Parameters influencing renal response to SGLT2 inhibitors and GLP1 receptor agonists in type 2 diabetes patients with preserved renal function: a comparative, prospective study.

PURPOSE: SGLT2 inhibitors (SGLT2i) and GLP1 receptor agonists (GLP1-RA) protect the kidney in type 2 diabetes (T2DM) subjects. The role of patient's phenotype years before starting the treatment in determining the kidney response to these drugs has never been evaluated. SUBJECTS AND METHODS: Clinical and biochemical parameters were collected in 92 T2DM patients with preserved kidney function from year -4 (T-4) to year +3 (T+3) from the introduction of semaglutide or empagliflozin (T0). Glomerular filtration rate (eGFR) slopes were evaluated to identify eGFR changes (ΔGFR) and predictors of treatment response. Urinary markers of kidney impairment were measured at T0, including KIM-1, TNFR1 and L-FABP. RESULTS: Characteristics of patients on semaglutide (n = 46) or empagliflozin (n = 37) were similar at T-4 and T0. ΔGFR from T0 to T+3 was -5.5 [-10.0; -0.7] vs -2.6 [-102.4] ml/min/1.73 m2 for GLP1-RA and SGLT2i, respectively (p = ns). Compared with patients with a slower eGFR decline, those with ΔGFR > 5 ml/min/1.73 m2 from T0 to T+3 (49%) or ΔGFR > 10 ml/min/1.73 m2 from T-4 to T+3 (25%) had similar characteristics and urinary markers at T-4 and T0. The latter group showed greater eGFR decline from T-3 to T0, which tended to be delayed more by SGLT2i than GLP1-RA (p = 0.09). CONCLUSION: In our cohort, subjects with T2DM and preserved renal function show similar eGFR response to treatment with GLP1-RA or SGLT2i. Baseline urinary biomarkers or prior phenotyping do not predict treatment response. An early eGFR decline identifies patients prone to lose more eGFR over time, who may benefit more from SGLT2i treatment.

DNA methylation of genes regulating appetite and prediction of weight loss after bariatric surgery in obese individuals.

PURPOSE: Epigenetic traits are influenced by clinical variables; interaction between DNA methylation (DNAmeth) and bariatric surgery-induced weight loss has been scarcely explored. We investigated whether DNAmeth of genes encoding for molecules/hormones regulating appetite, food intake or obesity could predict successful weight outcome following Roux-en-Y gastric bypass (RYGB). METHODS: Forty-five obese individuals with no known comorbidities were stratified accordingly to weight decrease one-year after RYGB (excess weight loss, EWL ≥ 50%: good responders, GR; EWL < 50%: worse responders, WR). DNAmeth of leptin (LEP), ghrelin (GHRL), ghrelin receptor (GHSR) and insulin-growth factor-2 (IGF2) was assessed before intervention. Single nucleotide polymorphisms of genes affecting DNAmeth, DNMT3A and DNMT3B, were also determined. RESULTS: At baseline, type 2 diabetes was diagnosed by OGTT in 13 patients. Post-operatively, GR (n = 23) and WR (n = 22) achieved an EWL of 67.7 ± 9.6 vs 38.2 ± 9.0%, respectively. Baseline DNAmeth did not differ between GR and WR for any tested genes, even when the analysis was restricted to subjects with no diabetes. A relationship between GHRL and LEP methylation profiles emerged (r = 0.47, p = 0.001). Searching for correlation between DNAmeth of the studied genes with demographic characteristics and baseline biochemical parameters of the studied population, we observed a correlation between IGF2 methylation and folate (r = 0.44, p = 0.003). Rs11683424 for DNMT3A and rs2424913 for DNMT3B did not correlate with DNAmeth of the studied genes. CONCLUSIONS: In severely obese subjects, the degree of DNAmeth of some genes affecting obesity and related conditions does not work as predictor of successful response to RYGB.

Phenotyping normal kidney function in elderly patients with type 2 diabetes: a cross-sectional multicentre study.

AIMS: Type 2 diabetes (T2D) accelerates the decline in glomerular function; however, some individuals do not develop chronic kidney disease despite advanced age and long-lasting T2D. We aimed to phenotype patients with T2D aged 80 years or older who presented with a fully preserved kidney function. METHODS: From an Italian population of 281,217 T2D outpatients, we collected data on demographics, anthropometrics, diabetes duration, HbA1c, fasting plasma glucose, lipids, liver enzymes, estimated glomerular filtration rate (eGFR), albumin excretion rate (AER), chronic complications, and medication use. We primarily compared patients with a fully preserved kidney function (eGFR > 90 ml/min/1.73 m2 and AER < 30 mg/24 h, or G1A1) with those with mild kidney impairment (eGFR 60-90 ml/min/1.73 m2 and AER < 30 mg/24 h, or G2A1). RESULTS: N = 113,860 had available data for eGFR and AER, 21,648 of whom were aged ≥ 80. G1A1 (n = 278) and G2A1 (n = 6647) patients represented 1.3 and 30.7% of aged T2D patients, respectively, with an average diabetes duration of 16 years. Differences between the G1A1 and G2A1 groups were entered in a multiple logistic regression analysis with and without imputation of missing data. After adjustment and in both imputed and non-imputed datasets, younger age, lower BMI and lower triglycerides were associated with fully preserved versus mildly impaired kidney function. The comparison between G1A1 and G1A2/3 yielded different results. CONCLUSIONS: In a rare population of patients with a fully preserved kidney function despite old age and long-lasting diabetes, lower BMI and triglycerides suggest that protection from lipotoxicity may preserve kidney function over time.

The P2X7 receptor-NLRP3 inflammasome complex predicts the development of non-Hodgkin's lymphoma in Sjogren's syndrome: a prospective, observational, single-centre study.

BACKGROUND: P2X7 receptor (P2X7R), trigger of acute inflammatory responses via the NLRP3 inflammasome, is hyperfunctioning in patients with Sjögren's syndrome (SS), where it stimulates IL-18 production. Some patients with SS develop a mucosa-associated lymphoid tissue non-Hodgkin's lymphoma (MALT-NHL). OBJECTIVES: To prospectively evaluate the involvement and the putative prognostic role of this inflammatory pathway in the development of MALT-NHL. METHODS: A total of 147 women with SS have been prospectively followed for a mean of 52 months, relating the expression and function of the P2X7R-inflammasome axis in salivary glands and circulating lymphomonocytes to the prognosis and the degree of the disease. RESULTS: At baseline, gene expression of P2X7R and of the inflammasome components NLRP3, caspase-1 and IL-18 increased according to the presence of germinative centres and was higher in autoantibody-positive individuals and strongly higher in those developing a MALT-NHL over the follow-up. Glandular expression of IL-18 was threefold higher in MALT-NHL than in controls or in the other patients with SS. P2X7R did not colocalize with generic markers of inflammatory infiltrate, like CD20, being selectively expressed by epithelial cells. P2X4R, sharing functional characteristics with P2X7R, did not differ in SS and controls. The increased P2X7R gene and protein expression was tissue specific, no difference being observed in peripheral lymphomonocytes between SS with MALT-NHL and SS not developing MALT-NHL. CONCLUSION: We propose the P2X7R-inflammasome axis as a novel potential pathway involved in both SS exocrinopathy and lymphomagenesis, reinforcing the hypothesis of a key role of IL-18, via its increased P2X7R-mediated production, in the pathogenesis of lymphoproliferative malignancies, and opening novel opportunities for the early diagnosis of lymphoproliferative complications and the development of potential targeted therapies.

Obesity reduces the pro-angiogenic potential of adipose tissue stem cell-derived extracellular vesicles (EVs) by impairing miR-126 content: impact on clinical applications.

BACKGROUND/OBJECTIVES: Soluble factors and cell-derived extracellular vesicles (EVs) are crucial tissue repair mediators in cell-based therapy. In the present study, we investigate the therapeutic impact of EVs released by adipose tissue-derived stem cells (ASCs) recovered from obese subjects' visceral and subcutaneous tissues. METHODS: ASCs were recovered from 10 obese (oASCs) and 6 non-obese (nASCs) participants and characterized. In selected experiments, nASCs and oASCs were cultured with palmitic acid (PA) or high glucose (HG), respectively. EVs from obese (oEVs) and non-obese (nEVs) subjects' visceral and subcutaneous ASCs were collected after ultracentrifugation and analyzed for their cargo: microRNA-126 (miR-126), vascular endothelial growth factor (VEGF), and matrix metalloproteinase 2 (MMP-2), and for their biological effects on endothelial cells (ECs). Western blotting analysis and loss- and gain-of function experiments were performed. RESULTS: oEVs show impaired angiogenic potential compared with nEVs. This effect depends on EV cargo: reduced content of VEGF, MMP-2 and, more importantly, miR-126. We demonstrate, using gain- and loss-of-function experiments, that this reduced miR-126 content leads to Spred1 upregulation and the inhibition of the extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase pathway in ECs. We also show that PA treatment of nASCs translates into the release of EVs that recapitulate oEV cargo. Moreover, HG treatment of oASCs further reduces miR-126 EV content and EV-mediated in vitro angiogenesis. Finally, impaired pro-angiogenic potential is also detected in EVs released from obese subcutaneous adipose tissue-derived ASCs. CONCLUSIONS: These results indicate that obesity impacts on EV pro-angiogenic potential and may raise concerns about the use of adipose tissue-derived EVs in cell-based therapy in the obese setting.

Acute effects of different degrees of ultra-endurance exercise on systemic inflammatory responses.

BACKGROUND: Intense physical stress might promote inflammatory responses, whereas a regular physical exercise has positive influence. Little is known on the acute metabolic and inflammatory responses to different levels of strenuous exercise in trained athletes. AIM: To compare the short-term effect of two different ultra-endurance competitions on the inflammatory profile in male triathletes. METHODS: We studied 14 Ironman (IR) and 13 Half Ironman (HIR) before and after their own specific race. We assessed body composition and measured blood cells, lipids, iron metabolism and plasma levels of some acute-phase cytokines and inflammatory markers. RESULTS: After the race, IR showed reduced total body water and fat-free mass, not related with the duration of exercise, and increased white cells and platelets; high-density lipoprotein levels also increased. IR, but not HIR, showed reduced iron levels, increased ferritin and transferrin, reduced % saturated transferrin. HIR showed higher basal interleukin (IL)-6, tumour necrosis factor (TNF)-α, IL-10, IL-1ß than IR; however, the post-performance rise was greater in IR. Irisin increased only in HIR and osteocalcin decreased in IR. In the whole study group, delta of white blood cells was directly related with delta of monocyte chemoattractant protein 1, and Δ ferritin was inversely related with Δosteocalcin. CONCLUSIONS: A single ultra-endurance competition induces an inflammatory response depending on the duration of physical effort, with increased acute-phase cytokines, and an altered iron metabolism. Irisin, whose biological meaning is still uncertain, seems to be associated with acute variations of some metabolic parameters.

Hormone replacement therapy, renal function and heart ultrasonographic parameters in postmenopausal women: an observational study.

BACKGROUND AND AIM: A certain degree of impaired kidney function is related to an increased cardiovascular risk. The cardiovascular protection exerted in the postmenopausal state by the hormone replacement therapy (HRT) is debated. No studies have so far explored the relationship between menopause, renal function and cardiovascular risk profile in healthy menopausal women in relation with HRT. SUBJECTS AND METHODS: A total of 362 postmenopausal healthy women with normal albumin excretion rate were recruited and divided into two groups (HRT+ and HRT-) according to the presence or absence of HRT. All participants underwent a complete routine biochemical analyses and an echocardiogram. RESULTS: Clinical characteristics of the two groups were similar, but HRT+ showed a significantly higher estimated glomerular filtration rate (GFR; by CKD-EPI formula). Regarding the heart ultrasonography, HRT+ had a significantly lower size of the aortic root and left atrium diameter (p = 0.038 and p = 0.012, respectively); no differences were found in the ejection fraction and Left Ventricular Mass Index (LVMI). In the whole study group, eGFR correlated inversely with LVMI and with the size of the aortic root (both p < 0.0001), being GFR the only determinant of the former by a stepwise regression. Dividing the study population according to an eGFR cut-off (> 80 and < 80 ml/min/1.73 m(2)); > 80 women, in comparison with < 80, showed a significantly lower LVMI and lower size of aortic bulb, further reduced in the HRT+. CONCLUSION: In a cohort of healthy, drug-naïve, postmenopausal women, HRT seems to positively affect glomerular filtration and is associated with lower values of left ventricular mass and aortic root size, thus offering a further mechanism through female hormones exert cardioprotection.

The ideal blood pressure target to prevent cardiovascular disease in type 2 diabetes: a neutral viewpoint.

Type 2 diabetes mellitus (T2DM) and essential hypertension are often associated, and retrospective data analyses suggest an association between lower blood pressure (BP) values and lower cardiovascular (CV) risk in patients with T2DM. However, the most recent intervention trials fail to demonstrate a further CV risk reduction, for BP levels <130/80 mm Hg, when compared to levels <140/90 mm Hg. Moreover, a J-shaped, rather than a linear, relationship of BP reduction with incident CV events has been strongly suggested. We here debate the main available evidences for and against the concept of 'the lower the better', in the light of the main intervention trials and meta-analyses, with a particular emphasis on the targets to be pursued in elderly patients. Finally, the most recent guidelines of the scientific societies are critically discussed.

VEGF-A polymorphisms predict progression-free survival among advanced castration-resistant prostate cancer patients treated with metronomic cyclophosphamide.

BACKGROUND: No data are available on the pharmacogenetics of metronomic chemotherapy in prostate cancer. The aim of this study was to evaluate the association between VEGF-A sequence variants and prostate-specific antigen (PSA) progression, progression-free survival (PFS) and overall survival (OS), in advanced castration-resistant prostate cancer patients treated with metronomic cyclophosphamide (CTX), celecoxib and dexamethasone. METHODS: Forty-three patients were enrolled, and genomic DNA was extracted. VEGF-A gene SNPs (-2578A/C, -634C/G, +936C/T) were analysed using TaqMan PCR assays. Hardy-Weinberg equilibrium was tested for each SNP, and genetic effects were evaluated by Fisher's exact test. PFS and OS were analysed with GraphPad Prism software, using the product limit method of Kaplan and Meier, and comparing survival curves using both the log-rank test and the Gehan-Wilcoxon test. We used Bonferroni correction to account for multiple testing, and a two-tailed P-value of <0.017 was considered statistically significant. RESULTS: Overall, 20 patients (46%) experienced a reduction in PSA levels from baseline and, among them, 14 (32%) showed a confirmed PSA ≥50% decrease. In non-responders, the -2578CC genotype was more frequent (18.60% vs 2.33% in responders; P=0.0212) whereas the -634CC genotype frequency was 22.73% vs 0% in responders (P=0.0485). With regard to PFS, patients harbouring the -634CC genotype had a median PFS of 2.2 months whereas patients with the genotype -634CG/GG had a median PFS of 6.25 months (P=0.0042). CONCLUSION: The -634CC genotype is significantly associated with a shorter PFS in patients treated with a metronomic CTX schedule.

Family history of hypertension, anthropometric parameters and markers of early atherosclerosis in young healthy individuals.

The predisposition to thrombogenesis is increased in essential hypertension, and hypertensive patients are prone to develop more vulnerable atherosclerotic plaques. To evaluate the possible influence of family history of hypertension on some indicators of early atherosclerosis, we studied eighty-five healthy normotensive individuals with (FH+) or without (FH-) family history of essential hypertension by measuring metabolic profile and concentrations of P-selectin, interleukin 6 and matrix metalloproteinase (MMP)-2, MMP-9, and tissue inhibitor of metalloproteinase (TIMP)-1. In a subset of individuals, MMP-9 activity was assessed in monocytes by zymography, and TIMP-1 expression by western blot. As compared with FH- individuals, FH+ individuals had significantly higher P-selectin but similar interleukin-6 levels. Although no difference was observed in MMP-2 levels between the two groups, MMP-9 and TIMP-1 were higher in FH+ individuals, who also had higher intracellular MMP-9 levels and TIMP-1 protein expression. P-selectin (r=-0.32; P<0.01), MMP-9 (r=-0.37; P<0.001) and TIMP-1 (r=-0.23; P<0.05) levels were inversely related to high density lipoprotein (HDL) cholesterol. P-selectin was also directly related to serum triglycerides (r=0.30; P<0.01). We conclude that a positive family history of hypertension is associated with an initial increase in markers of inflammation and plaque instability in otherwise healthy young normotensive individuals, likely conveying a predisposition to develop early atherothrombosis.

Short-term acute hyperinsulinemia and prothrombotic factors in subjects with normal glucose tolerance.

Some cytokines and proinflammatory mediators are considered markers of increased atherothrombotic risk. Few information is available on the effects of acute glucose and insulin variations on these markers of atherosclerosis. We assessed the acute effect of glucose and insulin on soluble CD40 ligand (sCD40L), IL-6, and P-selectin levels, evaluating their relationship with insulin sensitivity in normal glucose tolerance subjects (NGT). Twenty-four NGT subjects underwent a 3-h oral glucose tolerance test (OGTT) with measurements of sCD40L, IL-6, and P-selectin levels at 0, 90 and 180 min. Insulin sensitivity was assessed by the Oral Glucose Sensitivity Index (OGIS). To distinguish the role of glucose and insulin, eight subjects had the plasma glucose profile of the OGTT reproduced by a variable IV glucose infusion (ISO-G study) and nine underwent a euglycemic clamp. Lastly, a 3-h time-control (TC) study was performed in eleven subjects. A significant reduction of sCD40L was observed during OGTT and ISO-G study. This reduction was not due to time-related changes, since it was not observed in TC study. During the clamp, insulin induced a marked drop in sCD40L (from 4.89+/-1.34 to 1.60+/-0.29 ng/ml, p<0.05). In the pooled data from all studies, fasting sCD40L was indirectly related to LDL-cholesterol (r=-0.38; p=0.04), while IL-6 was directly related with BMI, fat mass, waist circumference, and P-selectin (p<0.05). sCD40L levels are downregulated during a short-term period of acute hyperinsulinemia, whether induced by oral or intravenous glucose administration or by insulin infusion, while it does not seem to affect P-selectin and IL-6.

Effect of statins on soluble CD40 ligand in hypercholesterolemic Type 2 diabetic patients.

Hypercholesterolemia and Type 2 diabetes are well-recognized risk factors for cardiovascular disease, promoted by a condition of subclinical inflammation and a hypercoagulable state. Soluble CD40 ligand (sCD40L), a marker of vascular inflammation, seems to predict vascular damage in patients with Type 2 diabetes. Beside the lipid-lowering effect, statins seem to slow the progression of atherosclerosis through a series of anti-inflammatory effects, including a reduction of sCD40L levels. This study compared the effect of a short-term (12 weeks) treatment with rosuvastatin or simvastatin on some markers of inflammation in 36 patients with Type 2 diabetes and moderate hypercholesterolemia. As expected, both drugs significantly modified lipid profile; moreover, rosuvastatin and simvastatin were both able to significantly reduce albumin excretion rate in these patients, without affecting urinary N-acetyl-beta-D-glucosaminidase. Serum homocysteine was not influenced by the treatment, as interleukin-6 levels, while C reactive protein diminished; moreover, rosuvastatin, but not simvastatin, was able to significantly reduce sCD40L. The only clinical parameter related with the variations in sCD40L was systolic blood pressure. In hypercholesterolemic Type 2 diabetic patients, sCD40L, a factor playing a pivotal role in the pathogenesis of atherosclerosis and associated with more rupture-prone lesions, is reduced by short-term treatment with rosuvastatin.

Effects of different LDL particles on inflammatory molecules in human mesangial cells.

AIMS/HYPOTHESIS: Inflammation is a mechanism of glomerular damage in chronic glomerulopathies. LDL may increase the production of inflammatory cytokines in renal tissues. However, the relative role of native, oxidised and glycated LDL in promoting this process has been only partially elucidated. METHODS: We tested the inflammatory and proapoptotic effects of native, oxidised and glycated LDL in human mesangial cells (HMCs) by measuring levels of IL6, CD40 and macrophage migration inhibitory factor (MIF) genes, MIF protein, release of IL6, soluble CD40, fibronectin and laminin, early and late apoptosis, and extracellular regulated kinases (ERK) 1/2 and c-Jun N-terminal kinase (JNK) activation. RESULTS: IL6 and CD40 mRNA were dose-dependently upregulated by all three species; this was closely paralleled by their increased release. MIF mRNA was potently stimulated by modified LDL, as confirmed by immunostaining. Fibronectin and laminin release was stimulated by both oxidised and glycated, but not native, LDL. All LDL species induced some increase in late, but not early, apoptosis, and similarly activated JNK2/3 phosphorylation; in contrast, ERK1/2 phosphorylation was more strongly upregulated by oxidised than either native or glycated LDL. CONCLUSIONS: In HMCs, the production and release of IL6 and CD40 is stimulated by both native and modified LDL, while MIF is more strongly stimulated by oxidised LDL. Regarding the pattern of mesangial expansion, fibronectin and laminin are upregulated by oxidised and glycated LDL. Apoptosis, if modest, is induced by all species. Intracellular signalling of native and modified LDL involves JNK2/3 and, perhaps more specifically, ERK1/2. Tight control of the lipid profile may be useful in preserving kidney function in patients with metabolic alterations.

Effect of short-term folic acid supplementation on insulin sensitivity and inflammatory markers in overweight subjects.

OBJECTIVE: Inflammation plays a pivotal role in the atherosclerotic process, and some chemokines seem to be crucial in the pathogenesis of vascular damage. High-serum homocysteine, recently recognized as an independent risk factor for vascular disease might increase cytokine and chemokine levels, thus amplifying endothelial damage; moreover, it might worse insulin resistance, thus further contributing to enhance cardiovascular risk. The effect of folic acid supplementation in improving in vivo endothelial function is still debated. In this study, we investigated the effect of folic acid supplementation on insulin sensitivity and peripheral markers of inflammation in overweight healthy subjects. DESIGN: The study was performed as an unmasked randomized placebo-controlled trial of 12 weeks duration. SUBJECTS: Sixty healthy volunteers with normal glucose tolerance and BMI between 25 and 29 kg/m2 were enrolled. MEASUREMENTS: Biochemical parameters and plasma concentrations of homocysteine and of some inflammatory molecules were measured at baseline and at the end of the study, together with an estimation of insulin sensitivity. RESULTS: Subjects receiving folic acid supplementation showed a decrement of homocysteine and an amelioration of insulin sensitivity; this treatment was also associated with a significant drop in the circulating concentration of monocyte chemoattractant protein-1, interleukin-8 and C-reactive protein, in the absence of any significant variation of BMI or fat mass. CONCLUSIONS: In healthy overweight subjects a short-term folic acid supplementation reduces the circulating level of some inflammatory mediators independently of weight change, thus suggesting a potential therapeutic role for folic acid in the protection from atherogenesis and cardiovascular diseases.

Metabolic profile in patients with benign prostate hyperplasia or prostate cancer and normal glucose tolerance.

Familial predisposition together with several environmental factors may be involved in the pathogenesis of common prostate disease such as benign hypertrophy or prostate neoplasm. A higher incidence of both these conditions has been described in some insulin-resistant states such as obesity, but not much information is available on the effect of metabolic profile on gland morphology. The aim of this study was to evaluate the relation between glucose and lipid pattern and prostate diameters in two groups of non-diabetic individuals with benign prostate hypertrophy or cancer. 109 patients were recruited; plasma glucose, lipids and hormonal profile as well as an ultrasonographic evaluation of the gland volume and diameters were determined. Patients with prostate cancer had significantly higher levels of insulin and were more insulin resistant; in contrast, in subjects with prostate hypertrophy, fasting plasma glucose and--to a lesser extent--serum triglycerides emerged as the main determinants of gland volume. These observations may indicate that an improvement of insulin sensitivity and strategies to maintain a strict glucose and lipid control even in non-diabetic subjects are useful objectives in the prevention of prostate diseases.

Role of diabetes in influencing leptin concentration in elderly overweight patients.

BACKGROUND: Leptin, the product of the ob gene, could have a significant role in the pathogenesis of obesity and non-insulin-dependent diabetes mellitus. However, it is still debated whether different degrees of glucose tolerance may affect plasma leptin concentrations in obese patients. OBJECTIVE: To investigate whether diabetes might influence leptin concentrations in obese patients. METHODS: We evaluated clinical parameters, anthropometric measures, and sex hormones, fasting plasma leptin, glucose and insulin concentrations in 100 elderly obese diabetic patients and 100 obese non-diabetic control individuals matched for age and sex. RESULTS: After adjustment for age and fat mass, plasma leptin concentrations did not differ between diabetic and non-diabetic obese individuals, in both men and women. In all patients leptin was significantly related to body mass index, fat mass and the homeostasis model insulin resistance index; moreover we observed a significant relationship with fasting plasma glucose and age in diabetic obese women, and with blood pressure values and testosterone concentrations in diabetic obese men. Multiple regression analysis revealed age and fasting plasma glucose to be the only independent determinants of fasting plasma leptin in diabetic obese women. CONCLUSIONS: These data suggest that leptin concentrations do not differ between obese diabetic and obese non-diabetic elderly patients. Among correlates of the metabolic syndrome, systolic pressure seems to be related to leptin only in men. In the postmenopausal or andropausal status, sex hormones are related to leptin concentrations only in diabetic men; in diabetic women, however, high glucose seems to be relevant in maintaining the same leptin concentrations as in non-diabetic women with similar degree of obesity.

A defect in glycogen synthesis characterizes insulin resistance in hypertensive patients with type 2 diabetes.

A subgroup of patients with type 2 diabetes shows a clustering of abnormalities such as peripheral insulin resistance, hypertension, and microalbuminuria. To evaluate whether these traits reflect intrinsic disorders of cell function rather than in vivo environmental effects, we studied a group of 7 nondiabetic hypertensive subjects with an altered albumin excretion rate (AER) (HyMA+) and 3 groups of patients with type 2 diabetes: 7 with normal blood pressure and normal AER (DH-MA-), 7 with high blood pressure and normal AER (DH+MA-), and 7 with both high blood pressure and altered AER (DH+MA+). Glucose disposal was measured during an hyperinsulinemic clamp (40 mU. m(2)(-1). min(-1)) with primed deuterated [6.6 (2)H(2)] glucose infusion. In the same subjects, a skin biopsy was performed and the following parameters were investigated: glucose transport (as determined by [(3)H]2-deoxyglucose uptake); glycogen synthase activity (as determined by [(14)C] glucose incorporation from UDP-[U-(14)C] glucose into glycogen); glycogen phosphorylase activity (as measured by the incorporation of [U-(14)C]glucose 1-phosphate into glycogen); and total glycogen content. In vivo glucose disposal was significantly reduced in DH+MA- and DH+MA+, with respect to DH-MA-, HyMA+, and controls. Insulin-stimulated glucose transport was similar in the 3 groups of patients with diabetes. A significant reduction of intracellular glycogen content was observed in DH+MA- and DH+MA+ compared with DH-MA- in both basal and insulin-stimulated conditions, probably because of a major impairment of glycogen synthase activity. Glycogen phosphorylase activity did not show differences between the groups. These results suggest that (1) the combination of type 2 diabetes with hypertension and altered AER is associated with impaired insulin sensitivity, and (2) intrinsic, possibly genetic, factors may account for increased peripheral insulin resistance in hypertensive microalbuminuric patients with type 2 diabetes, pointing to the reduction of glycogen synthase activity as a shared common defect.

Enlarged approach to the anterior cervical spine.

In this report a new enlarged approach to the anterior cervical spine is presented. A 66-year-old female, having a large C3-C4-C5 chordoma, recurrent after surgery and following radiotherapy, underwent a surgical resection. The approach allows a wide retraction of the nasopharynx, oropharynx and larynx from the midline, only sacrificing the superior laryngeal nerve on one side. Its continuity can be re-established later by adopting the stent in tube technique. The approach we used presents all the risks of infection common in trans-oral approaches. For this reason, closure of the pharynx in two layers must be meticulous and watertight and reinforced by using a myofascial sternocleidomastoid flap, according to the tracheoesophageal fistula closure technique. A correct alignment of the tongue, the pre-plating of the mandible and the correct suture of the vermillion border guarantee excellent cosmetic and functional results.

High glucose modulates P2X7 receptor-mediated function in human primary fibroblasts.

AIMS/HYPOTHESIS: Purinergic receptors are a family of newly characterized plasma membrane molecules involved in several and as yet only partially known cellular functions such as vascular reactivity, apoptosis and cytokine secretion. Little is known about the effect extracellular microenvironment has on their function. Fibroblasts share several features with smooth muscle cells and are an important constituent of the atherosclerotic plaque. Our aim was to evaluate the effect of high glucose concentration on ATP-mediated responses in human fibroblasts. METHODS: Fibroblasts were obtained by skin biopsies and grown at two different glucose concentrations. We evaluated receptor expression by RT-PCR and immunoblotting and receptor localization by immunofluorescence. Plasma membrane potential and calcium changes were measured by fluorescent indicators. Apoptosis was determined by ethidium bromide staining and caspase-3 activation. RESULTS: We show that cells grown in a medium with high glucose concentration underwent great ATP-mediated morphological changes, enhanced apoptosis, caspase 3 activation and interleukin-6 release. We identified P2X7 as the main purinergic receptor involved in these responses. Furthermore, high glucose concentration triggered the assembly of P2X7 into ring-like structures located at the periphery of the cells. CONCLUSION/INTERPRETATION: Given that ATP is frequently released into the extracellular milieu upon cell and tissue damage, secretory exocytosis or activation of plasma membrane transporters, we hypothesize that ATP receptors participate in the pathogenesis of vascular complications of diabetes.

Human primary fibroblasts in vitro express a purinergic P2X7 receptor coupled to ion fluxes, microvesicle formation and IL-6 release.

We have investigated reponses to extracellular ATP in human fibroblasts obtained by skin biopsies. Our data show that these cells express a P2X7 purinergic receptor, as judged by (1) RT-PCR with specific primers, (2) reactivity with a specific anti-P2X7 antiserum, (3) activation by the selective P2X agonist benzoylbenzoylATP and (4) stimulation of transmembrane ion fluxes. Stimulation with benzoylbenzoylATP, and to a lesser extent with ATP, also caused striking morphological changes and increased formation of cytoplasmic microvesicles. These changes were fully reversible upon nucleotide removal. Two known blockers of P2X receptors, oxidised ATP and pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid, inhibited the morphological changes fully and the ion fluxes partially. The residual rise in intracellular Ca2+ levels and membrane depolarization observed in the presence of the inhibitors were dependent upon activation of a P2Y-type receptor exhibiting a peculiar pharmacological profile, in that CTP was the preferred agonist. ATP stimulation triggered release of the pro-inflammatory cytokine IL-6 in fibroblasts pre-treated with PMA and bacterial endotoxin. These observations reveal a novel pathway for fibroblast activation and for their recruitment in the inflammatory response.