Serum leptin levels in premature pubarche and prepubertal girls with and without obesity

Lipid profile in girls with precocious puberty: a systematic review and meta-analysis

OBJECTIVE

Many studies have investigated the impact of precocious puberty on cardiovascular disease (CVD) outcomes and the association between lipid profile levels and precocious puberty. However, the results have been inconsistent. The aim of this meta-analysis was to evaluate whether triglyceride (TG), total cholesterol (TC), high density lipoprotein (HDL)and low density lipoprotein (LDL) levels were altered in girls with precocious puberty compared with healthy controls.

METHODS

References published before June 2022 in the EMBASE, Cochrane Library, PubMed and Web of Science databases were searched to identify eligible studies. A DerSimonian-Laird random-effects model was used to evaluate the overall standard mean difference (SMD) between precocious puberty and healthy controls. Subgroup analyses and sensitivity analyses were preformed, and publication bias was assessed.

RESULTS

A total of 14 studies featuring 1023 girls with precocious puberty and 806 healthy girls were selected for analysis. The meta-analysis showed that TG (SMD: 0.28; 95% CI: 0.01 to 0.55; P = 0.04), TC (SMD: 0.30; 95% CI: 0.01 to 0.59; P = 0.04), LDL (SMD: 0.45; 95% CI: 0.07 to 0.84; P = 0.02)levels were significantly elevated in girls with precocious puberty. HDL levels did not change significantly (SMD: -0.06; 95% CI: -0.12 to 0.61; P = 0.62). Subgroup analyses revealed that the heterogeneity in the association between lipid profile and precocious puberty in this meta-analysis may arise from disease type, region, sample size, chronological age, body mass index difference and drug usage.

CONCLUSION

Lipid profile levels altered in girls with precocious puberty compared with healthy controls. In order to minimize the risk of CVD morbidity and mortality, early interventions were needed to prevent obesity in children and adolescents, especially those with precocious puberty.

Evaluation of Glucose Metabolism and Cardiovascular Risk Factors in Prepubertal Girls with Premature Pubarche

OBJECTIVE

Premature pubarche (PP) is a risk factor for metabolic syndrome (MS). The aim was to evaluate if glucose-insulin metabolism, cardiovascular risk factors, familial cardiovascular risk factors (FCVRF) created a risk for insulin resistance (IR) and if PP was a risk factor alone for MS in normal weight prepubertal girls with PP.

METHODS

Thirty-five prepubertal, non-obese girls with PP with normal birth weight and 35 age-matched control girls were evaluated for FCVRF, anthropometric measurements, blood pressure, lipid profile, fasting blood glucose-insulin, hemoglobin A1c (HbA1c), sex hormone binding globulin (SHBG), leptin, adiponectin, tumor necrosis factor-alpha (TNF-α), androgen levels, and bone age. Oral glucose tolerance test was performed in PP participants. Homeostasis model of assessment of IR (HOMA-IR), fasting glucose/insulin ratio, atherogenic index (AI), and free androgen index (FAI) were calculated. PP participants were further stratified by FCVRF.

RESULTS

HbA1c, lipid profile, testosterone, leptin, adiponectin, TNF-α, HOMA-IR, glucose/insulin ratio, AI, and fasting glucose-insulin levels were similar. In the PP group FAI was significantly higher (p=0.001), whereas SHBG was significantly lower (p=0.010) than the control group. Leptin levels of FCVRF+ and FCVRF- subgroups were 15.2±9.1 and 9.7±7.2 ng/mL, respectively and the difference was significant (p=0.016).

CONCLUSION

As PP does not appear to be a risk factor alone for impaired glucose metabolism and IR in prepubertal non-obese girls with normal birth weight, it is our opinion that it is unnecessary to examine in detail such cases before puberty. Low SHBG levels in the PP group and high leptin levels in FCVRF+ subgroup might suggest that these may be predictive for MS in the future.

Hyper-androgenemia and obesity in early-pubertal girls

PURPOSE

The aim of this study was to examine the hormonal profile in early-pubertal girls with obesity. We hypothesized that these patients might already present hormonal alterations with POCS-like features.

METHODS

Cross-sectional study in a sample of 283 peri-pubertal girls (prepubertal and early-puberty subgroups), aged 6.1-12.0 years, diagnosed with obesity (BMI-SDS > 2.0, 97th percentile), so-called obesity group. They all underwent clinical examination and blood testing for hormonal measurements (leptin, TSH, FT4, IGF-1, IGFBP3, prolactin, insulin, FSH, LH, estradiol, ACTH, cortisol, 17-OH-P, DHE-S, androstenedione, testosterone and free testosterone). A control group was recruited: 243 healthy girls, aged 6.3-12.1 years, with normal BMI status.

RESULTS

Prepubertal girls with obesity had significantly higher values (p < 0.05) for BMI-SDS, leptin, insulin and HOMA-IR levels than control group. Early-pubertal girls with obesity also had significantly higher values (p < 0.05) for BMI-SDS, leptin, IGF-1, IGFBP3, insulin and HOMA-IR, LH, ratio LH/FSH, ACTH, DHE-S, androstenedione, testosterone and free testosterone levels than control group. In early-pubertal girls with obesity (not prepubertal girls), there was a positive correlation (p < 0.01) between leptin levels with LH, androstenedione and testosterone, and HOMA-IR with LH and testosterone levels. There was also a positive correlation (p < 0.01) between IGF-1 levels with LH, androstenedione, DHE-S and testosterone; and LH levels with testosterone.

CONCLUSION

The results obtained support our hypothesis that an abnormal hormonal profile with POCS-like features can already be detected (insulin resistance and hyperinsulinemia, increased secretion of LH and ACTH, and overproduction of ovarian and adrenal androgens) in early-pubertal girls with obesity.

High DHEAS in girls and metabolic features throughout pubertal maturation

CONTEXT

An association between premature adrenarche and metabolic syndrome at presentation has been described. Our aim was to assess whether the presence of high dehydroepiandrosterone sulphate (DHEAS [HD]) at the adrenarche determines the risk of metabolic syndrome during puberty, taking into account body mass index (BMI) and birth weight.

DESIGN

Prospective observational.

PATIENTS

Five hundred four girls from the Growth and Obesity Chilean Cohort Study were followed from birth through puberty. At age ~7, subjects were classified by DHEAS concentrations into the HD (>75th percentile) or normal DHEAS (ND, ≤75th percentile) subgroups.

MEASUREMENTS

Anthropometrics, semiannual clinical pubertal staging and hormonal and metabolic levels. The relationships among DHEAS at age ~7, metabolic syndrome, and each of its components independently, were analyzed by linear and logistic regression models during puberty and 1-year postmenarche, adjusted by confounders.

RESULTS

Girls with HD at 7 years exhibited higher BMI, more central fat and higher serum androgen and insulin like growth factor (IGF)-I levels throughout puberty. Also, girls with HD had a greater prevalence of hyperglycemia at B2 and B4 breast stages, and of low HDL at B4. At 1 year after menarche, HD girls had a higher prevalence of metabolic syndrome, and those with BMI > 1 SD score had a higher metabolic score and insulin levels than ND girls with similar BMI.

CONCLUSIONS

Our observations suggest that girls with HD at the age of adrenarche may be at greater risk for metabolic syndrome at adolescence, especially in those who are overweight or obese. Our results emphasize the importance of lifestyle interventions for childhood overweight and obesity among girls with HD.

Normal and Premature Adrenarche

Adrenarche is the maturational increase in adrenal androgen production that normally begins in early childhood. It results from changes in the secretory response to adrenocorticotropin (ACTH) that are best indexed by dehydroepiandrosterone sulfate (DHEAS) rise. These changes are related to the development of the zona reticularis (ZR) and its unique gene/enzyme expression pattern of low 3ß-hydroxysteroid dehydrogenase type 2 with high cytochrome b5A, sulfotransferase 2A1, and 17ß-hydroxysteroid dehydrogenase type 5. Recently 11-ketotestosterone was identified as an important bioactive adrenarchal androgen. Birth weight, body growth, obesity, and prolactin are related to ZR development. Adrenarchal androgens normally contribute to the onset of sexual pubic hair (pubarche) and sebaceous and apocrine gland development. Premature adrenarche causes ≥90% of premature pubarche (PP). Its cause is unknown. Affected children have a significantly increased growth rate with proportionate bone age advancement that typically does not compromise growth potential. Serum DHEAS and testosterone levels increase to levels normal for early female puberty. It is associated with mildly increased risks for obesity, insulin resistance, and possibly mood disorder and polycystic ovary syndrome. Between 5% and 10% of PP is due to virilizing disorders, which are usually characterized by more rapid advancement of pubarche and compromise of adult height potential than premature adrenarche. Most cases are due to nonclassic congenital adrenal hyperplasia. Algorithms are presented for the differential diagnosis of PP. This review highlights recent advances in molecular genetic and developmental biologic understanding of ZR development and insights into adrenarche emanating from mass spectrometric steroid assays.

Premature Adrenarche and its Association with Cardiovascular Risk in Females

Early activation of the adrenal zona reticularis, leading to adrenal androgen secretion, mainly dehydroepiandrosterone sulfate (DHEAS), is called premature adrenarche (PA). The fact that adrenal hyperandrogenism in females has been linked to a cluster of cardiovascular (CV) risk factors, even in prepubertal children, warrants investigation. Controversial results have been obtained in this field, probably due to genetic, constitutional, and environmental factors or differences in the characteristics of participants. In an attempt to understand, in depth, the impact of PA as a potential activator of CV risk, we critically present available data stratified according to pubertal status. It seems that prepubertally, CV risk is increased in these girls, but is somewhat attenuated during their second decade of life. Furthermore, different entities associated with PA, such as polycystic ovary syndrome, non-classical congenital adrenal hyperplasia, heterozygosity of CYP21A2 mutations, and the impact of DHEAS on CV risk, are reviewed. At present, firm and definitive conclusions cannot be drawn. However, it may be speculated that girls with a history of PA display a hyperandrogenic hormonal milieu that may lead to increased CV risk. Accordingly, appropriate long-term follow-up and early intervention employing a patient-oriented approach are recommended.

Cardiometabolic Risk Profile Among Young Adult Females With a History of Premature Adrenarche

Context

Premature adrenarche (PA) is associated with childhood overweight and hyperinsulinemia; the long-term cardiometabolic outcome is unknown.

Objective

To study cardiometabolic profile in adult women with previous PA.

Design and participants

Thirty women with PA and 41 control subjects were followed from prepuberty to young adulthood.

Main outcome measures

Prevalence of the metabolic syndrome (MetS) and clinical and biochemical cardiovascular risk factors.

Results

There were no differences in the prevalence of MetS or in any parameters indicating dyslipidemia, hypertension, hepatosteatosis, atherosclerosis, or low-grade inflammation between the study groups. However, prevalence of insulin resistance (IR; P = 0.014) and acanthosis nigricans (P = 0.010) was higher in the PA group. Neither fasting glucose nor insulin concentrations differed between the study groups, but HbA1c [adjusted for body mass index (BMI) P = 0.011] and Homeostatic Model Assessment of Insulin Resistance (P = 0.044; BMI-adjusted P = nonsignificant) were higher in the PA group. Although BMI and fat percentage were comparable between the study groups, the PA group had higher central fat mass than the control group. In the whole study population, MetS and IR were associated with greater adult fat mass, but no prepubertal factors predicting later IR were found.

Conclusion

PA does not seem to be associated with MetS, dyslipidemia, hypertension, atherosclerosis, or low-grade inflammation in young adult women. However, some women with PA may be at an increased risk of unfavorable glucose metabolism, which is associated with increased central adiposity at adult age rather than determined by prepubertal factors.

The relationship between obesity and body compositions with respect to the timing of puberty in Chongqing adolescents: a cross-sectional study

BACKGROUND

It is well known that excess adiposity during childhood may influence pubertal development. However, the extent to which body compositions vary in throughout puberty in boys and girls is currently unknown. The aim of this study was to investigate whether obesity and body compositions correlate with the timing of puberty in boys and girls.

METHODS

By random cluster sampling, our study analyzed data from 1472 students (690 girls, 782 boys) aged 6-17 years from two schools in the Chongqing area. Data were collected by physical examination of weight, height, and skinfold thicknesses. Testicular volume was measured in boys and breast development in girls. By which we got the indicators of obesity, timing of puberty and body compositions. Probit regression analysis was used to group subjects into early puberty (>P25), on-time puberty (P25 ~ P75), and delayed puberty (

RESULTS

There were significant differences in the distribution of fat levels (normal weigh, overweight, obesity) among different pubertal groups in different sex (boys:χ2 = 10.639, P = 0.031; girls:χ2 = 63.232, P = 0.000). Multivariate analysis of covariance showed that percentage of body fat, fat mass and fat-free mass in the delayed puberty girls were significantly lower than the girls in the on-time puberty and early puberty, while body density had the opposite result (all P < 0.001). Body density, percentage of body fat, fat mass and fat-free mass of boys all had no significant difference among different timing of puberty groups (all P > 0.05).

CONCLUSIONS

In girls, delayed puberty was negatively correlated with Obesity, percentage of body fat, fat mass and fat-free mass, and positively correlated with body density. But in boys, delayed puberty was only negatively correlated with Obesity, the relation between puberty and body compositions was not found.

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Key Words

• Adolescents
• Body compositions
• Obesity
• Timing of puberty

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MESH Headings

• Adolescent
• Body Composition/physiology
• Child
• China/epidemiology
• Cross-Sectional Studies
• Female
• Humans
• Male
• Pediatric Obesity/epidemiology
• Pediatric Obesity/physiopathology
• Puberty/physiology
• Time Factors

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Grants

• National Natural Science Foundation of China

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Affiliation(s)

Fang He School of Public Health and Management, Chongqing Medical University, Research Center for Medicine and Social Development, Collaborative Innovation Center of Social Risks Governance in Health, Chongqing Medical University, Chongqing, 400016 China
Peiyu Guan School of Public Health and Management, Chongqing Medical University, Research Center for Medicine and Social Development, Collaborative Innovation Center of Social Risks Governance in Health, Chongqing Medical University, Chongqing, 400016 China Chongqing Health Information Center, Chongqing, 400016 China
Qin Liu School of Public Health and Management, Chongqing Medical University, Research Center for Medicine and Social Development, Collaborative Innovation Center of Social Risks Governance in Health, Chongqing Medical University, Chongqing, 400016 China Duke Global Health Institute, Duke University, Durham, NC 27708 USA
Donna Crabtree School of Medicine, Duke University Medical Center, Durham, NC 27705 USA
Linli Peng School of Public Health and Management, Chongqing Medical University, Research Center for Medicine and Social Development, Collaborative Innovation Center of Social Risks Governance in Health, Chongqing Medical University, Chongqing, 400016 China
Hong Wang School of Public Health and Management, Chongqing Medical University, Research Center for Medicine and Social Development, Collaborative Innovation Center of Social Risks Governance in Health, Chongqing Medical University, Chongqing, 400016 China

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From Placenta to Polycystic Ovarian Syndrome: The Role of Adipokines

Adipokines are cytokines produced mainly by adipose tissue, besides many other tissues such as placenta, ovaries, peripheral-blood mononuclear cells, liver, muscle, kidney, heart, and bone marrow. Adipokines play a significant role in the metabolic syndrome and in cardiovascular diseases, have implications in regulating insulin sensitivity and inflammation, and have significant effects on growth and reproductive function. The objective of this review was to analyze the functions known today of adiponectin, leptin, resistin, and visfatin from placenta throughout childhood and adolescence. It is well known now that their serum concentrations during pregnancy and lactation have long-term effects beyond the fetus and newborn. With regard to puberty, adipokines are involved in the regulation of the relationship between nutritional status and normal physiology or disorders of puberty and altered gonadal function, as, for example, premature pubarche and polycystic ovarian syndrome (PCOS). Cytokines are involved in the maturation of oocytes and in the regular progression of puberty and pregnancy.

Premature adrenarche: novel lessons from early onset androgen excess

Adrenarche reflects the maturation of the adrenal zona reticularis resulting in increased secretion of the adrenal androgen precursor DHEA and its sulphate ester DHEAS. Premature adrenarche (PA) is defined by increased levels of DHEA and DHEAS before the age of 8 years in girls and 9 years in boys and the concurrent presence of signs of androgen action including adult-type body odour, oily skin and hair and pubic hair growth. PA is distinct from precocious puberty, which manifests with the development of secondary sexual characteristics including testicular growth and breast development. Idiopathic PA (IPA) has long been considered an extreme of normal variation, but emerging evidence links IPA to an increased risk of developing the metabolic syndrome (MS) and thus ultimately cardiovascular morbidity. Areas of controversy include the question whether IPA in girls is associated with a higher rate of progression to the polycystic ovary syndrome (PCOS) and whether low birth weight increases the risk of developing IPA. The recent discoveries of two novel monogenic causes of early onset androgen excess, apparent cortisone reductase deficiency and apparent DHEA sulphotransferase deficiency, support the notion that PA may represent a forerunner condition for PCOS. Future research including carefully designed longitudinal studies is required to address the apparent link between early onset androgen excess and the development of insulin resistance and the MS.

Postprandial plasma adiponectin response is reduced in prepubertal premature pubarche girls

The association between premature pubarche (PP) and metabolic syndrome is controversial and not supported by some authors. The aim of this study was to determine insulin resistance syndrome, plasma adiponectin, and fatty acid profile in PP girls to discern potential confounder variables and markers of metabolic disturbances. We studied 22 prepubertal girls with a diagnosis of PP and 20 healthy controls who differed in body mass index (BMI) (19.33 +/- 0.71 vs 17.30 +/- 0.60). We evaluated insulin resistance syndrome components and postprandial response of adiponectin, nonesterified fatty acids, and fatty acid profile after consumption of a standardized breakfast. No lipid disturbances were detected in the PP group. High-density lipoprotein to low-density lipoprotein cholesterol ratio tended to be lower in PP girls (P = .052), but this effect disappeared when data were adjusted for both BMI and age (P = .480). Insulin levels tended to be higher at 2 hours in PP girls, who showed significantly higher C-peptide area under the curve. In contrast, adiponectin at 3 hours after the meal and postprandial adiponectin area under the curve were significantly lower. The PP girls showed significantly higher percentages of eicosapentaenoic acid in total plasma and plasma phospholipids. No differences were found in the postprandial fatty acid clearance rate. In conclusion, PP girls and controls differed in postprandial plasma adiponectin response and in postprandial plasma C-peptide response after both BMI and age adjustment. Cholesterol plasma disturbances were mainly attributable to their higher BMI, although n-3 polyunsaturated fatty acids were higher because of the PP.

The Effect of Exercise on Leptin, Insulin, Cortisol and Lipid Profiles in Obese Children

This prospective, randomized study investigated the effect of exercise on leptin, insulin, cortisol and lipid profiles in obese children. A total of 40 obese boys aged 10-12 years with a body mass index (BMI) ≥ 30 kg/m2 were randomly separated into an exercise group ( n = 20) that underwent a 12-week aerobic exercise programme and a non-exercise (control) group ( n = 20). The BMI, low-density lipoprotein, cortisol, leptin and insulin levels were significantly lower in the exercise group after 12 weeks compared with baseline values, whereas high-density lipoprotein levels were significantly higher. In contrast, in the control group, low-density lipoprotein, cortisol and leptin levels were significantly higher after 12 weeks compared with baseline values while high-density lipoprotein levels were significantly lower. These findings indicate the importance of regular exercise in the regulation of body weight and protection against cardiovascular risk factors in obese children.

Childhood metabolic syndrome and its components in premature adrenarche

CONTEXT

Premature pubarche (PP), the main clinical manifestation of premature adrenarche (PA), has been associated with insulin resistance and dyslipidemia in selected populations.

OBJECTIVES

Our aim was to determine the prevalence of childhood metabolic syndrome (cMBS) and to study its components in prepubertal Northern European girls with PA.

DESIGN AND PATIENTS

We conducted a cross-sectional study on 63 prepubertal girls with PA (32 with PP = PP-PA, 31 without PP = nonPP-PA) and 80 healthy age-matched control girls. A standard 2-h oral glucose tolerance test with insulin sampling was performed. Plasma lipids and serum SHBG were analyzed, and blood pressure and weight-for-height were recorded. cMBS was defined by modified criteria of the U.S. National Cholesterol Education Project Adult Treatment Panel III and the World Health Organization.

SETTING

The study was performed at University Hospital.

RESULTS

The mean weight-for-height (P = 0.002) and the prevalence of cMBS by the modified Adult Treatment Panel III (24 vs. 10%) and World Health Organization definitions (16 vs. 5%) (P < 0.05 for both) were higher in the PA than control girls. The weight-for-height adjusted serum insulin concentrations during the oral glucose tolerance test were elevated in the whole PA group, whereas the fasting insulin concentrations were increased and SHBG was decreased only in the PP-PA subgroup. The weight-for-height adjusted blood pressure, lipid, or glucose levels did not differ between the study groups.

CONCLUSIONS

Prepubertal Northern European PA girls have increased prevalence of cMBS mainly due to being overweight and their hyperinsulinism. Among the PA children, the nonPP-PA girls have milder metabolic changes than the PP-PA girls.

Biomarker discovery in rat plasma for estrogen receptor-α action

To support in vivo screening efforts for estrogen receptor (ER) subtype selective therapeutic agents, we initiated work to discover surrogate markers (biomarkers) in blood plasma that would change in response to ER subtype-specific action. We used a proteomic approach employing strong anion exchange chromatography (SAX), PAGE, and MS to identify potential plasma markers for selective ER-alpha action. The methodology was used to compare blood from vehicle-treated rats to blood from rats treated with either 17beta-estradiol (an ER-alpha/ER-beta agonist) or compound 1 (17alpha-ethynyl-[3,2-c]pyrazolo-19-nor-4-androstene-17beta-ol, an ER-alpha-selective agonist). Blood samples were first fractionated by SAX to separate fractions containing dominant common plasma proteins from fractions enriched for less-abundant plasma proteins. 1-D PAGE analysis of fractions depleted of dominant plasma proteins revealed treatment-specific changes in protein profiles. Protein bands that changed reproducibly in response to ER-alpha action were excised from the gel, separated by capillary LC, and identified by microspray ESI-MS. Using this method, the plasma levels of two proteins, transthyretin and apolipoprotein E, were shown to decrease in response to ER-alpha agonism. The method lacked the sensitivity to identify the known, 1000-fold less-abundant, estrogenic marker prolactin (PRL). However, using a commercial RIA and immunoblots, we showed that PRL levels increase significantly in response to treatment with the ER-alpha selective agonist, compound 1.

Are growth factors and leptin involved in the pathogenesis of premature adrenarche in girls?

A transient increase in height and bone age as well as hyperinsulinism is seen in patients with premature adrenarche (PA). In addition, the weights of these patients are more than those of healthy peers. The aim of this study was to evaluate the role of leptin, IGF-I and IGFBPs in hyperandrogenemia and increased body weight observed in girls with PA. In this study, IGF-I, IGFBP-3, IGFBP-1 and leptin levels were investigated in 27 children with PA aged 5.4-8.6 years and 13 healthy children aged 5.7-8.58 years. Twenty patients were lean. The bone ages and BMIs of the children with PA were significantly higher than those of the healthy controls (p < 0.05). IGF-I (p < 0.005), IGFBP-3 (p < 0.05) and leptin (p < 0.0001) levels of lean PA girls were higher than controls. The leptin level of the obese PA girls was higher than that of the lean PA girls (p < 0.05) and controls (p < 0.0001). The IGFBP-1 level of the PA girls with and without obesity was lower than controls (p < 0.05). A negative correlation was observed between IGFBP-1 and leptin levels of the girls with PA (r = -0.64, p < 0.05). Serum leptin levels were influenced by BMI (p = 0.001), basal 17-OHP (p = 0.002) and stimulated 17-OHP (p = 0.019) in patients with PA. In conclusion, we suggest that elevated IGF-I and insulin give rise to increased adrenal androgens and leptin levels. On the other hand, both insulin and leptin cause decreased levels of IGFBP-1 in girls with PA, even if they are lean.