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Leptin-Mediated Changes in the Human Metabolome.
Lawler, K, Huang-Doran, I, Sonoyama, T, Collet, TH, Keogh, JM, Henning, E, O'Rahilly, S, Bottolo, L, Farooqi, IS
The Journal of clinical endocrinology and metabolism. 2020;(8):2541-52
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Abstract
CONTEXT While severe obesity due to congenital leptin deficiency is rare, studies in patients before and after treatment with leptin can provide unique insights into the role that leptin plays in metabolic and endocrine function. OBJECTIVE The aim of this study was to characterize changes in peripheral metabolism in people with congenital leptin deficiency undergoing leptin replacement therapy, and to investigate the extent to which these changes are explained by reduced caloric intake. DESIGN Ultrahigh performance liquid chromatography-tandem mass spectroscopy (UPLC-MS/MS) was used to measure 661 metabolites in 6 severely obese people with congenital leptin deficiency before, and within 1 month after, treatment with recombinant leptin. Data were analyzed using unsupervised and hypothesis-driven computational approaches and compared with data from a study of acute caloric restriction in healthy volunteers. RESULTS Leptin replacement was associated with class-wide increased levels of fatty acids and acylcarnitines and decreased phospholipids, consistent with enhanced lipolysis and fatty acid oxidation. Primary and secondary bile acids increased after leptin treatment. Comparable changes were observed after acute caloric restriction. Branched-chain amino acids and steroid metabolites decreased after leptin, but not after acute caloric restriction. Individuals with severe obesity due to leptin deficiency and other genetic obesity syndromes shared a metabolomic signature associated with increased BMI. CONCLUSION Leptin replacement was associated with changes in lipolysis and substrate utilization that were consistent with negative energy balance. However, leptin's effects on branched-chain amino acids and steroid metabolites were independent of reduced caloric intake and require further exploration.
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Menopause research in Latin America.
Tserotas, K, Blümel, JE
Climacteric : the journal of the International Menopause Society. 2019;(1):17-21
Abstract
For 15 years, the Collaborative Group for Research of the Climacteric in Latin America (REDLINC) has been conducting research on several topics including age of menopause, metabolic syndrome, quality of life and climacteric symptoms, sexual dysfunction, poor quality of sleep and insomnia, and use of menopausal hormone therapy (MHT) in the general population and among gynecologists. Examples of data to have emerged for this region include the age of menopause (49 years), a high prevalence of metabolic syndrome (42.9%), and a new waist circumference cut-off value for the Latin American population (88 cm). Sexual dysfunction, poor quality of life, and sleep disorders have a prevalence of over 50%, with obesity and sedentary lifestyles affected importantly. MHT use is still low (12.5%), lack of prescription the most important reason for not using it, and gynecologists use MHT for themselves but do not recommend it often to their patients. The prevalence of alternative therapy use, recommended by physicians, is high.
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Alternatives to Testosterone Therapy: A Review.
Lo, EM, Rodriguez, KM, Pastuszak, AW, Khera, M
Sexual medicine reviews. 2018;(1):106-113
Abstract
INTRODUCTION Although testosterone therapy (TTh) is an effective treatment for hypogonadism, recent concerns regarding its safety have been raised. In 2015, the US Food and Drug Administration issued a warning about potential cardiovascular risks resulting from TTh. Fertility preservation is another reason to search for viable alternative therapies to conventional TTh, and in this review we evaluate the literature examining these alternatives. AIMS To review the role and limitations of non-testosterone treatments for hypogonadism. METHODS A literature search was conducted using PubMed to identify relevant studies examining medical and non-medical alternatives to TTh. Search terms included hypogonadism, testosterone replacement therapy, testosterone therapy, testosterone replacement alternatives, diet and exercise and testosterone, varicocele repair and testosterone, stress reduction and testosterone, and sleep apnea and testosterone. MAIN OUTCOME MEASURES Review of peer-reviewed literature. RESULTS Medical therapies examined include human chorionic gonadotropins, aromatase inhibitors, and selective estrogen receptor modulators. Non-drug therapies that are reviewed include lifestyle modifications including diet and exercise, improvements in sleep, decreasing stress, and varicocele repair. The high prevalence of obesity and metabolic syndrome in the United States suggests that disease modification could represent a viable treatment approach for affected men with hypogonadism. CONCLUSIONS These alternatives to TTh can increase testosterone levels and should be considered before TTh. Lo EM, Rodriguez KM, Pastuszak AW, Khera M. Alternatives to Testosterone Therapy: A Review. Sex Med Rev 2018;6:106-113.
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Low INSL3 in Klinefelter syndrome is related to osteocalcin, testosterone treatment and body composition, as well as measures of the hypothalamic-pituitary-gonadal axis.
Overvad, S, Bay, K, Bojesen, A, Gravholt, CH
Andrology. 2014;(3):421-7
Abstract
Klinefelter syndrome (KS) is characterized by infertility and hypogonadism associated with increased prevalence of osteoporosis, diabetes and metabolic syndrome. Insulin-like factor 3 (INSL3) is produced in the Leydig cells. INSL3 has been suggested to play a role in bone health. Here, we studied INSL3 in relation to bone markers, body composition, the metabolic syndrome and diabetes. This was a case-control study. Sex hormones, anthropometric measures, vitamin D metabolites, parathyroid hormone, growth factors, muscle strength, maximal oxygen consumption and BMD were measured. We included 70 adult KS patients and 71 age-matched controls. INSL3 was lower in testosterone-treated KS compared with untreated KS. Correlation analyses showed a positive correlation between INSL3 and osteocalcin among KS, but not in controls; a significant positive correlation between INSL3 and testosterone in controls and in untreated KS, but not in treated KS men. Among controls a negative correlation was found between INSL3 and lipids, and glucose, but not in KS. HOMA2-B and impaired fasting glycaemia was positively correlated with INSL3 in controls. Among KS males we found a negative correlation between INSL3 and BMI, weight and waist/hip ratio, as well as positive correlations between INSL3 and FSH, LH, SHBG and testis volume. Multivariate analyses showed that age, testosterone and HDL cholesterol were the principal independent variables among healthy controls, whereas the determinants of INSL3 concentration among KS were age, LH, current testosterone treatment and testicular volume. INSL3 in KS is influenced by testosterone treatment and INSL3 is correlated with measures of bone metabolism, body composition and the metabolic syndrome. This may suggest that low INSL3 concentration is related to the pathogenesis behind an unfavourable change in body composition and bone metabolism among KS patients.
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Metabolic syndrome and the effect of testosterone treatment in young men with congenital hypogonadotropic hypogonadism.
Sonmez, A, Haymana, C, Bolu, E, Aydogdu, A, Tapan, S, Serdar, M, Altun, B, Barcin, C, Taslipinar, A, Meric, C, et al
European journal of endocrinology. 2011;(5):759-64
Abstract
OBJECTIVE The relationship between metabolic syndrome (MS) and hypogonadism has always been investigated in study groups confounded with aging, obesity or chronic metabolic disorders. So far, there has been no data about the presence of MS in young hypogonadal patients. Also, there is controversial data about the metabolic effects of testosterone replacement therapy. We investigated the frequency of MS in treatment-naïve, young men with congenital hypogonadal hypogonadism (CHH). We also searched for the effect of testosterone replacement on the metabolic profiles of this specific patient group. DESIGN Retrospective analysis. METHODS A total of 332 patients (age 21.68 ± 2.09 years) were enrolled. The control group included 395 age- and body mass index (BMI)-matched healthy young men (age 21.39 ± 1.49 years). Standard regimen of testosterone esters (250 mg/3 weeks) was given to 208 patients. RESULTS MS was more prevalent in CHH (P<0.001) according to healthy controls. The patients had higher arterial blood pressure, waist circumference (WC), triglyceride (P<0.001 for all), fasting glucose (P=0.02), fasting insulin (P=0.004), homeostatic model assessment of insulin resistance (HOMA-IR) (P=0.002) and lower high density lipoprotein (HDL) cholesterol (P<0.001) levels. After 5.63±2.6 months of testosterone treatment, the BMI, WC (P<0.001 for both), systolic blood pressure (P=0.002) and triglyceride level (P=0.04) were increased and the total and HDL cholesterol levels were decreased (P=0.02 and P<0.001 respectively). CONCLUSIONS This study shows increased prevalence of MS and unfavorable effects of testosterone replacement in young patients with CHH. Long-term follow-up studies are warranted to investigate the cardiovascular safety of testosterone treatment in this specific population.
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Protein metabolism in Turner syndrome and the impact of hormone replacement therapy.
Gravholt, CH, Riis, AL, Møller, N, Christiansen, JS
Clinical endocrinology. 2007;(3):413-8
Abstract
BACKGROUND Studies have documented an altered body composition in Turner syndrome (TS). Body fat is increased and muscle mass is decreased. Ovarian failure necessitates substitution with female hormone replacement therapy (HRT), and HRT induces favourable changes in body composition. It is unknown how HRT affects protein metabolism. AIM: To test whether alterations in body composition before and after HRT in TS are a result of altered protein metabolism. DESIGN We performed a randomized crossover study with active treatment (HRT in TS and oral contraceptives in controls) or no treatment. MATERIALS AND METHODS We studied eight women (age 29.7 +/- 5.6 (mean +/- SD) years) with TS, verified by karyotype, and eight age-matched controls (age 27.3 +/- 4.9 years). All subjects underwent a 3-h study in the postabsorptive state. Protein dynamics of the whole body and of the forearm muscles were measured by an amino acid tracer dilution technique using [(15)N]phenylalanine and [(2)H(4)]tyrosine. Substrate metabolism was examined by indirect calorimetry. RESULTS Energy expenditure was comparable among TS and controls, and did not change during active treatment. Whole-body phenylalanine and tyrosine fluxes were similar in the untreated situations, and did not change during active treatment. Amino acid degradation and protein synthesis were similar in all situations. Muscle protein breakdown was similar among groups, and was not affected by treatment. Muscle protein synthesis rate and forearm blood flow did not differ among groups or due to treatment. CONCLUSION Protein metabolism in TS is comparable to controls, and is not affected by HRT.
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Breast cancer risk in the WHI study: the problem of obesity.
Kuhl, H
Maturitas. 2005;(1):83-97
Abstract
In the climacteric, about 40% of the women have occult breast tumors the growth of which may be stimulated by hormones. Many genetic, reproductive and lifestyle factors may influence the incidence of breast cancer. Epidemiological data suggest that the increase in the relative risk (RR) of breast cancer induced by hormone replacement therapy (HRT) is comparable with that associated with early menarche, late menopause, late first birth, alcohol consumption, etc. One of the most important risk factors is obesity which exceeds the effect of HRT by far, and in overweight postmenopausal women the elevated risk of breast cancer is not further increased by HRT. As in the WHI study the majority of women was overweight or obese, this trial was unsuitable for the investigation of breast cancer risk. In the women treated with an estrogen/progestin combination, the RR of breast cancer rose only in those women who have been treated with hormones prior to the study, suggesting a selection bias. In the women not pretreated with hormones, it was not elevated. In the estrogen-only arm of the WHI study, there was no increase but a steady decrease in the RR of breast cancer during 6.8 years of estrogen therapy. This result was unexpected, as estrogens are known to facilitate the development and growth of breast tumors, and the effect is enhanced by the addition of progestins. Obese women are at high risk to develop a metabolic syndrome including insulin resistance and hyperinsulinemia. In postmenopausal women, elevated insulin levels are not only associated with an increased risk for cardiovascular disease, but also for breast cancer. This might explain the effects observed in both arms of the WHI study: HRT with relative low doses of estrogens may improve insulin resistance and, hence, reduce the elevated breast cancer risk in obese patients, whereas this beneficial estrogen effect may be antagonized by progestins. The principal options for the reduction of breast cancer risk in postmenopausal women are the prevention of overweight and obesity to avoid the development of hyperinsulinemia, the medical treatment of insulin resistance, the use of low doses of estrogens and the reduction of exposure to progestins. The latter might include long-cycles with the sequential use of appropriate progestins every 3 months for 14 days. There are large inter-individual variations in the proliferative response to estrogens of the endometrium. Control by vaginalsonography and progestin challenge tests may help to identify those women who may be candidates for low-dose estrogen-only therapy.