International Journal of Endocrinology and Metabolism
Year:2012 | Volume:10 | Issue:1|Papers Count:10

Background: Macroprolactinemia can be an overlooked cause of hyperprolactinemia. To document the presence of macroprolactin in serum indirectly, an initial precipitation of the complexed prolactin (PRL) using polyethylene glycol (PEG) is followed by measurement of free and total prolactin by immunoassay.Objectives: Adaptation of the PEG method to our PRL immunoassay to detect cases with predominant macroprolactinemia and to study the short- and long-term changes of the relationship between PRL forms.Patients and Methods: One hundred forty hyperprolactinemic patients (aged 17-72 years) in whom macroprolactin constituted ³  60% of the total PRL were included in our study.The predominance of macroprolactin was measured by adapted PEG procedure, followed by immunoradiometric and chemiluminescence methods.Long-term observations with repeated serum PRL measurements were made in 20 cases.For another 20 of 41 patients with indications for metoclopramide (MCP) stimulation test, we analyzed short-term alterations in free and complexed PRL levels.Results: Adjustment of the PEG method by testing samples in dilution minimized the interference of PEG in the immunoassays and let proper detection of predominant macroprolactinemia.During the long-term observations, the ratio of macroprolactin to total PRL remained relatively constant, independent of changes in total PRL levels. During the MCP test, in the majority of patients with macroprolactinemia (except those with associated PRL-secreting adenoma), an acute rise of PRL level followed by a rise in macroprolactin resulted in a short-term decrease in macroprolactin/total PRL ratio.Conclusions: Confirmation of the predominance in serum of macroprolactin explains the discordance between the raised PRL level and scant of absent symptoms characteristic for hyperprolactinemia. Its proper detection can influence further management.

Background: The pro-inflammatory cytokines that are associated with the decline in ovarian function during menopause are involved in the pathophysiology of postmenopausal bone loss, which has not been examined in Indian postmenopausal women.Objectives: This study assessed the extent of changes in pro-inflammatory cytokines in relation to bone turnover markers, hormones, and bone mineral density (BMD) during menopausal transition in Indian women.Materials and Methods: Levels of interleukin 1 (IL1 b), interleukin 6 (IL6), and tumor necrosis factor (TNFa), the bone markers osteocalcin (OC), bone-specific alkaline phosphatase (BSAP), carboxy terminal telopeptide (CTX), and deoxypyridoniline (DPD), and the hormones parathyroid hormone (PTH), follicle-stimulating hormone (FSH), and estrone glucuronide (E1G) were measured by enzyme linked immunosorbant assay (ELISA) in blood and urine samples of premenopausal (age: 21-40 years, n=124) and menopausal women (41-70 years, n=256) without fractures. Bone mineral density (BMD) in the femur and spine was measured by dual energy x-ray absorptiometry (DXA).Results: Of the cytokines that were measured, only IL6 increased significantly in all 3 groups of menopausal women (compared with premenopausal healthy women. The changes in IL6 paralleled changes in markers of bone resorption and correlated positively with bone turnover markers and negatively with BMD and E1G levels. In menopausal women, the rise in IL6, CTX, and DPD was high (>100%) and was associated with a decline in E1G (>75%) and BMD levels (>22%) during the first 5 years of menopause, indicating that bone loss is confined to the first decade of menopause.Conclusions: IL6 correlates negatively with estrogens and BMD and positively with bone resorption markers. Thus, IL6 levels, in conjunction with CTX, DPD, and estrogen levels, improve the prediction of bone loss in menopausal women.

Background: Variations in sex hormone levels can be caused by differences in ethnicity, smoking habits, and body composition and may be related to racial differences in the prevalence of certain diseases.Objectives: This study examined the effects of ethnicity, smoking, and body composition on testosterone and estradiol levels in a group of young Malaysian men.Patients and Methods: In this cross-sectional study, 189 Malay and Chinese men aged 20-39 years answered a detailed questionnaire, underwent body anthropometric measurements, and had their blood drawn for hormone assays.Results: The results indicated no differences in testosterone levels between races (P>0.05), but estradiol levels were significantly higher among Malay compared with Chinese men (P< 0.05). No difference was detected in sex hormone levels between smokers and non-smokers (P>0.05). However, smokers with more than 10 years of cigarette smoke exposure had a significantly higher estradiol level than smokers with 1-5 years of exposure (P<0.05). Testosterone (total, free, and non-SHBG-bound) levels correlated inversely and significantly (P<0.05) with body mass index (BMI), waist-to-hip circumference ratio (WHR), and percentage of body fat. By multiple stepwise regression, body fat percentage was the most influential predictor of testosterone (b=-0.456 for total, b=-0.279 for free, b=-0.297 for non-SHBG-bound fraction) and SHBG levels (b=-0.172).Conclusions: Estradiol levels are influenced by ethnicity and duration of smoking, whereas testosterone levels are governed by body fat percentage in Malaysian young adult males.

Background: The lungs are end organs that are adversely affected in Nigerian adults with type 2 diabetes. Assessment and monitoring of the progress of pulmonary functions postexercise prescription is paramount for optimal feedback on a patient’s progress.Objective: This study was designed to investigate the pulmonary responses of individuals with T2DM to progressive aerobic exercises and resistance exercises (PAREs) and assess changes at specified points in the intervention period.Patients and Methods: A total of 60 subjects (36 females and 24 males) aged 40-75 years were consecutively recruited into this randomized control study, which comprised a PARE and a control group. Outcome measures, which included pulmonary parameters (oxygen uptake (VO2max), forced vital capacity (FVC), forced expiratory volume in one second (FEV1)) and anthropometric parameters (body mass index (BMI), waist circumference (WC), and waist hiP ratio (WHR), were assessed at baseline and at the end of Weeks 4, 8, and 12 of the intervention period. Glycosylated hemoglobin level (HbA1c) was assessed at baseline and at the end of Week 12. Data were analyzed using descriptive statistics and inferential statistics. Level of significant was set at P<0.05 Results: Mean VO2max, FEV1, and FVC increased as early as 4 weeks postintervention. Significant improvements in these variables were noted in subjects (P<0.05). WC and HbA1C were significantly reduced (P=0.03 and 0.001, respectively) following intervention. Significant changes in pulmonary variables occurred from Week 8 week following the post hoc analysis.Conclusions: PARE is beneficial in the management of pulmonary complications in adult Nigerian T2DM patients. PARE for at least 4 weeks may improve the pulmonary function of individuals with T2DM. However, postexercise prescription assessment may be commenced 8 weeks post intervention.

Background: Postmenopausal osteoporosis is a systemic bone disease that is characterized by accelerated bone loss after menopause and an increased risk of fractures. The immune system and cytokines regulate bone metabolism. Toll-like receptors (TLRs) play an important role in the induction and regulation of the innate immune system and adaptive immune responses.Objectives: To investigate the association between TLR4 gene polymorphisms and bone mineral density (BMD) in postmenopausal osteoporotic (OP) and nonosteoporotic (NOP) Turkish women.Patients and Methods: The study population consisted of 178 OP and 178 NOP Turkish women.BMDs were obtained by dual-energy X-ray absorptiometry. Two single-nucleotide polymorphisms (SNPs) of the TLR4 gene (Asp299Gly and Thr399Ile) were examined by polymerase chain reaction-restriction fragment length polymorphism. The frequency of polymorphisms and the possible relationships between genotypes and BMD were the main outcome measures.Results: Lumbar BMD of OP women was significantly lower than in NOP women (P= 0.04), but total hip BMD and Z scores did not differ. The frequency of the Asp299Gly and Thr399Ile polymorphisms in our population was 18% and 15%, respectively. There was no significant difference in the frequency of TLR4 gene (Asp299Gly and Thr399Ile) polymorphisms between OP and NOP women, but carriers of heterozygous genotypes had lower BMDs (P<0.01 and P<0.01).Conclusions: We observed lower BMDs in carriers of heterozygous genotypes of polymorphisms than homozygous mutant genotypes. With our limited population, no firm conclusions can be drawn as to what extent low bone mineral density is associated with these heterozygous genotypes, and further studies are needed to analyze our results.

Background: The role of stress has been elucidated in cardiovascular disorders. The aim of this study was to determine and compare the effects of chronic physical and psychological stress on the contractility of isolated rat aorta and their reversibility.Materials and Methods: Wister rats were divided into 3 groups: control, physical stress, and psychological stress (n=12). Animals were kept on 12-h/12-h light/dark cycles at 22 ±2oC and had free access to food and water. Physical and psychological stress was induced using a communication box for 3 weeks. Physical stress was applied with electrical current (1 mA, 1 Hz, 10 sec/min) 1 hour twice daily. To assess the aortic response, the animals were anesthetized, abdominal aortas were removed, and the contractility response to potassium chloride and phenylephrine was measured with an isometric transducer. To study the reversibility of the effects, separate groups of stressed animals and a control group (n=12 in each group) were kept for 1 month following the stress period, and the aortic responses were evaluated and compared.Results: In the stressed group, the aortic responses to potassium chloride and phenylephrine were significantly lower compared with the controls, whereas the corticosterone concentration was higher. Following a 1-month recovery, both values returned to normal.Conclusions: Chronic physical stress and psychological stress have similar effects on vascular responsiveness, which are reversible, these findings may be clinically important in the treatment of stress-related cardiovascular disorders.

Background: Tacrolimus is commonly used in the medical area to avoid the rejection of grafted organs. Some studies have suggested that tacrolimus is an immune suppressor that increases bone turnover and the development of severe osteopenia. In dentistry this effect may interfere with oral treatments.Objectives: A systematic literature review to test the hypothesis that treatment with immunosuppressor tacrolimus may interfere with alveolar bone metabolism. Search Strategy: Research in the health science databases was performed and includes articles published up to August 2011. Selection Criteria: Studies in animals and humans using tacrolimus as an immune suppressor and capable of interfering with alveolar bone metabolism were included. Data Collection and Analysis: The key words used were: tacrolimus and alveolar bone or tacrolimus and alveolar bone loss or FK506 and alveolar bone or FK506 and alveolar bone loss. The articles were initially selected by title and abstract and then potentially eligible articles were read and those that fulfilled the inclusion criteria were carefully analyzed and classified (A, B and C).Results: From a total of 745 references, only 6 articles fulfilled the eligibility criteria. Three articles were classified as A and 3 as C. In spite of the methodological differences in the 6 articles (3 animal and 3 human) tacrolimus was not found to cause damage to alveolar bone tissue.Conclusions: In humans the results are still not conclusive. In animals: tacrolimus does not produce alveolar bone loss, whereas in humans there is no evidence that this immune suppressor produces alveolar bone loss.

This review covers the progress made by our group over the past two decades in understanding the effects of severe burn injuries on the endocrine system, especially in relation to calcium and vitamin D metabolism. We examine the phenomena of transient growth hormone deficiency and the dose-dependent effects of recombinant human growth hormone on bone and muscle mass. We move on to discuss the occurrence of post-burn secondary hypoparathyroidism caused by the up-regulation of the parathyroid calcium-sensing receptor, and finally, we discuss vitamin D status, the progressive nature of vitamin D deficiency post-burn, the causes of the progressive deficiency, and what must be done to prevent it. These conditions taken together, while not primarily responsible for post-burn bone loss, may impair the recovery of normal bone density and leave, especially younger populations of victims, vulnerable to a reduction in peak bone mass with subsequent elevated risk of developing osteoporosis as adults.

Most patients with dilated cardiomyopathy have a poor prognosis that is associated with progressive and irreversible myocardial dysfunction. Rarely, a reversible metabolic etiology that is amenable to specific therapy is identified. Thyroid hormones have many effects on the heart. Although cardiac output is reduced in hypothyroidism, heart failure is relatively rare due to the lower demand for peripheral oxygen delivery. We report a 14-year-old girl who presented with dilated cardiomyopathy (DCM) and was determined to have primary hypothyroidism, for whom cardiac function improved significantly after levothyroxine replacement therapy. Our case underscores the necessity of thyroid function testing to examine the etiology of nonischemic DCM, even in young subjects.

Diabetes mellitus is a metabolic disorder that is characterized by chronic hyperglycemia, due to defects in insulin secretion and/or action activity. In the past decades, there has been a renewed interest in the use of natural products, including herbs and honey, in the treatment of diabetes. This commentary is written to allay fears that the use of honey is detrimental in diabetes. Recent findings indicate that honey improves glycemic control and exerts hypoglycemic effect in non-diabetic, alloxan- and streptozotocin-induced diabetic rats.