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

Adiposity Metabolic Consequences for Adolescent Bone Health

Infancy and adolescence are crucial periods for bone health, since they are characterized by intense physical growth and bone development. The unsatisfactory acquisition of bone mass in this phase has consequences in adult life and increases the risk of developing bone diseases at more advanced ages. Nutrient deficiencies, especially calcium and vitamin D, associated with a sedentary lifestyle; lack of sun exposure; and epigenetic aspects represent some of the main risk factors for poor bone quality. In addition, recent studies relate childhood obesity to impaired bone health; however, studies on the adiposity effects on bone health are scarce and inconclusive. Another gap concerns the implications of obesity on child sexual maturity, which can jeopardize their genetic potential bone mass and increase fracture risk. Therefore, we reviewed the analyzed factors related to bone health and their association with obesity and metabolic syndrome in adolescents. We concluded that obesity (specifically, accumulated visceral fat) harms bones in the infant-juvenile phase, thereby increasing osteopenia/osteoporosis in adults and the elderly. Thus, it becomes evident that forming and maintaining healthy eating habits is necessary during infancy and adolescence to reduce the risk of fractures caused by bone-metabolic diseases in adulthood and to promote healthy ageing.

Effect of Sex Hormone-Binding Globulin on Polycystic Ovary Syndrome: Mechanisms, Manifestations, Genetics, and Treatment

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases causing infertility in women of childbearing age. It is characterized by hyperandrogenemia (HA), chronic anovulation, and polycystic ovary morphology (PCOM). Most women with PCOS have metabolic abnormalities. Sex hormone-binding globulin (SHBG), a transport carrier that binds estrogen and androgens and regulates their biological activity, is usually used as an indicator of hyperandrogenism in women with PCOS. Low serum SHBG levels are considered a biomarker of metabolic abnormalities and are associated with insulin resistance (IR), HA, and abnormal glucose and lipid metabolism in PCOS patients. SHBG is also related to the long-term prognosis of PCOS, whereas SHBG gene polymorphism is associated with PCOS risk. In addition, the administration of metformin (MET), glucagon-like peptide-1 receptor agonists (GLP-1 RAs), thiazolidinediones (TZDs), compound oral contraceptives (COCs), as well as nutrient supplements such as inositol (MI), vitamin D, and synbiotics can regulate SHBG levels to ameliorate PCOS complications and improve prognosis. This review focuses on the interaction between SHBG and various PCOS complications as well as the regulation of SHBG by various drugs and nutrients and its therapeutic effects on PCOS.

Early anthropometric indicators of type 2 diabetes mellitus

PURPOSE OF REVIEW

With the rapidly increasing incidence of type 2 diabetes mellitus (T2DM) in youth (as in adults), it is critical to recognize phenotypic markers that can help predict and potentially prevent its onset, and reduce the associated burden of the disease for patients, families, and society. In this review, we summarize the most recent literature characterizing growth, puberty, and body composition in youth at risk for or who have T2DM.

RECENT FINDINGS

There is an inverse, nonlinear relationship between birth weight and future risk of developing T2DM. Height seems to have an inverse correlation with risk for diabetes. Earlier onset of puberty in males and females is associated with the T2DM phenotype. While adiposity is a known correlate of T2DM, visceral adiposity as represented by waist circumference has emerged as one of the key determinants of T2DM in population-based studies globally. Thresholds for body mass index vary across ethnicities in predicting risk for T2DM, depending on genetic factors and fat-distribution profiles.

SUMMARY

Emerging links between T2DM and dysregulated parameters of growth and development highlight the importance of early recognition of modifiable risk factors and the creation of individualized screening protocols.

VIDEO ABSTRACT

http://links.lww.com/COE/A31.

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.

Elevated maternal androgen is associated with dysfunctional placenta and lipid disorder in newborns of mothers with polycystic ovary syndrome

OBJECTIVE

To investigate the placental morphology alterations and identify the clinical characteristics of women with polycystic ovary syndrome (PCOS) and their newborns. Pregnant women with PCOS (n = 12) and pregnant women without PCOS (n = 11) were recruited. Then, the placenta, maternal blood and cord blood were collected after delivery.

DESIGN

Clinical observational study.

SETTING

Not applicable.

PATIENT(S)

In the present study, pregnant women with PCOS and healthy pregnant women were recruited from the clinic of the Department of Obstetrics and Gynecology, First Affiliated Hospital, Heilongjiang University of Chinese Medicine, China, between February 2015 and October 2015.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

A proteomic analysis was performed on the placenta in women with PCOS and healthy women.

RESULT(S)

The maternal testosterone, androstenedione, dehydroepiandrosterone sulfate, free androgen index, cholesterol, apolipoprotein B, and apolipoprotein B/apolipoprotein A-I levels were significantly higher in the PCOS group than in the control group, and the offspring in the PCOS group had higher dehydroepiandrosterone sulfate, high-density lipoprotein, and cholesterol levels, when compared with the control group. The placenta in the PCOS group demonstrated infarction, calcification, and a greater intervillous space, when compared with the control group. A higher level of estrogen receptor-β protein was observed in the placenta of women with PCOS, when compared with women without PCOS. A total of 258 proteins in the placenta were identified to be significantly different, when the PCOS and control groups were compared, and fibronectin 1 exhibited the closest relationship with other differential proteins.

CONCLUSION(S)

The overexposure to hyperandrogenism and hyperlipidemia affects the functions of the placenta, which are associated with the development of metabolic disorders in newborns.

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.

Association of dioxin in maternal breast milk and salivary steroid hormone levels in preschool children: A five-year follow-up study of a Vietnam cohort

Recent studies have found elevated dioxin levels inside some former US military air bases in Vietnam, known as hotspots. The aim of the present study was to evaluate the association of dioxin exposure and steroid hormone in preschool children in Vietnam. In 2010, 2011, 52 primiparae mother-infant pairs in the hotspot and 52 pairs in a non-exposure region were enrolled. For the final analysis, 26 vs 26 pairs were selected, who participated at all three surveys. Univariable and multivariable linear regressions were used to evaluate associations between hormone and dioxin congeners. Geometric mean total TEQ of PCDD/DFs in the hotspot were significantly higher than in the non-exposure region, 8.7 and 3.4 pg TEQ/g lipid, respectively. In the hotspot, salivary dehydroepiandrosterone (DHEA) was significantly higher in 1-year-old children (Boys = 123 pg/mL, Girls = 120 pg/mL) than in the non-exposure region (Boys = 28 pg/mL, Girls = 27 pg/mL). In contrast, DHEA was significantly lower in 5-year-old children (Boys = 70 pg/mL, Girls = 106 pg/mL) in the hotspot than in the non-exposure region (Boys = 496 pg/mL, Girls = 654 pg/mL). Salivary testosterone was significantly lower in the hotspot (Boys = 1.9 pg/mL, Girls = 1.9 pg/m; Boys = 1.0 pg/mL, Girls = 1.1 pg/mL, respectively) than in the non-exposure region (Boys = 3.7 pg/mL, Girls = 3.8 pg/m; Boys = 5.7 pg/mL, Girls = 7.0 pg/mL, respectively) at 3 years and 5 years of age. Higher levels of highly chlorinated dioxins in breast milk were associated with higher DHEA in 1-year-old and lower DHEA and testosterone levels in 5-year-old children. Our findings indicated that dioxins were associated with changes of DHEA and testosterone levels in preschool Vietnamese children.