Albumin-corrected Zn and available free Zn-binding capacity as indicators of Zn status - potential for clinical implementation.

We have established and describe two measurement procedures to diagnose possible zinc (Zn) deficiency; albumin-corrected Zn concentration and available free Zn-binding capacity. Reference intervals for both biomarkers were established in healthy adults from the Danish population. The clinical usefulness of the measurement procedures was investigated in patients with cirrhosis and in patients given parenteral nutrition due to short bowel syndrome. The results of both methods indicate that there is a risk of overdiagnosing Zn deficiency based on low plasma Zn concentrations. Needless Zn supplementation may thus be avoided by using the albumin-corrected Zn concentration or available free Zn-binding capacity.

Baseline findings of the population-based, randomized, multifaceted Danish cardiovascular screening trial (DANCAVAS) of men aged 65-74 years.

BACKGROUND: The challenge of managing age-related diseases is increasing; routine checks by the general practitioner do not reduce cardiovascular mortality. The aim here was to reduce cardiovascular mortality by advanced population-based cardiovascular screening. The present article reports the organization of the study, the acceptability of the screening offer, and the relevance of multifaceted screening for prevention and management of cardiovascular disease. METHODS: Danish men aged 65-74 years were invited randomly (1 : 2) to a cardiovascular screening examination using low-dose non-contrast CT, ankle and brachial BP measurements, and blood tests. RESULTS: In all, 16 768 of 47 322 men aged 65-74 years were invited and 10 471 attended (uptake 62·4 per cent). Of these, 3481 (33·2 per cent) had a coronary artery calcium score above 400 units. Thoracic aortic aneurysm was diagnosed in the ascending aorta (diameter 45 mm or greater) in 468 men (4·5 per cent), in the arch (at least 40 mm) in 48 (0·5 per cent) and in the descending aorta (35 mm or more) in 233 (2·2 per cent). Abdominal aortic aneurysm (at least 30 mm) and iliac aneurysm (20 mm or greater) were diagnosed in 533 (5·1 per cent) and 239 (2·3 per cent) men respectively. Peripheral artery disease was diagnosed in 1147 men (11·0 per cent), potentially uncontrolled hypertension (at least 160/100 mmHg) in 835 (8·0 per cent), previously unknown atrial fibrillation confirmed by ECG in 50 (0·5 per cent), previously unknown diabetes mellitus in 180 (1·7 per cent) and isolated severe hyperlipidaemia in 48 men (0·5 per cent). In all, 4387 men (41·9 per cent), excluding those with potentially uncontrolled hypertension, were referred for additional cardiovascular prevention. Of these, 3712 (35·5 per cent of all screened men, but 84·6 per cent of those referred) consented and were started on medication. CONCLUSION: Multifaceted cardiovascular screening is feasible and may optimize cardiovascular disease prevention in men aged 65-74 years. Uptake is lower than in aortic aneurysm screening.

A role for collagen type IV in cardiovascular disease?

Over the past decade, studies have repeatedly found single-nucleotide polymorphisms located in the collagen ( COL) 4A1 and COL4A2 genes to be associated with cardiovascular disease (CVD), and the 13q34 locus harboring these genes is one of ~160 genome-wide significant risk loci for coronary artery disease. COL4A1 and COL4A2 encode the α1- and α2-chains of collagen type IV, a major component of basement membranes in various tissues including arteries. Despite the growing body of evidence indicating a role for collagen type IV in CVD, remarkably few studies have aimed to directly investigate such a role. The purpose of this review is to summarize the clinical reports linking 13q34 to coronary artery disease, atherosclerosis, and artery stiffening and to assemble the scattered pieces of evidence from experimental studies based on vascular cells and tissue collectively supporting a role for collagen type IV in atherosclerosis and other macrovascular disease conditions.

The DanCavas Pilot Study of Multifaceted Screening for Subclinical Cardiovascular Disease in Men and Women Aged 65-74 Years.

OBJECTIVE/BACKGROUND: This pilot study of a large population based randomised screening trial investigated feasibility, acceptability, and relevance (prevalence of clinical and subclinical cardiovascular disease [CVD] and proportion receiving insufficient prevention) of a multifaceted screening for CVD. METHODS: In total, 2060 randomly selected Danish men and women aged 65-74 years were offered (i) low dose non-contrast computed tomography to detect coronary artery calcification (CAC) and aortic/iliac aneurysms; (ii) detection of atrial fibrillation (AF); (iii) brachial and ankle blood pressure measurements; and (iv) blood levels of cholesterol and hemoglobin A1c. Web based self booking and data management was used to reduce the administrative burden. RESULTS: Attendance rates were 64.9% (n = 678) and 63.0% (n = 640) for men and women, respectively. In total, 39.7% received a recommendation for medical preventive actions. Prevalence of aneurysms was 12.4% (95% confidence interval [CI] 9.9-14.9) in men and 1.1% (95% CI 0.3-1.9) in women, respectively (p < .001). A CAC score > 400 was found in 37.8% of men and 11.3% of women (p < .001), along with a significant increase in median CAC score with age (p = .03). Peripheral arterial disease was more prevalent in men (18.8%, 95% CI 15.8-21.8) than in women (11.2%, 95% CI 8.7-13.6). No significant differences between the sexes were found with regard to newly discovered AF (men 1.3%, women 0.5%), potential hypertension (men 9.7%, women 11.5%), hypercholesterolemia (men 0.9%, women 1.1%) or diabetes mellitus (men 2.1%, women 1.3%). CONCLUSION: Owing to the higher prevalence of severe conditions, such as aneurysms and CAC ≥ 400, screening for CVD seemed more prudent in men than women. The attendance rates were acceptable compared with other screening programs and the logistical structure of the screening program proved successful.

Osteoprotegerin levels decrease during testosterone therapy in aging men and are associated with changed distribution of regional fat.

The cardiovascular effects of testosterone treatment are debated. Osteoprotegerin (OPG) is an independent marker of cardiovascular risk. We investigated the effect of testosterone therapy on OPG levels in aging men with low normal bioavailable testosterone levels. A randomized, double-blinded, placebo-controlled study of 6 months testosterone therapy (gel) in 38 men aged 60-78 years with bioavailable testosterone <7.3 nmol/l and waist circumference >94 cm was performed. Clinical evaluation, OPG, and C-reactive protein (CRP) measurements were carried out. Lean body mass (LBM), total fat mass, and bone mineral density (BMD) were established by dual X-ray absorptiometry. Visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were measured by magnetic resonance imaging. Power calculation was based on an increase in LBM during testosterone therapy and responders were defined as testosterone treated patients with increased LBM (Δ LBM positive), n=14. Data are presented as median (interquartile range). Testosterone therapy decreased total fat mass and SAT, whereas VAT was unchanged (n=38). OPG levels decreased during testosterone therapy (from 2.0 (1.9-2.5) to 1.9 (1.6-2.2) ng/ml, p<0.05 vs. placebo), whereas CRP levels were unchanged (n=38). In responders to testosterone therapy (n=14), ΔOPG levels were inversely associated with ΔSAT (r= - 0.60, p=0.03) and positively associated with ΔVAT (r=0.56, p=0.04). OPG levels decreased during testosterone therapy suggesting decreased cardiovascular risk. Decreased OPG levels were associated with changes in regional fat distribution and future studies are needed to further evaluate the association between OPG and regional fat mass distribution.

Plasma osteoprotegerin is associated with testosterone levels but unaffected by pioglitazone treatment in patients with polycystic ovary syndrome.

OBJECTIVE: Increased osteoprotegerin (OPG) levels are associated with increased cardiovascular risk and decreased bone resorption. Pioglitazone treatment reduces the inflammatory state but may decrease bone mineral density (BMD). OPG levels during pioglitazone treatment have not previously been evaluated in polycystic ovary syndrome (PCOS). RESEARCH DESIGN AND METHODS: Plasma OPG levels were measured in 30 PCOS patients before and after randomized treatment with 30 mg pioglitazone/placebo for 16 weeks. Fourteen age- and body mass index-matched healthy women were included as controls. Clinical and hormonal evaluations and whole body dual-energy X-ray absorptiometry scans were performed in all participants. RESULTS: OPG levels were comparable in PCOS patients [12.0 (10.5-14.6) ng/ml] and controls [12.9 (11.7-14.9) ng/ml]. In PCOS patients (no.=30), OPG levels were positively associated with testosterone (r=0.43), PRL (r=0.47), Pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (r=0.43), and hip BMD, whereas inverse associations were found between OPG levels and triglyceride (r=-0.49) and free fatty acid levels during euglycemic clamps (r=-0.38), all p<0.05. Pioglitazone treatment significantly decreased inflammatory markers, insulin sensitivity, and BMD without affecting OPG levels. CONCLUSIONS: OPG levels were comparable in PCOS patients and controls and unchanged during insulin sensitizing treatment with pioglitazone. OPG levels were associated with BMD in PCOS. Future studies need to evaluate OPG as a marker of cardiovascular disease in PCOS.

The relationship between HbA1c and fasting plasma glucose in patients with increased plasma liver enzyme measurements.

BACKGROUND: HbA(1c) is currently being introduced for diagnostic purpose in diabetes. Previous studies have, however, indicated that patients with liver disease have false low HbA(1c) levels. We therefore investigated the correlation between HbA(1c) and plasma glucose in patients with different levels of increased liver enzyme concentrations. METHODS: Data from 10,065 patients with simultaneous measurement of HbA(1c), venous fasting plasma glucose, alanine aminotransferase and γ-glutamyl transferase were extracted from our laboratory database. Correlations were investigated in four patient groups divided according to their liver enzyme concentrations. RESULTS: The correlation between HbA(1c) and plasma glucose was high in all groups, with r = 0.77 for men and r = 0.78 for women (P < 0.001), a correlation confirmed with multiple regression analysis (P < 0.001). However, interaction analysis revealed that linear regression lines were significantly different for men and women, with increase of both liver enzyme measurements and also, for women, with increased alanine aminotransferase. When compared with biological variation for HbA(1c), only men with increased measurements of both liver enzymes had a clinically important decrease in HbA(1c). CONCLUSIONS: Increased liver enzyme concentrations do not bias the correlation between HbA(1c) and fasting plasma glucose. However, men with low plasma glucose and increased concentrations of both liver enzymes do have a slightly decreased HbA(1c) and, if the clinical suspicion is strong enough, one should consider supplement testing.

Basement membrane collagen IV deficiency promotes abdominal aortic aneurysm formation.

Abdominal aortic aneurysm (AAA) is a complex disease which is incompletely accounted for. Basement membrane (BM) Collagen IV (COL4A1/A2) is abundant in the artery wall, and several lines of evidence indicate a protective role of baseline COL4A1/A2 in AAA development. Using Col4a1/a2 hemizygous knockout mice (Col4a1/a2+/-, 129Svj background) we show that partial Col4a1/a2 deficiency augmented AAA formation. Although unchallenged aortas were morphometrically and biomechanically unaffected by genotype, explorative proteomic analyses of aortas revealed a clear reduction in BM components and contractile vascular smooth muscle cell (VSMC) proteins, suggesting a central effect of the BM in maintaining VSMCs in the contractile phenotype. These findings were translated to human arteries by showing that COL4A1/A2 correlated to BM proteins and VSMC markers in non-lesioned internal mammary arteries obtained from coronary artery bypass procedures. Moreover, in human AAA tissue, MYH11 (VSMC marker) was depleted in areas of reduced COL4 as assessed by immunohistochemistry. Finally, circulating COL4A1 degradation fragments correlated with AAA progression in the largest Danish AAA cohort, suggesting COL4A1/A2 proteolysis to be an important feature of AAA formation. In sum, we identify COL4A1/A2 as a critical regulator of VSMC phenotype and a protective factor in AAA formation.

Plasma osteoprotegerin concentrations in peripheral sensory neuropathy in Type 1 and Type 2 diabetic patients.

AIMS: Osteoprotegerin (OPG) has been linked to different diabetes complications, including cardiovascular disease, and new findings have indicated a specific role in diabetic peripheral neuropathy, but the exact mechanism is unknown. To investigate a possible association between OPG and diabetic peripheral sensory neuropathy, we therefore analysed plasma OPG in Type 1 and Type 2 diabetic patients with and without peripheral neuropathy. SUBJECTS AND METHODS: Two hundred Type 1 diabetes mellitus (T1DM) patients and 305 Type 2 diabetes mellitus (T2DM) patients participated in the study. Plasma OPG was measured with a sandwich immunoassay. Peripheral neuropathy was assessed by the Semmes-Weinstein monofilament test. RESULTS: In T2DM, plasma OPG concentrations were significantly higher in the peripheral neuropathy group (P < 0.001). Furthermore, there was a significant relationship between the presence of neuropathy in T2DM and plasma OPG levels on logistic regression (P = 0.006). However, when investigated in a full multiple regression model including other long-term diabetes complications, the association became insignificant (P = 0.092). In T1DM, the difference in plasma OPG between groups did not reach significance (P = 0.066). However, plasma OPG significantly correlated to peripheral neuropathy in this group also (P = 0.022), although this correlation was not significant in a multiple linear regression model (P = 0.051). CONCLUSION: Plasma OPG levels are related to peripheral neuropathy in both Type 1 and Type 2 diabetes, although with the strongest relationship in T2DM. Before understanding the significance of this, the pathological mechanism involved and, speculatively, a possible use of plasma OPG as a peripheral sensory neuropathy marker, a larger prospective study is needed.

A 12-month follow-up of a transdiagnostic indicated prevention of internalizing symptoms in school-aged children: the results from the EMOTION study.

BACKGROUND: Anxious and depressive symptoms in youth are highly prevalent, are often comorbid and have a high rate of relapse. Preventive interventions are promising, but follow-up results are lacking. The transdiagnostic EMOTION program is an indicated preventive cognitive behavioral therapy (CBT) intervention targeting children aged 8-12 years. METHODS: The present study investigates the 12 months follow-up effects of the EMOTION intervention in a cluster randomized controlled trial (RCT) with 795 children that included both child self-reports and parental reports. RESULTS: Mixed model analyses showed a larger decrease of symptoms in the intervention group than in the control group for child self-reported anxious symptoms (The Multidimensional Anxiety Scale for Children (MASC) difference 4.56, CI 1.83 to 7.29, p = .001). Parental reports for both anxious (MASC difference 2.50, CI .26 to 4.74, p = .029) and depressive (The Mood and Feelings Questionnaire-short form (SMFQ) difference 1.55, CI .83 to 2.26, p ≤ .001) symptoms in children also showed a reduction. No statistically significant difference was found for child self-reported depressive symptoms (SMFQ difference .69, CI - .22 to 1.60, p = .139). CONCLUSION: The transdiagnostic EMOTION program has shown the potential for long-term reductions in symptoms of both anxiety and depression in school-aged children. However, results regarding depressive symptoms must be considered preliminary as only parental report indicated effect.Trial registration The regional ethics committee (REC) of Norway approved the study. Registration number: 2013/1909; Project title: Coping Kids: a randomized controlled study of a new indicated preventive intervention for children with symptoms of anxiety and depression. ClinicalTrials.gov Identifier; NCT02340637.

Medial arterial calcification in diabetes and its relationship to neuropathy.

Calcification of the media of arterial walls is common in diabetes and is particularly associated with distal symmetrical neuropathy. Arterial calcification also complicates chronic kidney disease and is an independent risk factor for cardiovascular and all-cause mortality. The term calcification is not strictly accurate because the morphological changes incorporate those of new bone formation, i.e. ossification. The processes are complex, but are closely related to those involved in bone homeostasis, and it is relevant that calcification of the arterial wall and osteopenia often co-exist. One particular factor linked to the development of arterial calcification is distal symmetrical neuropathy; indeed, it has been suggested that neuropathy explains the distal distribution of arterial calcification in diabetes. It has also been suggested that the link with neuropathy results from loss of neuropeptides, such as calcitonin gene-related peptide, which are inherently protective. The association between distal symmetrical neuropathy and calcification of the arterial wall highlights the fact that neuropathy may be an independent risk factor for cardiovascular mortality.

Antibodies against transforming growth factor-beta 1 suppress intimal hyperplasia in a rat model.

Intimal hyperplasia is induced by therapeutic vascular interventions and often results in clinically important narrowing of the vascular lumen. Examination of the role of TGF-beta 1 in a rat carotid artery injury model confirmed the presence of a previously reported increase in TGF-beta 1 mRNA in the media of injured arteries. Administration of neutralizing anti- TGF-beta 1 antibodies significantly (P < 0.05) reduced the size of the intimal lesions that developed after carotid balloon injury. A control antibody had no effect. The intimal/medial area ratio was also reduced in the anti-TGF-beta 1 group relative to controls (P < 0.01). Immunohistochemical staining showed that two TGF-beta 1-induced extracellular matrix components, EDA + fibronectin and versican, were greatly increased in the untreated neointimal lesions, but were almost completely absent from the lesions of the anti-TGF-beta 1-treated animals. We conclude that TGF-beta 1 is causally involved in the development of intimal hyperplasia, and that anti-TGF-beta 1 agents may be useful in achieving at least partial control of this condition.

Insulin resistance in vascular endothelial cells promotes intestinal tumour formation.

The risk of several cancers, including colorectal cancer, is increased in patients with obesity and type 2 diabetes, conditions characterised by hyperinsulinaemia and insulin resistance. Because hyperinsulinaemia itself is an independent risk factor for cancer development, we examined tissue-specific insulin action in intestinal tumour formation. In vitro, insulin increased proliferation of intestinal tumour epithelial cells by almost two-fold in primary culture of tumour cells from ApcMin/+ mice. Surprisingly, targeted deletion of insulin receptors in intestinal epithelial cells in ApcMin/+ mice did not change intestinal tumour number or size distribution on either a low or high-fat diet. We therefore asked whether cells in the tumour stroma might explain the association between tumour formation and insulin resistance. To this end, we generated ApcMin/+ mice with loss of insulin receptors in vascular endothelial cells. Strikingly, these mice had 42% more intestinal tumours than controls, no change in tumour angiogenesis, but increased expression of vascular cell adhesion molecule-1 (VCAM-1) in primary culture of tumour endothelial cells. Insulin decreased VCAM-1 expression and leukocyte adhesion in quiescent tumour endothelial cells with intact insulin receptors and partly prevented increases in VCAM-1 and leukocyte adhesion after treatment with tumour necrosis factor-α. Knockout of insulin receptors in endothelial cells also increased leukocyte adhesion in mesenteric venules and increased the frequency of neutrophils in tumours. We conclude that although insulin is mitogenic for intestinal tumour cells in vitro, impaired insulin action in the tumour microenvironment may be more important in conditions where hyperinsulinaemia is secondary to insulin resistance. Insulin resistance in tumour endothelial cells produces an activated, proinflammatory state that promotes tumorigenesis. Improvement of endothelial dysfunction may reduce colorectal cancer risk in patients with obesity and type 2 diabetes.

The water channel AQP1 is expressed in human atherosclerotic vascular lesions and AQP1 deficiency augments angiotensin II-induced atherosclerosis in mice.

AIM: The water channel aquaporin 1 (AQP1) promotes endothelial cell migration. It was hypothesized that AQP1 promotes neovascularization and growth of atherosclerotic plaques. METHODS: AQP1 immunoreactivity and protein abundance was examined in human and murine atherosclerotic lesions and aortic aneurysms. Apolipoprotein E (ApoE) knockout (-/-) and AQP1-/-ApoE-/- mice were developed and fed Western diet (WD) for 8 and 16 weeks to accelerate the atherosclerosis process. In ApoE-/- and AQP1-/-ApoE-/- mice abdominal aortic aneurysms (AAA) were induced by angiotensin II (ANGII) infusion by osmotic minipumps for 4 weeks. RESULTS: In human atherosclerotic lesions and AAA, AQP1 immunoreactive protein was associated with intralesional small vessels. In ApoE-/- mouse aorta, APQ1 mRNA levels were increased with time on WD (n = 7-9, P < 0.003). Both in murine lesions at the aortic root and in the abdominal aortic aneurysmal wall, AQP1 immunoreactivity was associated with microvascular structures. The atherosclerotic lesion burden was enhanced significantly in ANGII-infused AQP1-/-ApoE-/- mice compared with ApoE-/- mice, but neither incidence nor progression of AAA was different. The aortic lesion burden increased with time on WD but was not different between ApoE-/- and AQP1-/-ApoE-/- mice at either 8 or 16 weeks (n = 13-15). Baseline blood pressure and ANGII-induced hypertension were not different between genotypes. CONCLUSION: AQP1 is expressed in atherosclerotic lesion neovasculature in human and mouse arteries and AQP1 deficiency augments lesion development in ANGII-promoted atherosclerosis in mice. Normal function of AQP1 affords cardiovascular protection.

P/Q-type and T-type voltage-gated calcium channels are involved in the contraction of mammary and brain blood vessels from hypertensive patients.

AIM: Calcium channel blockers are widely used in cardiovascular diseases. Besides L-type channels, T- and P/Q-type calcium channels are involved in the contraction of human renal blood vessels. It was hypothesized that T- and P/Q-type channels are involved in the contraction of human brain and mammary blood vessels. METHODS: Internal mammary arteries from bypass surgery patients and cerebral arterioles from patients with brain tumours with and without hypertension were tested in a myograph and perfusion set-up. PCR and immunohistochemistry were performed on isolated blood vessels. RESULTS: The P/Q-type antagonist ω-agatoxin IVA (10-8  mol L-1 ) and the T-type calcium blocker mibefradil (10-7  mol L-1 ) inhibited KCl depolarization-induced contraction in mammary arteries from hypertensive patients with no effect on blood vessels from normotensive patients. ω-Agatoxin IVA decreased contraction in cerebral arterioles from hypertensive patients. L-type blocker nifedipine abolished the contraction in mammary arteries. PCR analysis showed expression of P/Q-type (Cav 2.1), T-type (Cav 3.1 and Cav 3.2) and L-type (Cav 1.2) calcium channels in mammary and cerebral arteries. Immunohistochemical labelling of mammary and cerebral arteries revealed the presence of Cav 2.1 in endothelial and smooth muscle cells. Cav 3.1 was also detected in mammary arteries. CONCLUSION: P/Q- and T-type Cav are present in human internal mammary arteries and in cerebral penetrating arterioles. P/Q- and T-type calcium channels are involved in the contraction of mammary arteries from hypertensive patients but not from normotensive patients. Furthermore, in cerebral arterioles P/Q-type channels importance was restricted to hypertensive patients might lead to that T- and P/Q-type channels could be a new target in hypertensive patients.

Diabetic macroangiopathy and atherosclerosis.

In the present study, we have compared and analyzed published data related to the pathogenesis of the large vessel disease in diabetes. The prevailing opinion appears to be that diabetes accelerates the mechanism that leads to the development of classical atherosclerosis. However, as an alternative, we have amassed data that point to the presence of a diabetic macroangiopathy. This phenomenon comprises a constellation of nonatherosclerotic large vessel abnormalities. Today, we know that accumulation of periodic acid-Schiff (PAS)-positive material, as laminin, fibronectin, and type IV collagen, occurs together with hyaluronic acid and various types of connective tissue and calcium deposition. All these changes occur independent of the presence of atherosclerosis in the large vessels of diabetic patients. It seems to us that these observations emphasize that the concept of a specific diabetic macroangiopathy is a more fruitful working hypothesis than the usual theory of a link between atherosclerosis and diabetes. It provides a causal relationship (although the mechanism is unknown) between such changes and the abnormal metabolism in diabetes and a background for research strategy and tactics, aiming finally at the possibility of prevention and/or treatment of this common and dangerous disease.

Under control of the Ren-1c promoter, locally produced transforming growth factor-beta1 induces accumulation of glomerular extracellular matrix in transgenic mice.

Our purpose was to elucidate the hypothesis that paracrine-produced transforming growth factor (TGF)-beta1 regulates the accumulation of extracellular matrix (ECM) in renal glomeruli, a hallmark of diabetic nephropathy. To produce TGF-beta1 from the juxtaglomerular apparatus in mouse kidneys, we cloned a mouse Ren-1c promoter fragment (-4.100 to +6 base pairs) upstream of porcine TGF-beta1 (pTGF-beta1) cDNA, mutated to ensure secretion of biologically active TGF-beta beta1. The resulting transgenic mice had significantly more TGF-beta1 in their kidneys than was in those of nontransgenic controls, as confirmed by immunohistochemistry, and the production of TGF-beta1 was enhanced in vivo by captopril-induced stimulation of the Ren-1c promoter. Overproduction of pTGF-beta1 close to the glomerulus resulted in a local accumulation of ECM, composed partly of collagen type IV and laminin, and thickening of the basement membrane, characteristic features of diabetic nephropathy. Interstitial accumulation of ECM and signs of tubular atrophy were present only in older mice (>5 months of age). Results from in situ hybridization and immunohistochemistry suggest that pTGF-beta1 stimulated the production of endogenous TGF-beta1 along collecting ducts and connecting tubules. The increased amount of biologically active TGF-beta1, transgenic as well as endogenous, was corroborated by heightened proteoglycan synthesis from incubated kidney slices. This transgenic model demonstrates that sustained local expression of TGF-beta1 leads to glomerulopathy. We conclude that autocrine- or paracrine-produced TGF-beta1 may play a role in the development of glomerular diseases, such as diabetic nephropathy.

Influence of insertion/deletion polymorphism in the ACE-I gene on the progression of diabetic glomerulopathy in type 1 diabetic patients with microalbuminuria.

OBJECTIVE: To investigate the influence of the insertion/deletion polymorphism of the ACE gene on the progression of early diabetic glomerulopathy in patients with and without antihypertensive treatment (AHT). RESEARCH DESIGN AND METHODS: There were 30 microalbuminuric patients with >5 years of type 1 diabetes who had renal biopsies taken at baseline and after 26-48 months of follow-up. Of the 30 patients, 13 (4 with II genotype and 9 with ID and DD genotypes) were randomized to AHT (enalapril or metoprolol) during the study. The ACE genotype was determined by a polymerase chain reaction. Glomerular structural changes were measured by stereological methods. RESULTS: Of the patients, 8 had the II genotype, 19 had ID genotype, and 3 had DD genotype. During the study, basement membrane thickness, matrix star volume, and the overall diabetic glomerulopathy index were increased in patients with ID and DD genotypes only (P < 0.001, P = 0.01, P < 0.001, respectively). Among those with ID and DD genotypes, progression of basement membrane thickening and diabetic glomerulopathy index were increased in those without AHT, as compared with the antihypertensive treated patients (P < 0.001, P = 0.02, respectively). In multivariate analysis, the ACE genotype had an independent influence on the progression of basement membrane thickening (P = 0.01), when AHT (P < 0.001) and the mean HbAlc during the study (P < 0.001) were also taken into account. ACE genotype tended to be independently associated with the diabetic glomerulopathy index (P = 0.05). CONCLUSIONS: Microalbuminuric type 1 diabetic patients carrying the D-allele have an increased progression of diabetic glomerulopathy. Presence of this allele and no AHT seems to enhance this process. Larger studies are needed to confirm the clinical significance of our findings.

Low-dose spironolactone reduces plasma fibulin-1 levels in patients with type 2 diabetes and resistant hypertension.

Diabetic patients with hypertension are at particularly high risk of vascular damage and consequently cardiovascular and renal disease. Fibulin-1, an extracellular matrix glycoprotein, is increased in arterial tissue and plasma from individuals with type 2 diabetes. This study aimed to evaluate whether antihypertensive treatment with spironolactone changes plasma fibulin-1 levels. In a multicenter, double-blind, randomized, placebo-controlled study, 119 patients with type 2 diabetes and resistant hypertension were included. A dose of spironolactone 25 mg or matching placebo was added to previous treatment at randomization. Blood pressure (BP) and plasma fibulin-1 were measured at baseline and at 16 weeks follow-up. Overall, 112 patients completed the study. All measures of BP were reduced in the spironolactone group at follow-up. Plasma fibulin-1 was significantly reduced after spironolactone treatment (P=0.009), but increased after placebo (P=0.017). Baseline plasma fibulin-1 correlated with BP and estimated glomerular filtration rate. Increased levels of plasma fibulin-1 (P=0.004) were observed in diabetic participants reporting erectile dysfunction as compared with participants who did not. Treatment with low-dose spironolactone reduced plasma fibulin-1 levels in patients with type 2 diabetes and resistant hypertension. This supports the hypothesis that the antihypertensive effect of the mineralocorticoid receptor blocker in part may be due to regression of vascular remodeling.

Gene transcription of receptors for growth hormone-releasing peptide and somatostatin in human pituitary adenomas.

Growth hormone (GH)-releasing peptides (GHRP) or secretagogs (GHS) constitute a family of synthetic compounds with potent and specific GH releasing activity. The receptor (GHS-R) has recently been cloned even though the endogenous ligand remains to be identified. GHRPs act both at the hypothalamic and the pituitary level through mechanisms involving amplification of GH-releasing hormone activity and functional somatostatin antagonism. In the present study we examined the co-expression of messenger RNA (mRNA) for GHS-R and all 5 somatostatin receptor subtypes (sstr 1-5) in 28 human pituitary tumors by RT-PCR. GHS-R transcription was detected in 11 out of 12 somatotroph adenomas and in 2 out of 2 prolactinomas, whereas GHS-R expression was detected in only 2 out of 14 clinically nonfunctioning adenomas (NFPA), and no expression was seen in the only ACTH secreting adenoma. Almost all tumors expressed sstr 2 mRNA (n = 24), whereas only 1 tumor expressed sstr 4 mRNA. The expression of sstr 3 mRNA was inversely associated with GHS-R expression (P < 0.001), which could be attributed to a high prevalence of sstr 3 expression in NFPA. This study suggests that GHS-R expression is predominantly observed in somatotroph adenomas and much less so in NFPA. Moreover, the presence of a distinct pattern of somatostatin receptor subtype co-expression is suggested, which may provide a molecular basis for the complex interaction between GHRPs and somatostatin.