Sex hormone-binding globulin levels predict insulin sensitivity, disposition index, and cardiovascular risk during puberty

Puberty, but not precocious puberty is influenced by weight gain in the first years of life

INTRODUCTION

Factors favouring the secular trend of decreasing average age of puberty include eating habits, environmental endocrine disruptors, genetics, stress and lifestyle. The association between higher BMI and timing and tempo of puberty has long been documented in the general population but data for children with precocious puberty are poor.

AIMS

To evaluate the relationship between the role of weight gain in the first years of life on the onset of central precocious puberty.

PATIENTS AND METHODS

We analyzed the data of 120 Caucasian girls diagnosed with CPP between May 2020 and March 2021 (group 1) and a control group of 540 girls. Patients with CPP associated with hypothalamic-pituitary congenital malformations, neurological, neurosurgical and/or genetic diseases, psychomotor delay, oncological diseases, other endocrine impairments requiring hormonal treatments, or taking drugs that may interfere with pubertal development were excluded.

RESULTS

In CPP girls (group 1), mean age of B2 was 7.67 ± 0.88 years; BMI was 0.14 ± 0.88 SDS, and average BW was -0.08 ± 1.04 SDS. In this group an evaluation of delta SDS BMIB2-BW did not reveal a statistically significant relationship between thelarche and increased BMI. In comparison, the mean age of B2 in the control group (group 2) was 10.06 ± 1.03 years, BMI was -0.02 ± 1.01 SDS, and mean BW was -0.03 ± 0.93 SDS and we found a clear correlation between delta SDS BMIB2-BW and thelarche age (R: 0.27; p < 0.0001).

CONCLUSIONS

Our data confirm that weight gain plays a crucial role in the trend of earlier pubertal development in the general population, but precocious puberty does not appear to be influenced by weight variation in the first years of life. It is therefore important to consider other factors which may contribute to triggering or aggravating this condition.

Longitudinal Associations Between Metabolic Dysfunction-Associated Steatotic Liver Disease and Subclinical Cardiovascular Measures in Chinese Children

INTRODUCTION

The clinical utility of metabolic dysfunction-associated steatotic liver disease (MASLD) in predicting subsequent subclinical cardiovascular damages in pediatric population remains poorly understood.

METHODS

Data on 1,161 Chinese children aged 10-15 years were used to assess the longitudinal associations of MASLD with subsequent subclinical cardiovascular measures.

RESULTS

Compared with relatively healthy children, children with MASLD had abnormal vascular and cardiac structures, along with reduced cardiac diastolic function at the 2-year follow-up. In addition, children with MASLD had a significantly increased risk of high carotid intima-media thickness and left ventricular hypertrophy.

DISCUSSION

These findings support the clinical utility of MASLD in predicting the development of subclinical cardiovascular damages in childhood.

Obesity is associated with SHBG levels rather than blood lipid profiles in PCOS patients with insulin resistance

OBJECTIVE

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder characterized by hormonal imbalances and insulin resistance (IR). Among the metabolic abnormalities associated with PCOS, obesity is often present concurrently. Nevertheless, the correlation between obesity, sex hormone levels, and blood lipid profiles in PCOS patients with IR remains uncertain.

METHODS

This is a cross-sectional study including a total of 206 Chinese women diagnosed with PCOS, enrolled between March 2016 and December 2021. The participants' anthropometric measurements, such as weight, height, waist circumference, and hip circumference, were recorded. Additionally, fasting blood samples were collected to measure various parameters, including fasting glucose, insulin levels, lipid profiles, and sex hormone levels.

RESULTS

Our findings highlight that obesity exhibited a significant correlation with lower levels of sex hormone binding globulin (SHBG) and elevated levels of free androgen index (FAI), fasting insulin, and HOMA-IR in PCOS patients diagnosed with IR. However, no significant association between obesity and blood lipid profiles was observed within this particular group of women.

CONCLUSION

This study suggests that among PCOS patients with IR, lower levels of SHBG and higher levels of FAI are associated with obesity. These findings indicate that SHBG and FAI may have the potential to serve as a biomarker for the initial identification and prognosis of IR in PCOS patients.

TRIAL REGISTRATION

Retrospectively registered on 25/04/2020 at ClinicalTrials.gov Identifer: NCT04264832.

Higher peak height velocity in early maturing girls depends on insulin rather than fat mass or IGF-I

OBJECTIVE

Age at pubertal onset has decreased over the recent decades. Early maturing girls have longer puberty duration, and higher peak height velocity (PHV) than late maturing girls. To what extent this is generated by increased insulin-like growth factor-I (IGF-I), fat mass, or fasting insulin levels is currently unknown.

DESIGN, SETTING, PARTICIPANTS

A population-based study-part of the COPENHAGEN puberty study-longitudinal part. Eighty-one girls evaluated biannually for a median of 10 (2-15) visits for a total of 815 evaluations.

METHODS

Pubertal staging, anthropometric measures, PHV, skin fold thickness (SFT), and IGF-I and fasting insulin levels were measured.

RESULTS

Early maturing girls achieved similar final height compared to late maturing girls (166.1 vs 167.1 cm, P = .36). Early pubertal onset was associated with significantly greater PHV (8.7 vs 7.4 cm/year, P < .001) and a longer puberty duration (age at onset of breast development to age at PHV [1.8 vs 1.1 years, P < .001]) compared with late maturation. After correcting for age at pubertal onset, neither body mass index, SFT, nor IGF-I levels differed between early vs late maturing girls. By contrast, fasting insulin levels were significantly higher in early compared with late maturing girls 1.5, 2.0, and 3.0 years after pubertal onset (all P = .039).

CONCLUSION

Growth velocity was higher and more prolonged in early compared with late maturing girls and associated with higher insulin levels. Thus, the higher insulin levels may compensate for the shorter total growth period by intensifying the pubertal growth period.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01411527.

SHBG and Insulin resistance - Nexus revisited

Sex hormone binding globulin (SHBG) is a liver-synthesized glycoprotein. Low SHBG levels are associated with insulin resistance (IR). Specific single nucleotide polymorphisms (SNPs) in the SHBG gene are linked to IR. Therefore, it is of interest to provide a review on the comprehensive overview for SHBG related to IR.

Association between body fat distribution and age at menarche: a two sample Mendelian randomization study

Background

Numerous studies have examined the association between obesity and age at menarche (AAM), with most focusing on traditional obesity indicators such as body mass index. However, there are limited studies that explored the connection between body fat distribution and AAM, as well as a scarcity of Mendelian randomization (MR) studies.

Methods

In this study, we conducted a two-sample MR study to evaluate the causal effects of eight body fat distribution indicators on AAM. Inverse variance weighted (IVW) method was used for primary analysis, while supplementary approaches such as MR-Egger and weighted median were also utilized. Considering that the eight exposures were highly correlated, we performed an MR Bayesian model averaging (MR-BMA) analysis to prioritize the effect of major exposure on AAM. A series of sensitivity analyses were also performed.

Results

From a range of 82-105 single nucleotide polymorphisms (SNPs) were utilized as genetic instrumental variables for each of the exposure factors. After Bonferroni correction, we found that whole body fat mass (β: -0.17; 95% CI: -0.24, -0.11), left leg fat percentage (β: -0.14; 95% CI: -0.21, -0.07), left leg fat mass (β: -0.20; 95% CI: -0.27, -0.12), left arm fat percentage (β: -0.18; 95% CI: -0.26, -0.11) and left arm fat mass (β: -0.18; 95%CI: -0.26, -0.10) were associated with decreased AAM using random effects IVW method. And the beta coefficients for all MR evaluation methods exhibited consistent trends. MR-BMA method validated that left arm fat percentage plays a dominant role in AAM.

Conclusions

Our MR study suggested that body fat has broad impacts on AAM. Obtaining more information on body measurements would greatly enhance our comprehension of pubertal development.

Endocrine Disruptors and Metabolic Changes: Impact on Puberty Control

OBJECTIVE

This study aims to explore the significant impact of environmental chemicals on disease development, focusing on their role in developing metabolic and endocrine diseases. The objective is to understand how these chemicals contribute to the increasing prevalence of precocious puberty, considering various factors, including epigenetic changes, lifestyle, and emotional disturbances.

METHODS

The study employs a comprehensive review of descriptive observational studies in both human and animal models to identify a degree of causality between exposure to environmental chemicals and disease development, specifically focusing on endocrine disruption. Due to ethical constraints, direct causation studies in human subjects are not feasible; therefore, the research relies on accumulated observational data.

RESULTS

Puberty is a crucial life period with marked physiological and psychological changes. The age at which sexual characteristics develop is changing in many regions. The findings indicate a correlation between exposure to endocrine-disrupting chemicals and the early onset of puberty. These chemicals have been shown to interfere with normal hormonal processes, particularly during critical developmental stages such as adolescence. The research also highlights the interaction of these chemical exposures with other factors, including nutritional history, social and lifestyle changes, and emotional stress, which together contribute to the prevalence of precocious puberty.

CONCLUSION

Environmental chemicals significantly contribute to the development of certain metabolic and endocrine diseases, particularly in the rising incidence of precocious puberty. Although the evidence is mainly observational, it adequately justifies regulatory actions to reduce exposure risks. Furthermore, these findings highlight the urgent need for more research on the epigenetic effects of these chemicals and their wider impact on human health, especially during vital developmental periods.

Plasma proteome profiling reveals the therapeutic effects of the PPAR pan-agonist chiglitazar on insulin sensitivity, lipid metabolism, and inflammation in type 2 diabetes

Chiglitazar is a novel peroxisome proliferator-activated receptor (PPAR) pan-agonist, which passed phase III clinical trials and was newly approved in China for use as an adjunct to diet and exercise in glycemic control in adult patients with Type 2 Diabetes (T2D). To explore the circulating protein signatures associated with the administration of chiglitazar in T2D patients, we conducted a comparative longitudinal study using plasma proteome profiling. Of the 157 T2D patients included in the study, we administered chiglitazar to a specific group, while the controls were given either placebo or sitagliptin. The plasma proteomes were profiled at baseline and 12 and 24 weeks post-treatment using data-independent acquisition mass spectrometry (DIA-MS). Our study indicated that 13 proteins were associated with chiglitazar treatment in T2D patients, including 10 up-regulated proteins (SHBG, TF, APOA2, APOD, GSN, MBL2, CFD, PGLYRP2, A2M, and APOA1) and 3 down-regulated proteins (PRG4, FETUB, and C2) after treatment, which were implicated in the regulation of insulin sensitivity, lipid metabolism, and inflammation response. Our study provides insight into the response of chiglitazar treatment from a proteome perspective and demonstrates the multi-faceted effects of chiglitazar in T2D patients, which will help the clinical application of chiglitazar and further study of its action mechanism.

Low Levels of Serum Total Vitamin B12 Are Associated with Worse Metabolic Phenotype in a Large Population of Children, Adolescents and Young Adults, from Underweight to Severe Obesity

Vitamin B12 (or cobalamin) is an essential vitamin for DNA synthesis, fatty acid and protein metabolism as well as other metabolic pathways fundamental to the integrity of cells and tissues in humans. It is derived from the diet and mostly stored in the liver. Its deficiency has been associated with metabolic derangements, i.e., obesity, glucose intolerance, increased lipogenesis and metabolic dysfunction-associated steatotic liver disease (MASLD) and steatohepatitis (MASH). However, data with regard to body weight across the whole spectrum (from underweight to severe obesity) in children and young individuals are scarce. The present study aims to describe the association between serum total vitamin B12 and body mass index (BMI) ranging from underweight to severe obesity in a large population of children, adolescents and young adults. This study also investigates associations with visceral adiposity, glucose and lipid metabolism and liver dysfunction. A cross-sectional, single-centre study was conducted at the Paediatrics and Endocrinology units of the "Bambino Gesù Children Hospital", a tertiary referral institution for eating disorders. Clinical charts were reviewed and 601 patients aged from 5 to 25 years were enrolled in order to analyse anthropometric, auxological, clinical, biochemical and liver ultrasound data using robust statistical approaches. Analyses were adjusted for potential confounders. A reduction in serum total B12 levels was associated with a linear increase in body weight, as expressed by WHO BMI SDS (r = -0.31, p < 0.001, BCa 95% -0.38, -0.24). Lower B12 levels were associated with higher waist circumference but only in pubertal girls (r = -0.33, p = 0.008, BCa 95% -0.53, -0.11). Hepatic insulin resistance was higher in males with lower B12 levels (B = -0.003 (-0.007, -0.0001), p = 0.039), but not in females, whereas whole-body insulin resistance was unaffected. Serum lipid profiles (total, HDL and LDL cholesterol and triglycerides) were not influenced by serum cobalamin levels. However, lower cobalamin levels were associated with higher grading of ultrasound-scored hepatic steatosis (ptrend = 0.035). Lastly, both AST and ALT showed a significant and direct correlation with total B12 levels in underweight (r = 0.22 and 0.24, p = 0.002 and <0.001, respectively) and severely obese subjects (r = 0.24 and 0.32, p = 0.002 and <0.001). In conclusion lower vitamin B12 levels are associated with higher body weight, adiposity and with worse metabolic health in a large population of children, adolescents and young adults.

Circulating sex hormone-binding globulin levels and ischemic stroke risk: a Mendelian randomization study

PURPOSE

Previous studies have presented conflicting findings regarding the protective effects of circulating sex hormone-binding globulin (SHBG) on ischemic stroke (IS). This study aimed to assess the causal effect of SHBG on IS using Mendelian randomization (MR) analysis and to identify potential mediators.

METHODS

First, the causal effect of SHBG on any IS (AIS), cardioembolic stroke (CES), large artery stroke (LAS), and small vessel stroke (SVS) was assessed by inverse variance weighed (IVW) method. Two additional MR methods (weighted median and MR-Egger) were used to supplement the IVW results. Subsequently, a two-step MR was further performed to assess whether three glycemic profiles [fasting glucose, fasting insulin, and glycated hemoglobin (HbA1c)] and five lipid profiles (high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, non-HDL cholesterol, total cholesterol, and triglycerides) mediated the causal effect. Furthermore, Cochrane's Q test, MR-Egger intercept test, MR-PRESSO global test, and leave-one-out analysis were performed for sensitivity analyses.

RESULTS

The IVW results showed that SHBG significantly reduced SVS risk (odds ratio= 0.60, 95% confidence interval: 0.47-0.77, P = 4.60E-05). The weighted median and MR-Egger results were parallel to IVW. However, no significant associations were found between SHBG and AIS, CES, and LAS. Mediation analysis indicated that HbA1c may be involved in SHBG reducing SVS risk. Sensitivity tests demonstrated the reliability of causal estimates.

CONCLUSIONS

Circulating SHBG levels may decrease SVS risk by lowering HbA1c levels. Therefore, individuals with low circulating SHBG levels should focus on glycemic control to reduce future SVS risk.

Association of size for gestational age and dehydroepiandrosterone sulfate with cardiometabolic risk in central precocious puberty girls

OBJECTIVE

The aim of this study was to assess whether size for gestational age and dehydroepiandrosterone sulfate (DHEAS) are associated with cardiometabolic risk in central precocious puberty (CPP) girls.

METHODS

The retrospective study included 443 patients with newly diagnosed CPP. Subjects were categorized by birth weight for gestational age (appropriate [AGA], small [SGA], and large [LGA] for gestational age) and serum DHEAS concentration (high [≥75th percentile] and normal [<75th percentile] DHEAS). Cardiometabolic parameters were examined. Composite cardiometabolic risk (CMR) score was calculated based on BMI, blood pressure, glucose, insulin, triglyceride, and HDL cholesterol. Non-obesity CMR score was computed, omitting the value from BMI. Logistic regression models, general linear models, and partial correlation analyses were used to evaluate associations. Propensity score matching was performed for sensitivity analyses.

RESULTS

Overall, 309 patients (69.8%) were born AGA, 80 (18.1%) were born SGA, and 54 (12.2%) were born LGA. Compared with AGA counterparts, CPP girls born SGA were more prone to have elevated HbA1c (adjusted OR = 4.54; 95% CI, 1.43-14.42) and low HDL cholesterol (adjusted OR = 2.33; 95% CI, 1.18-4.61). In contrast, being born LGA was not associated with increased risk for any glucose or lipid derangements. Despite the fact that elevated CMR score was more common among individuals born LGA than AGA (adjusted OR = 1.84; 95% CI, 1.07-4.35), no significant difference was found on non-obesity CMR score (adjusted OR = 0.75; 95% CI, 0.30-1.88). When controlling for age, birth weight SDS, and current BMI-SDS, individuals with high DHEAS exhibited higher HDL cholesterol and apolipoprotein A-1 concentrations and lower triglyceride level and non-obesity CMR score. Furthermore, DHEAS correlated positively with HDL cholesterol and apolipoprotein A-1 and negatively with triglyceride, prominently in girls born SGA, after adjustments for the three abovementioned confounders. Sensitivity analyses corroborated the findings.

CONCLUSION

Among CPP girls, those born SGA were more likely to possess cardiometabolic risk factors compared to their AGA peers. The difference we observed in cardiometabolic risk between individuals born LGA and AGA was driven by BMI. High DHEAS was associated with favorable lipid profile in CPP girls, even in subjects born SGA.

Links between Childhood Obesity, High-Fat Diet, and Central Precocious Puberty

In recent years, the existing relationship between excess overweight and central precocious puberty (CPP) has been reported, especially in girls. Different nutritional choices have been associated with different patterns of puberty. In particular, the involvement of altered biochemical and neuroendocrine pathways and a proinflammatory status has been described in connection with a high-fat diet (HFD). In this narrative review, we present an overview on the relationship between obesity and precocious pubertal development, focusing on the role of HFDs as a contributor to activating the hypothalamus-pituitary-gonadal axis. Although evidence is scarce and studies limited, especially in the paediatric field, the harm of HFDs on PP is a relevant problem that cannot be ignored. Increased knowledge about HFD effects will be useful in developing strategies preventing precocious puberty in children with obesity. Promoting HFD-avoiding behavior may be useful in preserving children's physiological development and protecting reproductive health. Controlling HFDs may represent a target for policy action to improve global health.

Insulin-resistance in paediatric age: Its magnitude and implications

Insulin resistance (IR) is insulin failure in normal plasma levels to adequately stimulate glucose uptake by the peripheral tissues. IR is becoming more common in children and adolescents than before. There is a strong association between obesity in children and adolescents, IR, and the metabolic syndrome components. IR shows marked variation among different races, crucial to understanding the possible cardiovascular risk, specifically in high-risk races or ethnic groups. Genetic causes of IR include insulin receptor mutations, mutations that stimulate autoantibody production against insulin receptors, or mutations that induce the formation of abnormal glucose transporter 4 molecules or plasma cell membrane glycoprotein-1 molecules; all induce abnormal energy pathways and end with the development of IR. The parallel increase of IR syndrome with the dramatic increase in the rate of obesity among children in the last few decades indicates the importance of environmental factors in increasing the rate of IR. Most patients with IR do not develop diabetes mellitus (DM) type-II. However, IR is a crucial risk factor to develop DM type-II in children. Diagnostic standards for IR in children are not yet established due to various causes. Direct measures of insulin sensitivity include the hyperinsulinemia euglycemic glucose clamp and the insulin-suppression test. Minimal model analysis of frequently sampled intravenous glucose tolerance test and oral glucose tolerance test provide an indirect estimate of metabolic insulin sensitivity/resistance. The main aim of the treatment of IR in children is to prevent the progression of compensated IR to decompensated IR, enhance insulin sensitivity, and treat possible complications. There are three main lines for treatment: Lifestyle and behavior modification, pharmacotherapy, and surgery. This review will discuss the magnitude, implications, diagnosis, and treatment of IR in children.

Investigation of androgen receptor gene CAG repeat length polymorphism in pubertal gynecomastia

OBJECTIVES

Androgen receptor gene CAG repeat, AR (CAG)_n, polymorphism is thought to have an effect on male reproductive functions and a relationship between long AR (CAG)_n and decreased androgenic activity has been shown. Therefore, we hypothesized that in adolescents with long AR CAG repeat the prevalence of pubertal gynecomastia (PG) will be higher and we aimed to investigate the association between AR (CAG)_n polymorphism and PG in Turkish adolescents.

METHODS

Adolescents with PG between 11 and 19 years of age were enrolled as the study group and healthy individuals without a history of PG, who were at least 14 years of age and Tanner 4 or 5 were enrolled as the control group. The AR (CAG)_n length was detected by direct DNA sequencing analysis and reproductive hormones were measured by standardized analyses.

RESULTS

The mean AR (CAG)_n was 22.3 ± 2.6 (mean ± SD) in the PG group (n=101) and 21.9 ± 3.1 (mean ± SD) in the control group (n=88) (p=0.276). The adolescents with short AR (CAG)_n had lower body mass index standard deviation scores (BMI SDS) compared to the adolescents with intermediate and long repeat numbers (p=0.029).

CONCLUSIONS

The results of this study showed a lack of direct association between AR (CAG)_n and PG. However, the significant relationship between the AR (CAG)_n quartiles and BMI SDS suggests that long AR (CAG)_n might cause PG indirectly. Further studies are needed to better clarify this relationship.

Hepatokine Pregnancy Zone Protein Governs the Diet-Induced Thermogenesis Through Activating Brown Adipose Tissue

Intermittent fasting (IF), as a dietary intervention for weight loss, takes effects primarily through increasing energy expenditure. However, whether inter-organ systems play a key role in IF remains unclear. Here, a novel hepatokine, pregnancy zone protein (PZP) is identified, which has significant induction during the refeeding stage of IF. Further, loss of function studies and protein therapeutic experiment in mice revealed that PZP promotes diet-induced thermogenesis through activating brown adipose tissue (BAT). Mechanistically, circulating PZP can bind to cell surface glucose-regulated protein of 78 kDa (GRP78) to promote uncoupling protein 1 (UCP1) expression via a p38 MAPK-ATF2 signaling pathway in BAT. These studies illuminate a systemic regulation in which the IF promotes BAT thermogenesis through the endocrinal system and provide a novel potential target for treating obesity and related disorders.

Different threshold levels of circulating total and free 25-hydroxyvitamin D for the diagnosis of vitamin D deficiency in obese adolescents

The total serum 25-hydroxyvitamin D [25(OH)D_T] level is lower in obese individuals than in their nonobese peers, despite similar bone turnover markers and bone mineral density. This study aimed to investigate whether the threshold level of 25(OH)D for the diagnosis of vitamin D deficiency (VDD) in obese adolescents was lower than that in controls and to compare 25(OH)D_T, free [25(OH)D_F] and bioavailable [25(OH)D_B] vitamin D with VDBP levels in obese individuals and their controls. A total of 173 adolescents (90 obese individuals and 83 controls) aged 12-18 years were included in the study. The metabolic and anthropometric parameters of the participants were recorded, the 25(OH)D_T, 25(OH)D_F, and VDBP levels were measured, and the 25(OH)D_B levels were calculated. The cutoff values for VDD were estimated according to the level of 25(OH)D below which parathyroid hormone begins to rise. The obese subjects had lower 25(OH)D_T (12.1 ± 5.8 vs. 16.4 ± 9.3 ng/mL, p < 0.001), 25(OH)D_F (12.6 ± 4.2 vs. 16.7 ± 7.6 pg/mL, p < 0.001), 25(OH)D_B [4.8 (2.3) vs. 6.1 (5.2) ng/mL, p = 0.012], and VDBP [112.2 (51.3) vs. 121.9 (95.5) μg/mL, p < 0.001] levels than the controls. The cutoff values for 25(OH)D_T and 25(OH)D_F levels for VDD were lower in the obese group than in the control group (9.4 vs. 14.1 ng/mL; 12.2 vs. 16.8 pg/mL, respectively).Conclusion: The vitamin D cutoff values for the diagnosis of VDD were different in the obese and control groups. Using the same cutoff value for VDD may cause overtreatment in obese adolescents. What is Known: • Vitamin D deficiency is more prevalent in obese children than nonobese controls, despite the same bone turnover markers and bone mineral density • The cutoff value of vitamin D level for the diagnosis of VDD is based on the PTH elevation What is New: • In obese adolescents, total and free vitamin D cutoff value for the diagnosis of VDD was lower than nonobese peers • Using the same cutoff value for vitamin D deficiency in both obese and nonobese adolescents may cause overtreatment.

Predictive value of circulating sex hormone-binding globulin for gestational diabetes: a meta-analysis

Aim: To detect predictive value of preconception or early pregnancy sex hormone-binding globulin (SHBG) for subsequent gestational diabetes mellitus (GDM). Materials & methods: We searched Embase, Medline, PubMed, Web of Science and Cochrane library up to January 2020. Studies assessing diagnostic performance of SHBG for GDM diagnosed by well-defined diagnostic criteria using oral glucose tolerance test. Results: Totally seven studies with 1947 women were included and 247 were diagnosed as GDM. SHBG had a combined diagnostic odds ratio of 6.68 (95% CI: 4.58-9.74), sensitivity of 0.70 (95% CI: 0.51-0.84), specificity of 0.74 (95% CI: 0.52-0.88), positive likelihood ratio of 2.49 (95% CI: 1.73-3.57) and negative likelihood ratio of 0.37 (95% CI: 0.23-0.61). The area under the summary receiver operating characteristic curve was 0.78 (95% CI: 0.74-0.82). Conclusion: SHBG had a predictive value for GDM and might improve GDM screening. However, heterogeneity between studies warrants more research into this topic.

Early menarche is associated with insulin-resistance and non-alcoholic fatty liver disease in adolescents with obesity

OBJECTIVES

Recent evidence linked early menarche to a higher risk of insulin-resistance (IR) and nonalcoholic fatty liver disease (NAFLD) in adulthood. We aimed to evaluate the impact of early menarche on glucose derangements and NAFLD in a sample of Italian adolescents with obesity.

METHODS

Anthropometric and biochemical evaluations were conducted in all the enrolled 318 obese patients (mean age 12.31 ± 2.95 years). NAFLD was defined by the presence of ultrasound detected liver steatosis and/or alanine transaminase (ALT) levels >40 IU/L.

RESULTS

Patients with early menarche showed both higher homeostasis model assessment of insulin-resistance (HOMA-IR) (p=0.008) and ALT (p=0.02) values, an increased prevalence of NAFLD (p=0.001), and lower Matsuda and Insulinogenic Index (IGI) values than the other obese patients. The association between early menarche and both ALT and Matsuda Index remained significant in General Linear Models (GLMs) in which respectively body mass index standard deviation score (BMI-SDS) and Matsuda Index, and BMI-SDS were included as covariates. Patients with early menarche also showed a higher risk of both HOMA-IR>3 (OR 1.69, CI 1.05-2.70, p=0.02) and NAFLD (OR 1.10, CI 1.01-1.21, p=0.03).

CONCLUSIONS

Girls with obesity presenting early menarche showed higher HOMA-IR levels, lower Matsuda Index and IGI values, and higher risk of NAFLD compared to girls without early menarche.

Early menarche and its consequence in Korean female: reducing fructose intake could be one solution

The mean age at menarche (AAM) of Korean females has been rapidly decreasing over the last 50 years; currently, the prevalence of early menarche (<12 years) is 22.3%. Female adolescents who experience early menarche are known to be at greater risk of psychosocial and behavioral problems along with several physical health problems such as menstrual problems. They also tend to achieve a shorter final height and develop obesity. Population-based Korean studies have shown a strong association between early menarche and the risk of obesity, insulin resistance, metabolic syndrome, nonalcoholic fatty liver disease, diabetes, breast cancer, and cardiovascular disease in adulthood. Although the exact mechanism of how early menarche causes cardiometabolic derangement in later adulthood is unknown, childhood obesity and insulin resistance might be major contributors. Recent studies demonstrated that an excessive consumption of fructose might underlie the development of obesity and insulin resistance along with an earlier AAM. A positive association was observed between sugar-sweetened beverages (a major source of fructose) intake and obesity, metabolic syndrome, insulin resistance, and cardiometabolic risk in Korean females. In pediatrics, establishing risk factors is important in preventing disease in later life. In this regard, early menarche is a simple and good marker for the management of cardiometabolic diseases in adulthood. Decreasing one's fructose intake might prevent early menarche as well as the development of obesity, insulin resistance, and cardiometabolic diseases.

Sex steroid hormones, leptin, and high-sensitivity C-reactive protein levels in adolescents

BACKGROUND

The association of sex hormones with C-reactive protein (CRP) levels has been reported. However, this association remains unexplored in children in whom important anthropometric and hormonal changes are taking place.

OBJECTIVES

To analyze the association between high-sensitivity CRP (hs-CRP) and testosterone, estradiol and sex hormone-binding globulin (SHBG) levels in a population-based sample of adolescents, and to evaluate the influence of leptin levels on this association.

MATERIALS AND METHODS

The sample population of this cross-sectional study was comprised of 338 male and 385 female adolescents, aged 12-16 years. Information on anthropometric variables, hormone, leptin, and hs-CRP levels was available.

RESULTS

In male adolescents in our study, higher age is significantly associated with higher testosterone levels and with lower leptin and SHBG concentrations across the range of age studied. No significant changes in leptin and SHBG levels by age are observed in females. In males, leptin correlates negatively with testosterone levels (-0.263, p < 0.001), showing a stronger correlation after adjusting by body mass index (BMI) (-0.424, p < 0.001). A significant correlation between hs-CRP and testosterone levels is observed in males after adjusting by BMI, but the correlation disappears after adjusting by leptin. No association between testosterone and hs-CRP was observed in females. The negative association between hs-CRP levels and SHBG remains significant after adjusting by leptin in both sexes but disappears in males after adjusting by BMI.

CONCLUSION

The negative association between hs-CRP and testosterone concentrations observed in 12- to 16-year-old males seems to be related to leptin levels which are closely negatively related to testosterone levels in males independently of BMI.

Sex Hormone-Binding Globulin (SHBG) as an Early Biomarker and Therapeutic Target in Polycystic Ovary Syndrome

Human sex hormone-binding globulin (SHBG) is a glycoprotein produced by the liver that binds sex steroids with high affinity and specificity. Clinical observations and reports in the literature have suggested a negative correlation between circulating SHBG levels and markers of non-alcoholic fatty liver disease (NAFLD) and insulin resistance. Decreased SHBG levels increase the bioavailability of androgens, which in turn leads to progression of ovarian pathology, anovulation and the phenotypic characteristics of polycystic ovarian syndrome (PCOS). This review will use a case report to illustrate the inter-relationships between SHBG, NAFLD and PCOS. In particular, we will review the evidence that low hepatic SHBG production may be a key step in the pathogenesis of PCOS. Furthermore, there is emerging evidence that serum SHBG levels may be useful as a diagnostic biomarker and therapeutic target for managing women with PCOS.

Serum SHBG Is Associated With the Development and Regression of Nonalcoholic Fatty Liver Disease: A Prospective Study

CONTEXT

SHBG, a homodimeric glycoprotein produced by hepatocytes has been shown to be associated with metabolic disorders. Whether circulating SHBG levels are predictive of later risk of nonalcoholic fatty liver disease (NAFLD) remains unknown. In this study, we prospectively investigated the association between SHBG and NAFLD progression through a community-based cohort comprising 3389 Chinese adults.

METHODS

NAFLD was diagnosed using abdominal ultrasonography. Serum SHBG levels were measured by chemiluminescent enzyme immunometric assay, and their relationship with NAFLD development and regression was investigated after a mean follow-up of 3.09 years using multivariable logistic regression.

RESULTS

Basal SHBG was negatively associated with NAFLD development, with a fully adjusted odds ratio (OR) and its 95% confidence interval (CI) of 0.22 (0.12-0.40) (P < .001). In contrast, basal SHBG was positively associated with NAFLD regression, with a fully adjusted OR of 4.83 (2.38-9.81) (P < .001). Multiple-stepwise logistic regression analysis showed that SHBG concentration was an independent predictor of NAFLD development (OR, 0.28 [0.18-0.45]; P < .001) and regression (OR, 3.89 [2.43-6.22]; P < .001). In addition, the area under the receiver operating characteristic curves were 0.764 (95% CI, 0.740-0.787) and 0.762 (95% CI, 0.738-0.785) for the prediction models of NAFLD development and regression, respectively.

CONCLUSIONS

Serum SHBG concentration is associated with the development and regression of NAFLD; moreover, it can be a potential biomarker for predicting NAFLD progression, and also a novel preventive and therapeutic target for NAFLD.

Dietary habits, metabolic health and vitamin D status in Greenlandic children

OBJECTIVE

To compare the dietary habits of children living in northern villages and in the capital of Greenland, given the reported transition from traditional to westernised diet in adults over recent decades, and to explore the association between consumption of marine mammals and fish (MMF) and the children's metabolic profile and vitamin D status.

DESIGN

Children answered an FFQ encompassing sixty-four individual food types pooled into six food categories. Their pubertal stage, body fat, fitness level, metabolic profile (non-HDL-cholesterol, glycated Hb, insulin, glucose, high-sensitivity C-reactive protein) as well as serum 25-hydroxyvitamin D (25(OH)D) concentration were evaluated.

SETTING

Siorapaluk and Qaanaaq (north of Greenland) and Nuuk (west).

PARTICIPANTS

Children aged 6-18 years (n 177).

RESULTS

MMF were most frequently eaten by children from Siorapaluk (mean (sd): 73·4 (14·1) times/month), followed by children from Qaanaaq (37·0 (25·0) times/month), and least often eaten by children from Nuuk (23·7 (24·6) times/month; P < 0·001). Children from Qaanaaq consumed 'junk food' more frequently (P < 0·001) and fruits and vegetables less frequently (P < 0·01) than children from Nuuk. MMF consumption was positively associated with serum 25(OH)D concentration (P < 0·05), but the overall prevalence of vitamin D deficiency was high (18 %). No association was found between MMF consumption and metabolic parameters.

CONCLUSIONS

The dietary transition and influence of western diets have spread to the north of Greenland and only the most remote place consumed a traditional diet highly based on MMF. We found no strong associations of MMF consumption with metabolic health, but a positive association with vitamin D status.

Why Do Normal Children Have Acromegalic Levels of IGF-I During Puberty?

CONTEXT

The rapid pubertal height growth is unique to humans, but why do we have it? Although the spurt contributes 13% to 15% to the final adult height, we hypothesized that the biological significance of the high acromegalic levels of GH and IGF-I, which are behind the pubertal growth spurt, might primarily occur to stimulate the reproductive organs.

EVIDENCE SYNTHESIS

Animal data have demonstrated that adult Igf1 and Igf2 gene knockout mice that survive show a dramatic reduction in the size of the reproductive organs and are infertile. In humans, case reports of mutations in the genes affecting the GH-IGF axis and growth (GH, GHRH, GH-R, STAT5b, IGF-I, IGF-II, IGF-1R, PAPPA2) are also characterized by delayed pubertal onset and micropenis. Furthermore, GH treatment will tend to normalize the penile size in patients with GH deficiency. Thus, the endocrine effects of high IGF-I levels might be needed for the transition of the sexual organs, including the secondary sex characteristics, from the "dormant" stages of childhood into fully functioning reproductive systems. The peak IGF-I levels, on average, occur 2 years after the peak height growth velocity, suggesting reasons other than longitudinal growth for the high IGF-I levels, and remain high in the years after the height spurt, when the reproductive systems become fully functional.

CONCLUSION

We suggest that the serum levels of IGF-I should be monitored in children with poor development of sexual organs, although it remains to be investigated whether GH should be added to sex steroids in the management of hypogonadism for some pubertal children (e.g., boys with micropenis).

Does sex hormone-binding globulin cause insulin resistance during pubertal growth?

BACKGROUND

The directional influences between serum sex hormone-binding globulin (SHBG), adiposity and insulin resistance during pubertal growth remain unclear. The aim of this study was to investigate bidirectional associations between SHBG and insulin resistance (HOMA-IR) and adiposity from childhood to early adulthood.

METHODS

Participants were 396 healthy girls measured at baseline (age 11.2 years) and at 1, 2, 4 and 7.5 years. Serum concentrations of estradiol, testosterone and SHBG were determined by ELISA, glucose and insulin by enzymatic photometry, insulin-like growth factor 1 (IGF-1) by time-resolved fluoroimmunoassays, whole-body fat mass by dual-energy X-ray absorptiometry and HOMA-IR were determined by homeostatic model assessment. The associations were examined using cross-lagged path models.

RESULTS

In a cross-lagged path model, SHBG predicted HOMA-IR before menarche β = -0.320 (95% CI: -0.552 to -0.089), P = 0.007, independent of adiposity and IGF-1. After menarche, no directional effect was found between SHBG and insulin resistance or adiposity.

CONCLUSIONS

Our results suggest that in early puberty, decline in SHBG predicts development of insulin resistance, independent of adiposity. However, after menarche, no directional influences between SHBG, adiposity and insulin resistance were found, suggesting that observational associations between SHBG, adiposity and insulin resistance in pubertal children may be subject to confounding. Further research is needed to understand the underlying mechanisms of the associations between SHBG and cardiometabolic risk markers in peripubertal children.

Early age at menarche is associated with insulin resistance: a systemic review and meta-analysis

OBJECTIVES

We aimed to conduct a systemic review and meta-analysis of the relevant studies to further investigate the association between age at menarche and insulin resistance.

METHODS

PubMed, EMBASE, and Web of Science (SCI) databases were systemically searched until December 2017. Observational studies comparing the incidences of insulin resistance in patients with early, average, and late menarchal ages were identified. Weighted mean difference (WMD) for HOMA-IR scores and fasting serum insulin levels in early vs late, early vs average. and average vs late comparisons were calculated with a random- or fixed-effects model.

RESULTS

A total of eight articles involving 5504 subjects were finally included. In the analysis of HOMA-IR, the pooled WMDs in five studies were 0.45 (95% confidence interval [CI] 0.31-0.60, p < 0.001), 0.40 (95% CI 0.28-0.52, p < 0.001), and -0.01 (95% CI -0.09 to 0.07, p = 0.854) for early vs late, early vs average, and average vs late comparisons, respectively. The fasting serum insulin levels in eight studies were analyzed, and it was significantly higher in subjects with earlier age at menarche (WMD 1.28, 95% CI 0.92-1.63, p < 0.001 for early vs late comparison, WMD 1.28, 95% CI 1.13-1.43, p < 0.001 for early vs average comparison) with mild and acceptable heterogeneity (I² = 42.5% and 7.4%, respectively). Publication bias was not detected via funnel plots and Egger's tests.

CONCLUSIONS

Our study revealed that earlier age at menarche was significantly associated with insulin resistance.

TRIAL REGISTRATION NUMBER

CRD42018083874.

Is there a causal relationship between obesity and puberty?

The onset of puberty in adolescents and whether it is related to obesity is an ongoing topic for debate. Epidemiological cross-sectional and longitudinal studies show a shift towards earlier onset of puberty in girls who are obese; however, the situation is less clear in boys. Boys who are overweight seem to mature earlier, and boys who are obese mature later, than boys at a healthy weight. The underlying mechanisms are not yet fully understood, and whether earlier onset of puberty in obese girls is based on the activation of the hypothalamic-pituitary-gonadal axis is unclear. The most promising link between obesity and puberty is the adipokine leptin and its interaction with the kisspeptin system, which is an important regulator of puberty. However, peripheral action of adipose tissue (eg, via other adipokines, aromatase activity) could also be involved in changes to the onset of puberty. In addition, nutritional factors, epigenetics, or endocrine disrupting chemicals are potential mediators linking the onset of puberty to obesity. This Review summarises our knowledge concerning the relationship between obesity and onset and tempo of puberty, and the consequences of early puberty on obesity.

The Influence of Obesity on Puberty and Insulin Resistance in Mexican Children

Obesity is considered the main risk factor associated with the development of insulin resistance (IR). The aim of this study was to evaluate the influence of obesity on puberty onset and IR in Mexican children. A total of 378 children (189 boys and 189 girls) aged 8-14 years participated in the study. IR was estimated using the homeostasis model assessment for IR (HOMA-IR). The mean fasting glucose (FG) and basal insulin levels were 82 mg/dl and 11.0 μIU/ml in boys and 77.3 mg/dl and 12.3 μIU/ml in girls (P < 0.05). Subjects with obesity at Tanner stages II-V showed increased FG levels (P < 0.05). In boys with obesity, there was a decrease in HOMA-IR in Tanner stage IV and differences in age between boys with normal weight and those with obesity in Tanner V, being older the boys with obesity. Obesity in children and adolescents was associated with higher HOMA-IR values. In boys with obesity, IR increased at the end of pubertal maturation, with a delay in puberty. These findings should be considered on the establishment of IR cutoff values for pubertal population in Mexico and in the establishment of strategies to prevent the health problems related to obesity.

Serum IL-1 Receptor Antagonist Concentrations Associate With Unfavorable Metabolic Features in 12-Year-Old Children

Context

Elevated IL-1 receptor antagonist (IL-1Ra) concentrations are associated with obesity, insulin resistance, and cardiovascular disease (CVD) risk in adults.

Objective

To determine if serum IL-1Ra and high-sensitivity C-reactive protein (hs-CRP) levels are associated with markers of reduced insulin sensitivity (IS) and serum lipids in 12-year-old children.

Design and Participants

Of 191 children (n = 109 girls), 78 were categorized as having had birth weight and length appropriate for gestational age (AGA), 69 were small for gestational age, and 44 were AGA and from preeclamptic pregnancies. Serum markers of low-grade inflammation, IS, and lipids were measured. Quantitative Insulin Sensitivity Check Index (QUICKI) was calculated.

Results

Mean serum IL-1Ra levels did not differ between the sexes or among the gestational categories. Children in the highest IL-1Ra tertile had lower QUICKI, IGF-binding protein-1, SHBG, and high-density lipoprotein cholesterol values; and higher body mass index (BMI), waist circumference to height ratio (WHtR), and serum insulin, hs-CRP, leptin, and triglyceride concentrations than those in the lowest IL-1Ra tertile. Logistic regression analysis showed higher serum hs-CRP and leptin levels, and WHtR were associated with high serum IL-1Ra levels. IL-1Ra concentration could be used to discriminate the children with lowest IS (area under the curve, 0.68; P < 0.001); hs-CRP level could not.

Conclusion

Children with the highest IL-1Ra levels had lower IS, higher hs-CRP levels and BMI, and a less favorable lipid profile than those with the lowest IL-1Ra levels, suggesting that high IL-1Ra concentrations may be associated with increased CVD risk in 12-year-old children.

Bisphenol A, phthalate metabolites and glucose homeostasis in healthy normal-weight children

INTRODUCTION

Bisphenol A and several of the most commonly used phthalates have been associated with adverse metabolic health effects such as obesity and diabetes. Therefore, we analyzed these man-made chemicals in first morning urine samples from 107 healthy normal-weight Danish children and adolescents.

METHOD

This was a cross-sectional study. Participants were recruited as part of the Copenhagen Puberty Study. The subjects were evaluated by an oral glucose tolerance test (OGTT), a dual-energy X-ray absorptiometry (DXA) scan, direct oxygen uptake measurement during cycle ergometry and fasting blood samples. First morning urine was collected and phthalate metabolites and BPA were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with prior enzymatic deconjugation. Individual chemical concentrations were divided into tertiles and analyzed in relation to biological outcome.

RESULTS

Children in the lowest tertile of urinary BPA had significantly higher peak insulin levels during OGTT (P = 0.01), lower insulin sensitivity index (P < 0.01), higher leptin (P = 0.03), triglyceride (P < 0.01) and total cholesterol levels (P = 0.04), lower aerobic fitness (P = 0.02) and a tendency toward higher fat mass index (P = 0.1) compared with children in the highest tertile for uBPA. No significant differences in anthropometrics, body composition or glucose metabolism were associated with any of the phthalate metabolites measured.

CONCLUSION

This pilot study on healthy normal-weight children suggests an inverse association between BPA and insulin resistance. Our findings contrast other cross-sectional studies showing a positive association for BPA, which may be due to confounding or reverse causation because diet is an important source of both BPA exposure and obesity.

An update on the assessment and management of metabolic syndrome, a growing medical emergency in paediatric populations

In the last decades the increasing rate of obesity in children and adolescents worldwide has led to the onset in paediatric age of metabolic syndrome, a disease commonly associated to adulthood. Central obesity, dyslipidaemia, hyperglycaemia, and hypertension are typical features of metabolic syndrome that seem to hesitate often in type 2 diabetes, cardiovascular disease, non-alcoholic fatty liver disease, and many other clinical conditions. Thus preventing and curing metabolic syndrome in paediatric patients is becoming an urgent need for public health. While diagnostic criteria and therapy of metabolic syndrome in adults are very well defined, there is no consensus on the definition of metabolic syndrome in children and adolescents as well as on healing approaches. The aim of this review is to describe the recent advances on the pathogenesis and clinical outcomes of paediatric metabolic syndrome. We then detail the therapeutic strategies (i.e. dietary regimens, physical exercise, nutraceuticals, and medications) employed to manage the disease. Finally, we analyse the safety profile of the drugs used in children and adolescents by performing a retrospective review of paediatric adverse reactions reported in the FDA's Adverse Event Reporting System database.

Associations of Serum Levels of Sex Hormones in Follicular and Luteal Phases of the Menstrual Cycle with Breast Tissue Characteristics in Young Women

Background

In previous work in young women aged 15–30 years we measured breast water and fat using MR and obtained blood for hormone assays on the same day in the follicular phase of the menstrual cycle. Only serum growth hormone levels and sex hormone binding globulin (SHBG) were significantly associated with percent breast water after adjustment for covariates. The sex hormones estradiol, progesterone and testosterone were not associated with percent water in the breast in the follicular phase of the menstrual cycle. In the present study we have examined the association of percent breast water with serum levels of sex hormones in both follicular and luteal phase of the menstrual cycle.

Methods

In 315 healthy white Caucasian young women aged 15–30 with regular menstrual cycles who had not used oral contraceptives or other hormones in the previous 6 months, we used MR to determine percent breast water, and obtained blood samples for hormone assays within 10 days of the onset of the most recent menstrual cycle (follicular phase) of the cycle on the same day as the MR scan, and a second blood sample on days 19–24 of the cycle. Serum progesterone levels of > = 5 mmol/L in days 19–24 were used to define the 225 subjects with ovulatory menstrual cycles, whose data are the subject of the analyses shown here.

Results

SHBG was positively associated with percent water in both follicular and luteal phases of the menstrual cycle. Total and free estradiol and total and free testosterone were not associated with percent water in the follicular phase, but in young women with ovulatory cycles, were all negatively associated with percent water in the luteal phase.

Conclusions

Our results from young women aged 15–30 years add to the evidence that the extent of fibroglandular tissue in the breast that is reflected in both mammographic density and breast water is associated positively with higher serum levels of SHBG, but not with higher levels of sex hormones.

Indexes of Insulin Resistance in Hyperinsulinemic Polycystic Ovary Syndrome in a Macedonian Cohort of Women of Reproductive Age: A Cross-Sectional Study

BACKGROUND:

Polycystic ovary syndrome (PCOS) is complex hormonal, metabolic and reproductive disorder and is a leading cause of female infertility. Hyperinsulinemia secondary to insulin resistance plays important role in the pathogenesis of PCOS.

AIM:

To assess the sensitivity of different indices of insulin resistance and their relevance in a clinical setting.

MATERIAL AND METHODS:

A cross-sectional study of 43 patients with PCOS and 29 noromo ovulatory women as a control group was conducted. Standard clinical, anthropometrical and hormonal testing for hyperandrogenism was conducted, as well as oral glucose tolerance test with determination of basal and stimulated glucose and insulin values.

RESULTS:

The dynamic I/G index showed the highest sensitivity and specificity, but the static indexes HOMA-IR and QUICKI, although based on only basal glycemic and insulinemic values, showed good sensitivity, 90.38% and 94.01% respectively. HOMA-IR showed significant positive correlation with the stimulated insulin values.

CONCLUSIONS:

Our results support the use of static indexes in the evaluation of insulin resistance in women with PCOS in a clinical setting, offering a simple assessment of insulin resistance in PCOS, which holds great prognostic and treatment implications.

Sex Hormone-Binding Globulin in Children and Adolescents

Sex hormone-binding globulin (SHBG) is a circulating glycoprotein that transports testosterone and other steroids in the blood. Interest in SHBG has escalated in recent years because of its inverse association with obesity and insulin resistance, and because many studies have linked lower circulating levels of SHBG to metabolic syndrome, type 2 diabetes, nonalcoholic fatty liver disease, polycystic ovary syndrome, and early puberty. The purpose of this review is to summarize molecular, clinical, endocrine, and epidemiological findings to illustrate how measurement of plasma SHBG may be useful in clinical medicine in children.

Male Reproductive Disorders and Fertility Trends: Influences of Environment and Genetic Susceptibility

It is predicted that Japan and European Union will soon experience appreciable decreases in their populations due to persistently low total fertility rates (TFR) below replacement level (2.1 child per woman). In the United States, where TFR has also declined, there are ethnic differences. Caucasians have rates below replacement, while TFRs among African-Americans and Hispanics are higher. We review possible links between TFR and trends in a range of male reproductive problems, including testicular cancer, disorders of sex development, cryptorchidism, hypospadias, low testosterone levels, poor semen quality, childlessness, changed sex ratio, and increasing demand for assisted reproductive techniques. We present evidence that several adult male reproductive problems arise in utero and are signs of testicular dysgenesis syndrome (TDS). Although TDS might result from genetic mutations, recent evidence suggests that it most often is related to environmental exposures of the fetal testis. However, environmental factors can also affect the adult endocrine system. Based on our review of genetic and environmental factors, we conclude that environmental exposures arising from modern lifestyle, rather than genetics, are the most important factors in the observed trends. These environmental factors might act either directly or via epigenetic mechanisms. In the latter case, the effects of exposures might have an impact for several generations post-exposure. In conclusion, there is an urgent need to prioritize research in reproductive physiology and pathophysiology, particularly in highly industrialized countries facing decreasing populations. We highlight a number of topics that need attention by researchers in human physiology, pathophysiology, environmental health sciences, and demography.

Metabolic Syndrome in Children and Adolescents: a Critical Approach Considering the Interaction between Pubertal Stage and Insulin Resistance

Pediatricians increasingly diagnose the metabolic syndrome (MetS) in recent years to describe cardiovascular risk and to guide management of the obese child. However, there is an ongoing discussion about how to define the MetS in childhood and adolescence. Since insulin resistance-the major driver of MetS-is influenced by pubertal stage, it is questionable to use definitions for MetS in children and adolescents that do not take into account pubertal status. A metabolic healthy status in prepubertal stage does not predict a metabolic healthy status during puberty. Furthermore, cardiovascular risk factors improve at the end of puberty without treatment. However, having a uniform internationally accepted definition of the MetS for children and adolescents would be very helpful for the description of populations in different studies. Therefore, the concept of MetS has to be revisited under the influence of puberty stage.

Early menarche is associated with metabolic syndrome and insulin resistance in premenopausal Korean women

In pediatrics, identifying risk factors is important in planning the prevention of cardiovascular disease. The aim of this study was to determine whether there is an independent association between early menarche (<12 years) and metabolic syndrome (MetS) in Korean women. We analyzed data from 4463 premenopausal women from the Fourth Korea National Health and Nutrition Examination Survey-IV (2007-2009). MetS was defined by the International Diabetes Federation for Asians and insulin resistance (IR) was defined as HOMA-IR more than 3.05. The prevalence of MetS and IR was 7.9 and 15.0%. Women (55.6%) with MetS also showed IR. The prevalence of MetS was higher in both women with early menarche and late menarche (≥16 years) compared with the reference group (early, 12.8%; reference, 7.0%; late, 11.0%, both P = 0.002). However, the odds ratio for MetS was 3.54 (95% confidence interval (CI), 2.14-5.87) and for IR was 2.98 (95% CI, 1.99-4.47) after adjusting for age and other confounders such as lifestyle variables, reproductive variables and sociodemographic variables only in women with early menarche

CONCLUSION

Early menarche was associated with an increased risk of MetS and IR in premenopausal Korean women.

WHAT IS KNOWN

Early menarche is associated with higher risk of CVD-related death and all-cause mortality in Western studies. Early menarche is associated with higher risk of diabetes in Korean premenopausal women.

WHAT IS NEW

Early menarche (<12 years) is associated with metabolic syndrome and insulin resistance in nationally representative Korean premenopausal women. However, late menarche (>16 years) is not associated with metabolic syndrome after controlling for age and other confounders.

Gender-specific associations of serum sex hormone-binding globulin with features of metabolic syndrome in children

BACKGROUND

Sex hormone-binding globulin (SHBG) has been proposed as a biomarker of MetS in children and adults. We aim to determine the associations of SHBG with components of MetS in children from the Middle-East where the prevalence of MetS are on the rise.

METHODS

In this cross-sectional study, a total of 509 randomly selected school children (226 boys and 283 girls) aged 12-16 years were recruited. Fasting blood glucose and lipid profile were determined using routine laboratory procedures. Serum SHBG is measured with Cobas e411 using an electrochemiluminescence immunoassay. The modified definition of ATP-III (NHANES III) was used for the diagnosis of MetS.

RESULTS

Among 509 children, 23.4 % had metabolic syndrome. Boys had a significantly higher waist circumference and systolic blood pressure (p < 0.032, 0.024, respectively) than girls, while levels of glucose (p < 0.029), and SHBG (p < 0.003) were significantly higher in girls than in boys. In overall population, a significant inverse correlation of SHBG level with age, BMI, systolic blood pressure and triglycerides and a significant direct correlation between SHBG level and HDL-c was exhibited. Children with the lowest tertile of serum SHBG had significantly higher prevalence of MetS (p < 0.05). ROC curve shows SHBG level as more sensitive marker of MetS in boys (AUC = 0.70, p < 0.001).

CONCLUSIONS

Serum SHBG is significantly more sensitive in identifying MetS in boys, not girls, indicating gender dimorphism.

Metformin treatment to reduce central adiposity after prenatal growth restraint: a placebo-controlled pilot study in prepubertal children

BACKGROUND

Children born small-for-gestational-age (SGA) who experience rapid postnatal catch-up in weight are at risk for central adiposity and hyperinsulinemia.

OBJECTIVES

To study the effects of prepubertal metformin intervention over 24 months on the body composition and endocrine-metabolic profile of catch-up SGA children.

METHODS

Double-blind, placebo-controlled, pilot study including 23 post-catch-up non-obese prepubertal SGA children [age, 7.7 yr; body mass index standard deviation score (BMI SDS) >50th and <97th centile for age] with increased visceral fat [by magnetic resonance imaging (MRI) and insulin-like growth factor-I (IGF-I) both p > 75th for age]. Patients were randomized to receive either placebo or metformin (425 mg/d) for 24 months. Clinical, biochemical [IGF-I, glucose, insulin, lipids, androgens, sex-hormone-binding globulin (SHBG) and high-molecular-weight (HMW)-adiponectin] and imaging [body composition (absorptiometry and MRI; carotid intima-media thickness (ultrasonography)] variables were assessed at baseline, and at 6, 12, and 24 months.

RESULTS

After 24 months, metformin-treated children were leaner, had higher SHBG levels, and less total and abdominal fat than placebo-treated children (all p ≤ 0.05). Longitudinal analyses showed that metformin had a significant effect on anthropometric (weight, BMI, and waist) and biochemical variables [glucose, homeostasis model assessment-insulin resistance (HOMA-IR), and triglycerides] (all p ≤ 0.05); and in total and abdominal fat (p = 0.01 and p = 0.02).

CONCLUSIONS

Prepubertal intervention with metformin reduces central adiposity and improves insulin sensitivity in non-obese catch-up SGA children.

Age at Menarche and Cardiometabolic Risk in Adulthood: The Coronary Artery Risk Development in Young Adults Study

OBJECTIVE

To examine the association of menarche timing with cardiometabolic risk factors into early to mid-adulthood, comparing African American and White women.

STUDY DESIGN

Analyses included 2583 women (African American = 1333; White = 1250) from the Coronary Artery Risk Development in Young Adults cohort study over 25 years of follow-up (1985-2011). Outcomes included type 2 diabetes, metabolic syndrome, adiposity, glucose, insulin, blood pressure, and blood lipids. Cox models or repeated measures linear regression models estimated the association between age at menarche and the outcomes.

RESULTS

Each 1-year earlier age at menarche was associated with higher mean body mass index among African American (0.88 ± 0.12 kg/m(2), P < .0001) and White (0.89 ± 0.10 kg/m(2), P < .0001) women. After body mass index adjustment, each 1-year earlier age at menarche was associated with higher triglycerides (2.26 ± 0.68 mg/dL, P = .001) and glucose (0.34 ± 0.11 mg/dL, P = .002), and greater risk for incident impaired fasting glucose (hazard ratio = 1.13, 95% CI 1.04-1.20) and metabolic syndrome (hazard ratio 1.19, 95% CI 1.11-1.26) among White women only.

CONCLUSIONS

Excess adiposity associated with earlier menarche is sustained through mid-adulthood, and primarily drives higher cardiometabolic risk factor levels. However, White women with earlier menarche had increased risk of a number of insulin-resistance related conditions independent of adiposity. The cardiometabolic impact of earlier menarche was weaker in African American women despite higher average adiposity. Weight maintenance would likely reduce but may not completely eliminate the elevated cardiometabolic risk of earlier menarche.

Markers of Insulin Sensitivity in 12-Year-Old Children Born from Preeclamptic Pregnancies

OBJECTIVE

To determine whether maternal preeclampsia influences insulin sensitivity (IS) or its biochemical markers in offspring.

STUDY DESIGN

Sixty children born from a preeclamptic pregnancy (PRE) and 60 matched control subjects born from a normotensive pregnancy (non-PRE) were studied at age 12 years. IS was estimated using the Quantitative Insulin Sensitivity Check Index (QUICKI), and serum concentrations of adiponectin, leptin, insulin-like growth factor (IGF)-1, IGF-2, IGF-binding protein-1 (IGFBP-1), sex hormone-binding globulin, lipids, and casual blood pressure (BP) were measured.

RESULTS

The mean values of QUICKI, serum adiponectin, leptin, IGF-1, IGF-2, IGFBP-1, and sex hormone-binding globulin did not differ between the PRE group and non-PRE group (P > .05 for all). The PRE subjects with the lowest IS (the lowest QUICKI tertile; n = 20) had significantly higher mean serum leptin (P = .007), triglyceride (P = .008), and IGF-1 (P = .005) levels and systolic BP (P = .019), and lower serum IGFBP-1 level (P = .007) compared with PRE subjects with higher QUICKI values (n = 40). Similarly, in logistic regression analysis, higher serum leptin (OR, 1.2; P = .009), triglyceride (OR, 1.2; P = .040), and IGF-1 (OR, 1.1; P = .031) levels and systolic BP (OR, 5.8; P = .024) were associated with low QUICKI in the PRE group.

CONCLUSION

Maternal preeclampsia did not produce decreased IS in offspring by age of 12 years. However, the offspring with the lowest IS had higher mean serum triglyceride level and systolic BP, suggesting that components of the metabolic syndrome may cluster in this subgroup.

Early menarche increases the risk of Type 2 diabetes in young and middle-aged Korean women

AIMS

To investigate the association between early menarche (menarche age < 12 years) and Type 2 diabetes mellitus in young and middle-aged Korean women.

METHODS

We analysed data for 4657 women aged 20-50 years from the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV) (2007-2009).

RESULTS

The prevalence of Type 2 diabetes was 2.8%. Women with early menarche had a higher prevalence of impaired fasting glucose than did women with later menarche (age ≥ 12 years) in the 20-30 age group (7.4% vs. 3.0%), and a higher prevalence of diabetes in the 30-40 (6.3% vs. 1.7%) and 40-50 (18.5% vs. 4.4%) age groups. The odds ratio (OR) of Type 2 diabetes in women with early menarche was 3.61 [95% confidence interval (CI), 1.90-6.88] after adjusting for age. In multivariate regression, the OR of Type 2 diabetes decreased to 2.52 (95% CI, 1.29-4.94) after further adjusting for BMI. However, the OR decreased to 2.04 (95% CI, 0.95-4.39) without significance after adjusting for HOMA-IR.

CONCLUSIONS

Early menarche increased the risk of Type 2 diabetes in young and middle-aged Korean women although adulthood adiposity attenuated the relationship. Knowledge of age at menarche is important in identifying women at risk for diabetes.

A randomized controlled trial on a multicomponent intervention for overweight school-aged children - Copenhagen, Denmark

Background

Obesity amongst children is a growing problem worldwide. In contrast to adults, little is known on the effects of controlled weight loss on components of the metabolic syndrome in children. The primary aim of the study was to evaluate the effects of a 20-week exercise and diet guidance intervention on body mass index (BMI) in a group of overweight children. Our hypothesis was an observed reduction in BMI and secondarily in body fat content, insulin insensitivity, and other components of the metabolic syndrome in the intervention group.

Methods

School children from Copenhagen were randomly allocated to an intervention group (n = 19) or a control group (n = 19). Anthropometric assessment, whole body dual-energy X-ray absorptiometry scan, two hours oral glucose tolerance test, steps measured by pedometer, and fitness tests were measured at baseline and at 20 weeks.

Results

Thirty-seven children (30 girls) participated at baseline, aged 8.7 ± 0.9 years with a BMI of 21.8 ± 3.7 kg/m² (mean ± SD), and 36 children completed the study. The intervention group decreased their BMI (the intervention effect is the difference in change between the groups adjusted for the respective baseline values (DELTA) = -2.0 kg/m², 95% CI: -2.5; -1.5, P <0.001), total body mass (DELTA = -4.0 kg, 95% CI: -4.9; -3.0, P <0.001), and fat mass (DELTA = -3.3 kg, 95% CI: -4.2; -2.7, P <0.001) compared to the control group after the intervention. The intervention group displayed decreased waist, hip and waist-to-height ratio (WHtR) (all three variables; P <0.001), area under curve for plasma insulin (P <0.05), and increased mean and minimum steps/day (P <0.05 and P <0.01, respectively).

Conclusions

The multicomponent intervention had significant favorable effects on BMI, weight, WHtR, mean and minimum steps/day, and fat mass. In addition, similar beneficial metabolic effects were found in the children as shown in adults, e.g. increase in peripheral insulin sensitivity.

Trial registration

Clinicaltrials.gov Identifier number NCT01660789.

Plasma non-esterified fatty acid levels in children and their relationship with sex steroids

OBJECTIVE

Puberty is associated with decreased insulin sensitivity. Sexual hormones have been related with the onset of insulin resistance, but their relationship with non-esterified fatty acids (NEFA) remains unexplored. The aim of this study was to evaluate circulating NEFA levels in population-based samples of prepubertal children and adolescents and to analyze the association of NEFA with obesity, insulin resistance, and sexual hormones in adolescents.

EXPERIMENTAL

The studied population included 854 randomly selected 6-8-year-old children and 822 children aged 12-16years. NEFA levels were determined using a commercial kit. Testosterone and estradiol levels were determined by RIA, and insulin and sex hormone binding protein by IRMA. HOMA was calculated as an indicator of insulin resistance.

RESULTS

NEFA levels were lower in adolescents than in 6-8-year-old children, and decreased progressively with age between 12-year-olds and 16-year-olds. No significant differences in NEFA levels were observed between obese and non-obese adolescents. NEFA were not correlated with insulin or HOMA in 12-16-year-old girls, and appear negatively correlated with these variables in boys. Insulin and HOMA were negatively correlated with SHBG levels in both sexes adjusting by age but NEFA levels were not.

CONCLUSIONS

NEFA levels decrease with age in adolescents and are not significantly increased in obese children, supporting the fact that the decreased insulin sensitivity at this age is not affecting NEFA metabolism. Although SHBG is related to insulin and HOMA independently of age in both sexes, SHBG levels are not associated with NEFA.

Heart rate variability in pubertal girls with type 1 diabetes: its relationship with glycaemic control, insulin resistance and hyperandrogenism

OBJECTIVE

To examine the association between glycaemic control, insulin resistance and hyperandrogenism on cardiac autonomic function in peripubertal girls with type 1 diabetes.

DESIGN

Prospective, clinic-based study of 125 girls with diabetes and 46 age-matched nondiabetic girls.

MEASUREMENTS

Heart rate variability (HRV) parameters derived from a 10-min ECG recording using LabChart Pro were as follows: standard deviation of mean NN intervals (SDNN), where NN = adjacent QRS complexes; root mean squared difference of successive NN intervals (RMSSD) - estimates of overall HRV; and low-/high-frequency (LF:HF) ratio - an estimate of the sympathovagal balance. Androgens and sex hormone binding globulin (SHBG) were measured in girls with diabetes, and free androgen index (FAI) calculated. HRV and anthropometry were measured in nondiabetic controls.

RESULTS

Adolescents with diabetes (median age 15·1 years [13·3-16·0], diabetes duration 7·0 years [4·6-10·0] and median HbA1c 8·4% [7·5-9·3]) had higher HR and lower HRV compared with controls. Using multivariate models in the diabetes group, higher HR was associated with higher HbA1c, total daily dose insulin/kg body weight and systolic BP standard deviation scores (SDS), whilst reduced HRV was associated with higher HbA1c (SDNN, RMSSD and LF:HF ratio), lower SHBG (SDNN and RMSSD) and higher weight SDS (LF:HF ratio). Higher FAI was associated with higher HR and reduced HRV measures in the univariate analyses only.

CONCLUSIONS

In adolescent girls with diabetes, reduced HRV parameters are associated with worse glycaemic control, lower SHBG and higher weight SDS. SHBG should be considered in the cardiac risk models for this population.

Significant gender difference in serum levels of fibroblast growth factor 21 in Danish children and adolescents

Introduction

Fibroblast Growth Factor 21 (FGF21) is a novel metabolic factor with effect on glucose and lipid metabolism, and shown to be elevated in diseases related to metabolic syndrome. Due to the increasing frequency of metabolic syndrome in the pediatric population, and as FGF21 studies in children are limited, we investigated baseline serum levels of FGF21 in healthy children during an oral glucose tolerance test.

Methods

A total of 179 children and adolescents from the COPENHAGEN Puberty Study were included. An OGTT with glucose and insulin measurements, a dual energy X-ray absorptiometry (DXA) scan and a clinical examination including pubertal staging were done on all subjects. Serum levels of FGF21, adiponectin, and leptin were determined by immunoassays at baseline.

Results

The girls had significantly higher levels of FGF21 compared with boys (155 pg/mL vs. 105 pg/mL, P = 0.04). 38 children (21%) had levels below detection limit of assay. Baseline levels of FGF21 showed positive correlation with triglycerides, but no significant correlations were found between FGF21-concentration and body mass index (BMI), DXA-derived fat percentage, LDL- HDL- and non-HDL cholesterol, leptin or adiponectin levels, respectively. Neither was any correlation found between baseline FGF21-levels and the dynamic changes in glucose and insulin levels during the OGTT.

Conclusion

FGF21 is independent of adiposity in children, and the significant metabolic effect seems to be limited to pathological conditions associated with insulin resistance. The higher levels of triglycerides in the girls may explain the significantly higher levels of FGF21 in girls compared with boys.

Systematic review registration

The COPENHAGEN Puberty Study was registered in ClinicalTrials.gov (identifier NCT01411527), and approved by the local ethics committee (reference no. KF 01 282214 and KF 11 2006–2033).

Puberty as an accelerator for diabetes complications

Much is written about how difficult it is to deal with diabetes during adolescence, and rightly so. Less is understood as to how puberty may be an accelerator of vascular complications. With the increase in childhood diabetes, complication risks need to be revisited in relation to puberty and the secular increase in adiposity. Recent data suggest greater risk for severe vascular complications in those with diabetes during puberty, compared with young people who develop diabetes after puberty. It is also widely recognized that higher hemoglobin A1c (HbA1c) results are often seen during the pubertal period. This article will review complication outcomes in relation to puberty and examine mechanisms by which puberty may modify risk above glycemic exposure, and possible gender disparities in the risk of complications in the adolescent period.

Insulin resistance indices are inversely associated with vitamin D binding protein concentrations

CONTEXT

We hypothesized that, similar to the coordinated homeostatic regulation of most hormones, the concentration of free and bioavailable 25-hydroxyvitamin D [25(OH)D] will be tightly controlled by total 25(OH)D and vitamin D binding protein (VDBP) and that the VDBP concentrations will be associated with insulin resistance status.

OBJECTIVE

Our primary objective was to investigate associations between total, free, and bioavailable 25(OH)D and VDBP. We also evaluated the relationships of VDBP with insulin resistance indices.

STUDY DESIGN

The study design was cross-sectional in the setting of a university children's hospital. The relative concentration of bioavailable 25(OH)D to total 25(OH)D [bioavailable 25(OH)D/total 25(OH)D was expressed as a percentage [percentage bioavailable 25(OH)D].

RESULTS

Subjects were 47, postmenarchal, female adolescents, with a mean age of 15.8±1.4 years, a mean body mass index of 23.1±4.0 kg/m2. The total 25(OH)D was strongly associated with VDBP (rho=0.57, P<.0001). At lower total 25(OH)D concentrations, the concentration of bioavailable 25(OH)D relative to total 25(OH)D was higher (23.8% vs 14.9%, P<.0001), whereas the relative concentration of free 25(OH)D was similar (P=.44). VDBP was inversely associated with fasting insulin (rho=-0.51, P=.0003) and homeostatic model assessment of basal insulin resistance (rho=-0.45, P=.002) and positively with whole-body insulin sensitivity (rho=0.33, P=.02); these relationships persisted after adjusting for percentage fat and attenuated after adjusting for race.

CONCLUSION

Our data suggest that VDBP concentrations are regulated by total 25(OH)D levels to maintain adequate concentrations of bioavailable 25(OH)D. VDBP concentrations are inversely associated with hyperinsulinemia and insulin resistance.

Increased sex hormone-binding globulin levels in children and adolescents with thyrotoxicosis

BACKGROUND

Thyrotoxicosis is a rare condition in pediatric patients, and optimal treatment can be difficult to achieve in some children. To our knowledge, no studies have evaluated sex hormone-binding globulin (SHBG) levels in hyperthyroid children and adolescents in relation to age- and gender-related normative data.

METHODS

SHBG serum levels were determined before and after 4 months of antithyroid therapy (ATT) in 10 children and adolescents with Graves' disease. A total of 903 healthy children and adolescents served as controls.

RESULTS

Serum SHBG levels were elevated (>2 SD) at diagnosis in all hyperthyroid children but normalized rapidly following ATT. At diagnosis, median SHBG was +2.51 SD (interquartile range 2.20-3.27) compared to healthy children without thyroid illness, and it declined significantly during ATT (-0.16 SD, -0.66 to 1.64; p < 0.05).

CONCLUSION

This is the first study to demonstrate that serum SHBG levels are markedly increased in children with Graves' disease, and we suggest that SHBG may be an additional marker of thyroid hormone action in children, as has been shown in adults.