Insulin Resistance in Puberty

Insulin sensitivity, body composition and bone mineral density after testosterone treatment in transgender youth with and without prior GnRH agonist therapy

Background

1.8% of youth identify as transgender; a growing proportion are transgender male (female sex, male gender identity). Many receive gonadotropin releasing hormone agonist (GnRHa) therapy to suppress endogenous puberty and/or will start testosterone to induce secondary sex characteristics that align with gender identity.

Objectives

To determine the effects of 12 months of testosterone on cardiometabolic health among transgender youth, including insulin sensitivity, body composition, and bone mineral density and whether changes in outcomes differ based on prior GnRHa treatment.

Methods

Participants (n = 19, baseline age 15.0 ± 1.0 years) were examined prior to and 12 months after testosterone therapy in a longitudinal observational study. Fasted morning blood draw, a 2-hour 75-gram oral glucose tolerance test, body composition and bone mineral density (dual-energy X-ray absorptiometry) were assessed at baseline and 12 months. Insulin sensitivity was estimated by HOMA-IR and Matsuda index. Changes were compared with mixed linear regression models evaluating time (baseline, 12 months), group (GnRHa treatment yes/no), and their interaction.

Results

In the entire cohort, fasted insulin decreased (median [25,75 %ile]: -3 [-5, 0] mIU/L, p = 0.044) and 2-hour glucose increased (mean ± standard deviation): +18.5 ± 28.9 mg/dL, p = 0.013 from baseline after 12 months of testosterone therapy. There were no significant changes in HOMA-IR (p = 0.062) or Matsuda index (p = 0.096), nor by GnRHa status. Absolute (+6.2 [4.7, 7.5] kg, p = 0.016) and percent fat-free mass increased (+7.3 [5.4, 9.1] %, p = 0.003) and percent fat mass declined (-7.4 [-9.3, 5.3]%, p = 0.005) for the entire cohort. There were time*group interactions for absolute (p = 0.0007) and percent fat-free mass (p = 0.033). There were time*group interactions for bone mineral content (p = 0.006).

Conclusions

Twelve months of testosterone in transgender adolescents resulted in changes in body composition and bone mineral density, with baseline differences between the +/-GnRHa group and convergence after 12 months. There were no changes in insulin sensitivity over time or between groups.

Pathophysiological Effects of Contemporary Lifestyle on Evolutionary-Conserved Survival Mechanisms in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is increasingly being characterized as an evolutionary mismatch disorder that presents with a complex mixture of metabolic and endocrine symptoms. The Evolutionary Model proposes that PCOS arises from a collection of inherited polymorphisms that have been consistently demonstrated in a variety of ethnic groups and races. In utero developmental programming of susceptible genomic variants are thought to predispose the offspring to develop PCOS. Postnatal exposure to lifestyle and environmental risk factors results in epigenetic activation of developmentally programmed genes and disturbance of the hallmarks of health. The resulting pathophysiological changes represent the consequences of poor-quality diet, sedentary behaviour, endocrine disrupting chemicals, stress, circadian disruption, and other lifestyle factors. Emerging evidence suggests that lifestyle-induced gastrointestinal dysbiosis plays a central role in the pathogenesis of PCOS. Lifestyle and environmental exposures initiate changes that result in disturbance of the gastrointestinal microbiome (dysbiosis), immune dysregulation (chronic inflammation), altered metabolism (insulin resistance), endocrine and reproductive imbalance (hyperandrogenism), and central nervous system dysfunction (neuroendocrine and autonomic nervous system). PCOS can be a progressive metabolic condition that leads to obesity, gestational diabetes, type two diabetes, metabolic-associated fatty liver disease, metabolic syndrome, cardiovascular disease, and cancer. This review explores the mechanisms that underpin the evolutionary mismatch between ancient survival pathways and contemporary lifestyle factors involved in the pathogenesis and pathophysiology of PCOS.

Prevalence of type 2 diabetes mellitus, metabolic syndrome, and related morbidities in overweight and obese children

OBJECTIVES

The aim of the study was to determine the prevalence of metabolic syndrome (MetS), type 2 diabetes mellitus (T2DM), and other comorbidities in overweight and obese children in Malatya, Turkey.

METHODS

Retrospective cross-sectional study. We studied 860 obese and overweight children and adolescents (obese children Body mass index (BMI) >95th percentile, overweight children BMI >85th percentile) aged between 6 and 18 years. The diagnosis of MetS, impaired glucose tolerance (IGT), impaired fasting glucose (IFG), and T2DM were defined according to modified the World Health Organization criteria adapted for children. Other comorbidities were studied.

RESULTS

Subjects (n=860) consisted of 113 overweight and 747 obese children of whom 434 (50.5%) were girls. MetS was significantly more prevalent in obese than overweight children (43.8 vs. 2.7%, p<0.001), and in pubertal than prepubertal children (41.1 vs. 31.7%, p<0.001). Mean homeostasis model assessment for insulin ratio (HOMA-IR) was 3.6 ± 2.0 in the prepubertal and 4.9 ± 2.4 in pubertal children (p<0.001). All cases underwent oral glucose tolerance test and IGT, IFG, and T2DM were diagnosed in 124 (14.4%), 19 (2.2%), and 32 (3.7%) cases, respectively. Insulin resistance (IR) was present in 606 cases (70.5%).

CONCLUSIONS

Puberty and obesity are important risk factors for MetS, T2DM, and IR. The prevalence of MetS, T2DM, and other morbidities was high in the study cohort. Obese children and adolescents should be carefully screened for T2DM, insulin resistance, hyperinsulinism, dyslipidemia, hypertension, IGT, and IFG. The prevention, early recognition, and treatment of obesity are essential to avoid associated morbidities.

Hyperinsulinemia during pregnancy across varying degrees of glucose tolerance: An examination of the Kraft database

AIM

Hyperinsulinemia is a known underlying driver of metabolic disease; however, its role in pregnancy complications is less understood due to insulin measurement not being a part of standard clinical assessments. This study aimed to characterize hyperinsulinemia in pregnancy by gestational diabetes (GD) status using Kraft methodology.

METHODS

We analyzed historical data from 926 pregnant women who underwent a 100-g oral glucose tolerance test (OGTT), which included insulin measurement. Subjects were grouped by GD diagnosis status ("Normal", "Borderline", "GD") and insulin responses over 3 h were compared between groups.

RESULTS

"GD" was diagnosed in 20.3% of the subjects and 13.8% were grouped as "Borderline." The prevalence of hyperinsulinemia using the Kraft algorithm was 33.1% for Kraft IIB and 42.0% for Kraft III. Compared to normal glucose-tolerant mothers, individuals from the "Borderline" group had an exacerbated insulin response, although not to the same magnitude as those with "GD."

CONCLUSIONS

Dynamic OGTT insulin measurement during pregnancy may provide a meaningful assessment of metabolic risk among women who would otherwise not be diagnosed with GD.