Etty Osher

Postoperative treatment of clinically nonfunctioning pituitary adenomas with dopamine agonists decreases tumour remnant growth

Objective  There is no consensus as to the optimal postoperative treatment of patients with clinically nonfunctioning pituitary adenomas (NFPA) in whom total tumour removal has not been achieved. In this study we assessed whether dopamine agonist (DA) treatment can prevent postoperative remnant enlargement in NFPA.

The 5 lipoxygenase system in the vasculature: Emerging role in health and disease

Activation of the 5 lipoygenase (5LO) system within the vascular bed requires the presence of several cell types with distinct transcellular cross-talk mechanisms, resulting in the generation of 5LO produced metabolites and increased expression of receptors for these metabolites in vascular cells. The key products in this system, the leukotriens LTB4, LTC4 and LTD4, are potent mediators of vascular inflammation initiated by white blood cells and sustained or propagated thereafter through amplified metabolite generation and direct effects in endothelial and vascular smooth muscle cells. Leukotrienes act to enhance cell permeability and increase oxidative stress, vascular smooth muscle cell migration and arterial tone. 5LO activation is highly regulated, and is apparently both model/species-specific and region-specific. 5LO activation is also linked to plaque progression, plaque stability, activation of matrix metalloproteinases, propensity to coronary and cerebrovascular events and the evolution of aortic aneurysms. Genetic variants in the 5LO activating protein are strongly linked to increased cardiovascular risk and may serve as useful markers for future therapy targeting down regulation of 5LO expression and activity as a means to combat cardiovascular disease.

Effect of testosterone replacement therapy on arterial stiffness in older hypogonadal men

OBJECTIVE To assess arterial stiffness in a cohort of hypogonadal males and to investigate the effect of testosterone replacement therapy on arterial properties in this specific group. DESIGN Eighteen male patients with untreated acquired hypogonadism due to either adult-onset idiopathic hypogonadotropic hypogonadism (n=9) or pituitary tumor (n=9) and 12 age-, sex, and weight-matched eugonadal healthy controls were recruited for the study. Arterial properties, plasma glucose, lipid profile, total, and bioavailable testosterone (BT) levels were measured in fasting state. In the hypogonadal subjects, the effect of transdermal testosterone replacement therapy on arterial properties was studied by repeat noninvasive measurements at baseline, as well as 48 h and 90 days following the initiation of treatment. METHODS Arterial stiffness was evaluated using applanation tonometry and pulse wave analysis by three different standard devices that assess various measures of arterial stiffness: pulse wave velocity (PWV), augmentation index (AIx), and large/small artery compliance (C1 and C2). RESULTS Age- and blood pressure-adjusted PWV was significantly higher in hypogonadal men (8.90+/-2.29 vs 6.78+/-1.16 m/s in the control group; P=0.025). Testosterone therapy increased BT level from 2.01+/-1.04 to 4.68+/-2.43 and 7.83+/-6.2 nmol/l after 48 h and 3 months respectively (P=0.001). PWV decreased from 8.9+/-2.29 to 8.24+/-1.39 and 8.25+/-1.82 m/s after 48 h and 3 months of treatment respectively (P=0.03). CONCLUSIONS Male hypogonadism is associated with increased PWV, which is rapidly but incompletely ameliorated by normalization of circulating testosterone levels.

Cardiovascular risk factors and arterial rigidity are similar in asymptomatic normocalcemic and hypercalcemic primary hyperparathyroidism.

OBJECTIVE It is still uncertain whether mild primary hyperparathyroidism (PHPT) carries the same risk for increased cardiovascular (CV) morbidity as the more severe symptomatic form. In recent years, the even more subtle normocalcemic (NC) variant is being increasingly recognized. We sought to compare the prevalence of CV risk factors in patients with NC- and hypercalcemic (HC)-PHPT, and to examine whether they differ on a battery of non-invasive vascular parameters. DESIGN/SUBJECTS/METHODS: A retrospective study of two cohorts of patients with PHPT in a referral center: 32 subjects with NC-PHPT and 81 subjects with HC-PHPT, compared for the presence of clinical and biochemical risk factors, and CV morbidity. Non-invasive parameters of arterial stiffness (augmentation index; pulse wave velocity; and vascular compliance indices, C1 and C2) were extracted from the data of gender- and age-matched subsets of these patients, and were related to those of a group of matched control subjects. RESULTS Despite a similar prevalence of hypertension (approximately 62%), hyperlipidemia (approximately 30%), and impaired glucose metabolism in both PHPT groups, CV or cerebrovascular disease was more common in the HC-PHPT group (24.7 vs 3.1%, P=0.007). Arterial stiffness parameters did not differ in the three groups, and were unrelated to serum calcium or parathyroid hormone concentration. CONCLUSIONS NC-PHPT and HC-PHPT subjects exhibit similar high rates of traditional CV risk factors, and have comparable indices of arterial stiffness. The lower clinical CV morbidity observed with NC-PHPT remains unexplained, and requires confirmation. Until then, the CV risk associated with NC-PHPT should not be underestimated.

Obesity in Elderly Subjects In sheep's clothing perhaps, but still a wolf!

Although the negative impact of high BMI on the risk of death from all-cause mortality is now well established, there is an apparent decline in the relative added risk of obesity with increasing age (1,2). This has led some experts to conclude that obesity should not necessarily be viewed as a disease in individuals older than 55 years. If such shift in the approach to adiposity during the latter phases of life is prematurely accepted, it may not only discourage attempted weight loss in older subjects, but also promote nutritional and lifestyle indulgence, which is presently difficult enough to overcome. It is the purpose of the present commentary to briefly outline the full spectrum of obesity-related hardships in the elderly. In our opinion, obesity-induced complications amount to real disease, which gravely affects quality of life and limits effective lifespan. The incidence of hypertension, diabetes, and the metabolic syndrome intensifies with age, and aging per se is closely linked to increased prevalence of most of the abnormalities contributing to the metabolic syndrome (3). The incidence of the metabolic syndrome rises with increasing BMI, and a broader waist circumference is more common in men older than 65 years than in younger age-groups (3). The occurrence of the metabolic syndrome reaches peak levels in the 6th decade for men and the 7th decade for women, and a decline is noted only in the 8th decade for men and for some women in different ethnic groups (3). As recently outlined by the American Heart Association Professional Education Committee of the Council for High Blood Pressure Research, older age and obesity are two of the most powerful risk factors for uncontrolled hypertension (4), and high blood pressure, in turn, is a major determinant of mortality and stroke incidence, particularly in senior years. BMI …

Absence of Peroxisome Proliferator-Activated Receptor- Abolishes Hypertension and Attenuates Atherosclerosis in the Tsukuba Hypertensive Mouse

Peroxisome proliferator-activated receptor-&agr; is widely distributed in the vasculature where it is believed to exert pleiotropic antiatherogenic effects. Its role in the regulation of blood pressure is still unresolved; however, some evidence suggests that it may affect the renin-angiotensin system. We investigated its role in angiotensin II–induced hypertension in the Tsukuba hypertensive mouse (THM). This is a model of hypertension and atherosclerosis because of high angiotensin II and aldosterone levels as a result of the transgenic expression of the entire human renin-angiotensin system. Making the THM animals deficient in Peroxisome proliferator-activated receptor-&agr; (THM/PPARKO) totally abolished hypertension and myocardial hypertrophy. This was accompanied by a reduction in plasma human active renin in THM/PPARKO mice compared with THM animals from 3525±128 mU/L to 1910±750 mU/L (P<0.05) and by a normalization of serum aldosterone (1.6±0.29 nmol/L versus 3.4±0.69 nmol/L; P=0.003). In the THM/PPARKO mice, the extent of atherosclerosis at the aortic sinus after a 12-week period on an atherogenic diet was decreased by >80%. In addition, the spontaneous formation of foam cells from peritoneal macrophages, a blood pressure–independent event, was reduced by 92% in the THM/PPARKO mice, suggesting protection from the usual oxidative stress in these animals, possibly because of lower prevailing angiotensin II levels. Finally, chronic fenofibrate treatment further elevated blood pressure in THM animals but not in THM/PPARKO animals. Taken together, these data indicate that peroxisome proliferator-activated receptor-&agr; may regulate the renin-angiotensin system. They raise the possibility that its activation may aggravate hypertension and hasten atherosclerosis in the context of an activated renin-angiotensin system.

Hyperandrogenism is Associated with Earlier Age of Onset of Idiopathic Intracranial Hypertension in Women

Abstract Purpose: Previous reports have connected between Idiopathic intracranial hypertension (IIH), obesity and different hormonal states. The aim of this study was to characterize the endocrine profile in women with IIH. Methods: This is a data-based study of 51 IIH patients. We measured anthropometric parameters and assessed hormonal profile including cortisol, testosterone, bioavailable testosterone (BT), prolactin, dehydroepiandrosterone sulfate (DHEA-S), androstenedione, insulin, aldosterone, estradiol, follicle stimulating hormone (FSH) and luteinizing hormone (LH). Pearson or Spearman rank correlation for non-normally distributed variables were calculated to evaluate the relation among the anthropometric measurements: age, body mass index (BMI), waist and hip circumference and waist to hip ratio (WHR) with hormones levels. Results: Seventy-eight percent of the cohort had WHR < 0.85 and 21.6% had a WHR > 0.85. Increased levels of testosterone, BT and androstenedione were all positively related to younger age of diagnosis in patient who are diagnosed after the age of 25 (R = −1.066, −0.845, −0.735, p < 0.001, =0.024, 0.019, respectively). No correlation was found between any of the analyzed hormones and the duration of the disease, WHR or BMI, except insulin, which was positively related to BMI (R = 0.461, p = 0.001). Conclusions: Increased levels of circulating androgens are associated with earlier age of onset of IIH in women.

Diastolic Pressure in Type 2 Diabetes Can target systolic pressure be reached without “diastolic hypotension”?

The practicality of vigorous lowering of systolic pressure in diabetes to <130 mmHg remains uncertain. Baseline blood pressure data from several recent trials indicate that, in diabetic subjects, there is nearly a fourfold excess in systolic pressure (the difference between baseline pressure and target pressure) over diastolic pressure with respect to the recommended systolic/diastolic target pressure of <130/80 mmHg. Additionally, systolic pressure was 2–3 mmHg higher and diastolic pressure was 1–3 mmHg lower in diabetic hypertensive than in nondiabetic hypertensive individuals, which adds ∼4 mmHg to pulse pressure and also to the difference between the excess systolic and excess diastolic pressure. We attempted to force (titrate both systolic and excess diastolic pressure) systolic and diastolic blood pressure to <130/85 mmHg based on Joint National Committee VI guidelines in the setting of a clinical practice in 257 diabetic patients. Although target systolic pressure was attained in a third of this cohort, in 57% of the patients, the attained diastolic pressure was ≤70 mmHg. Patients with final diastolic pressure <70 mmHg were older, had a higher prevalence of coronary artery disease, and had higher initial systolic and pulse pressures. Review of achieved blood pressure in studies such as the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) indicates that a significant fraction of the diabetic subjects’ diastolic pressure was also driven down to <70 mmHg or even <60 mmHg. Thus, attempted lowering of blood pressure to target systolic pressure is associated with inordinate lowering of diastolic pressure in a significant number of patients. Whether the benefits of tight systolic control to <130 mmHg outweigh the risks of excessive diastolic reduction, especially in older diabetic subjects or diabetic patients with coronary artery disease, remains unresolved.

Serum free cortisol as an ancillary tool in the interpretation of the low‐dose 1‐μg ACTH test

Objective  Serum free cortisol, rather than serum total cortisol (TC), determines glucocorticoid activity in vivo, but how the considerable inter‐subject variation in ambient serum free cortisol affects the outcome of dynamic hypothalamic–pituitary–adrenal (HPA) assessment in noncritically ill subjects is unknown.

Two novel exonic point mutations in HEXA identified in a juvenile Tay-Sachs patient: Role of alternative splicing and nonsense-mediated mRNA decay

We have identified three mutations in the beta-hexoseaminidase A (HEXA) gene in a juvenile Tay-Sachs disease (TSD) patient, which exhibited a reduced level of HEXA mRNA. Two mutations are novel, c.814G>A (p.Gly272Arg) and c.1305C>T (p.=), located in exon 8 and in exon 11, respectively. The third mutation, c.1195A>G (p.Asn399Asp) in exon 11, has been previously characterized as a common polymorphism in African-Americans. Hex A activity measured in TSD Glial cells, transfected with HEXA cDNA constructs bearing these mutations, was unaltered from the activity level measured in normal HEXA cDNA. Analysis of RT-PCR products revealed three aberrant transcripts in the patient, one where exon 8 was absent, one where exon 11 was absent and a third lacking both exons 10 and 11. All three novel transcripts contain frameshifts resulting in premature termination codons (PTCs). Transfection of mini-gene constructs carrying the c.814G>A and c.1305C>T mutations proved that the two mutations result in exon skipping. mRNAs that harbor a PTC are detected and degraded by the nonsense-mediated mRNA decay (NMD) pathway to prevent synthesis of abnormal proteins. However, although NMD is functional in the patients fibroblasts, aberrant transcripts are still present. We suggest that the level of correctly spliced transcripts as well as the efficiency in which NMD degrade the PTC-containing transcripts, apparently plays an important role in the phenotype severity of the unique patient and thus should be considered as a potential target for drug therapy.