocytic thyroiditis. We assessed serum thyroid hormone levels, antithyroid antibodies, US thyroid parameters, and in vitro pituitary type 2 deiodinase (D2) expression and activity.

RESULTS

Thyroid autoimmunity was more prevalent among individuals with KS at all ages, although the antibody (Ab)-negative vs Ab-positive cohorts were not different. Signs of thyroid dysfunction (reduced volume, lower echogenicity, and increased inhomogeneity) were more prominent in KS than in euthyroid controls. Free thyroid hormones were lower in prepubertal, pubertal, and adult patients with KS, whereas thyrotropin values were lower only in adults. Peripheral sensitivity to thyroid hormones was unaltered in KS, suggesting a dysfunctional HPT axis. Testosterone (T) was the only factor associated with thyroid function and appearance. In vitro testing demonstrated an inhibitory effect of T on pituitary D2 expression and activity, supporting enhanced central sensing of circulating thyroid hormones in hypogonadism.

CONCLUSION

From infancy through adulthood, KS is characterized by increased morphofunctional abnormalities of the thyroid gland, combined with a central feedback dysregulation sustained by the effect of hypogonadism on D2 deiodinase.

Testosterone deficiency and metabolic disturbances in men who fathered a child by use of donated spermatozoa

Dose–response association between level of impairment of semen quality and risk of morbidity or premature death has been reported. Therefore, it can be presumed that men utilizing donated spermatozoa, i.e. patients with non-obstructive azoospermia, are at highest risk for adverse health outcomes. To evaluate the risks of prescription of medications for common metabolic disturbances and testosterone replacement therapy (TRT) among men who father children with donated spermatozoa—who presumably do it due to severe impairment of fertility. We used Swedish nationwide register data on all fathers who had a live-born child between 2007 and 2014 in order to compare men who fathered children with donated spermatozoa to the ones who became fathers by using own gametes. Cox regression analysis was used in order to estimate the post-conception incidence of prescription of medicines for hypertension (HT), diabetes (type 1 and 2), dyslipidaemia (DLE) or TRT. Starting the follow up at time of conception, models were adjusted for age, educational level, and previous cancer treatment. In total 410,119 childbirths were included in the analysis. Among them, for 390 fathers donated spermatozoa were utilized. Fathers to children conceived with donated spermatozoa had higher risk for having TRT prescribed (HR: 18.14; 95%CI: 11.71–28.10; p ≪ 0.001). Same was true for DLE (HR: 2.08; 95%CI: 1.27–3.39; p = 0.003) but not diabetes. Fathers to children conceived by use of donated spermatozoa are at significantly increased risk for testosterone treatment and dyslipidaemia, necessitating stringent follow up and inclusion in prevention programs.

Illuminating the Mechanisms Underlying Sex Differences in Cardiovascular Disease

Sex is a key risk factor for many types of cardiovascular disease. It is imperative to understand the mechanisms underlying sex differences to devise optimal preventive and therapeutic approaches for all individuals. Both biological sex (determined by sex chromosomes and gonadal hormones) and gender (social and cultural behaviors associated with femininity or masculinity) influence differences between men and women in disease susceptibility and pathology. Here, we focus on the application of experimental mouse models that elucidate the influence of 2 components of biological sex-sex chromosome complement (XX or XY) and gonad type (ovaries or testes). These models have revealed that in addition to well-known effects of gonadal hormones, sex chromosome complement influences cardiovascular risk factors, such as plasma cholesterol levels and adiposity, as well as the development of atherosclerosis and pulmonary hypertension. One mechanism by which sex chromosome dosage influences cardiometabolic traits is through sex-biased expression of X chromosome genes that escape X inactivation. These include chromatin-modifying enzymes that regulate gene expression throughout the genome. The identification of factors that determine sex-biased gene expression and cardiometabolic traits will expand our mechanistic understanding of cardiovascular disease processes and provide insight into sex differences that remain throughout the lifespan as gonadal hormone levels alter with age.

Metabolic and Nutritional Aspects in Paediatric Patients with Klinefelter Syndrome: A Narrative Review

Klinefelter syndrome is the most common sex chromosomal aneuploidy in males. It is well known that patients with this syndrome have greater mortality and morbidity compared to the general population due to cardiovascular diseases and endocrine metabolism disorders. This augmented risk is due both to hypogonadism and to the syndrome itself. Therefore, correct hormonal replacement therapy and early primary prevention are crucial to these patients. Even though different studies are available on this topic in adult patients, only a few authors have focused on the paediatric population. Thus, in this narrative review, we report the current knowledge of metabolic and nutritional aspects in children with Klinefelter syndrome.

Pediatrics for Disability: A Comprehensive Approach to Children with Syndromic Psychomotor Delay

Intellectual disability is the impairment of cognitive, linguistic, motor and social skills that occurs in the pediatric age and is also described by the term "mental retardation". Intellectual disability occurs in 3-28 % of the general population due to a genetic cause, including chromosome aberrations. Among people with intellectual disabilities, the cause of the disability was identified as a single gene disorder in up to 12 %, multifactorial disorders in up to 4 %, and genetic disorders in up to 8.5 %. Children affected by a malformation syndrome associated with mental retardation or intellectual disability represent a care challenge for the pediatrician. A multidisciplinary team is essential to manage the patient, thereby controlling the complications of the syndrome and promoting the correct psychophysical development. This requires continuous follow-up of these children by the pediatrician, which is essential for both the clinical management of the syndrome and facilitating the social integration of these children.