Sex steroids and bone turnover markers in men with symptomatic vertebral fractures.

Sex steroids play an important role in the maintenance of bone density in men and women, but the circulating, biologically active unbound fraction is influenced by the concentration of sex hormone binding globulin (SHBG). SHBG increases with advancing age in men and leads to a reduction in serum free testosterone and oestradiol, which may then affect bone turnover, bone mineral density (BMD) and the risk of fractures. We have therefore measured total and unbound sex steroids, SHBG, bone turnover markers and BMD in 57 men with symptomatic low trauma vertebral fractures and 57 age-matched male control subjects. Fasting blood and urine samples were collected from all subjects, who also underwent BMD measurement of the lumbar spine and hip. Serum testosterone, oestradiol, SHBG, bone specific alkaline phosphatase (bone ALP) and urine free deoxypyridinoline/creatinine ratio (fDPD/Cr) were measured. Free sex steroid concentrations were calculated using their ratio with SHBG and albumin and bioavailable testosterone was measured using radioimmunoassay. The two groups were then compared and regression models developed to determine the best predictors of BMD and fracture. Men with vertebral fractures had significantly lower weight and BMD at all sites than control subjects (p<0.0001). Serum total testosterone and oestradiol did not differ between the two groups, but calculated free androgen and free oestradiol indices were lower in the fracture group than the control subjects (p=0.04), due to higher SHBG (46.6 versus 36.1 nmol/L: p=0.005). The men with vertebral fractures had significantly higher mean bone ALP (15.8 versus 11.8 microg/L: p=0.002) and fDPD/Cr (5.5 versus 4.0 nmol/mmol: p=0.03). Stepwise multiple regression analysis in both fracture and control groups found body weight to be the best predictor of BMD. In the fracture group weight predicted between 19.7 and 30.7% of the variance in BMD and in control subjects this was between 12.3 and 13.2%. SHBG contributed to the model for hip BMD in the fracture group alone, so that weight and SHBG together accounted for 32 to 42.9% of the variance. A model combining BMD at the spine, total femur and femoral neck with height loss best predicted fracture. In conclusion, men with symptomatic vertebral fractures have higher SHBG and lower calculated free sex steroid indices, increased bone turnover and lower BMD. Whilst body weight was the best predictor of BMD, symptomatic vertebral fracture was best predicted by BMD and height loss.

Hypoadrenalism is not associated with early mortality during tuberculosis treatment in Malawi.

SETTING: In the developing world, early mortality within 1 month of commencing tuberculosis (TB) treatment is high, particularly with human immunodeficiency virus (HIV) co-infection. In Malawi, 40% of those who die do so in the first month of treatment. Reasons remain unclear and may include delayed diagnosis, opportunistic infections, immune restoration inflammatory syndrome (IRIS) or malnutrition. One possible contributing factor is underlying hypoadrenalism associated with TB-HIV, exacerbated by rifampicin (RMP) induction of P450 and glucocorticoid metabolism. OBJECTIVE: To assess the prevalence of hypoadrenalism in TB patients before and after commencement of TB treatment, and relationship with early mortality. DESIGN: Prospective descriptive study assessing hypoadrenalism before and after anti-tuberculosis treatment, HIV status and outcome up to 3 months post-treatment. RESULTS: Of 51 patients enrolled, 29 (56.9%) were female (median age 32 years, range 18-62). Of 43 patients HIV-tested, 38 (88.3%) were HIV-positive and 15.7% died within the first month. At 3 months, 11 (21.6%) were known to have died. Adequate cortisol levels were found in 49/51 (95.9%) before commencing RMP. Neither of the two with reduced response died. All 34 patients revealed adequate cortisol responses at 2 weeks. CONCLUSION: No evidence of hypoadrenalism was found in this first study to assess adrenal function and outcome of anti-tuberculosis treatment.

Biological variation of total testosterone, free androgen index and bioavailable testosterone in polycystic ovarian syndrome: implications for identifying hyperandrogenaemia.

OBJECTIVE: Hyperandrogenaemia is one of the three Rotterdam consensus diagnostic criteria for polycystic ovarian syndrome (PCOS) and may be measured by estimation of total testosterone, free androgen index (FAI) or bioavailable testosterone (BioT). The aim of this study was to compare the biological variability of total testosterone with that of the biological variability of both the FAI and BioT, to determine the least variable measurement for clinical practice. DESIGN: Comparative study. PATIENTS: Blood samples were collected after an overnight fast at 4-day intervals on 10 consecutive occasions from 12 PCOS patients and 11 weight- and age-matched control women. MEASUREMENTS: Duplicate samples of stored serum were analysed for total testosterone, SHBG and BioT in a single batch. RESULTS: The PCOS group had a significantly higher median BioT, FAI and total testosterone than controls. In both the PCOS and control groups, the intraindividual variance was small and similar for BioT and FAI. There was no significant difference between the within-subject biological coefficient of variation (CV(I)) for BioT, FAI and total testosterone. The maximum and minimum critical differences were +58% and -37% for BioT and +70% and -40% for FAI, respectively. CONCLUSION: FAI appears to be the better diagnostic marker to distinguish hyperandrogenism in patients with PCOS, but once diagnosis has been made, all three methods should be equally good in monitoring further changes in the androgen status.

Greater antiarrhythmic activity of acute 17beta-estradiol in female than male anaesthetized rats: correlation with Ca2+ channel blockade.

BACKGROUND AND PURPOSE: Female sex hormones may protect pre-menopausal women from sudden cardiac death. We therefore investigated the effects of the main female sex hormone, 17beta-estradiol, on ischaemia-induced cardiac arrhythmias and on the L-type Ca2+ current (ICaL). EXPERIMENTAL APPROACH: In vivo experiments were performed in pentobarbital-anaesthetized rats subjected to acute coronary artery occlusion. ICaL was measured by the whole-cell patch-clamp technique, in rat isolated ventricular myocytes. KEY RESULTS: Acute intravenous administration of 17beta-estradiol as a bolus dose followed by a continuous infusion, commencing 10 min before coronary artery occlusion, had dose-dependent antiarrhythmic activity. In female rats 300 ng kg(-1) + 30 ng kg(-1) min(-1) 17beta-estradiol significantly reduced the number of ventricular premature beats (VPBs) and the incidence of ventricular fibrillation (VF). A ten fold higher dose of 17beta-estradiol was required to cause similar effects in male rats. In vitro 17beta-estradiol reduced peak ICaL in a concentration-dependent manner. The EC50 was ten-fold higher in male myocytes (0.66 microM) than in females (0.06 microM). CONCLUSIONS AND IMPLICATIONS: These results indicate that 17beta-estradiol has marked dose-dependent antiarrhythmic activity that is greater in female rats than in males. A similar differential potency in blocking ICaL in myocytes from female and male rats can account for this effect. This provides an explanation for the antiarrhythmic activity of 17beta-estradiol and gender-selective protection against sudden cardiac death.

Analytical and physiological factors affecting the interpretation of serum testosterone concentration in men.

Most hospital laboratories estimate the concentration of total circulating testosterone using a non-extraction method on an automated multi-channel immunoassay analyser supplied by a small number of multi-national diagnostic companies. Although these platforms offer advantages of quick turnaround times, small volume sampling and random access analysis, proficiency testing schemes suggest the quality of results produced remains similar to that of the early manual radioimmunoassay. An estimate of the bioavailable, non-sex hormone binding globulin (SHBG) bound fraction of circulating testosterone, be that the free or the free plus albumin-bound, may be a better index of gonadal status than total testosterone alone, especially when a borderline hypogonadal level of total testosterone is found, and may avoid misclassification of hypogonadal or eugonadal men. Free or bioavailable testosterone may be calculated or measured. The free androgen index may not give a true reflection of androgen status in men. In the interpretation of serum testosterone concentrations with results >40 nmol/L, the possibility of exogenous administration or abuse needs to be considered. The marked diurnal rhythm in total testosterone should also be taken into account. There may be a diminution of testosterone secretion with advancing age, but the great majority of older men have a circulating total testosterone concentration well within the accepted reference intervals established for younger men. As testosterone concentration may fluctuate markedly both seasonally and from day to day, it may be judicious to measure levels on more than one occasion. Provided that estimates of serum testosterone are unequivocally eugonadal (12.5-40 nmol/L) or hypogonadal (<7.0 nmol/L), results produced by routine automated immunoassays will in all probability give a satisfactory assessment of androgen status in men.Routine biochemical assessment of gonadal function in men should include measurement of early morning luteinizing hormone, follicle stimulating hormone, prolactin and SHBG together with total testosterone, and if necessary some estimate of bioactive testosterone.

Effect of menstrual cycle phase on the concentration of bioavailable 17-beta oestradiol and testosterone and muscle strength.

To investigate the effect of changes in sex hormone concentration on muscle strength and the bioavailability of 17-beta oestradiol (oestradiol) and testosterone, seven eumenorrheic females were tested during two phases of the menstrual cycle. Maximum voluntary isometric strength of the first dorsal interosseus muscle was measured during the early follicular and mid-luteal phases of the menstrual cycle. These phases were chosen for testing as the concentration of total oestradiol is significantly different in these two phases. Total oestradiol has been repeatedly associated with changes in muscle strength in females, whereas the effects of bioavailable oestradiol are unknown. The concentrations of total and bioavailable oestradiol and testosterone were measured in addition to the concentration of total progesterone. Concentrations of total progesterone and oestradiol were significantly different between the early follicular and mid-luteal phases of the menstrual cycle (P <0.05 and P <0.001 respectively). The concentration of total testosterone (0.7+/-0.2 and 0.8+/-0.1 nmol.l(-1) respectively) and the ratio of total oestradiol to progesterone (153.0+/-251.2 and 108.5+/-27.8 respectively) did not change significantly between the early follicular and mid-luteal phases. Bioavailable testosterone (102.2+/-66.3 and 105.0+/-90.2 pmol.l(-1) respectively) and bioavailable oestradiol (90.5+/-35.5 and 120.0+/-60.6 pmol.l(-1) respectively) did not differ significantly between phases. There were no significant differences in muscle strength during the menstrual cycle (P =0.1). Mean maximum voluntary isometric force of the first dorsal interosseus muscle did not correlate significantly with the mean concentration of any reproductive hormone measured. These results indicate that cyclical variation in endogenous reproductive hormones does not affect muscle strength.

Low-dose transdermal testosterone therapy improves angina threshold in men with chronic stable angina: A randomized, double-blind, placebo-controlled study.

BACKGROUND: Experimental studies suggest that androgens induce coronary vasodilatation. We performed this pilot project to examine the clinical effects of long-term low-dose androgens in men with angina. METHODS AND RESULTS: Forty-six men with stable angina completed a 2-week, single-blind placebo run-in, followed by double-blind randomization to 5 mg testosterone daily by transdermal patch or matching placebo for 12 weeks, in addition to their current medication. Time to 1-mm ST-segment depression on treadmill exercise testing and hormone levels were measured and quality of life was assessed by SF-36 at baseline and after 4 and 12 weeks of treatment. Active treatment resulted in a 2-fold increase in androgen levels and an increase in time to 1-mm ST-segment depression from (mean+/-SEM) 309+/-27 seconds at baseline to 343+/-26 seconds after 4 weeks and to 361+/-22 seconds after 12 weeks. This change was statistically significant compared with that seen in the placebo group (from 266+/-25 seconds at baseline to 284+/-23 seconds after 4 weeks and to 292+/-24 seconds after 12 weeks; P:=0.02 between the 2 groups by ANCOVA). The magnitude of the response was greater in those with lower baseline levels of bioavailable testosterone (r=-0. 455, P:<0.05). There were no significant changes in prostate specific antigen, hemoglobin, lipids, or coagulation profiles during the study. There were significant improvements in pain perception (P:=0.026) and role limitation resulting from physical problems (P:=0.024) in the testosterone-treated group. CONCLUSIONS: Low-dose supplemental testosterone treatment in men with chronic stable angina reduces exercise-induced myocardial ischemia.

Men with coronary artery disease have lower levels of androgens than men with normal coronary angiograms.

AIMS: High androgen levels are presumed by many to explain the male predisposition to coronary artery disease. However, natural androgens inhibit male atherosclerosis(1). Our aim was to determine whether levels of androgens differ between men with and without coronary artery disease. METHODS AND RESULTS: Ninety male subjects (60 with positive, and 30 with negative coronary angiograms) were recruited. Early morning, fasting blood samples were taken from each patient and free, total and bioavailable testosterone, sex hormone binding globulin, oestradiol, and lipids were measured. Bioavailable testosterone was assayed using a modified technique. Free androgen index was calculated. Men with coronary artery disease had significantly lower levels of free testosterone (mean (standard deviation)); 47.95 (13.77) vs 59.87 (26. 05) pmol. l(-1), P=0.027), bioavailable testosterone; 2.55 (0.77) vs 3.26 (1.18) nmol. l(-1), P=0.005 and free androgen index; 37.8 (10. 4) vs 48.47 (18.3), P=0.005, than controls. After controlling for differences in age and body mass index the differences in free androgen index and bioavailable testosterone remained statistically significant (P=0.008 and P=0.013, respectively). CONCLUSION: Men with coronary artery disease have significantly lower levels of androgens than normal controls, challenging the preconception that physiologically high levels of androgens in men account for their increased relative risk for coronary artery disease.

Admission cortisol and adrenocorticotrophic hormone levels in children with meningococcal disease: evidence of adrenal insufficiency?

OBJECTIVE: To measure admission cortisol and adrenocorticotrophic hormone (ACTH) levels in children with meningococcal disease to try and determine the prevalence of adrenal insufficiency. DESIGN: Prospective observational study. SETTING: Pediatric departments of four hospitals in Merseyside, United Kingdom. PATIENTS: Ninety-six children with meningococcal disease; 29 with hypotension, ten of whom died. MEASUREMENTS AND MAIN RESULTS: Admission cortisol, ACTH, and proinflammatory cytokine levels were measured. Serial cortisol levels also were measured during the first 48 hrs. Significantly lower cortisol levels were found in those who died compared with survivors. Significantly higher ACTH levels also were found in those who died. However, no child had a cortisol level <5 microg/dL (<138 nmol/L) implying definite adrenal insufficiency. Three of 29 children with hypotension had plasma cortisol levels implying possible adrenal insufficiency (<18 microg/dL [<497 nmol/L]), but high ACTH levels were only found in one of those three. Cortisol levels decreased significantly after antibiotic treatment, unless steroid therapy was administered. ACTH levels did not correlate with cortisol or proinflammatory cytokine levels. CONCLUSIONS: Children with meningococcal disease have a wide range of initial plasma cortisol levels, with lower levels found in those who die. Many factors may affect cortisol levels, but adrenal insufficiency is probably uncommon.

Angiotensin II concentrations and gut mucosal perfusion in infants undergoing cardiopulmonary bypass.

OBJECTIVES: To determine whether hypothermic cardiopulmonary bypass (CPB) per se causes an increase in angiotensin II (A-II) concentration in infants and to investigate the relationship between A-II concentration and gut mucosal perfusion. DESIGN: Prospective, open, nonrandomized, observational study. SETTING: Children's teaching hospital. PARTICIPANTS: Thirty acyanotic infants requiring CPB. INTERVENTIONS: A-II concentrations were measured on six occasions before, during, and after CPB. An orogastric tonometer allowed intermittent calculations of gastric intramucosal pH (pHi). Gastric mucosal blood flow (flux) was monitored using a laser Doppler flowmeter. Ten infants acted as controls (group 1); 10 infants received captopril, 0.9 mg/kg orally, 45 minutes before induction of anesthesia (group 2), and 10 infants received enalaprilat, 0.06 mg/kg intravenously, just before CPB (group 3). MEASUREMENTS AND MAIN RESULTS: A-II concentrations were abnormally high in 28 of 30 patients before CPB (median, 450 pg/mL (range, 83 to 5,787 pg/mL). A-II concentrations in groups 1 and 2 decreased during CPB, but values remained at twice normal levels throughout surgery (median, 171 to 198 pg/mL post-CPB). A-II concentrations remained normal (range, 52 to 120 pg/mL) during and after CPB in patients receiving enalaprilat (group 3). The authors found no significant correlation between A-II concentration and pHi or flux before, during, or after surgery. CONCLUSIONS: Acyanotic infants requiring cardiac surgery may have high perioperative concentrations of A-II. Hypothermic CPB is associated with a decrease in A-II concentration. Reductions in gut mucosal perfusion seen in some infants during hypothermic CPB are not related to increases in A-II concentrations.

Undiagnosed morbidity in adult women with Turner's syndrome.

OBJECTIVE: Adult patients with Turner's syndrome are rarely followed up at specialist clinics after discharge from paediatric care but do have a predisposition to several long-term medical problems. We have assessed the undiagnosed morbidity that exists among adult women with Turner's syndrome. PATIENTS: A group of 32 women (age range 17-52 years; mean 25 years) attending a specialist out-patient clinic. MEASUREMENTS: Blood samples were obtained at the initial visit for lipid assessment, thyroid function, gonadal status and routine biochemical profile. Bone mineral density (BMD) was measured in 31 of the women. RESULTS: Thirty-one women were receiving some form of oestrogen replacement. Two were receiving T4 therapy. In 50%, total cholesterol was greater than 5.2 mmol/l (range 3.4-9.3 mmol/l, mean 5.8 mmol/l) and 28% had an abnormality of thyroid function tests. Two women were newly diagnosed as hypothyroid, 6 had compensated hypothyroidism and one was under-replaced with T4. Lumbar spine BMD was below 100% of age matched reference range in 84% and below 75% in 26% of patients. Femoral neck BMD was below 100% of age matched reference range in 90% and below 75% in 10% of patients. CONCLUSIONS: There is a high incidence of undiagnosed lipid, thyroid and bone mineral density abnormalities in the adult population with Turner's syndrome. Doctors caring for these women need to be aware of and look for the potential problems. Appropriate long-term treatment should be commenced to help prevent the development of lipid, skeletal and thyroid abnormalities which may cause these patients major problems in the future.

Exaggerated effects of progestogen on uterine artery pulsatility index in Turner's syndrome patients receiving hormone replacement therapy.

OBJECTIVE: To investigate the effect of estrogen and progestogen on the resistance to blood flow in the uterine arteries of Turner's syndrome patients. DESIGN: Prospective clinical study. SETTING: A tertiary infertility clinic. PATIENTS: Five Turner's syndrome patients, six patients who had surgical castration, and five patients with idiopathic primary ovarian failure. INTERVENTIONS: The patients were treated with 2 mg E2 valerate to which 500 micrograms norgesterel was added for 10 days in a 28-day cycle. Transvaginal color Doppler was used to measure pulsatility index in the uterine arteries at eight regular intervals during a single cycle. MAIN OUTCOME MEASURE: Pulsatility index of the uterine arteries. RESULTS: The administration of norgesterel to Turner's syndrome patients resulted in an increase in pulsatility index that was significantly higher than in patients who had surgical castration (confidence interval = 0.17 to 2.42). CONCLUSION: The uterine arteries of Turner's syndrome patients are more sensitive to the tonic effect of progestogen. If manifest in cardiac arteries also this phenomenon may be partly responsible for the increased incidence of cardiovascular disease and shorter life expectancy in Turner's syndrome patients. To achieve optimal protection from cardiovascular disease, Turner's syndrome patients may benefit from hormone replacement treatment containing altered doses of estrogen and progestogen.

The long-term stability in whole blood of 14 commonly-requested hormone analytes.

Concentrations of 14 commonly-requested plasma hormones were measured in octuplicate in each of six subjects to determine their stability when unseparated from red cells for periods up to 1 week. Most of the analytes were stable when stored in this way and although statistically significant changes were recorded, in the great majority of cases the changes seen would have no bearing on the clinical interpretation of the result. In the light of these findings, we would confidently report results of analyses for these hormones in plasma that had remained in contact with red cells at ambient temperature for long periods of time.

The effect of free fatty acids on the in-vitro binding of testosterone in human plasma.

The effect of supraphysiological levels of free fatty acids (FFA) on the binding of testosterone to sex-hormone binding globulin (SHBG) and on non-SHBG binding in both male plasma and plasma from pregnant women was studied. Six FFAs were added to plasma as individual acids. No alteration in testosterone binding to SHBG could be demonstrated with any of the FFAs in either male plasma or plasma from pregnant women. When the same plasma was heated to destroy SHBG binding, a highly significant (P < 0.01) increase in non-SHBG binding was seen in both male plasma and plasma from pregnant women when the unsaturated FFAs oleic, linoleic and linolenic acids were added. No significant difference was demonstrated with the saturated FFAs, palmitic, stearic and arachidic acids.

Autoimmune Addison's disease and thyrotoxic thyroiditis presenting as encephalopathy in twins.

An 11 year old boy who presented with neuropsychiatric symptoms including delirium and pronounced agitation was found to have simultaneous onset of autoimmune adrenocortical insufficiency and hyperthyroidism. His identical twin also had hyperthyroidism and six months later developed symptoms of adrenocortical insufficiency. In children presenting with neuropsychiatric symptoms, adrenal (or pituitary) and other endocrine disorders should be considered.