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1.
Diabetologia ; 54(7): 1615-9, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21340620

ABSTRACT

AIMS/HYPOTHESIS: The aim of this study was to investigate whether components of the renin-angiotensin system and semicarbazide-sensitive amine oxidase (SSAO) are associated with the development of pre-eclampsia in women with type 1 diabetes. METHODS: This was an observational study of 107 consecutive pregnant women with type 1 diabetes (median duration 16 years [range 1-36 years], HbA(1c) 6.6% [range 4.9-10.5%]) in early pregnancy. At 8, 14, 21, 27 and 33 weeks and once within 5 days postpartum, blood was sampled for measurements of prorenin, renin, angiotensinogen, ACE and SSAO. HbA(1c), blood pressure and urinary albumin excretion were recorded. Pre-eclampsia was defined as blood pressure >140/90 mmHg and proteinuria ≥300 mg/24 h after 20 weeks. RESULTS: Pre-eclampsia developed in nine women (8%) with longer diabetes duration (median 20 [range 10-32] vs 16 [range 1-36] years, p = 0.04), higher SSAO concentrations (592 [range 372-914] vs 522 [range 264-872] mU/l, p = 0.04) and a tendency towards higher prorenin levels (136 [range 50-296] vs 101 [range 21-316] ng angiotensin I ml(-1) h(-1), p = 0.06) at 8 weeks compared with women without pre-eclampsia. Levels of renin, angiotensinogen and ACE did not differ in the two groups. Throughout pregnancy, prorenin and SSAO levels were 30% (p = 0.004) and 16% (p = 0.04) higher, respectively, in women developing pre-eclampsia. Using multivariate logistic regression analysis, prorenin concentration at 8 weeks was associated with pre-eclampsia (OR 4.4 [95% CI 1.5-13.0], p = 0.007), i.e. an increase of prorenin of 100 ng angiotensin I ml(-1) h(-1) implies a 4.4 times higher risk of subsequent pre-eclampsia. CONCLUSIONS/INTERPRETATION: In type 1 diabetic women with pre-eclampsia, a higher concentration of prorenin in early pregnancy and higher levels of prorenin and SSAO throughout pregnancy were seen.


Subject(s)
Diabetes Mellitus, Type 1/blood , Diabetes Mellitus, Type 1/complications , Pre-Eclampsia/blood , Pre-Eclampsia/etiology , Renin/blood , Adult , Diabetes Mellitus, Type 1/epidemiology , Female , Humans , Pre-Eclampsia/epidemiology , Pregnancy , Prospective Studies , Young Adult
2.
Diabetologia ; 53(8): 1576-80, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20480132

ABSTRACT

AIM: The optimal antiproteinuric dose of aliskiren is unknown. This study compared the effect of placebo and increasing doses of aliskiren on urinary albumin excretion rate (UAER). METHODS: The trial was a double-blind crossover design. Twenty-six patients with type 2 diabetes mellitus, hypertension and albuminuria were randomised to 2-month treatments with placebo or aliskiren 150 mg, 300 mg or 600 mg once daily, in random order. Primary endpoint was change in UAER; secondary endpoints included changes in 24-h BP, GFR, biomarkers and components of the renin-angiotensin-aldosterone system. RESULTS: Placebo geometric mean UAER was 350 mg/day, mean 24-h BP was 137/81 (SD 12/9) mmHg, GFR was 85 (SD 26) ml min(-1) 1.73 m(-2). Aliskiren 150, 300 and 600 mg daily reduced UAER significantly by 36% (95% CI 17-51), 48% (33-60) and 52% (38-63) respectively (p < 0.001) compared with placebo. UAER reduction during the 600 mg dose was not significantly different from the 300 mg dose. Twenty-four-hour systolic BP was reduced by 4.5, 8.0 and 9.2 mmHg versus placebo, significant for 300 and 600 mg (p < or = 0.001). Twenty-four-hour diastolic BP was reduced by 3.0, 4.1 and 4.4 mmHg, significant versus placebo (p = 0.019, p = 0.001 and p < 0.001). GFR was reduced by 3.0, 5.1 and 6.5 ml min(-1) 1.73 m(-2). hsPRA was reduced by 63%, 70%, and 82% (p < 0.001 for all). Adverse events, most frequently dizziness and fatigue, occurred during all doses. CONCLUSIONS: In patients with type 2 diabetes mellitus, hypertension and albuminuria there is no improved antiproteinuric effect when using 600 mg aliskiren daily compared with the maximal recommended antihypertensive dose of 300 mg. TRIAL REGISTRATION: Clinicaltrials.gov NCT00464776 FUNDING: Novartis Pharma AG.


Subject(s)
Albuminuria/drug therapy , Amides/administration & dosage , Blood Pressure/drug effects , Diabetes Mellitus, Type 2/drug therapy , Fumarates/administration & dosage , Hypertension/drug therapy , Adult , Albuminuria/complications , Amides/therapeutic use , Antihypertensive Agents/administration & dosage , Antihypertensive Agents/therapeutic use , Cross-Over Studies , Diabetes Mellitus, Type 2/complications , Double-Blind Method , Drug Administration Schedule , Fumarates/therapeutic use , Humans , Hypertension/complications , Renin/antagonists & inhibitors
3.
Neth Heart J ; 18(4): 190-6, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20428417

ABSTRACT

Background. Neurohormonal activation is generally recognised to play an important role in the pathophysiology, prognosis and treatment of chronic heart failure (HF). While the number of patients with diabetes increases, little if anything is known about neurohormonal activation in HF patients with diabetes. Methods. The study population consisted of 371 patients with advanced HF who were enrolled in a multicentre survival trial. Ten different plasma neurohormones were measured (noradrenaline, adrenaline, dopamine, aldosterone, renin, endothelin, atrial natriuretic peptide [ANP], N-terminal (pro)ANP, brain natriuretic peptide [BNP] and N-terminal (pro)BNP. Comparisons were made between patients with diabetes (n=81) and those without (n=290). Results. At baseline, the two groups were comparable regarding age (mean 68 years), left ventricular ejection fraction (23%), severity and aetiology of HF, while body weight was higher in those with diabetes (77.4 vs. 74.2 kg, p=0.04). Most plasma neurohormones were similar between groups, but patients with diabetes had higher values of BNP (94 vs. 47 pmol/l, p=0.03), while a similar trend was observed for N-terminal (pro)BNP (750 vs. 554 pmol/l, p=0.10). During almost five years of follow-up, 51/81 patients with diabetes died (63%), as compared with 144 of 290 non-diabetic patients (50%) who died (p=0.046). Natriuretic peptides and noradrenaline were the most powerful predictors of mortality in both diabetic and non-diabetic HF patients. Conclusion. HF patients with diabetes have higher (N-terminal (pro)) BNP levels than non-diabetic patients, while other neurohormones are generally similar. Natriuretic peptides are also good prognostic markers in diabetic HF patients. (Neth Heart J 2010;18:190-6.).

5.
Diabetes Res Clin Pract ; 84(1): 61-7, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19188000

ABSTRACT

AIMS: To investigate whether increased risk of severe hypoglycaemia in early pregnancy is related to pregnancy-induced changes in renin-angiotensin system (RAS) activity in women with type 1 diabetes (T1DM). METHODS: Severe hypoglycaemic events the year preceding pregnancy were recorded retrospectively in 107 consecutive pregnant women with T1DM. Events during pregnancy were recorded prospectively. Measurements of ACE, renin and angiotensinogen were determined at 8, 14, 21, 27 and 33 weeks and postpartum. RESULTS: The rate of severe hypoglycaemia was 1.1 and 5.3 events/patient-year the year preceding pregnancy and in first trimester, respectively (p<0.0001). Levels of ACE, renin or angiotensinogen did not differ between women with and without severe hypoglycaemia during pregnancy. Multivariate regression analysis identified a positive association between rate of severe hypoglycaemia the year preceding pregnancy and postpartum ACE activity (relative rate of severe hypoglycaemia above versus below median ACE activity: 4.4 (CI: 1.7-11.9), p=0.003). No association was found between severe hypoglycaemia during pregnancy and renin angiotensin system activity at 8 weeks. CONCLUSIONS: In early pregnancy increased RAS activity does not explain the 5-fold increase in severe hypoglycaemia in women with T1DM. A positive association between occurrence of severe hypoglycaemia and ACE activity outside pregnancy was demonstrated.


Subject(s)
Diabetes Mellitus, Type 1/metabolism , Hypoglycemia/metabolism , Renin-Angiotensin System/physiology , Adult , Angiotensinogen/metabolism , Case-Control Studies , Diabetes Mellitus, Type 1/complications , Female , Humans , Hypoglycemia/etiology , Peptidyl-Dipeptidase A/metabolism , Pregnancy , Pregnancy Complications/physiopathology , Renin/metabolism
6.
Diabetologia ; 52(1): 46-9, 2009 Jan.
Article in English | MEDLINE | ID: mdl-18974967

ABSTRACT

AIMS/HYPOTHESIS: The purpose of this study was to evaluate the optimal renoprotective effect of ultrahigh doses of lisinopril, as reflected by short-term changes in urinary albumin excretion rate (UAER), in type 1 diabetic patients with diabetic nephropathy. METHODS: At the Steno Diabetes Center, 49 type 1 diabetic patients with diabetic nephropathy completed this double-masked randomised crossover trial consisting of an initial washout period followed by three treatment periods each lasting 2 months, where all patients received lisinopril 20, 40 and 60 mg once daily in randomised order in addition to slow-release furosemide. Allocation was concealed by sequentially numbered opaque sealed envelopes. UAER, 24 h ambulatory blood pressure (ABP) and estimated GFR were determined at baseline and after each treatment period. RESULTS: All 49 patients completed all three treatment periods. Baseline values were: UAER (geometric mean [95% CI]) 362 (240-545) mg/24 h, 24 h ABP (mean [SD]) 142 (14)/74 (8) mmHg and estimated GFR 75 (29) ml min(-1) 1.73 m(-2). Reductions in UAER from baseline were 63%, 71% and 70%, respectively, with the increasing doses of lisinopril (p < 0.001). Compared with lisinopril 20 mg there was a further reduction in UAER of 23% with lisinopril 40 mg and 19% with 60 mg, p < 0.05. ABP was reduced from baseline by 10/5, 13/7 and 12/7 mmHg (p < 0.001 vs baseline, p < 0.05 for diastolic ABP 20 vs 40 mg, otherwise NS between doses). The difference in UAER between 20 and 40 mg lisinopril was significant after adjustment for changes in ABP (p < 0.01). Two patients were excluded from the study because of an increase in plasma creatinine and one because of high BP; otherwise the study medication was well tolerated with few, mild, dose-independent adverse effects. CONCLUSIONS/INTERPRETATION: Lisinopril 40 mg once daily is generally safe and offers additional reductions in BP and UAER in comparison with the currently recommended dose of 20 mg. Lisinopril 60 mg offers no further beneficial effect. TRIAL REGISTRATION: ClinicalTrials.gov NCT00118976.


Subject(s)
Diabetic Nephropathies/drug therapy , Lisinopril/therapeutic use , Adult , Albuminuria/drug therapy , Antihypertensive Agents/therapeutic use , Cross-Over Studies , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 1/physiopathology , Diabetic Angiopathies/drug therapy , Dose-Response Relationship, Drug , Double-Blind Method , Female , Glomerular Filtration Rate/drug effects , Humans , Male , Middle Aged , Protective Agents/therapeutic use
7.
Eur J Clin Invest ; 38(12): 939-44, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19021719

ABSTRACT

BACKGROUND: Decompensated liver cirrhosis is characterized by activation of the renin-angiotensin-aldosterone system (RAAS). We investigated whether compartmentalization of these components occurs in ascitic fluid. METHODS: In 26 patients with cirrhosis RAAS components and albumin were quantified in simultaneously obtained plasma and ascitic fluid samples. Renin degradation was determined in vitro in plasma and ascites. RESULTS: Plasma angiotensinogen was below normal reference values in all but two patients and correlated inversely with plasma renin (r = -0.73, P < 0.001). Plasma renin activity was elevated in most subjects. The plasma and ascites concentrations of renin, prorenin, angiotensinogen and aldosterone were closely (P < 0.001) correlated. Expressed as a percentage of plasma levels, the angiotensinogen level (18 +/- 11%) was slightly lower than the albumin level (23 +/- 8%), whereas the aldosterone level (43 +/- 18%) was considerably higher (P < 0.0001). For renin and prorenin these percentages were much lower (P < 0.0001), despite the fact that their molecular weight is lower than that of albumin and angiotensinogen. This was not due to a more rapid degradation of renin in ascites fluid, since the in-vitro degradation rates of renin in plasma and ascitic fluid were identical. CONCLUSION: In hepatic cirrhosis ascites can be regarded as an ultrafiltrate of plasma RAAS components. Since differences in molecular weight or metabolic rate cannot explain the low ascites-to-plasma ratio of renin and prorenin, either their transcapillary transport is impaired and/or they selectively bind to (pro)renin binding sites.


Subject(s)
Aldosterone/blood , Angiotensinogen/blood , Ascites/metabolism , Ascitic Fluid/metabolism , Liver Cirrhosis/blood , Renin-Angiotensin System/physiology , Renin/blood , Aged , Aldosterone/metabolism , Angiotensinogen/metabolism , Angiotensins/blood , Female , Humans , Liver Cirrhosis/metabolism , Male , Middle Aged , Plasma , Renin/metabolism
8.
Neth J Med ; 66(5): 220-8, 2008 May.
Article in English | MEDLINE | ID: mdl-18490805

ABSTRACT

Since the introduction of the aldosterone-to-renin ratio (ARR ) as a screening tool for primary aldosteronism (PA), there has been a marked increase in the reported prevalence of this condition among hypertensive subjects. A meta-analysis from the literature shows a PA prevalence of almost 8% among hypertensive patients, with a twofold higher prevalence in referred patients as compared with primary care patients (9.0 vs 4.3%). However, the usefulness of the ARR remains subject of debate, because of doubts on its validity, and the many factors affecting the ARR , including posture, time of day of blood sampling, and use of antihypertensive medication. Furthermore, there is no clear cut-off value and it is unknown what population should be screened. Recently, The Dutch ARR AT Study was initiated. This is a multicentre, prospective trial aiming to evaluate the test characteristics of the ARR within a Dutch population of therapy-resistant hypertensive patients. The effect of antihypertensive medication on the ARR will be studied. Furthermore, from this study the prevalence of PA in this population will follow. Last, the blood pressure response to the selective aldosterone-receptor-antagonist eplerenone will be evaluated. The Dutch ARR AT Study will run until the end of 2009 and will contribute to the formulation of uniform guidelines for the screening for PA in the Netherlands.


Subject(s)
Clinical Trials as Topic , Hyperaldosteronism/diagnosis , Hypertension/physiopathology , Renin-Angiotensin System/physiology , Antihypertensive Agents/therapeutic use , Drug Resistance , Eplerenone , Humans , Hyperaldosteronism/complications , Hyperaldosteronism/epidemiology , Hypertension/drug therapy , Mass Screening/methods , Mineralocorticoid Receptor Antagonists/therapeutic use , Netherlands/epidemiology , Prevalence , Risk Factors , Spironolactone/analogs & derivatives , Spironolactone/therapeutic use
9.
Kidney Int ; 73(12): 1419-25, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18337712

ABSTRACT

Inhibition of renin with an active site inhibitor, aliskiren, lowers blood pressure (BP) in diabetic patients. Here, we studied the time course of the antihypertensive and antiproteinuric effect of renin inhibition in 15 patients with type 2 diabetes and elevated urinary albumin/creatinine ratios (UACRs) to check whether aliskiren can decrease proteinuria. After a 4-week washout of previous medications, patients received aliskiren and furosemide daily for 28 days followed by a 4-week withdrawal period. Twenty-four-hour BPs were measured at baseline throughout treatment and withdrawal periods. The UACR was significantly reduced after 2-4 days of treatment with another significant reduction after 28 days. Systolic blood pressure (SBP) was significantly lower after 7 days with no further reduction after 28 days. The BP returned toward baseline 3 days after withdrawal, whereas the UACR was still significantly reduced compared with baseline 12 days after withdrawal. Our study shows that aliskiren reduced 24 h SBP, and this was associated with a reduction in albuminuria in type 2 diabetic patients.


Subject(s)
Albuminuria/drug therapy , Amides/therapeutic use , Antihypertensive Agents/therapeutic use , Diabetes Mellitus, Type 2/complications , Fumarates/therapeutic use , Hypertension/drug therapy , Renin/antagonists & inhibitors , Aged , Albuminuria/etiology , Albuminuria/urine , Amides/pharmacology , Antihypertensive Agents/pharmacology , Blood Pressure/drug effects , Creatinine/urine , Female , Fumarates/pharmacology , Glomerular Filtration Rate/drug effects , Humans , Hypertension/etiology , Hypertension/urine , Male , Middle Aged , Treatment Outcome
10.
J Appl Physiol (1985) ; 104(4): 1080-5, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18258801

ABSTRACT

Brain-derived natriuretic peptide (BNP) is a cardioprotective peptide released, together with the inactive NH(2)-terminal part of its prohormone (NT-pro-BNP), in response to different kinds of myocardial stress. Hypoglycemia and hypoxemia are conditions that threaten cellular function and hence potentially stimulate BNP release. BNP interacts with the renin-angiotensin system (RAS). The aim of this study was, therefore, to explore if basal RAS activity has an impact on NT-pro-BNP concentrations during myocardial stress induced by hypoglycemia and hypoxemia. From a cohort of 303 healthy young men, 10 subjects with high-RAS activity and 10 subjects with low-RAS activity (age 26 +/- 1 yr; mean +/- SE) were studied in a single-blinded, randomized, counterbalanced, crossover study on three occasions separated by at least 3 wk: 1) hypoglycemia (mean nadir plasma glucose 2.7 +/- 0.5 mmol/l), 2) hypoxemia (mean nadir Po(2) 5.8 +/- 0.5 kPa), and 3) normoglycemic normoxia (control). NT-pro-BNP was measured at baseline, during the stimuli, and in the recovery phase. Hypoxemia was associated with a 9% increase in NT-pro-BNP from 2.2 +/- 1.5 pmol/l at baseline to 2.4 +/- 1.5 pmol/l during hypoxemia (P < 0.001). Hypoglycemia did not affect the NT-pro-BNP level. RAS activity had no impact on NT-pro-BNP levels during hypoglycemia and hypoxemia. Hypoxemia, but not hypoglycemia, stimulates NT-pro-BNP. This indicates that cardiac defense mechanisms against hypoglycemia, if any, are probably different from those against hypoxemia. Basal RAS activity had no impact on NT-pro-BNP levels.


Subject(s)
Hypoglycemia/metabolism , Hypoxia/metabolism , Natriuretic Peptide, Brain/metabolism , Peptide Fragments/metabolism , Renin-Angiotensin System/physiology , Adult , Angiotensin II/blood , Blood Glucose/metabolism , Blood Pressure/physiology , Cross-Over Studies , Humans , Hypoglycemia/chemically induced , Hypoglycemic Agents , Insulin , Male , Reference Values , Renin/blood
11.
Ned Tijdschr Geneeskd ; 151(46): 2553-7, 2007 Nov 17.
Article in Dutch | MEDLINE | ID: mdl-18074722

ABSTRACT

Biologically active B-type natriuretic peptide or brain natriuretic peptide (BNP) and biologically inactive N-terminal proBNP (NT-proBNP) are secreted into the bloodstream by the heart and provide primarily information regarding the filling pressures in the heart. The accuracy of plasma BNP levels in the diagnosis of heart failure is comparable to that of plasma NT-proBNP levels. Reliable assays have been developed for both peptides, some of which can be used for rapid diagnosis in the emergency clinic. In both groups of patients with heart failure and the general population, there is a relationship between the plasma BNP and NT-proBNP levels and the risk of cardiovascular death, after correction for the traditional risk factors. Screening studies using the determination of BNP or NT-proBNP levels in order to detect patients with heart failure at an early stage cannot be recommended because their specificity is too low: in addition to heart failure, the plasma BNP or NT-proBNP level is affected by age, gender, body mass index, renal function, and pulmonary capacity. There are indications that the introduction ofa rapid BNP determination for patients that present to the emergency clinic with acute dyspnoea will lead to more effective diagnosis and treatment. Sequential determinations ofthe plasma BNP or NT-proBNP levels in inpatients and outpatients with heart failure can help to optimise the treatment, thus decreasing the morbidity and mortality that are associated with heart failure.


Subject(s)
Heart Failure/diagnosis , Natriuretic Peptide, Brain/blood , Peptide Fragments/blood , Heart Failure/blood , Humans , Predictive Value of Tests , Sensitivity and Specificity
12.
J Neural Transm (Vienna) ; 114(6): 775-6, 2007.
Article in English | MEDLINE | ID: mdl-17385068

ABSTRACT

Recently, a new FAD-dependent amine oxidase, renalase, was described. It was secreted by the kidney into the blood and shown to have significant cardiovascular actions, which were attributed to its catecholamine-metabolising activity. The authors concluded that renalase might be an important regulatory factor in human (patho)physiology. The catecholamine-metabolising activity of renalase in plasma contrasts with previous investigations where catecholamines were found to be stable in human plasma, provided autoxidation is prevented by an antioxidant. The claim of catecholamine-metabolising activity of renalase was based on the generation of H(2)O(2) during incubation of the enzyme with catecholamines. Careful inspection and calculations of the data lead to the conclusion that the rate of H(2)O(2) generation is far too low to be ascribed to enzymatic conversion of catecholamines by renalase. Renalase may well have important cardiovascular functions, but there is no proof that its actions are mediated through catecholamine-metabolising activity.


Subject(s)
Catecholamines/metabolism , Kidney/enzymology , Monoamine Oxidase/metabolism , Animals , Cardiovascular Physiological Phenomena , Cardiovascular System/innervation , Cardiovascular System/metabolism , Humans , Hydrogen Peroxide/metabolism , Monoamine Oxidase/chemistry , Monoamine Oxidase/isolation & purification
13.
Int J Cardiol ; 116(2): 242-8, 2007 Mar 20.
Article in English | MEDLINE | ID: mdl-16843544

ABSTRACT

Orthostatic intolerance (OI) syndromes are frequent and share symptoms like dizziness and orthostatic syncope. Their pathophysiology however seems to be different. The aim of our work was to evaluate autonomic and hemodynamic behaviour in patients with familial amyloidotic polyneuropathy and neurally mediated syncope in supine position and after acute orthostatic passive stress. We studied 12 patients with autonomic failure (group A), 12 patients with neurally mediated syncope (group B) and 16 aged matched normal controls (group C), in supine position and during the first 10 min of head-up tilt test (HUTT). Beat-by-beat blood pressure and heart rate were continuously monitored and digitised at 500 Hz. The baroreceptor alfa-index gain (vagal reflex-BRG), high frequency of RR variability (HFRR, vagal tonus) and low frequency of systolic arterial pressure variability (LFSAP, sympathetic tone) were calculated. Catecholamines, plasma brain (BNP) and atrial natriuretic (ANP) peptides were also measured. Hemodynamic data were derived and calculated by the non-invasive modelflow method. During supine position, cardiac output (CO) and stroke volume (SV) were similar in all groups. Mean arterial pressure (MAP) and BNP were higher in group A. Noradrenaline (NOR), BRG, HFRR and LFSAP were extremely low in this group. BRG and adrenaline (ADR) were higher in group B than in controls. Within the first 10 min of HUTT, there was a huge drop of CO, SV and MAP in group A, maintenance of very low levels of neurohormones and lack of autonomic function. HR, LFSAP and ADR had a higher rise at HUTT in group B compared with controls (p<0.01) but a significant decrease of BRG was noted (p<0.05). ANP or BNP did not change with tilt in any group. Different orthostatic intolerance syndromes may show important hormonal, autonomic and hemodynamic differences during supine rest and enhanced after passive orthostatism.


Subject(s)
Amyloid Neuropathies, Familial/physiopathology , Dizziness/complications , Nervous System Diseases/physiopathology , Stress, Physiological/physiopathology , Supine Position , Syncope/physiopathology , Adult , Autonomic Nervous System/physiopathology , Blood Pressure , Cardiovascular System/physiopathology , Female , Head-Down Tilt , Heart Function Tests , Heart Rate , Humans , Male , Neurotransmitter Agents/metabolism , Stress, Physiological/etiology
14.
Scand J Clin Lab Invest ; 66(7): 559-65, 2006.
Article in English | MEDLINE | ID: mdl-17101547

ABSTRACT

OBJECTIVE: Semicarbazide-sensitive amine oxidase (SSAO) is widely expressed in adipose tissue, where it may contribute to stimulation of glucose transport via GLUT4 recruitment. We tested the relationships of soluble SSAO, as reflected by its plasma activity, with insulin sensitivity and indices of body fat, and determined whether insulin is involved in regulating plasma SSAO activity. MATERIAL AND METHODS: In 24 non-diabetic subjects, the relationships of plasma SSAO activity with insulin sensitivity (M-value and free fatty acid (FFA) suppression during a 3-h hyperinsulinemic (8.3 microU kg-1 s-1), euglycemic clamp), body mass index (BMI 25.5 +/- 3.1 kg m-2), waist-hip ratio and fat mass were assessed. In 16 subjects, the effect of insulin infusion, administered at a rate of 8.3 microU kg-1 s-1 during 3 h, followed by 3-h insulin infusion at a high rate of 41.7 microU kg-1 s-1 on plasma SSAO activity was determined. In the other 8 subjects, the response of plasma SSAO activity to 24-h insulin infused at 8.3 microU kg-1 s-1 was assessed. RESULTS: There were no relationships (all p > 0.10) of plasma SSAO activity (215 +/- 60 mU L-1) with the M-value or with any indices of body fat and FFA before and after insulin suppression. Plasma SSAO activity changed by -7.2 (95% CI, -14.5 to +0.2)% after 3 h (NS) and decreased by 10.1 (95% CI, 19.2 to 1)% after 6 h of insulin infusion (p < 0.05). Plasma SSAO activity did not significantly change after 8 h (change 0.4 (95% CI, -15.3 to +16.2)%, NS) and after 24 h (change -8.8 (95% CI, -27.4 to +9.7)%, NS) of insulin infusion. CONCLUSIONS: It is unlikely that circulating SSAO is a clinically important marker of insulin sensitivity on glucose and fatty acid metabolism. The reduction in plasma SSAO activity in response to pronounced hyperinsulinemia suggests that insulin is involved in the regulation of the soluble form of this enzyme.


Subject(s)
Adipose Tissue/enzymology , Amine Oxidase (Copper-Containing)/blood , Hyperinsulinism/chemically induced , Insulin/blood , Biomarkers/blood , Humans , Hyperinsulinism/enzymology , Male
16.
Kidney Int ; 70(3): 536-42, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16775595

ABSTRACT

Reduction of nephrotic range albuminuria is associated with markedly improved renal and cardiovascular outcome in patients with diabetic nephropathy. Aldosterone has been suggested to play a role in the progression of diabetic nephropathy. We therefore aimed to evaluate the short-term effect of aldosterone antagonism with spironolactone on nephrotic range albuminuria and blood pressure in diabetic nephropathy. Twenty Caucasian patients with diabetic nephropathy and nephrotic range albuminuria (>2500 mg/24 h) despite recommended antihypertensive treatment completed this double-masked, randomized crossover trial. Patients were treated in random order with spironolactone 25 mg once daily and matched placebo for 2 months, on top of ongoing antihypertensive treatment, including an angiotensin-converting enzyme inhibitor or an angiotensin II receptor blocker in maximally recommended doses. Median (range) number of antihypertensive drugs was 3 (2-5). After each treatment period, albuminuria, 24-h ambulatory blood pressure, and glomerular filtration rate (GFR) were determined. Spironolactone on top of recommended renoprotective treatment induced a 32% (95% confidence interval (CI): 21-42%) reduction in albuminuria from (geometric mean (95% CI)) 3718 (2910-4749) mg/24 h on placebo treatment (P<0.001). There was a significant reduction in 24-h blood pressure of 6 (2-10)/4 (2-6) mm Hg and day blood pressure of 7 (3-12)/5 (3-7) mm Hg (P<0.01), whereas night blood pressure remained unchanged. Spironolactone induced an insignificant reversible reduction in GFR of 3 ml/min/1.73 m2 from 64 (27) ml/min/1.73 m2. No patients were excluded due to adverse events. Our results suggest that spironolactone treatment on top of recommended renoprotective treatment including maximal renin-angiotensin system blockade may offer additional renoprotection in patients with diabetic nephropathy and nephrotic range albuminuria.


Subject(s)
Albuminuria/drug therapy , Diabetic Nephropathies/drug therapy , Mineralocorticoid Receptor Antagonists/administration & dosage , Spironolactone/administration & dosage , Adult , Angiotensin II Type 1 Receptor Blockers/administration & dosage , Angiotensin-Converting Enzyme Inhibitors/administration & dosage , Cross-Over Studies , Drug Therapy, Combination , Female , Humans , Male , Middle Aged , Mineralocorticoid Receptor Antagonists/adverse effects , Nephrosis/drug therapy , Spironolactone/adverse effects , Treatment Outcome
17.
J Thromb Haemost ; 4(3): 552-6, 2006 Mar.
Article in English | MEDLINE | ID: mdl-16405522

ABSTRACT

BACKGROUND: Controversy exists about the indication of thrombolytic therapy in the subgroup of hemodynamically stable patients with acute pulmonary embolism (PE) and right ventricular dysfunction. Brain natriuretic peptide (BNP) is excreted from the cardiac ventricles in response to cardiomyocyte stretch and can be measured with an easy-to-perform blood test. OBJECTIVE: The objective of this study was to determine the predictive value of elevated BNP levels for early recurrent venous thromboembolism with or without fatal outcome in hemodynamically stable patients with acute PE. In addition, we assessed the potential clinical consequences of initiating thrombolytic therapy based on the BNP levels alone. METHODS: A nested case-control study was performed within the framework of a large randomized-controlled trial totalling 2213 hemodynamically stable patients with confirmed acute, symptomatic PE. Ninety patients experienced a fatal or non-fatal recurrent venous thromboembolism during the first 3 months of follow-up (cases); Two hundred and ninety-seven patients with uneventful follow-up served as controls. Blood for BNP levels was obtained at referral and assayed in a central laboratory. RESULTS: Cases had significantly higher mean baseline BNP levels (P = 0.0002). The odds ratio (OR) for every logarithmic (log) unit increase in BNP concentration was 2.4 (95% CI: 1.5-3.7). A BNP cut-off level of 1.25 pmol L(-1) [the optimal point on the receiver-operating characteristic (ROC) curve] was associated with a sensitivity and specificity of 60% and 62%, respectively. In theory, for every patient correctly receiving thrombolytic therapy at this cut-off, 16 patients will receive this therapy unnecessarily. CONCLUSIONS: Brain natriuretic peptide level at presentation is significantly associated with early (fatal) recurrent venous thromboembolism in hemodynamically stable patients with acute PE. However, this relationship appears clinically insufficient to guide the initiation of thrombolytic therapy.


Subject(s)
Fibrinolytic Agents/therapeutic use , Natriuretic Peptide, Brain/blood , Pulmonary Embolism/blood , Thrombolytic Therapy , Acute Disease , Aged , Biomarkers/blood , Humans , Middle Aged , Predictive Value of Tests , Pulmonary Embolism/drug therapy , Pulmonary Embolism/mortality , Risk Factors , Secondary Prevention , Thromboembolism/blood , Thromboembolism/mortality , Thromboembolism/prevention & control , Venous Thrombosis/blood , Venous Thrombosis/mortality , Venous Thrombosis/prevention & control , Ventricular Dysfunction, Right/blood , Ventricular Dysfunction, Right/drug therapy , Ventricular Dysfunction, Right/mortality
18.
Int J Cardiol ; 106(3): 367-72, 2006 Jan 26.
Article in English | MEDLINE | ID: mdl-16337046

ABSTRACT

INTRODUCTION: The beneficial effects of ACE inhibitors are generally ascribed to blockade of neurohormonal activation. However, especially in chronic heart failure (CHF) patients plasma angiotensin II and aldosterone levels can be elevated despite ACE inhibition, the so-called ACE escape. In the present study, we aimed to identify the frequency and determinants of ACE escape in CHF patients. METHODS: We studied 99 stable chronic heart failure patients (NYHA class III and IV, 66% ischemic etiology) receiving long-term therapy with ACE inhibitors. In all patients, cardiac, renal, and neurohormonal parameters were measured. ACE escape was defined as plasma angiotensin level > or = 16 pmol/L. RESULTS: Mean (+/- SD) left ventricular ejection fraction of our 99 patients (79 men and 20 women, age 69 +/- 12 years) was 28 +/- 10%. In addition to an ACE inhibitor, 93% of patients received diuretics, 71% a beta-blocker, and 49% spironolactone. None of the patients used an angiotensin receptor blocker. In our population, 45% of the patients had an angiotensin II plasma concentration higher than 16 pmol/L (median concentration was 14.1 pmol/L). Spironolactone use was an independent predictor of elevated plasma angiotensin II levels. Furthermore, spironolactone users had significantly higher plasma active renin protein and aldosterone levels. Plasma angiotensin II concentration was positively correlated to active renin, plasma angiotensin I and plasma aldosterone. No correlation was found between plasma angiotensin II levels and serum ACE activity, dose of ACE inhibitor, or duration of use. CONCLUSION: In a group of severe chronic heart failure patients, 45% had elevated plasma angiotensin II levels independent of serum ACE activity despite long-term ACE inhibitor use. Although a causal link could not be proven, an association was found between spironolactone use and active renin protein, angiotensin II and aldosterone levels, suggesting that escape from ACE is mainly caused by a feedback mechanism.


Subject(s)
Angiotensin II/blood , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Heart Failure/drug therapy , Aged , Aged, 80 and over , Angiotensin I/blood , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Feedback, Physiological/drug effects , Feedback, Physiological/physiology , Female , Heart Failure/blood , Humans , Male , Middle Aged , Mineralocorticoid Receptor Antagonists/pharmacology , Peptidyl-Dipeptidase A/blood , Renin/blood , Renin-Angiotensin System/drug effects , Spironolactone/pharmacology
19.
Anticancer Res ; 25(5): 3651-7, 2005.
Article in English | MEDLINE | ID: mdl-16101196

ABSTRACT

BACKGROUND: Plasma natriuretic peptides are increased in patients with cardiac dysfunction. N-terminal (NT-ANP) and B-type (BNP) natriuretic peptides were measured in disease-free breast cancer survivors, during long-term follow-up after epirubicin (360 mg/m2 or 450 mg/m2 cumulatively) and chest irradiation. PATIENTS AND METHODS: Plasma samples for natriuretic peptide measurement were repeated after extended follow-up in 54 patients, who had participated in 2 studies evaluating cardiotoxicity. RESULTS: From a median follow-up of 2.7 to 6.5 years, median BNP was raised almost three-fold (p<0.001). Symptomatic heart failure was now present in 2 patients. Compared to the epirubicin 360 mg/m2 group, BNP was higher (p=0.006) in the 450 mg/m2 group, with a trend (p=0.054) for higher NT-ANP. CONCLUSION: These findings suggest that anticancer therapy initiates an autonomically progressive process that may ultimately lead to symptomatic cardiac dysfunction, years after treatment. BNP measurement may be of value to identify patients requiring intensive cardiac follow-up.


Subject(s)
Atrial Natriuretic Factor/blood , Breast Neoplasms/blood , Heart Diseases/blood , Natriuretic Peptide, Brain/blood , Adult , Antibiotics, Antineoplastic/administration & dosage , Antibiotics, Antineoplastic/adverse effects , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Breast Neoplasms/radiotherapy , Cyclophosphamide/administration & dosage , Cyclophosphamide/adverse effects , Epirubicin/administration & dosage , Epirubicin/adverse effects , Female , Fluorouracil/administration & dosage , Fluorouracil/adverse effects , Heart Diseases/chemically induced , Heart Diseases/etiology , Humans , Middle Aged
20.
Horm Metab Res ; 37 Suppl 1: 4-8, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15918104

ABSTRACT

Dual blockade of the renin-angiotensin-aldosterone system (RAAS) with both ACE inhibitors and angiotensin II receptor-blockers has been shown to reduce both albuminuria and blood pressure compared to either monotherapy. The mechanisms behind these beneficial effects are not known, and we hypothesized that the effect of dual RAAS blockade may be due to a more complete suppression of circulating aldosterone. We performed a combined analysis on three randomized, double-masked, cross-over trials where 51 type 1 diabetic patients suffering from diabetic nephropathy received 8 weeks of dual RAAS blockade using an angiotensin II receptor blocker in combination with an ACE inhibitor and 8 weeks of monotherapy with the same ACE inhibitor. Albuminuria, 24 h blood pressure, GFR, and plasma aldosterone were determined at the end of each treatment period. Compared to ACE inhibition alone, dual RAAS blockade lowered blood pressure by 7/5 mm Hg from 137/76 mm Hg, decreased albuminuria by 37% from 558 mg/24 hour, and reduced plasma aldosterone by 28% from 59 pg/ml and caused a reversible decline in GFR of 4 ml/min/1.73 m2 (p < or = 0.01 for all comparisons). There was and a significant correlation between changes in 24-hour diastolic blood pressure and changes in albuminuria. Furthermore, the antialbuminuric response to dual blockade was influenced by the ACE/ID polymorphism, that is, patients carrying the D-allele had a significantly lower reduction of 31% compared to the 55% in patients with the II genotype (p = 0.021). Multiple linear regression analysis revealed that ACE/ID genotypes and reduction in plasma aldosterone, diastolic blood pressure and GFR is associated with changes in albuminuria on dual blockade treatment (R2 (adjusted) = 0.57, p < 0.001). Dual RAAS blockade is a new treatment concept that may offer additional cardiovascular and renal protection in type 1 diabetic patients with diabetic nephropathy. The beneficial response may be influenced by genetic factors and reductions in blood pressure and plasma aldosterone concentrations.


Subject(s)
Aldosterone/blood , Angiotensin II Type 1 Receptor Blockers/administration & dosage , Angiotensin-Converting Enzyme Inhibitors/administration & dosage , Diabetes Mellitus, Type 1 , Diabetic Nephropathies/drug therapy , Renin-Angiotensin System , Adult , Blood Pressure/drug effects , Diabetes Mellitus, Type 1/complications , Diabetic Nephropathies/blood , Diabetic Nephropathies/etiology , Female , Humans , Male , Renin-Angiotensin System/drug effects
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