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Obesity and Insulin Resistance, Not Polycystic Ovary Syndrome, Are Independent Predictors of Bone Mineral Density in Adolescents and Young Women.
Pereira-Eshraghi, CF, Chiuzan, C, Zhang, Y, Tao, RH, McCann, M, Neugut, YD, Printz, A, Fennoy, I, Cree-Green, M, Oberfield, SE, et al
Hormone research in paediatrics. 2019;(6):365-371
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Abstract
INTRODUCTION Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders that affects females of reproductive age. The characteristic features of PCOS individually have opposing effects on bone mineral density (BMD); however, their cumulative effect on BMD has not been clearly defined. Adolescence and young adulthood span a crucial period in achieving peak bone mass. Thus, a better understanding of the impact of PCOS on BMD in this age group is needed. OBJECTIVES To determine whether BMD is different between young females with PCOS and controls and to identify factors that influence BMD in this population. METHODS Data from four cross-sectional studies with a total of 170 females aged 12-25 years with PCOS (n = 123) and controls (n = 47) with a wide range of BMIs (18.7-53.4 kg/m2) were analyzed. Participants had fasting glucose, insulin, and free and total testosterone concentrations measured. HOMA-IR was calculated. Whole-body BMD was assessed by dual-energy X-ray absorptiometry. Multiple regression analysis for predicting BMD included PCOS status, menstrual age, obesity, HOMA-IR, and free testosterone. RESULTS HOMA-IR and total and free testosterone were significantly higher in PCOS compared to controls but there was no difference in BMD z-score between PCOS (0.8 ± 1.0) and controls (0.6 ± 1.0) (p = 0.36). Obesity (p = 0.03) and HOMA-IR (p = 0.02) were associated with BMD z-score. CONCLUSIONS Obesity status and insulin resistance, but not PCOS status, were each independently associated with BMD in adolescents and young women who spanned a wide range of BMIs.
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Androgen-forming stem Leydig cells: identification, function and therapeutic potential.
Zhang, Y, Ge, R, Hardy, MP
Disease markers. 2008;(4-5):277-86
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Abstract
Leydig cells are the primary source of testosterone in the male, and differentiation of Leydig cells in the testes is one of the primary events in the development of the male body and fertility. Stem Leydig cells (SLCs) exist in the testis throughout postnatal life, but a lack of cell surface markers previously hindered attempts to obtain purified SLC fractions. Once isolated, the properties of SLCs provide interesting clues for the ontogeny of these cells within the embryo. Moreover, the clinical potential of SLCs might be used to reverse age-related declines in testosterone levels in aging men, and stimulate reproductive function in hypogonadal males. This review focuses on the source, identification and outlook for therapeutic applications of SLCs. Separate pools of SLCs may give rise to fetal and adult generations of Leydig cell, which may account for their observed functional differences. These differences should in turn be taken into account when assessing the consequences of environmental pollutants such as the phthalate ester, diethylhexylphthalate (DEHP).