Endocrines, Volume 6, Issue 4 (December 2025) – 6 articles

For many years, menopause-related bone loss has been attributed solely to declining estrogen levels. Recently it has been suggested that bone loss accelerates during perimenopause, often preceding declines in estradiol (E₂), proposing that follicle-stimulating hormone (FSH), the levels of which are high during late perimenopause, may play a role in skeletal deterioration independently of E₂. The aim of this narrative review was to present aspects of bone health throughout the menopause transition with a focus on the relationship between FSH and bone-related outcomes. Epidemiological studies evaluating bone mineral density (BMD) and bone turnover markers (BTMs) were analyzed. Higher FSH levels were associated with reduced BMD, particularly at the spine and hip, as well as enhanced bone remodeling activity. In several longitudinal studies, FSH was found to be a more reliable predictor of bone loss than estrogen. In conclusion, FSH may serve as an early marker of perimenopausal bone health deterioration by identifying women at risk for bone loss and allowing for more personalized prevention strategies; however, further research is needed before its clinical use. Full article

The ovarian corpus luteum has functional mechanisms for formation and regression in the reproductive endocrine system. The main functional events of the corpus luteum are angiogenesis and apoptosis mechanisms. The development of the corpus luteum involves homogeneous physiological mechanisms, including cellular functions and reproductive hormones. Angiogenesis is controlled by pro-angiogenic and anti-angiogenic factors. The microenvironment involves various signaling molecules and pathways that may play a potential role in angiogenic response during corpus luteum growth. In luteolysis, the corpus luteum undergoes degeneration, notably induced by reproductive hormones that promote programmed cell death in luteal cells through the apoptosis mechanism. In this sudy, we discuss the mechanisms and functional roles of angiogenesis and apoptosis in the endocrine microenvironment during corpus luteum formation and regression, based on the interrelationship of physiological events in the ovary. Full article

Background/Objectives: The association between gestational weight gain (GWG) and adverse outcomes in individuals with gestational diabetes mellitus (GDM) and obesity remains unclear. This study aimed to evaluate the relationship between total GWG and maternal, obstetric, and neonatal outcomes in patients with GDM, stratified by obesity class. Methods: This retrospective cohort included 695 pregnant individuals with GDM treated at a tertiary university hospital in Brazil between 2007 and 2021. GWG was categorized as insufficient, adequate, or excessive per National Academy of Medicine guidelines. Outcomes included maternal, obstetric, and neonatal events. Analyses were conducted for the entire cohort and stratified by obesity class (I and II/III), using multivariate regression models adjusted for maternal age, parity, and pre-pregnancy BMI. Results: The mean age was 33.6 (SD 5.7) years. GWG was insufficient in 33.2%, adequate in 28.2%, and excessive in 37.8%. Excessive GWG was associated with increased odds of cesarean delivery (OR 1.69; 95% CI 1.15–2.48) and large-for-gestational-age newborns (OR 3.29; 95% CI 1.61–6.46). As a continuous variable, GWG was positively associated with cesarean delivery (OR 1.04), LGA (OR 1.10), and birthweight (β = 0.02). Lower GWG was independently associated with reduced preeclampsia risk (OR 1.09 per kg). Insufficient GWG was not linked to increased risk of small-for-gestational-age newborns or other adverse outcomes and was associated with lower insulin requirement. Results remained consistent across obesity subgroups, except for cesarean delivery in class II/III obesity. Conclusions: In individuals with GDM and obesity, insufficient GWG was not associated with increased adverse outcomes, while excessive GWG was consistently linked to unfavorable maternal and neonatal risks. Stricter GWG control may be safe and beneficial in this population. Full article

Background/Objectives: Insulin resistance (IR) in adolescents contributes to the development of metabolic and immunological alterations. These alterations can lead to chronic, systemic, low-grade inflammation in adulthood. Evidence suggests that alterations in miRNA expression play a significant role in the onset of IR by influencing insulin signaling pathways. Therefore, identifying specific miRNAs may aid in the early diagnosis of cardiometabolic risk, particularly during the transition from adolescence to adulthood. Methods: This population-based study aimed to analyze the expression of 21 miRNAs in the plasma of adolescents. We considered IR status, overweight, sex, and age for the analyses. The study measured miRNA expression in plasma samples from 187 adolescents aged 12 to 19 years from the cross-sectional study of the 2015 São Paulo Health Survey (ISA-Nutrition). MiRNA expression was assessed using Exiqon^® assays on Fluidigm^® technology (Les Ulis, France). Statistical analyses were performed to identify differences in miRNA expression and correlations between variables, using a complex research design to ensure representativeness at the population level. Results: The incidence of IR and overweight was high in adolescents (44% and 33%, respectively). High-sensitivity C-reactive protein (hs-CRP) concentration was higher in overweight adolescents. IR was correlated with higher plasma expression of miR-122 and miR-139-3p. Furthermore, miR-486, miR-363, miR-30d, miR-28, miR-223, miR-21, miR-146, miR-130b, miR-126, miR-122, and miR-139-3p showed specific correlations with individual risk for IR, sex, and adolescent stage. Conclusions: The miRNAs showed differential expression according to sex and adolescent stage, and were correlated with cardiometabolic risk factors, suggesting their potential utility for early screening in adolescents. The study highlights age- and sex-related differences in miRNA levels between adolescents with IR and overweight. The cross-sectional design is a limitation of this study, as we cannot infer causality for the associations observed here. Full article

Background: Obesity has been proposed as a risk factor for differentiated thyroid carcinoma (DTC), though findings in the literature remain conflicting. While some studies suggest an association between elevated body mass index (BMI) and thyroid malignancy, others attribute this link to diagnostic bias. The Calabria region in Southern Italy, historically affected by iodine deficiency and endemic goiter, offers a valuable population for investigating this relationship. Objective: This study aimed to evaluate the association between obesity and clinical, sonographic, and cytological characteristics of thyroid nodules in a Calabrian cohort undergoing fine-needle aspiration biopsy (FNAB). Methods: This retrospective observational study included 1192 patients evaluated at a single endocrine referral center between 2015 and 2024. Patients were stratified by BMI (<30 vs. ≥30 kg/m²). Demographic, biochemical, ultrasound, and cytological data were collected and analyzed. Cytological results were classified according to the SIAPEC 2014 system. Results: Obese patients had significantly larger thyroid nodules in terms of anteroposterior and transverse diameters, as well as overall volume (p < 0.05). However, the distribution of high-risk cytological categories (TIR 3B, TIR 4, and TIR 5) did not differ significantly between obese and non-obese patients (9.4% in both groups). Multivariate analysis confirmed that BMI was not an independent predictor of malignancy risk (OR 0.988; p = 0.723), whereas younger age was inversely associated with malignancy. Conclusions: Obesity appears to influence thyroid nodule size but does not constitute an independent risk factor for cytological malignancy. BMI should not influence indications for FNAB or subsequent treatment decisions. Thyroid nodule management should instead rely on ultrasound risk stratification and cytological findings. Special attention should be given to younger patients as they may carry a higher malignancy risk. Full article

Background/Objectives: Adequate sleep has a fundamental role in human health, mainly in cognitive and physiological functions. However, the daily demands of modern society have led to a constant pursuit of better living conditions, requiring more active hours at the expense of sleeping hours. This sleep deprivation has been associated with human health deterioration, namely an increase in Diabetes Mellitus incidence. This metabolic disease is a chronic pathology that imposes a big burden on health systems and is associated with the rise in insulin resistance. In this sense, the aim of this review is to analyze the relation between sleep deprivation and insulin resistance, emphasizing the metabolic parameters and hormones that may be involved in the subjacent mechanism. Methods: A literature review of the last 10 years was performed with specific terms related to “sleep deprivation” and “insulin resistance”. Results: Overall, the studies analyzed showed a decrease in insulin sensitivity in cases of sleep deprivation, even with different study protocols. In addition, an association between sleep deprivation and increased non-esterified fatty acids was also noticeable; however, other parameters such as cortisol, metanephrines, and normetanephrines showed no consistent results among the studies. Conclusions: This review allowed us to confirm the relationship between sleep deprivation and insulin resistance; however, despite the difficulties to monitor sleep, more research is needed to understand the related mechanisms that have not yet been clarified. Full article