ESE Clinical Practice Guideline on functioning and nonfunctioning pituitary adenomas in pregnancy.

Pregnancies are rare in women with pituitary adenomas, which may relate to hormone excess from secretory subtypes such as prolactinomas or corticotroph adenomas. Decreased fertility may also result from pituitary hormone deficiencies due to compression of the gland by large tumours and/or surgical or radiation treatment of the lesion. Counselling premenopausal women with pituitary adenomas about their chance of conceiving spontaneously or with assisted reproductive technology, and the optimal pre-conception treatment, should start at the time of initial diagnosis. The normal physiological changes during pregnancy need to be considered when interpreting endocrine tests in women with pituitary adenomas. Dose adjustments in hormone substitution therapies may be needed across the trimesters. When medical therapy is used for pituitary hormone excess, consideration should be given to the known efficacy and safety data specific to pregnant women for each therapeutic option. In healthy women, pituitary gland size increases during pregnancy. Since some pituitary adenomas also enlarge during pregnancy, there is a risk of visual impairment, especially in women with macroadenomas or tumours near the optic chiasm. Pituitary apoplexy represents a rare acute complication of adenomas requiring surveillance, with surgical intervention needed in some cases. This guideline describes the choice and timing of diagnostic tests and treatments from the pre-conception stage until after delivery, taking into account adenoma size, location and endocrine activity. In most cases, pregnant women with pituitary adenomas should be managed by a multidisciplinary team in a centre specialised in the treatment of such tumours.

Changes in the prognostic values of modern cardiovascular biomarkers in relation to duration of diabetes mellitus.

BACKGROUND: Based on the complex pathophysiology of type 2 diabetes and atherosclerosis we hypothesized a dynamic change in prognostic value of cardiovascular biomarkers over time. METHODS: In this prospective study 746 patients with type 2 diabetes mellitus, being followed up for 60 months were analysed. The primary endpoint was defined as unplanned hospitalization for cardiovascular disease or death. Beside others, especially the prognostic performance of the biomarkers of interest (GDF-15, NT-proBNP, hs-TnT) was evaluated in relation to quartiles of diabetes duration. RESULTS: In patients having a diabetes duration below 7 years lnGDF-15 (HR 2.84; p < 0.01) and lnhs-TnT (HR 2.96; p < 0.01) were significant predictors of the primary endpoint. LnAge (HR 40.01; p < 0.01) and lnNT-proBNP (HR 1.56; p = 0.03) were significant predictors in patients with a diabetes duration between 7 and 12 years. In the third quartile (diabetes duration 12-22 years) lnurinary albumin to creatinine ratio (HR 1.25; p = 0.005) and lnNT-proBNP (HR 2.13, p < 0.001) predicted the endpoint. In patients with a diabetes duration above 22 years, lnAge (HR 75.35; p = 0.001) and lnNT-proBNP (HR 2.0; p < 0.01) were the only significant predictors of the endpoint. CONCLUSION: Prognostic power of cardiovascular biomarkers changes dynamically in relation to duration of type 2 diabetes mellitus. In patients with shorter duration of the disease markers of subclinical cardiovascular dysfunction and inflammation perform better than markers of systemic advanced organ dysfunction and cardiovascular disease.

Micro- and macrovascular function in patients suffering from primary adrenal insufficiency: a cross-sectional case-control study.

BACKGROUND: Despite adequate glucocorticoid (GC) and mineralocorticoid (MC) replacement therapy, patients suffering from primary adrenal insufficiency (AI) have an increased mortality, mainly due to cardiovascular diseases. Only little knowledge exists on the contribution of MC substitution to the cardiovascular risk. Therefore, this study investigates the impact of plasma renin concentration on parameters of micro- and macrovascular function. METHODS: 26 patients with primary AI [female = 18, age: 51 (28; 78) years; BMI: 24 (18; 40) kg/m2; disease duration: 18 (5; 36) years] were included in this cross-sectional analysis. Intima media thickness (IMT) and pulse wave velocity (PWV) were investigated to assess macrovascular remodeling and arterial stiffness. Microvascular function was estimated by post-occlusive reactive hyperemia using laser Doppler fluxmetry. Baseline perfusion, biological zero, peak perfusion, time to peak and recovery time were recorded. Patients were grouped according to their median plasma renin concentration of previous visits (Reninhigh vs Reninlow) and were compared to a group of healthy women [age: 44 (43; 46) years; BMI: 24.2 (21.8; 27.5)]. RESULTS: PWV was significantly higher in AI patients compared to controls [9.9 (5; 18.5) vs 7.3 (6.8; 7.7) m/s; p < .01], whereas no differences in microvascular function could be found. In Reninlow time to peak perfusion was significantly longer [6.0 (3; 15) vs 3.5 (1.5; 11) s; p < .05], whereas no differences in IMT and PWV were observed between Reninhigh and Reninlow. No impact of GC dose was observed. CONCLUSIONS: Microvascular function is not impaired in patients with primary AI under adequate replacement therapy, although higher renin concentrations are associated with subclinical improvements. No relation between RAAS activity and macrovascular function is observed, while arterial stiffness might be increased in primary AI.

Quasi-Herglotz functions and convex optimization.

We introduce the set of quasi-Herglotz functions and demonstrate that it has properties useful in the modelling of non-passive systems. The linear space of quasi-Herglotz functions constitutes a natural extension of the convex cone of Herglotz functions. It consists of differences of Herglotz functions and we show that several of the important properties and modelling perspectives are inherited by the new set of quasi-Herglotz functions. In particular, this applies to their integral representations, the associated integral identities or sum rules (with adequate additional assumptions), their boundary values on the real axis and the associated approximation theory. Numerical examples are included to demonstrate the modelling of a non-passive gain medium formulated as a convex optimization problem, where the generating measure is modelled by using a finite expansion of B-splines and point masses.

GDF15 reflects beta cell function in obese patients independently of the grade of impairment of glucose metabolism.

BACKGROUND AND AIMS: Growth differentiation factor 15 (GDF15) is a strong predictor of cardiovascular morbidity and mortality found to be both marker and target of impaired glucose metabolism. GDF15 increases following glucose administration and is up-regulated in obesity and diabetes. We investigate here the relationship between GDF15 and beta cell function. METHODS AND RESULTS: In this cross-sectional study we evaluated GDF15 concentrations in 160 obese subjects (BMI 35-63 kg/m2, age 39.4 ± 18.6 years, m/f 38/122) who underwent a 75 g oral glucose tolerance test (OGTT). Based on the OGTT results, the cohort was divided into two groups: 1) normal fasting glucose and normal glucose tolerance (n = 80), 2) impaired fasting glucose, impaired glucose tolerance or type 2 diabetes (n = 80). The relationship of GDF15 to fasting and OGTT-based dynamic insulin sensitivity and insulin secretion parameters was evaluated. GDF15 was higher in the prediabetes and diabetes groups and correlated with HbA1c, glucose, insulin as well as baseline and dynamic indices of insulin sensitivity and estimated beta cell function. Multiple regression analysis revealed that age, waist-to-height ratio, glomerular filtration rate and prehepatic beta cell function, but not the grade of impairment of glucose metabolism, were independent predictors of GDF15. Subgroup analysis showed that of all parameters of glucose metabolism only C-peptide, fasting prehepatic beta cell function and insulinogenic index remained significantly related to GDF15 in both groups. CONCLUSION: We conclude that in patients with severe obesity, GDF15 strongly relates to beta cell function and should be further investigated as a potential therapeutic target and biomarker guiding treatment options.

Out of the pot and into the fire: Explaining the vulnerability of an endangered small headwater stream fish to black-bass Micropterus spp. invasion.

Introduced predatory fishes have had consistently severe consequences for native fishes in stream environments around the world, although the drivers of these effects are often unclear. In the Swartkops River headwaters in South Africa, native Eastern Cape redfin Pseudobarbus afer were always absent from sites occupied by non-native black basses Micropterus salmoides and Micropterus dolomieu, but generally co-occurred with the native predators Anguilla marmorata and Anguilla mossambica. A natural experiment provided by flood-mediated recolonization of black-bass occupied sites by P. afer demonstrated depletion in black-bass invaded sites. Field behavioural observations of P. afer indicated that they foraged among benthic cover during the day, but suspended in open water at night. As the nocturnal A. marmorata and A. mossambica foraged actively within structural cover at night and M. dolomieu and M. salmoides are diurnal or crepuscular predators, P .afer is thus optimized to avoid predation by native anguillid predators and not the functionally unique predatory black basses. The integration of distributional, temporal population dynamics and behavioural data suggests that the severe effects of Micropterus spp. are probably a consequence of prey naïveté and behaviour evolved to evade native predators.

[Diagnostics and treatment of acromegaly : Necessity for targeted monitoring of comorbidities]. / Diagnostik und Therapie der Akromegalie : Notwendigkeit der gezielten Überwachung von Komorbiditäten.

Acromegaly is a rare and severe condition, presenting with typical signs and symptoms. The diagnosis is often initially made years after the first manifestations of the disease. In more than 99% of patients the disease is caused by a benign pituitary tumor that secretes growth hormone (GH). The diagnosis is based on the presence of increased insulin-like growth factor 1 (IGF-1) levels and a lack of GH suppression in the oral glucose tolerance test. The standard imaging procedure for tumor detection is magnetic resonance imaging in the region of the sella turcica. Treatment includes surgical, drug and radiation therapy. Important factors are an intensive aftercare of the patient, controls for detection of tumor recurrence and pituitary insufficiency as well as assessment of various organ functions and risk constellations. Patient care should involve close cooperation between endocrinologists, neurosurgeons and general practitioners as well as other specialist disciplines.

[Ultrasonography of the prostate gland : From B­image through multiparametric ultrasound to targeted biopsy]. / Ultraschall der Prostata : Vom B­Bild über den multiparametrischen Ultraschall zur gezielten Biopsie.

BACKGROUND: Prostate cancer is the most frequent cancer in men. The diagnosis is normally achieved by a systematic prostate biopsy; however, this is a randomized approach by which a substantial number of significant carcinomas go undetected. For this reason, in recent years imaging techniques have been continuously developed, which enable visualization and therefore targeted biopsies. STANDARD PROCEDURE: The use of systematic biopsies is a standard procedure for the detection of prostate cancer. The quality of biopsies can be increased if the prostate is examined for the presence of suspected cancerous alterations during the biopsy. This can be carried out using multiparametric transrectral ultrasound. PERFORMANCE: Multiparametric ultrasound within the framework of a targeted biopsy increases the detection rate of significant prostate carcinomas with a simultaneous decrease in detection of insignificant carcinomas; however, the diagnostic reliability and the evidence level of multiparametric transrectal ultrasound are not yet sufficiently high to be able to replace a systematic biopsy. CONCLUSION: In the hands of a well-trained examiner multiparametric transrectal ultrasound represents a good method for detection of prostate carcinomas. With the progression in technical developments of ultrasound technology, the detection rate will presumably be further increased.

Targeted multiple biomarker approach in predicting cardiovascular events in patients with diabetes.

OBJECTIVE: We hypothesised that biomarkers representing different pathophysiological pathways of atherosclerosis namely growth differentiation factor 15 (GDF-15), N-terminal pro B-type natriuretic peptide (NT-proBNP) and high-sensitive troponin T (hs-TnT) could enhance cardiovascular risk prediction in patients with type 2 diabetes mellitus. METHODS: This is a prospective study in 746 patients with type 2 diabetes mellitus, who were followed up for 60 months. The primary endpoint was defined as unplanned hospitalisation for cardiovascular disease or death. The prognostic performance of the biomarkers of interest (GDF-15 in comparison with NT-proBNP and hs-TnT) was evaluated in univariate as well as in stepwise Cox regression models. HRs are presented per standard unit increase. RESULTS: The primary endpoint was registered in 171 patients (22.9%). In univariate Cox regression models, GDF-15 as well as hs-TnT provided significant prognostic information. Even after adjusting for established cardiovascular risk factors, GDF-15, hs-TnT and NT-proBNP remained strong independent predictors of the endpoint (logGDF-15: HR 1.37, p<0.01, CI 1.12 to 1.68; loghs-TnT: HR 1.43, p<0.01, CI 1.13 to 1.1.82; logNT-proBNP: HR 1.45, p<0.01, CI 1.26 to 1.66). The number of elevated markers showed a strong complementarity to predict future long-term risk. Adding hs-TnT and GDF-15 to a zero model already including NT-proBNP led to a net reclassification improvement (NRI) of 33.6% (CI 16.0% to 50.8%, NRI for patients with event: 11.1% CI -4.7% to 26.6%, for patients without event: 22.5% CI 13.6% to 30.5%). CONCLUSIONS: GDF-15 and hs-TnT are strong independent cardiovascular biomarkers augmenting the predictive value of NT-proBNP in patients with diabetes.

Suppression of plasma free fatty acids reduces myocardial lipid content and systolic function in type 2 diabetes.

BACKGROUND AND AIM: Type 2 diabetes (T2DM) is closely associated with the development of heart failure, which might be related with impaired substrate metabolism and accumulation of myocardial lipids (MYCL). The aim of this study was to investigate the impact of an acute pharmacological inhibition of adipose tissue lipolysis leading to reduced availability of circulating FFA on MYCL and heart function in T2DM. METHODS AND RESULTS: 8 patients with T2DM (Age: 56 ± 11; BMI: 28 ± 3.5 kg/m(2); HbA1c: 7.29 ± 0.88%) were investigated on two study days in random order. Following administration of Acipimox or Placebo MYCL and heart function were measured by (1)H-magnetic-resonance-spectroscopy and tomography at baseline, at 2 and at 6 h. Acipimox reduced circulating FFA by -69% (p < 0.001), MYCL by -39 ± 41% (p < 0.001) as well as systolic heart function (Ejection Fraction (EF): -13 ± 8%, p = 0.025; Cardiac Index: -16 ± 15%, p = 0.063 compared to baseline). Changes in plasma FFA concentrations strongly correlated with changes in MYCL (r = 0.707; p = 0.002) and EF (r = 0.651; p = 0.006). Diastolic heart function remained unchanged. CONCLUSIONS: Our results indicate, that inhibition of adipose tissue lipolysis is associated with a rapid depletion of MYCL-stores and reduced systolic heart function in T2DM. These changes were comparable to those previously found in insulin sensitive controls. MYCL thus likely serve as a readily available energy source to cope with short-time changes in FFA availability.

Strong association of serum- and glucocorticoid-regulated kinase 1 with peripheral and adipose tissue inflammation in obesity.

OBJECTIVE: The serum- and glucocorticoid-regulated kinase 1 (SGK1) is an early transcriptional target of glucocorticoids and is activated via insulin. Here we investigate the regulation of SGK1 expression in human obesity, diet-induced murine obesity and human monocytic cell line THP-1 monocytes. SUBJECTS AND METHODS: SGK1 expression was studied in subcutaneous and omental adipose tissue (AT) of 20 morbidly obese and 20 age- and gender-matched non-obese controls in murine diet-induced obesity and the THP-1 cell line. The regulation of SGK1 by inflammatory signals was tested in THP-1 cells. RESULTS: Murine diet-induced obesity is associated with a significant upregulation of Sgk1 in gonadal AT. Sgk1 expression is highest in the macrophage-rich stromal vascular fraction and lower in adipocytes. In humans, AT SGK1 is predominantly expressed in CD14(+) macrophages and significantly upregulated in omental and subcutaneous AT of obese subjects. SGK1 mRNA expression in both omental and subcutaneous AT correlates with body mass index, circulating leptin and C-reactive protein, and the local expression of inflammatory markers including monocyte chemotactic protein-1 and macrophage inflammatory protein-1α. The expression of SGK1 in THP-1 cells is upregulated by inflammatory signals, such as lipopolysaccharide and tumour necrosis factor-α, as well as during the induction of monocyte-to-macrophage maturation. CONCLUSIONS: Our data present the first link between SGK1 and obesity-associated inflammation. SGK1 expression is stimulated in response to inflammatory signals and increased in AT macrophages. The characterisation of SGK1 functions in obesity and immunity may help identify potential therapeutic targets in the treatment of obesity.

Effects of B-type natriuretic peptide on cardiovascular biomarkers in healthy volunteers.

Cardiovascular biomarkers provide independent prognostic information in the assessment of mortality and cardiovascular complications. However, little is known about possible interactions between these biomarkers. In the present study, we evaluated the influence of B-type natriuretic peptide (BNP) on midregional-proadrenomedullin (MR-proADM), C-terminal-proendothelin-1 (CT-proET-1), growth differentiation factor-15 (GDF-15), midregional-proatrial natriuretic peptide (MR-proANP), copeptin, and procalcitonin in healthy volunteers. Ten healthy male subjects (mean age 24 yr) participating in a randomized, placebo-controlled, single-blinded crossover study received placebo or 3.0 pmol·kg(-1)·min(-1) human BNP 32 during a continuous infusion lasting for 4 h. Effects of BNP on other cardiovascular biomarkers were assessed. BNP did not change concentrations of MR-proADM, copeptin, CT-proET1, GDF-15, or procalcitonin. In contrast, MR-proANP was significantly decreased during BNP infusion. BNP as an established cardiovascular biomarker did not affect plasma concentrations of other cardiovascular biomarkers in a model of healthy volunteers.

Fasting and postprandial liver glycogen content in patients with type 1 diabetes mellitus after successful pancreas-kidney transplantation with systemic venous insulin delivery.

BACKGROUND: In patients with type 1 diabetes mellitus (T1DM), insulin is usually replaced systemically (subcutaneously) and not via the physiological portal route. According to previous studies, the liver's capacity to store glycogen is reduced in T1DM patients, but it remains unclear whether this is due to hyperglycaemia, or whether the route of insulin supply could contribute to this phenomenon. T1DM patients after successful pancreas-kidney transplantation with systemic venous drainage (T1DM-PKT) represent a suitable human model to further investigate this question, because they are normoglycaemic, but their liver receives insulin from the pancreas transplant via the systemic route. MATERIALS AND METHODS: In nine T1DM-PKT, nine controls without diabetes (CON) and seven patients with T1DM (T1DM), liver glycogen content was measured at fasting and after two standardized meals employing (13) C-nuclear-magnetic-resonance-spectroscopy. Circulating glucose and glucoregulatory hormones were measured repeatedly throughout the study day. RESULTS: The mean and fasting concentrations of peripheral plasma glucose, insulin, glucagon and C-peptide were comparable between T1DM-PKT and CON, whereas T1DM were hyperglycaemic and hyperinsulinaemic (P < 0·05 vs T1DM-PKT and CON). Total liver glycogen content at fasting and after breakfast did not differ in the three groups. After lunch, T1DM-PKT and T1DM had a 14% and 21% lower total liver glycogen content than CON (P < 0·02). CONCLUSION: In spite of normalized glycaemic control, postprandial liver glycogen content was reduced in T1DM-PKT with systemic venous drainage. Thus, not even optimized systemic insulin substitution is able to resolve the defect in postprandial liver glycogen storage seen in T1DM patients.

Mechanisms of antihyperglycaemic action of efaroxan in mice: time for reappraisal of α2A-adrenergic antagonism in the treatment of type 2 diabetes?

AIMS/HYPOTHESIS: Inspired by recent speculation about the potential utility of α(2A)-antagonism in the treatment of type 2 diabetes, the study examined the contribution of α(2)-antagonism vs other mechanisms to the antihyperglycaemic activity of the imidazoline (±)-efaroxan. METHODS: Effects of the racemate and its pure enantiomers on isolated pancreatic islets and beta cells in vitro, as well as on hyperglycaemia in vivo, were investigated in a comparative manner in mice. RESULTS: In isolated perifused islets, the two enantiomers of efaroxan were equally potent in counteracting inhibition of insulin release by the ATP-dependent K(+) (K(ATP)) channel-opener diazoxide but (+)-efaroxan, the presumptive carrier of α(2)-antagonistic activity, was by far superior in counteracting inhibition of insulin release by the α(2)-agonist UK14,304. In vivo, (+)-efaroxan improved oral glucose tolerance at 100-fold lower doses than (-)-efaroxan and, in parallel with observations made in vitro, was more effective in counteracting UK14,304-induced than diazoxide-induced hyperglycaemia. The antihyperglycaemic activity of much higher doses of (-)-efaroxan was associated with an opposing pattern (i.e. with stronger counteraction of diazoxide-induced than UK14,304-induced hyperglycaemia), which implicates a different mechanism of action. CONCLUSIONS/INTERPRETATION: The antihyperglycaemic potency of (±)-efaroxan in mice is almost entirely due to α(2)-antagonism, but high doses can also lower blood glucose via another mechanism. Our findings call for reappraisal of the possible clinical utility of α(2A)-antagonistic compounds in recently identified subpopulations of patients in which a congenitally higher level of α(2A)-adrenergic activation contributes to the development and pathophysiology of type 2 diabetes.

B-type natriuretic peptide (BNP) affects the initial response to intravenous glucose: a randomised placebo-controlled cross-over study in healthy men.

AIMS/HYPOTHESIS: B-type natriuretic peptide (BNP) is a hormone released from cardiomyocytes in response to cell stretching and elevated in heart failure. Recent observations indicate a distinct connection between chronic heart failure and diabetes mellitus. This study investigated the role of BNP on glucose metabolism. METHODS: Ten healthy volunteers (25 ± 1 years; BMI 23 ± 1 kg/m(2); fasting glucose 4.6 ± 0.1 mmol/l) were recruited to a participant-blinded investigator-open placebo-controlled cross-over study, performed at a university medical centre. They were randomly assigned (sequentially numbered opaque sealed envelopes) to receive either placebo or 3 pmol kg(-1) min(-1) BNP-32 intravenously during 4 h on study day 1 or 2. One hour after beginning the BNP/placebo infusion, a 3 h intravenous glucose tolerance test (0.33 g/kg glucose + 0.03 U/kg insulin at 20 min) was performed. Plasma glucose, insulin and C-peptide were frequently measured. RESULTS: Ten volunteers per group were analysed. BNP increased the initial glucose distribution volume (13 ± 1% body weight vs 11 ± 1%, p < 0.002), leading to an overall reduction in glucose concentration (p < 0.001), particularly during the initial 20 min of the test (p = 0.001), accompanied by a reduction in the initial C-peptide levels (1.42 ± 0.13 vs 1.62 ± 0.10 nmol/l, p = 0.015). BNP had no impact on beta cell function, insulin clearance or insulin sensitivity and induced no adverse effects. CONCLUSIONS/INTERPRETATION: Intravenous administration of BNP increases glucose initial distribution volume and lowers plasma glucose concentrations following a glucose load, without affecting beta cell function or insulin sensitivity. These data support the theory that BNP has no diabetogenic properties, but improves metabolic status in men, and suggest new questions regarding BNP-induced differences in glucose availability and signalling in various organs/tissues. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01324739 FUNDING: The study was funded by Jubilée Fonds of the Austrian National Bank (OeNB-Fonds).

Serum uric acid is related to cardiovascular events and correlates with N-terminal pro-B-type natriuretic peptide and albuminuria in patients with diabetes mellitus.

BACKGROUND: Hyperuricemia is a risk factor for cardiovascular events and renal insufficiency. It correlates to intima-media thickness and microalbuminuria. In this study we evaluated uric acid as an independent marker for cardiac events in patients with diabetes. METHODS: In a prospective observational study we recruited 494 patients with diabetes. Patients were then followed for 12.8 months (mean follow-up) and hospitalizations as a result of cardiac events (ischaemic heart disease, arrhythmias, heart failure) were recorded. RESULTS: The median duration of diabetes was 11 ± 10.35 years. Patients were in the mean 60 ± 13 years old and mean HbA(1c) was 62 ± 13 mmol/mol (7.8 ± 3.3%). At baseline, mean uric acid was 321.2 ± 101.1 µmol/l (range 101.1-743.5 µmol/l), median N-terminal pro-B-type natriuretic peptide was 92 ± 412 pg/ml and median urinary albumin to creatinine ratio was 8 ± 361 mg/g; Uric acid significantly correlated to N-terminal pro-B-type natriuretic peptide (r = 0.237, P < 0.001) and urinary albumin:creatinine ratio (r = 0.198, P < 0.001). In a Cox regression model, including age, estimated glomerular filtration rate, gender, systolic blood pressure, smoking and alcohol consumption, uric acid was the best predictor of cardiac events (hazard ratio 1.331, confidence interval 1.095-1.616, P = 0.04). However, uric acid lost its prognostic value when the natural logarithm of N-terminal pro-B-type natriuretic peptide was added to the model. CONCLUSION: Serum uric acid is a predictor of cardiac events and correlates to N-terminal pro-B-type natriuretic peptide and albuminuria, underscoring the importance of uric acid as a cardiovascular risk marker in patients with diabetes.

Insulin resistance is not associated with myocardial steatosis in women.

AIMS/HYPOTHESIS: Insulin resistance, an independent risk-factor for cardiovascular disease, precedes type 2 diabetes and is associated with ectopic lipid accumulation in skeletal muscle and liver. Recent evidence indicates that cardiac steatosis plays a central role in the development of diabetic cardiomyopathy. However, it is not known whether insulin resistance as such in the absence of type 2 diabetes is associated with heart steatosis and/or impaired function. We therefore assessed myocardial steatosis and myocardial function in a sample of women with normal insulin sensitivity, insulin resistance, impaired glucose tolerance (IGT) and type 2 diabetes. METHODS: Magnetic resonance imaging and localised spectroscopy were used to measure left ventricular dynamic variables and myocardial lipid accumulation in interventricular septum of non-diabetic, age- and BMI-matched insulin-sensitive (n = 11, 47 ± 6 years, BMI 25 ± 2 kg/m(2); clamp-like index [CLIX] = 9.7 ± 0.7) and insulin-resistant (n = 10, 48 ± 5 years, 27 ± 4 kg/m(2); CLIX = 4.5 ± 0.4) women with normal glucose tolerance as well as of women with IGT (n = 6, 45 ± 5 years, 28 ± 6 kg/m(2); CLIX = 3.6 ± 1.1) and type 2 diabetes (n = 7, 52 ± 10 years, 27 ± 3 kg/m(2)). RESULTS: Myocardial lipid content was increased in type 2 diabetic women only (insulin-sensitive 0.4 ± 0.2% [means ± SD]; insulin-resistant 0.4 ± 0.1%; IGT 0.5 ± 0.2%; type 2 diabetes 0.7 ± 0.3%; p < 0.05). In insulin-resistant and type 2 diabetic women, stroke volume was lower (-15% and -27%, respectively, vs insulin-sensitive) and heart rate was higher (11% and 14%, respectively, vs insulin-sensitive, p < 0.05). No other differences in systolic and diastolic function were observed between study groups. CONCLUSIONS/INTERPRETATION: In contrast to liver and skeletal muscle, insulin resistance as such is not associated with increased myocardial lipid accumulation.

Reduction of both number and proliferative activity of human endothelial progenitor cells in obesity.

OBJECTIVE: Circulating endothelial progenitor cells (EPCs), responsible for neoangiogenesis and vascular repair, negatively correlate with vascular dysfunction and atherosclerotic risk factors. Because obesity may have a crucial role in the development of endothelial dysfunction, this study evaluated the number and proliferative activity of circulating human EPCs in obese (body mass index (BMI)=48+/-9, n=45) compared with lean (23+/-2, n=45) volunteers. METHODS: EPCs were quantified after isolation of peripheral blood mononuclear cells (PBMCs) using fluorescence-activated cell sorting analyses. In addition, plated PBMCs developed colony-forming units (CFUs) from which 'outgrowth' endothelial cells (OECs) sprouted and differentiated into mature endothelial cells. Growth rates were monitored by periodical microscopic evaluation. Cell-cycle protein expression was determined by western blot analyses. RESULTS: BMI negatively correlated (P<0.01) with the number of CD34(+)/CD133(+)/KDR(+) (r=-0.442), CD34(+)/KDR(+) (r=-0.500) and CD133(+)/KDR(+) (r=-0.282) EPCs. Insulin, leptin, HbA(1c), high-sensitivity C-reactive protein and hypertension, as well as diminished high-density lipoprotein and apolipoprotein A1, were not only associated with obesity but also with significantly reduced EPC levels. Applying selective culture conditions, EPC-CFUs differentiated into OECs that proliferated more slowly when derived from obese compared with lean subjects (obese: 19.9+/-2.2% vs lean: 30.9+/-3.2% grown area per week, P<0.01). The reduced proliferation was reflected by decreased (P<0.05, n=24 for each group) expression of cell-cycle-promoting cyclins and E2F-1, by hypophosphorylation of retinoblastoma protein and by increased (P<0.05, n=24 for each group) expression of the cell-cycle inhibitor p21(WAF-1/Cip1). CONCLUSIONS: Reduced numbers of EPCs along with their premature senescence, as shown in this study, could function as early contributors to the development and progression of vascular dysfunction in obesity.

Beta cell (dys)function in non-diabetic offspring of diabetic patients.

AIMS/HYPOTHESIS: The first-degree offspring of patients with type 2 diabetes are prone to develop type 2 diabetes, and have both insulin resistance and beta cell impairment. However, it is still unclear whether both pathophysiological features are inseparably combined and which is the outstanding determinant in the offspring. METHODS: Glucose metabolism, insulin sensitivity (calculated as M value divided by insulin [M/I]) and beta cell function were studied in the offspring of individuals with type 2 diabetes (n = 187; 57% females; age 43.8 +/- 8.1 years; BMI 26.8 +/- 4.5 kg/m(2)) and in individuals without a family history of type 2 diabetes (controls, n = 519, 55% females; age 43.4 +/- 8.2 years; BMI 26.4 +/- 3.7 kg/m(2), no significant differences between the groups for any characteristic) by performance of 75 g OGTT and 2 h hyperinsulinaemic (40 mU min(-1) m(-2))-isoglycaemic clamp tests. Beta cell function was evaluated by calculating insulinogenic index (IGI) from C-peptide AUC:glucose AUC ratios from the first hour of OGTT (IGI[60 min]) and from the total OGTT (IGI[120 min]). RESULTS: During the OGTT, the offspring of individuals with type 2 diabetes showed 4-14% higher plasma glucose from 30 to 120 min (p < 0.05) and 20-29% higher serum insulin from 90 to 120 min, but decreased IGI(60 min) and IGI(120 min) (p < 0.05). M/I was 11% lower in the offspring of affected individuals than in controls (p < 0.01). To study the offspring of patients with type 2 diabetes with insulin sensitivity similar to that of the control group, the offspring of affected patients were divided into M/I quartiles. Those in the third M/I quartile showed M/I values and major anthropometric characteristics similar to those of the controls, but insulin AUC and C-peptide AUC values were lower in the first hour and the total OGTT (p < 0.05). The third M/I quartile had lower IGI values at 60 min and 120 min: 11% and 14% lower, respectively (p < 0.02). CONCLUSIONS/INTERPRETATION: The first-degree offspring of type 2 diabetic patients show insulin resistance and beta cell dysfunction in response to oral glucose challenge. Beta cell impairment exists in insulin-sensitive offspring of patients with type 2 diabetes, suggesting beta cell dysfunction to be a major defect determining diabetes development in diabetic offspring.