What are the health outcomes of trans and gender diverse young people in Australia? Study protocol for the Trans20 longitudinal cohort study.

INTRODUCTION: Being transgender is frequently accompanied by gender dysphoria, which often coexists with mental health concerns. Increased referrals of transgender and gender diverse (TGD) youth to gender clinics have been observed in many countries. Nevertheless, there are limited empirical data on the presentation and outcomes of these patients, and there is an urgent need for more evidence to ensure optimal medical and psychosocial interventions. Here, we describe Trans20, a longitudinal study of TGD patients attending a multidisciplinary paediatric gender service in Melbourne, Australia. Trans20 aims to understand the demographic and clinical characteristics of these patients, to document the natural history of gender diversity presenting in childhood and to investigate long-term outcomes for those receiving interventions. METHODS AND ANALYSIS: Trans20 is a prospective cohort study based on children and adolescents first seen at the Royal Children's Hospital Gender Service (RCHGS) between February 2017 and February 2020. Current estimates indicate the final sample size will be approximately 600. Patients and their parents complete online questionnaires prior to the first appointment with RCHGS and regularly thereafter as part of routine clinical care. On discharge from RCHGS, patients are invited to continue undertaking questionnaires biennially. In this way, a naturally forming cohort study has been created. The primary outcomes include gender dysphoria, physical and mental health, schooling, family functioning and quality of life. Subgroup analyses based on factors such as gender identity, birth-assigned sex and treatment received will be performed using bivariate and multivariate modelling as appropriate, and relevant statistical methods will be applied for the repeated measures over time. ETHICS AND DISSEMINATION: The Royal Children's Hospital Human Research Ethics Committee approved this study (#36323). Findings from Trans20 will have translational impact by informing future treatment guidelines and gender affirming healthcare practices and will be disseminated through conferences and peer reviewed journals.

Postnatal nutrition alters body composition in adult offspring exposed to maternal protein restriction.

The insulin-like growth factor (IGF) system is altered with intra-uterine growth retardation and in adult metabolic disease. The aim of the present study was to observe effects of continued protein restriction on the IGF-I system and body composition in offspring of mothers fed a low-protein (LP) diet. Offspring from Wistar dams fed either a 20 % (CON) or 8 % (LP) protein diet during gestation and lactation were studied at birth, 10 d, weaning and at 12 weeks after maintenance on either the 8 % (lp) or 20 % (con) protein diet from weaning. LP offspring had reduced weaning weights (P < 0.05) and reduced serum insulin (P < 0.005). Serum IGF-I (P < 0.001) and acid-labile subunit (ALS) (P < 0.0001) were reduced at 10 and 21 d. Hepatic expression of IGF-I (P < 0.05) and ALS (P < 0.005) were reduced at 10 and 21 d. IGF binding protein (IGFBP)-1 hepatic expression was elevated at 10 d (P < 0.001) but not at 21 d. Adult LP-con offspring had reduced body weight (P < 0.05), lean (P < 0.0001) and bone (P < 0.0001) but not fat (P = 0.6) mass with no persistent effects on IGF-I, ALS and IGFBP-1.Postnatal lp feeding reduced lean mass (P < 0.0001) and bone mass (P < 0.0001) in CON and LP animals. Percentage fat (LP P = 0.04; CON P = 0.6) and IGFBP-1 (LP P = 0.01; CON P = 0.2) were increased in LP-lp but not CON-lp offspring. This suggests that postnatal nutrition is important in the effects of maternal protein restriction on adult body composition and that IGFBP-1 may be involved.

Leptin as a potential treatment for obesity: progress to date.

Despite significant reductions in the consumption of dietary fat, the prevalence of obesity is steadily rising in western civilization. Of particular concern is the recent epidemic of childhood obesity, which is expected to increase the incidence of obesity-related disorders. The obese gene (ob) protein product leptin is a hormone that is secreted from adipocytes and functions to suppress appetite and increase energy expenditure. Leptin is an attractive candidate for the treatment of obesity as it is an endogenous protein and has been demonstrated to have potent effects on bodyweight and adiposity in rodents. Whereas leptin has been successfully used in the treatment of leptin-deficient obese patients, trials in hyperleptinemic obese patients have yielded variable results. Long-acting leptins have been tried but with no greater success. Other strategies including the use of leptin analogs and other factors that bypass normal leptin delivery systems are being developed. Identifying the mechanisms at the molecular level by which leptin functions will create new avenues for pharmaceutical targeting to simulate the intracellular effects of leptin.

Maternal protein restriction increases hepatic glycogen storage in young rats.

This study aimed to determine whether maternal protein restriction alters hepatic glycogen metabolism. Mated female rats were fed diets containing 20% protein throughout pregnancy and lactation (CONT), 8% protein throughout pregnancy and lactation (LP), or 8% protein during the last week of pregnancy only and lactation (LLP). Weights and lengths were reduced in the LLP and LP offspring compared with the CONT offspring. The LLP and LP offspring demonstrated reduced insulin concentrations at both 10 and 26 d and also failed to show the increase in insulin seen with time in the CONT offspring. Serum glucose and leptin levels increased with time but were not different among the groups; however, in relation to adiposity leptin levels were greater in the LLP and LP offspring at 26 d. The LLP and LP offspring had increased hepatic glycogen at day 10 (CONT, 75.1 +/- 9.8; LLP, 103.4 +/- 11.0; LP, 116.0 +/- 18.4 glucose residues/g tissue) and d 26 (CONT, 183.1 +/- 38.9; LLP, 395.3 +/- 16.8; LP, 396.6 +/- 15.1 glucose residues/g tissue). Glycogen synthase expression was increased in the LLP and LP offspring at 10 d but not 26 d; glucose transporter 2 and glycogen phosphorylase expressions were not different at either time. At 26 d glycogen synthase activity was not different; however, glycogen phosphorylase a activity was reduced. The enhanced capacity to store glycogen despite reductions in insulin secretion suggests increased insulin sensitivity possibly acting with an alternative non-insulin-dependent glycogen storage mechanism.

Site-specific changes in the expression of fat-partitioning genes in weanling rats exposed to a low-protein diet in utero.

OBJECTIVE: Intrauterine growth restriction is associated with increased prevalence of the metabolic syndrome in adult life, including increased adiposity. The aim of this study was to investigate if maternal protein energy malnutrition is associated with changes in expression of genes involved in fat partitioning in weanling rats. RESEARCH METHODS AND PROCEDURES: Time-mated mothers were placed on one of two isocaloric diets, low protein [(LP), 8% protein] or control (20% protein). All mothers remained on the diet throughout pregnancy and lactation. A third group received control for 2 weeks and was switched to LP for the last week of pregnancy and lactation [late low protein (LLP) group]. Offspring were analyzed at weaning for serum glucose, nonesterified fatty acids, triglyceride, and insulin. Expression of the genes acetyl-coenzyme A carboxylase, fatty acid synthase, and carnitine palmitoyl transferase 1 were measured in liver, quadriceps muscle, and subcutaneous white adipose tissue using semiquantitative reverse transcription-polymerase chain reaction. RESULTS: LLP and LP offspring were shorter, weighed less, had reduced serum insulin and nonesterified fatty acids, and had increased serum glucose, serum triglycerides, and hepatic triglycerides. Hepatic gene expression of acetyl-coenzyme A carboxylase and fatty acid synthase was increased 2-fold in LLP and LP offspring (p < 0.001). These changes were not seen in muscle or subcutaneous white adipose tissue. CPT-1 gene expression was unaltered in all tissues examined. DISCUSSION: Maternal protein energy malnutrition programs gene expression of lipogenic enzymes in the liver of weanling offspring in a manner favoring fat synthesis that may predispose these offspring to fat accumulation and insulin resistance later in life.

Creatine supplementation affects glucose homeostasis but not insulin secretion in humans.

AIMS: In this study, it was investigated whether the glucose homeostasis is affected by dietary creatine supplementation. For this purpose, the plasma glucose concentration and the plasma insulin response to an oral glucose load were measured in creatine-supplemented vegetarians. METHODS: The subjects were supplemented with either 5 g of creatine monohydrate (creatine-treated group, CREAT) or 5 g of maltodextrin (control group, CON) per day for 42 days. On days 0 and 43, blood samples were collected before as well as 10, 20, and 30 min following an oral glucose load and analyzed for plasma creatine, insulin, and glucose levels. RESULTS: Creatine supplementation resulted in an increase in plasma creatine (CREAT 92.7 +/- 14.6 micro M vs. CON 31.2 +/- 3.2 micro M; p = 0.001). There was a trend (p = 0.07) towards elevated fasting plasma glucose levels following creatine supplementation, while the plasma glucose response to the glucose load was enhanced (CREAT 168.2 +/- 5.3 mM. min vs. CON 129.6 +/- 14.7 mM.min; p = 0.05). There was no difference observed in the plasma insulin response to the glucose load between the groups. CONCLUSION: This study shows that creatine supplementation may result in abnormalities in glucose homeostasis in the absence of changes in insulin secretion.

Association of the TNF-alpha -308 G/A promoter polymorphism with insulin resistance in obesity.

OBJECTIVE: Obesity is a major risk factor for the development of type 2 diabetes. Tumor necrosis factor (TNF)-alpha is a candidate gene for the development of both obesity and insulin resistance. We investigated whether a common polymorphism in the promoter region (-308 G/A) of the TNF-alpha gene was associated with increased risk for the development of insulin resistance and cardiovascular disease in an obese Australian population. RESEARCH METHODS AND PROCEDURES: Obese, non-diabetic subjects (146 women and 34 men) were genotyped with polymerase chain reaction-restriction fragment length polymorphism techniques, and anthropometric and biochemical measurements were analyzed. A homeostasis model assessment (HOMA) score was used to gauge the level of insulin resistance. RESULTS: The frequencies of the G allele and the A allele were 0.759 and 0.241, respectively. Subjects homozygous for the A allele had higher fasting insulin levels (226 vs. 131 pM; p < 0.001), higher HOMA scores (10.2 vs. 5.3; p < 0.001), higher systolic blood pressure (143 vs. 129 mm Hg; p = 0.02), and lower high-density lipoprotein (HDL) cholesterol (1.13 vs. 1.25 mM; p = 0.04) than did subjects homozygous for the G allele. Whereas an association between insulin resistance and body mass index or waist circumference was seen in all subjects, a highly significant negative correlation of HDL cholesterol to HOMA scores (r = -0.710; p < 0.001) occurred in subjects with the A allele only. DISCUSSION: The -308 G/A TNF-alpha gene variant conveys an increased risk for the development of insulin resistance in obese subjects. The presence of low HDL cholesterol levels further increases the risks associated with insulin resistance in carriers of the A allele.

Creatine supplementation alters insulin secretion and glucose homeostasis in vivo.

Dietary creatine supplementation has been used to improve skeletal muscle performance. However, dietary creatine manipulation also affects glucose homeostasis. The aim of this study was to investigate the effect of dietary creatine supplementation on insulin secretion, glucose tolerance, and quadriceps glycogen metabolism in chow-fed rats. Forty-eight rats in total were divided into 2 groups of 24 and were then subdivided into 6 groups of 8. Rats were fed a diet supplemented with 0% (CON) or 2% (CREAT) creatine for 2, 4, or 8 weeks. At these 3 time points an oral glucose tolerance test was performed. Two days later, rats were euthanized and the pancreas and quadriceps muscles were collected. The peak insulin response to a glucose challenge was significantly elevated after both 4 (CON 327 +/- 72 v CREAT 735 +/- 140 pmol/L, P =.01) and 8 (CON 248 +/- 48 v CREAT 588 +/- 136 pmol/L, P =.02) weeks. Fasting insulin levels were also increased by creatine supplementation for 8 weeks (CON 78 +/- 14 v CREAT 139 +/- 14 pmol/L, P =.01). Glucose tolerance was not affected until 8 weeks at which point the peak plasma glucose was elevated in the creatine supplemented group (CON 10.1 +/- 0.6 v CREAT 13.5 +/- 1.5 mmol/L, P =.05). A significant increase in pancreatic total creatine content was seen in supplemented animals at 2 (CON 1.2 +/- 0.1 v CREAT 2.7 +/- 0.1 micromol/g wet wt, P =.005), 4 (CON 1.5 +/- 0.2 v CREAT 2.7 +/- 0.3 micromol/g wet wt, P =.02) and 8 (CON 1.5 +/- 0.1 v CREAT 2.6 +/- 0.1 micromol/g wet wt, P =.005) weeks, whereas no change in quadriceps total creatine or glycogen content was observed at any individual time point. This study shows that prolonged creatine supplementation induces abnormalities in pancreatic insulin secretion and changes in glucose homeostasis.