Increased tissue factor and thrombomodulin expression and histopathological changes in placentas of pregnancies with preeclampsia

INTRODUCTION

Preeclampsia has a global frequency of 2-8% and a frequency of 10% in developing countries. In Colombia, preeclampsia causes 42% of maternal mortality. Alterations in placental homeostasis have been proposed to be involved in its pathophysiology. The aim of this study was to compare mRNA and protein levels of tissue factor (F3) and thrombomodulin (THBD) and the histopathological findings of placentas.

MATERIALS AND METHODS

We studied 16 placentas from patients with preeclampsia and 19 term placentas with uncomplicated pregnancy. An expert pathologist, who was masked to the group assignment, conducted an evaluation to determine specific histological changes. Assessments of mRNA and protein levels of F3 and THBD were performed using real-time PCR and ELISA, respectively.

RESULTS

Cases and controls differed in the frequency of decidual arteriopathy (p = 0.027), acute infarction (p = 0.001) and hyperplasia of the syncytiotrophoblast (p = 0.0017). Cases had increased levels of F3 mRNA (p = 0.0124) and protein (p <  0.0001) and THBD mRNA (p <  0.0001) and protein (p <  0.0001).

CONCLUSION

In placenta of patients with preeclampsia, we detected abnormal expression of F3 and THBD with increased protein and mRNA levels. The role of these molecules in the pathogenesis of this disease and in alterations of hemostatic and histopathological aspects of placentas need further studying.

Expression of cystathionine beta-synthase and histopathological observations in placentas of patients with Down syndrome

Down syndrome is the most frequent aneuploidy in live births, with an overall frequency of 1/600-700 births. The overexpression of cystathionine β-synthase is thought to participate in the presentation of some phenotypes observed in Down syndrome.

OBJECTIVE

The aim of this study was to compare the expression levels of cystathionine β-synthase and histopathological observations from placentas of infants with Down syndrome and healthy newborns.

MATERIALS AND METHODS

Six placentas of fetuses/infants with Down syndrome and sixteen placentas of healthy fetuses were studied. Cystathionine β-synthase mRNA and protein expression were performed by real-time PCR and immunohistochemistry, respectively.

RESULTS

We observed an increase in cystathionine β-synthase mRNA expression (p = 0.0465) and protein levels (p = 0.009) in placentas of fetus/infants with Down syndrome compared with controls. Significantly more circinate edges (p = 0.0007) and trophoblast inclusions (p = 0.0037) were observed in the group with Down syndrome compared with control group.

CONCLUSION

The results demonstrate overexpression of cystathionine β-synthase mRNA and protein in placentas of fetuses/infants with trisomy 21. Further histological abnormalities were found in placentas of patients with Down syndrome, suggesting an alteration in the development of placenta.

[Relationship between severity of essential arterial hypertension and the prevalence hyperuricemia]

BACKGROUND

Hyperuricemia has been associated with an increased risk of cardiovascular disease in hypertensive patients. However, the relation between serum urate and severity of hypertension has not been conclusively defined as yet. We aimed at finding out whether there exists an independent relationship between changes in the prevalence of hyperuricemia and severity of hypertension.

PATIENTS AND METHOD

We studied 3 cohorts of patients aged 35 to 60 years with essential hypertension diagnosed at a university hospital in Madrid, Spain. The first cohort (before 1981) included 325 patients, the second (from 1981 to 1989) comprised 271 patients and the third cohort (from 1990 to 1999) included 545 patients. Disease severity ranged from 1 to 6 according to blood pressure levels at diagnosis (WHO/ISH grades 1, 2 or 3 were assigned 1, 2 or 3 points, respectively) and target organ damage (left ventricular hypertrophy, hypertensive retinal vascular changes, and proteinuria above 300 mg/day; one point each).

RESULTS

Mean serum urate concentrations in the 3 cohorts were 6.6, 5.8 and 5.5 mg/dL, respectively (p < 0.05 for all comparisons). 39% of patients in the first cohort had a serum urate concentration > 7.0 mg/dL whereas only 18.1% patients in the third group showed hyperuricemia (difference: 20.9%; 95% CI, 10.1 to 32.3; p < 0.05). Severity of hypertension was higher in the first cohort (mean SD, 2.50 1.31 points) than in the third group (1.96 1.06 points; p < 0.05), with the second cohort showing an intermediate severity (2.23 1.01 points). Serum urate levels were directly related to the severity of hypertension in the 3 groups (r = 0.08, p < 0.05). In a multivariate analysis, after adjustment for confounding variables, serum urate had no significant association with severity of hypertension. However, target organ damage, systolic blood pressure and serum creatinine were all independent predictors of severity.

CONCLUSIONS

Favourable changes in the severity of hypertension for a time period significantly correlate with decreases in hyperuricemia prevalence in the same period. On the other hand, hyperuricemia appears to be an indirect marker of hypertensive renal damage.

White blood cell count and insulin resistance in patients with coronary artery disease

White blood cell (WBC) count has been shown as a risk factor for cardiovascular disease. Decreased insulin sensitivity has been suggested as the link between these two entities. Our aim was to study the potential relation between insulin sensitivity and WBC count in patients with coronary artery disease. In order to assess insulin sensitivity, we performed 83 insulin suppression tests before and after therapy in 50 patients with coronary artery disease. Patients with glucose intolerance, arterial hypertension or obesity were excluded. Steady-state plasma glucose (SSPG) and insulin sensitivity index (ISI=1 000 x glucose infusion rate/SSPG) were considered as a measure of insulin sensitivity. WBC count, blood platelets, fibrinogen, microalbuminuria, creatinine, urea and HbA1c were also assessed. Simple and multiple correlation analysis were carried out between insulin sensitivity parameters and the other variables measured. There were significant correlation between SSPG and WBC count (r=0,32: p=0,003) and microalbuminuria (r=0,28: p=0,012). We also found statistically significant correlation between ISI and WBC count (r=0,27: p=0,015) and microalbuminuria (r=0,24: p=0,029). No correlation could be detected between either SSPG or ISI and the other variables measured. In multiple regression analysis, WBC count was found to be an independent predictor of both SSPG (p<0.01) and ISI (p<0.05). Our data show the existence of a significant relationship between decreased insulin sensitivity and WBC count in patients with coronary artery disease. The results of this study suggest that an elevated WBC count could be postulated as part of the insulin resistant syndrome.

High prevalence of the polycystic ovary syndrome and hirsutism in women with type 1 diabetes mellitus

The current recommendation for strict metabolic control of type 1 diabetes mellitus requires the administration of supraphysiological doses of insulin, which might result in insulin-mediated stimulation of androgen synthesis, as occurs in insulin-resistant states. At present, the prevalence of hyperandrogenic disorders in women with type 1 diabetes mellitus is unknown. Eighty-five women with type 1 diabetes mellitus were evaluated for symptoms and signs of hyperandrogenism. In 68 of the patients, several serum androgen and hormone concentrations were measured. The polycystic ovary syndrome (PCOS) was defined by the presence of menstrual dysfunction, together with clinical and/or biochemical evidence of hyperandrogenism, and exclusion of other etiologies. Eighteen healthy women, menstruating regularly, served as controls for the androgenic profiles. Thirty-three patients (38.8%) presented hyperandrogenic disorders (16 had PCOS, and 17 had hirsutism without menstrual dysfunction). Type 1 diabetic patients with PCOS presented increased serum total and free testosterone concentrations, and serum androstenedione levels, but had normal serum sex hormone-binding globulin and dehydroepiandrosterone-sulfate levels. Hirsute type 1 diabetic women without menstrual dysfunction presented normal serum androgen levels. There were no significant differences between hyperandrogenic and nonhyperandrogenic type 1 diabetes mellitus women in clinical variables such as the duration of diabetes, age at diagnosis of diabetes, conventional or intensive insulin therapy, mean daily insulin dosage, or metabolic control. In conclusion, women with type 1 diabetes mellitus have a high prevalence of hyperandrogenic disorders, including PCOS and hirsutism.

Prostacyclin: its pathogenic role in essential hypertension and the class effect of ACE inhibitors on prostaglandin metabolism

Angiotensin-converting enzyme inhibitors (ACEI) block degradation of bradykinin, and bradykinin stimulates prostacyclin synthesis. Therefore, we set out to determine whether the effects of ACE inhibitors on prostaglandin production in essential hypertensive patients are class effects or are dependent on ACE inhibitor structure. In addition, we studied whether hypertensives show an impaired capacity to synthesize vasodilator prostaglandins. To address these questions, we compared the effects of captopril (sulfhydryl-containing inhibitor), enalapril and ramipril (carboxyl-containing inhibitors) and fosinopril (phosphoryl-containing inhibitor) on blood pressure and urinary excretion of 6-keto-prostaglandin (PG) F1-alpha (the breakdown product of prostacyclin) in 44 mild-to-moderate essential hypertensive subjects before and 8 weeks after administration of an ACEI. We also studied prostacyclin excretion in 15 normotensive healthy controls. Levels of urinary 6-keto-PGF1-alpha (pg/ml) were measured by specific radioimmunoassay. Hypertensive subjects showed a lower excretion of 6-keto-PGF1-alpha than normotensive controls (212+/-147 vs 353+/-98 pg/ml, p < 0.001). All ACEI induced a significant decrease in MAP and increased the rate of excretion of the prostacyclin metabolite: C, 211+/-200 to 338+/-250 pg/ml, p < 0.05; E, 202+/-133 to 296+/-207 pg/ml, p < 0.05; R, 205+/-127 to 342+/-211 pg/ml, p < 0.05; F, 235+/-128 to 347+/-241 pg/ml, p < 0.05. In hypertensives (n = 44) the decrease in blood pressure correlated negatively with the rise in 6-keto-PGF1-alpha excretion (r = -0.51, p < 0.001). These data suggest that impaired prostacyclin biosynthesis in hypertensive patients could account for haemodynamic changes leading to the hypertensive state. Moreover, the hypotensive mechanisms of ACEI may be mediated by an increase in prostacyclin production; this effect seems to be class-dependent.

Effects of hyperinsulinemia on vascular blood flows in experimental obesity

Human obesity, which is very common in Polycystic Ovaries Syndrome and in "X Syndrome", constitutes an insulin-resistance state in which multiple clinical, biochemical and hemodynamic alterations coexist. Insulin resistance in the obese has been recently associated with an endothelial dysfunction. To investigate the possibility that clinical and metabolic derangements related to insulin resistance could induce changes in vascular blood flows, we have studied the levels of mesenteric (MBF), renal (RBF) and femoral (FBF) blood flows in Beagle dogs kept for 2 years on a normal (control group) or high fat diet (obese group). This experimental model exhibits many of the abnormalities with the human syndrome. In addition, we have tested the effects of chronic treatment with captopril (capto group) in monotherapy or in association with pravastatin (prava+capto group) on the hemodynamic changes associated with this diet. After the two year follow-up, Transonic flow probes were placed around the three arteries to measure basal blood flows and their response to a hyperinsulinemic-normoglycemic test in anesthetized animals. During this test the degree of insulin sensitivity was estimated. In association with higher body weight, blood pressure, insulin resistance, and fasting levels of insulin and total cholesterol, the obese group exhibited decreased basal levels of FBF and a greater femoral vasoconstriction during hyperinsulinism (P < 0.05 vs control). Combined therapy with captopril and pravastatin ameliorated the reduction in basal FBF and hyperinsulinism-induced vasoconstriction (P < 0.05), in addition to the beneficial effects on insulin sensitivity, and clinical and metabolic parameters. Synergistic beneficial effects of both drugs on lipid and carbohydrate profiles may account for this positive outcome, by attenuating the atherogenic process associated with this model.

Evolution of insulin resistance in coronary artery disease patients on four different pharmacological therapies

The objective of the study was to examine the evolution of insulin sensitivity in a group of patients with stable coronary artery disease receiving one of four different pharmacological therapies. Insulin sensitivity was evaluated using an insulin suppression test in 40 newly diagnosed patients with coronary artery disease and no previous history of metabolic disorders, who were not taking any medication which might affect insulin sensitivity. The insulin suppression test consisted of a constant infusion of glucose, insulin and somatostatin for 150 min; insulin resistance was estimated by determining the steady-state plasma glucose concentrations during the last 60 minutes of the test. The insulin sensitivity index was calculated by the formula: insulin sensitivity index = (glucose infusion rate/steady state plasma glucose concentrations) x 10(3). A second insulin suppression test was performed after 6 months' therapy with either isosorbide mononitrate, atenolol, diltiazem or captopril in 30 of the 40 patients. There were no differences between any of the groups before therapy was initiated. After 6 months, patients treated with captopril and, to a lesser extent, those treated with diltiazem showed statistically significantly decreased steady state plasma glucose concentrations and increased insulin sensitivity index compared to basal values. No statistically significant differences were found in the other two groups. We conclude that captopril and, to a lesser extent, diltiazem improve insulin sensitivity in patients with stable coronary artery disease.

Abnormalities in the serum insulin-like growth factor-1 axis in women with hyperandrogenism

OBJECTIVE

To study the insulin-like growth factor-1 (IGF-1) axis in hirsute women.

DESIGN

Controlled clinical study.

SETTING

Tertiary care institutional hospital.

PATIENT(S)

Forty hirsute women and 17 women with normal menstrual cycles.

INTERVENTION(S)

Basal and ACTH-stimulated samples were obtained, and sampling was repeated 1 (gonadal stimulation) and 21 (gonadal suppression) days after a single 3.75-mg IM dose of triptorelin. Controls did not receive triptorelin for ethical reasons.

MAIN OUTCOME MEASURE(S)

Serum GH, IGF-1, IGF-binding protein-3 (IGFBP-3), insulin, glucose, total testosterone, sex hormone-binding globulin, E2, and gonadotropin levels. Basal and ACTH-stimulated steroid precursors were measured.

RESULT(S)

Patients with idiopathic hirsutism were identified by normal serum androgen levels (n=17). Those with functional ovarian hyperandrogenism (n=15) were identified by an increase in the serum testosterone level that normalized during gonadal suppression, whereas those with functional adrenal hyperandrogenism (n=8) were identified by an initial increase in the testosterone level that persisted during gonadal suppression. The adrenal hyperandrogenism group had increased IGF-1 levels compared with the control, idiopathic hirsutism, and ovarian hyperandrogenism groups. Patients with ovarian hyperandrogenism had normal TGF-1 concentrations, but their IGFBP-3 concentrations were lower than those of controls. No differences were observed in GH levels between any of the groups. These results persisted when the influence of age was corrected for.

CONCLUSION(S)

The IGF-1 axis appears to be involved in the pathogenesis of hyperandrogenism, especially in patients with adrenal hyperandrogenism, who have a clear increase in IGF-1 levels. Moreover, patients with ovarian hirsutism have decreased IGFBP-3 concentrations, which might enhance IGF-1 bioavailability.

Effects of hyperinsulinemia on the regulation of regional blood flow and blood pressure in anesthetized dogs: hemodynamic role of nitric oxide

The purpose of this study was to investigate whether acute hyperinsulinemia induces selective hemodynamic effects in the mesenteric, renal, and iliac vascular beds, and to determine whether nitric oxide (NO) plays a role in the regulation of blood flow and mean arterial pressure (MAP) during acute hyperinsulinism. In eight anesthetized dogs (Group A), the response to a hyperinsulinemic test was determined before and after NO inhibition, with L-nitro-arginine methyl esther (L-NAME), during the last 45 min of the experiment. In seven dogs (Group B), NO inhibition was induced before and maintained throughout hyperinsulinemia. In Group A, the hyperinsulinemic test did not alter MAP, but induced a significant reduction in both renal and mesenteric blood flow without a significant change in iliac blood flow. In contrast, the administration of L-NAME in Group B was followed by a significant decrease in mesenteric, renal, and iliac blood flow, but mean arterial pressure remained unchanged. In this group, hyperinsulinemia instituted after the blockade of NO was followed by a significant elevation in blood pressure levels, concomitant with reductions in blood flow to the three vascular beds. In summary, acute hyperinsulinemia induced a redistribution of blood supply, which preserves skeletal muscle irrigation while reducing blood flow to the kidney. Nitric oxide participates in this redistribution because L-NAME infusion abolishes the compensatory influence on skeletal muscle blood flow.

Effects of chronic combined treatment with captopril and pravastatin on the progression of insulin resistance and cardiovascular alterations in an experimental model of obesity in dogs

Obesity is a metabolic disorder in which multiple clinical and biochemical alterations coexist. However, the progression of these alterations in relation to weight gain has not been investigated in detail. Therefore, we studied the evolution of insulin resistance and associated risk factors in a model of experimental obesity in dogs. We also studied whether chronic exposure to these pathogenic factors could induce cardiac and vascular alterations. Twenty male age- and body weight-matched beagle dogs were divided into four groups (n = 5), according to diet and pharmacologic therapy received, and followed for 2 years. Control animals were maintained with a regular diet, while the 15 remaining animals were fed a high-fat diet. The Obese group of dogs received no therapy, whereas the Capto group received 25 mg/12 h captopril, and the Prava+Capto was treated with 10 mg/24 h pravastatin plus the same dose of captopril throughout the study. Periodical determinations of clinical and biochemical parameters were made, and the degree of insulin resistance was also estimated. After the 2-year follow-up, the dogs were killed and vascular thickening in the aorta and the coronary arteries was evaluated. In addition, cardiac hypertrophy was estimated by heart weight and free-wall left ventricular width. Chronic pravastatin plus captopril treatment, together with decreasing weight gain rate, ameliorated the progression of insulin resistance and associated risk factors (hyperinsulinemia, hypercholesterolemia) related to this severe model. In addition, this combined therapy showed cardioprotective action, as cardiac and vascular hypertrophy observed in the Obese group was prevented. These positive results seems to emerge from the synergistic effects of both drugs, as captopril as monotherapy induced only a slight benefit on these parameters.

Insulin resistance, dehydroepiandrosterone sulfate and sex hormone-binding globulin in essential hypertension

OBJECTIVE

To evaluate insulin sensitivity, and serum levels of sex hormone-binding globulin (SHBG) and dehydroepiandrosterone sulfate (DHEA-sulfate), in patients with essential hypertension.

DESIGN AND METHODS

In 15 non-treated hypertensive patients, insulin resistance was measured by an insulin suppression test (IST). Serum levels of DHEA-sulfate and SHBG were measured at the beginning and at the end of the IST. The results were compared to those of a control group of 10 healthy normotensive subjects matched for age, sex and body mass index (BMI).

How to treat the diabetic hypertensive individual appropriately

ASSOCIATION OF HYPERTENSION AND DIABETES: Diabetes mellitus and arterial hypertension are closely related and strongly predispose an individual to atherosclerosis and renal failure. Hypertension is twice as frequent in diabetic individuals as it is in the general population, and often precedes the development of diabetic nephropathy. The prevalence of coexisting arterial hypertension and non-insulin-dependent diabetes mellitus is increasing because of ageing of the population, allowing an augmented prevalence of atherosclerosis and end-stage diabetic renal disease. ANTIHYPERTENSIVE TREATMENT OF DIABETIC PATIENTS: The goal of blood pressure control in diabetic patients is to reduce death and disability as much as possible. In addition, other reversible risk factors for cardiovascular disease, which are so frequently seen in hypertensive diabetic individuals, need to be addressed. The optimal blood pressure level in diabetic individuals has not yet been established, but it has been suggested that it be should lower than that recommended by current guidelines. In fact, the literature indicates that 130/85 mmHg should be the systolic/diastolic blood pressure goal in hypertensive diabetic individuals. According to most guidelines the threshold for intervention when multiple associated risk factors coexist with hypertension is a blood pressure level 140/90 mmHg. In diabetic patients therapy has to be instituted early and aggressively. In this regard, angiotensin converting enzyme inhibitors alone or in association with other drugs seem to be the best choice for hypertensive diabetic patients.

Relationship between insulin sensitivity and dehydroepiandrosterone sulfate in patients with ischemic heart disease

Insulin resistance has been related to the pathogenesis and development of ischemic heart disease (IHD). Dehydroepiandrosterone sulfate (DHEA-S) has been suggested as the possible link between these two entities. The aim of this study was to clarify the relationship between insulin resistance and DHEA-S in patients with IHD. Thirty-two male patients with newly-diagnosed IHD and without known metabolic disorders and 11 healthy matched controls were included in this study. Insulin sensitivity was assessed by an insulin suppression test, and DHEA-S levels were measured before the test (basal) and at the end of the test (during hyperinsulinemia). Insulin resistance, defined as an insulin sensitivity index (ISI) below the normal range derived from the control group, was present in 78% of IHD patients; they also displayed, as a group, lower ISI (P < 0.0001) than controls. DHEA-S levels were lower in IHD than in controls, both basal and during hyperinsulinemia (P < 0.05). DHEA-S levels decreased when hyperinsulinemia was achieved, both in IHD patients and controls (P < 0.0005). The magnitude of the decrease was the same in both groups. No correlation between ISI and DHEA-S levels was found. In conclusion, insulin sensitivity is lower in patients with IHD, even when major metabolic abnormalities associated with insulin resistance are excluded. These patients also show decreased DHEA-S levels, which are further reduced when acute induced hyperinsulinemia is achieved, although, as the decline was similar to that of controls, there does not seem to be resistance to this particular action of insulin.

Circulating leptin concentrations in women with hirsutism

OBJECTIVE

To evaluate serum leptin concentrations in hirsute women.

DESIGN

Controlled clinical study.

SETTING

Tertiary institutional hospital.

PATIENT(S)

Thirty-three hirsute women and 11 healthy female controls.

INTERVENTION(S)

Serum samples were obtained at baseline and on day 1 (gonadal stimulation) and day 21 (gonadal suppression) after the IM injection of a single 3.75-mg dose of triptorelin.

MAIN OUTCOME MEASURE(S)

Leptin, T, sex hormone-binding globulin (SHBG), insulin, and glucose levels and free androgen index.

RESULT(S)

Leptin levels were increased in hirsute women in comparison with control subjects at baseline and on day 1. Leptin levels increased on day 1 compared with baseline and then decreased to baseline by day 21. Leptin levels correlated with body mass index (r = 0.76), SHBG levels (r = -0.52), free androgen index (r = 0.38), insulin levels (r = 0.46), and the glucose/insulin ratio (r = -0.38). When the effect of obesity on these results was removed by analysis of covariance and partial correlation analysis, leptin levels remained elevated only on day 1 and the only correlations that remained significant were those of leptin with insulin (r = 0.24) and the glucose/insulin ratio (r = -0.24).

CONCLUSION(S)

The increased leptin levels found in hirsute women are related mainly to obesity and also to insulin resistance. Leptin levels increased during gonadal stimulation and returned to baseline during gonadal suppression, suggesting that leptin also is influenced by the gonadal axis.

Mild adrenal and ovarian steroidogenic abnormalities in hirsute women without hyperandrogenemia: does idiopathic hirsutism exist?

To study ovarian and adrenal steroid profiles of women with idiopathic hirsutism, we compared sex steroid and basal and corticotropin (ACTH)-stimulated adrenal steroid levels before and after ovarian suppression induced by a long-acting gonadotropin-releasing hormone agonist analog (GnRH-a) in 24 hirsute women without hyperandrogenemia. Twelve healthy women served as controls for basal and ACTH-stimulated adrenal steroid levels. Serum levels of testosterone (T), sex hormone-binding globulin (SHBG), estradiol (E2), basal and ACTH-stimulated 17-hydroxyprogesterone (17OHP), dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), delta 4-androstenedione (delta 4-A), 11-deoxycortisol (S) and cortisol (F), and basal and luteinizing hormone-releasing hormone (LHRH)-stimulated gonadotropin levels were measured before and 21 days after 3.75 mg intramuscular triptorelin in hirsute women. Basal T levels and basal and ACTH-stimulated delta 4-A, DHEA, and DHEAS levels were not different in hirsute women with respect to controls. Basal and ACTH-stimulated 17OHP was elevated, and decreased to normal after ovarian suppression with triptorelin. Although basal and ACTH-stimulated delta 4-A levels were normal, the delta delta 4-A/delta F and delta delta 4-A/delta 17OHP ratios were elevated and remained elevated after ovarian suppression, suggesting enhanced adrenal delta 4-17,20-lyase activity. T, F, S, and DHEAS levels were not affected by ovarian suppression. Basal and ACTH-stimulated 17OHP and delta 4-A, and stimulated DHEA concentrations were reduced with ovarian suppression, but their net increment and ratio to the increase of F in response to ACTH remained unchanged, reflecting the ovarian contribution to the secretion of these steroids. We conclude that idiopathic hirsute women with normoandrogenemia show an increase in ovarian secretion of 17OHP and a minimally increased adrenal delta 4-17, 20-lyase activity, suggesting that mild forms of ovarian and adrenal functional hyperandrogenism may be present in these patients with otherwise unexplained hirsutism.

L-arginine reverses the antinatriuretic effect of cyclosporin in renal transplant patients

BACKGROUND

Cyclosporin has been shown to facilitate renal vasoconstriction and to have an antinatriuretic effect. The existence of an interference of cyclosporin with the vasodilating properties of endothelium mediated by nitric oxide production could mediate these effects. On the other hand, the infusion of the nitric oxide precursor L-arginine has been shown to induce renal vasodilatation and to facilitate natriuresis in normal volunteers. We have investigated the renal effects of the administration of an infusion of L-arginine in renal transplant patients chronically treated with cyclosporin. To facilitate the analysis of the data the effects of the administration of a similar dose of cyclosporin on renal function during the infusion of a vehicle were also investigated during the administration of a vehicle of L-arginine.

DESIGN

Ten male renal transplant patients, chronically treated with cyclosporin and with a stable renal function were studied during 2 consecutive days after the administration of the usual morning dose of cyclosporin. The first day they received an intravenous infusion of vehicle and the second the infusion of graded doses of L-arginine (50, 100, 150 mg/kg/h) during 3 consecutive h.

RESULTS

The first day, after cyclosporin administration a significant fall (P < 0.01) was observed in natriuresis and kaliuresis in the absence of changes in renal plasma flow and glomerular filtration rate. After the administration of L-arginine significant (P < 0.01) increases of renal plasma flow, glomerular filtration rate, and natriuresis were seen. The increase in blood levels of cyclosporin after its administration did not differ between days 1 and 2.

CONCLUSION

These results indicate that L-arginine facilitates renal vasodilatation and natriuresis in renal transplant patients. Furthermore, the observed increase in sodium excretion could indicate that L-arginine counteracts the antinatriuretic effect of cyclosporin.

Lack of an ovarian function influence on the increased adrenal androgen secretion present in women with functional ovarian hyperandrogenism

OBJECTIVE

To evaluate whether ovarian function might have an influence on the adrenal hyperandrogenism present in patients with functional ovarian hyperandrogenism.

DESIGN

Controlled clinical study.

SETTING

Tertiary institutional hospital.

PATIENT(S)

Twenty-nine hirsute women with functional ovarian hyperandrogenism and 12 normal controls.

INTERVENTION(S)

The ACTH and GnRH tests were performed before and during triptorelin-induced ovarian suppression in patients. The normal women served as controls for the ACTH test.

MAIN OUTCOME MEASURE(S)

Basal and ACTH-stimulated steroid values.

RESULT(S)

All patients presented elevated T and free androgen index, which normalized after triptorelin. Patients with functional ovarian hyperandrogenism and adrenal hyperandrogenism, defined by elevated basal DHEAS (n = 10), presented enhanced delta 4-17, 20-lyase activity, which persisted during ovarian suppression. delta 4-17,20-lyase activity was normal in the functional ovarian hyperandrogenism patients without adrenal hyperandrogenism (n = 19). No correlation was observed between the any of the indexes of the adrenal enzymatic activities evaluated and plasma E2 or T.

CONCLUSION(S)

Increased adrenal delta 4-17,20-lyase activity is present in functional ovarian hyperandrogenism women with adrenal hyperandrogenism. No influence of the excess ovarian androgens or estrogens was found on any of the adrenal enzymatic pathways explored.

Cardiac involvement in acromegaly: specific myocardiopathy or consequence of systemic hypertension?

To evaluate the relative contributions of past or present GH hypersecretion and of hypertension to the cardiac abnormalities present in acromegaly, we have studied the serum GH and insulin-like growth factor I concentrations, systolic and diastolic blood pressures, and morphological and functional cardiac indexes as measured by echocardiography-Doppler, in 39 patients with active or cured acromegaly, 16 hypertensive controls, and 17 normotensive controls. Hypertension was present in 42.8% of patients with active acromegaly and in 28.0% of patients in which acromegaly was cured. Hypertension was independently related to an increase in indexes of cardiac morphology (left ventricular mass, left ventricular posterior wall thickness, interventricular septum thickness, relative wall thickness with respect to the diastolic diameter of the left ventricle, and left atrial end-systolic diameter), systolic function (stroke volume, fractional shortening, and end-systolic stress), and diastolic function (isovolumic relaxation time and maximal late diastolic flow velocity) and to a reduction in the early to late maximal diastolic flow velocity ratio. Acromegaly was related to an increase in left ventricular mass, stroke volume, cardiac output, and isovolumic relaxation time, which were independent from the presence of hypertension. End-systolic stress was reduced by acromegaly. In the five patients in which active acromegaly was successfully treated, left ventricular mass and left ventricular posterior wall thickness were reduced 1 yr later. In conclusion, the asymptomatic morphological and functional cardiac abnormalities present in acromegalic patients are independently related to acromegaly and hypertension, pointing to the existence to a specific acromegalic myocardiopathy that might be aggravated by the coexistence of hypertension.

Effects of UP269-6, a new angiotensin II receptor antagonist, and captopril on the progression of rat diabetic nephropathy

To estimate the effects of UP269-6, a nonpeptide angiotensin II receptor antagonist, and captopril, a converting enzyme inhibitor, on the progression of nephropathy, 77 uninephrectomized diabetic rats were maintained for 8 months with plasma glucose levels from 300 to 500 mg/dL. Systemic and renal parameters were periodically measured, and, at the time of death, a histological evaluation of renal damage was performed. Control rats (no additional treatment but insulin) showed increased blood pressure and urinary albumin levels, together with prominent alterations in the kidney (renal and glomerular hypertrophies, tubular atrophy, and 19% of sclerotic glomeruli). Captopril (50 mg/kg/day) and UP269-6 (10 mg/kg/day) reduced blood pressure and albumin excretion levels, and improved histological renal preservation (lower renal and glomerular hypertrophies, tubular atrophy, and percentage of sclerotic glomeruli: 5% and 7%, respectively). Finally, a low dose of UP269-6 (1 mg/kg/day), which induced an intermediate level of blood pressure between control and the other treated groups, produced an equivalent degree of nephroprotection. Our data demonstrate the efficacy of this new angiotensin II receptor antagonist on the progression of diabetic renal damage. These results also reinforce the role attributed to angiotensin II in the development of renal derangement in this model, as UP269-6 is devoid of agonistic effect on the kinin system.

How far should blood pressure be reduced in diabetic hypertensive patients?

EPIDEMIOLOGY OF DIABETES: Diabetes mellitus and arterial hypertension are closely related diseases that strongly predispose an individual to atherosclerotic cardiovascular disease and to renal failure. High blood pressure is twice as frequent in diabetics compared with the general population, and often precedes and contributes to the development of diabetic nephropathy. The prevalence of coexisting arterial hypertension and non-insulin-dependent diabetes mellitus (NIDDM) is increasing as populations age, giving an increased prevalence of both diseases. TREATMENT OF HYPERTENSIVE DIABETIC PATIENTS: The goal of treating arterial hypertension in diabetic patients is to prevent death and disability associated with high blood pressure. In addition, other reversible risk factors for cardiovascular disease, seen so frequently in hypertensive diabetics, also need to be addressed. The optimal goal of blood pressure control in diabetics has not been established, but there are indications that it should be lower than the 130/85 mmHg systolic/diastolic pressure recommended by current guidelines. In the presence of multiple associated risk factors, most guidelines suggest a threshold for intervention of > or = 140/90 mmHg. In particular, in hypertensive diabetic patients intervention must be early and aggressive.

Effects of cicaprost and fosinopril on the progression of rat diabetic nephropathy

We have studied the effects of chronic therapy with cicaprost (a PGI2 analog), fosinopril (a converting enzyme inhibitor), and the combination of both drugs on the progression of experimental diabetic nephropathy. Uninephrectomized streptozotocin-induced diabetic rats were maintained for 8 months with plasma glucose between 13.7 and 22.0 mmol/L to hasten renal damage. Systemic and renal parameters were measured periodically, and at sacrifice structural and morphometrical renal studies were performed to evaluate diabetic injury. Control rats exhibited characteristic features of this model, such as high blood pressure and plasma creatinine and urinary albumin excretion, together with prominent alterations in the kidney (renal and glomerular hypertrophies, mesangial matrix expansion, and tubular alterations). The three therapies attenuated equivalently the progression of diabetic renal injury, as estimated by lower urinary albumin excretion, renal and glomerular hypertrophies, and a better renal architectural preservation. No synergistic action was appreciated with the combined therapy. However, renal preservation achieved with cicaprost was not linked to reductions in systemic blood pressure, whereas in the groups treated with fosinopril the hypotensive effect of this drug could have contributed to the positive outcome of the therapy. Therefore, nephroprotection exerted by this PGI2 analog in this model seems more related to the derangement of renal local mechanisms than to systemic blood pressure control. Finally, the possibility that an impaired prostacyclin synthesis or bioavailability is involved in the pathogenesis of the diabetic nephropathy in this model underlies our results.

Methimazole-induced severe aplastic anemia: unsuccessful treatment with recombinant human granulocyte-monocyte colony-stimulating factor

Aplastic anemia is a rare but severe complication of thionamide therapy. Although colony-stimulating factors have been used extensively in thionamide-induced agranulocytosis with good results, the same might not apply to aplastic anemia. We present a case of a patient with methimazole-induced aplastic anemia in which, as administration of recombinant human granulocyte-monocyte colony-stimulating factor for a week did not result in an increase in peripheral blood cell count, standard immunosuppressive treatment was needed to restore normal hematopoiesis. The clinical characteristics of this patient are compared with those of previous cases of thionamide-induced aplastic anemia, especially with the only other reported patient in which colony-stimulating factors were used.

Insulin resistance in patients with a recent diagnosis of coronary artery disease

OBJECTIVE

To elucidate whether insulin resistance is present in coronary artery disease (CAD) at diagnosis and to study its relationship with other known cardiovascular risk factors.

METHODS

We evaluated the incidence of insulin resistance in 40 newly diagnosed CAD patients. Fifteen healthy subjects were used as a control group. The patients and controls had no previous history of metabolic disorders, and were not being administered any medication that might have affected their insulin sensitivity. Immediately after diagnosis of CAD, a standard 75 g oral glucose-tolerance test (OGTT) and an insulin suppression test (IST) were performed on separate days. The IST consisted of a constant infusion of glucose, insulin and somatostatin for 150 min; insulin resistance was estimated by determining the steady-state plasma glucose (SSPG) concentrations during the last 60 min of the test. The insulin sensitivity index (ISI) was calculated by the formula ISI = (glucose infusion rate/SSPG]x10(3).

RESULTS

Insulin resistance, defined by an ISI below the normal range derived from the control group, was present in 82.5% of the CAD patients. As a group, the patients with CAD displayed lower ISI (means +/- SD:29.23 +/- 11.23 versus 50.33 +/- 9.37 dl/kg per min, P < 0.001) than did controls. Serum triglycerides and uric acid were higher and high-density lipoprotein cholesterol levels were lower in patients than they were in controls. No differences were observed in fasting plasma insulin, glucose, total and low-density lipoprotein cholesterol concentration. An abnormal OGTT result was observed in 27 patients. The ISI was low in 88.8% of the patients with an abnormal OGTT result and in 69% of the 13 patients with a normal OGTT result.

CONCLUSIONS

Insulin resistance and even impaired glucose tolerance are common findings in CAD at diagnosis. The changes in the lipid profile and in uric acid levels paralleled the changes in insulin sensitivity. These results suggest that insulin resistance might play a role in the development of coronary atherosclerosis and that its early diagnosis might be important in the prophylaxis of CAD.

Effects of indomethacin and iloprost on contraction of the afferent arterioles by endothelin-1 in juxtamedullary nephron preparations from normotensive Wistar-Kyoto and spontaneously hypertensive rats

The contractile effects of endothelin-1 on the afferent arterioles of normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) and the modulation of these responses by cyclooxygenase blockade or by the prostacyclin analog iloprost were investigated. For this, the preglomerular vasculature was visualized by using the juxtamedullary nephron preparation. Endothelin-1 (100 pM-1 microM) induced concentration-dependent reduction of afferent diameters either in WKY and SHR kidneys, which were inhibited by 1 microM nifedipine, indicating its dependence on extracellular calcium. After incubation with 20 microM indomethacin, the endothelin-1-induced contractions were potentiated in WKY but abolished in SHR vessels. These results could be explained if endothelin-1 is releasing vasodilator prostanoids in WKY, whereas in SHR preparations, vasoconstrictor prostanoids predominate. The prostacyclin analog iloprost (1 nM-1 microM) did not modify basal diameters of the WKY afferent arterioles, whereas a weak vasodilatatory effect was observed in the SHR afferent vasculature. Both in WKY and SHR preparations, iloprost (10 nM-1 microM) abolished the afferent contractility by endothelin-1, this effect being more prominent in SHR. We conclude that a defective production of vasodilator prostanoids or an enhanced release of vasoconstrictor cyclooxygenase derivatives may determine the renovascular effects of endothelins in SHR kidneys.

Clinical features of adrenal insufficiency in patients with acquired immunodeficiency syndrome

OBJECTIVE

Adrenal insufficiency (AI) is a well known complication of AIDS. However, the clinical and biochemical features of AI in HIV infected patients have not been extensively studied.

DESIGN

A retrospective clinical study.

PATIENTS

We reviewed clinical records of 74 AIDS patients with clinical and/or biochemical indications of AI who underwent Synacthen testing in order to determine adrenocortical function during a 5-year period.

MEASUREMENTS

AI was diagnosed when cortisol levels failed to rise above 496 nmol/l at any time during the test. Cortisol was measured by RIA.

RESULTS

Sixteen patients (22%) were diagnosed with AI. Most were young males and all of them had a known risk factor, principally i.v. drug users. The main complaint was fatigue. Hyponatraemia or hyperkalaemia were uncommon. All of them were severely immunosuppressed, with AIDS-defining conditions from at least 6 months before the diagnosis of AI, and had been diagnosed with at least one disease that has been reported to produce AI in AIDS patients. Survival was poor. Thirteen of these patients (81%) died within 6 months. Basal cortisol levels were lower than 275 nmol/l in 75% of patients with AI but in only 2% of the group of 58 patients who had normal adrenal responses to Synacthen.

CONCLUSIONS

Adrenal insufficiency features in AIDS patients with advanced disease, without specific findings and with a history of previous opportunistic diseases. Basal cortisol values at 0830 h lower than 275 nmol/l are highly suggestive of adrenal insufficiency in patients with AIDS.

Effects of L-arginine infusion on renal hemodynamics and sodium excretion during hypo-, normo-, and hyperinsulinemia, as studied in dogs

The response of renal hemodynamics and sodium excretion (NaU) to an infusion of L-arginine, in the presence (experiment I) or absence (experiment II) of endogenous insulin secretion and during a sustained hyperinsulinemic euglycemic state (experiment III), was studied in 10 age-matched beagle dogs. The experiments were preceded by a standard oral glucose tolerance test (OGTT), performed 1 week before experiment I. One week resting periods were allowed between experiments I, II, and III. No differences in renal hemodynamics and NaU were observed between basal (experiment I) and insulin secretion suppressed states (experiment II). L-Arginine infusion increased renal plasma flow (RPF), glomerular filtration rate (GFR), and NaU to a similar extent in both experiments. The hyperinsulinemic-euglycemic state (experiment III) induced a decrease in renal hemodynamics and NaU. In this situation, the infusion of L-arginine increased NaU, but was unable to increase RPF and GFR. Our data suggest that a sustained hyperinsulinemic state can interact with the physiological vasoactive mechanisms involved in the regulation of renal vasculature. These results may be pertinent to human disease, especially in pathological conditions in which insulin resistance is present.

Methimazole has no dose-related effect on the serum concentrations of soluble class I major histocompatibility complex antigens, soluble interleukin-2 receptor, and beta 2-microglobulin in patients with Graves' disease

Soluble class I major histocompatibility antigens (sHLA), beta 2-microglobulin (beta 2-M), and soluble interleukin-2 receptor (sIL-2R), are secreted by B and T lymphocytes upon activation, and have been used as markers of immune activation in several diseases. Thirty-two Graves' disease patients were randomly assigned to three methimazole (MMI) regimens of treatment: (1) low-dose, starting with 45 mg/day, and lowering the dose thereafter to maintain normal serum thyroid hormones; (2) MMI 60 mg/day + levothyroxine, and (3) MMI 30 mg/day + levothyroxine. Serum sHLA, beta 2-M, sIL-2R, TSH receptor antibodies (TSH-R Ab), T3, and free T4 (fT4) were measured at diagnosis and at weeks 4, 12, and 24 (end of treatment). Patients were followed-up after treatment for at least 24 weeks (24 to 89). At diagnosis, serum levels of sIL-2R, beta 2-M, sHLA, and TSH-R Ab were elevated. Serum sIL-2R, beta 2-M, sHLA, and TSH-R Ab decreased with treatment. No effect of the varying MMI regimens on these parameters was observed. Soluble IL-2R correlated positively with T3, fT4, beta 2-M, sHLA, and TSH-R Ab. Statistically significant, but weak, correlations (r < 0.35) were observed between beta 2-M, sHLA, and TSH-R Ab, between beta 2-M, T3, and fT4, and between TSH-R Ab and T3. Recurrence rates were not associated either with the MMI regimen or any of the parameters studied, with the exception of elevated initial TSH-R Ab levels. Serum sHLA, beta 2-M, and sIL-2R are increased in untreated Graves' disease, and decrease during treatment. No MMI dose-related differences were observed in these parameters, and in the recurrence rate. Unfortunately, sHLA, beta 2-M, and sIL-2R were not useful predictors of prolonged remission after MMI treatment.

Ovarian suppression with triptorelin and adrenal stimulation with adrenocorticotropin in functional hyperadrogenism: role of adrenal and ovarian cytochrome P450c17 alpha

OBJECTIVES

To validate combined ovarian suppression with triptorelin and adrenal stimulation with ACTH in the diagnosis of female hyperandrogenism and to provide new insights into the adrenal-ovarian relationship present in this disorder.

DESIGN

Comparison of sexual steroids and basal and ACTH-stimulated steroid levels before and after ovarian suppression induced by triptorelin.

SETTING

Department of Endocrinology, Hospital Ramón y Cajal, Madrid, Spain.

PARTICIPANTS

Thirty-nine nonselected women with hyperandrogenism.

MAIN OUTCOME MEASURES

Serum levels of T, 17-hydroxyprogesterone (17-OHP), 17-hydroxy-pregnenolone, DHEA and DHEAS, androstenedione (delta 4-A), 11-deoxycortisol, and cortisol.

RESULTS

Elevated T independent of ovarian suppression pointed to an adrenal disorder in six patients (one with an androgen-producing adenoma, two with late-onset 21-hydroxylase deficiency, three with functional adrenal hyperandrogenism). Nineteen patients had functional ovarian hyperandrogenism as elevated T normalized after ovarian suppression and were subdivided into ovDHEAS+ (n = 7) and ovDHEAS = (n = 12) subgroups depending on the presence of DHEAS hypersecretion. Finally, 14 patients had idiopathic hirsutism according to normal T before and after ovarian suppression. Comparisons of initial hormonal values between groups and with reference values obtained from normal women (n = 11) disclosed in functional adrenal hyperandrogenism an elevation of T and basal and stimulated DHEAS, delta 4-A, and 17-OHP with respect to normal women. These abnormalities were also present in ovDHEAS+ except for basal delta 4-A, which was normal, whereas only T and stimulated 17-OHP were elevated in ovDHEAS =. In the idiopathic group all steroids were normal with the exception of a mild elevation in stimulated DHEAS.

CONCLUSIONS

These results show a continuum of abnormalities in hyperandrogenic women, suggesting an enhanced cytochrome P450c17 alpha activity in the adrenal and the ovary as the shared mechanism between functional adrenal hyperandrogenism and functional ovarian hyperandrogenism.

Diagnosis of insulin resistance

Soon after the discovery of insulin, the importance of insulin sensitivity assessment was recognised. Recently, the role of insulin resistance in cardiovascular morbidity and mortality has been widely accepted and many methods for in vivo assessment of insulin resistance have been developed. They may be classified as 'closed-loop' techniques (in which insulin and glucose concentrations are allowed to interact freely), 'open-loop' techniques (in which insulin and/or glucose levels are fixed) and 'model methods' (which use a mathematical model to analyse the interactions between insulin secretion patterns and glucose disposal). Although there is no ideal method available to date, open-loop techniques avoid many of the difficulties involved in the interpretation of closed-loop or model methods, and are preferred by most investigators. The glucose clamp technique is recognised as the 'gold standard' for assessment of insulin sensitivity; however, the insulin suppression test is adequate in most circumstances and is much simpler to perform.

Characterization of the renal effects of an intravenous calcium gluconate infusion in normotensive volunteers

The effects on renal function of an intravenous infusion of calcium gluconate at subpressor doses have been investigated in a group of seven normotensive male volunteers. In the absence of changes in blood pressure, the calcium gluconate induced a significant increase in renal plasma flow and the glomerular filtration rate (P less than 0.01) with a significant fall in the filtration fraction (P less than 0.01). Both diuresis and natriuresis increased significantly (P less than 0.01), plasma renin activity fell (P less than 0.01) and the urinary excretion of 6-keto prostaglandin F1 alpha (PGF1 alpha) and prostaglandin E2 (PGE2) increased (P less than 0.01). These results indicate that calcium infusion at subpressor doses has renal vasodilating, diuretic and natriuretic properties that appear to be facilitated by an increase in the renal production of vasodilatory and natriuretic prostaglandins.

Diuretic and natriuretic properties of fenoldopam in chronic renal failure

The effect of intravenously administered fenoldopam on diuresis and natriuresis was investigated in a group of 10 patients with advanced chronic renal failure. After an initial basal period of 1 h, a fenoldopam infusion was started and maintained for 12 h at rates varying between 0.025 and 0.1 microgram/kg per min. During the study, blood pressure was measured every 10 min and urine volume, natriuresis and creatinine clearance were measured hourly. Fenoldopam induced a significant increase in urine volume, natriuresis and creatinine clearance (P less than 0.05-0.001) accompanied by a small but significant drop in blood pressure (P less than 0.05-0.01). These results show that for advanced chronic renal failure, fenoldopam has diuretic and natriuretic properties that could be of clinical relevance.

Dopaminergic modulation of aldosterone secretion: effect of sodium balance and postural changes

The influence of an increased endogenous production of angiotensin II and of sodium homeostasis upon the response of plasma aldosterone to metoclopramide administration has been investigated in 5 normal volunteers. Our results show that the increase of plasma aldosterone after metoclopramide administration is independent of angiotensin II, ACTH and potassium, and that it increases even further due to the endogenous production of angiotensin II induced by postural changes. The state of sodium balance seems to influence the response of plasma aldosterone to metoclopramide administration as it occurs with other stimuli of aldosterone secretion.

Aldosterone regulation in anephric patients

The response of plasma aldosterone to hemodialysis, 3 h orthostatism, K-loading and angiotensin II and ACTH infusions has been studied. Hemodialysis, orthostatism and angiotensin II infusion do not modify aldosterone levels. By the contrary ACTH and potassium originate a significant increase in plasma aldosterone. They seem to be the main aldosterone secretion regulators in the absence of renin production.

Response of plasma aldosterone to orthostatism during follicular and luteal phases of the normal menstrual cycle

The responses of plasma aldosterone (A) and plasma renin activity (PRA) to orthostatism have been evaluated in 47 women during the follicular and/or luteal phase of the menstrual cycle. Three postmenopausal women and 51 men were also studied for control. Fourteen cycling women and 11 men were studied on a low sodium diet (20 mEq/day) while the rest of the subjects were on normal sodium intake. In addition, 18 women (including those postmenopausal) and 17 men were studied after intravenous administration of 20 mg frusemide. The response of A to orthostatism in women during luteal phase on normal sodium diet with or without frusemide was much greater than in men or women during follicular phase (p less than 0.01) or menopuase (p less than 0.05). However, no differences between groups could be observed in A response while on a low sodium diet. PRA response was similar during follicular of luteal phase fo the cycle as well as in men either on low or normal sodium intake with or without frusemide.