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.

Sex- and gender-differences in chronic long-term complications of type 1 and type 2 diabetes mellitus in Italy

AIMS

This review summarizes the contribution of Italian diabetologists devoted to a better understanding of the complex relationship linking sex/gender and long-term complications of type 1 (T1DM) and type 2 diabetes (T2DM) over the last fifteen years.

DATA SYNTHESIS

Microvascular and macrovascular complications of diabetes show sex- and gender-related differences, involving pathophysiological mechanisms, epidemiological features and clinical presentation, due to the interaction between biological and psychosocial factors. These differences greatly impact on the progression of diabetes and its long-term complications, especially in the cardiovascular, renal and liver districts.

CONCLUSION

A better knowledge of such sex- and gender-related characteristics is required for a more precise patient phenotypization, and for the choice of a personalized antihyperglycemic treatment. Despite such mounting evidence, current diabetes clinical guidelines do not as yet adequately consider sex/gender differences.

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.

Dapagliflozin modulates glucagon secretion in an SGLT2-independent manner in murine alpha cells

AIM

SGLT2 inhibitors reduce renal glucose uptake through an insulin-independent mechanism. They also increase glucagon concentration, although the extent to which this is due to a direct effect on pancreatic alpha cells remains unclear.

METHODS

In the present work, αTC1 cells treated with the SGLT2 inhibitor dapagliflozin (Dapa) were analyzed for glucose transporters, molecular mediators of hormone secretion, glucagon and GLP-1 release, and the effects of somatostatin. Data were validated in murine and human pancreatic islets.

RESULTS

SLC5A2 (the SGLT2-encoding gene) was nearly undetectable in αTC1 cells, not even by a digital PCR technique using different probes. In contrast, SLC5A1 (the SGLT1-encoding gene) was constitutively abundant in αTC1 cells and in islets, and increased with Dapa. This was associated with greater glucagon release, preceded by increased expression of preproglucagon and HNF4α. Looking at the candidate intracellular signalling pathway, reduced PASK and increased AMPK-α2 expression were also detected. GLUT1 and GLUT2, as well as regulators of glucagon release and alpha-cell phenotype (chromogranin A, paired box 6, proprotein convertase 1/2, synaptophysin), were unaffected by Dapa, as were GLP-1 receptor expression and GLP-1 release. Low glucose did not influence the stimulatory effect of Dapa on glucagon release, but was instead almost fully reverted by SLC5A1 silencing. When the effect of Dapa on AMPK and PASK, emerging regulators of lipid and glucose metabolism, was tested, upregulated AMPK-α2 appeared to be involved in molecular signalling.

CONCLUSION

Our study has shown that, in αTC1 cells, Dapa acutely upregulates SGLT1 expression and increases glucagon release through an SGLT1-dependent mechanism, with SGLT2 expression virtually undetectable. These results suggest the involvement of SGLT1 in modulating glucagon increases following SGLT2 inhibition.

La nucleoaspirazione secondo Onik nel trattamento dell'ernia discale lombare analisi multicentrica dei primi risultati su oltre 650 trattamenti

Gli autori espongono i risultati ottenuti applicando la nucleotomia percutanea secondo Onik al trattamento dell'ernia discale lombare. Le casistiche sommate complessivamente ammontano a oltre 600 pazienti. Nel complesso i risultati sono buoni o ottimi nel 72% circa dei casi. I risultati insoddisfacenti, considerando globalmente i modest e gli invariati, corrispondonoal 26% circa. Eccezionali le complicanze (meno dell' 1 %): 1 discite (risolta con intervento chirurgico). La metodica di Onik può già essere serenamente considerata una possibilitanon trascurabile nel campo vasto e variegato dei trattamentidisponibili per l'ernia discale lombare

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-1β 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.

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.

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.

Predictive value of dynamic renal resistive index (DRIN) for renal outcome in type 2 diabetes and essential hypertension: a prospective study

BACKGROUND

Hypertension (EH) and type 2 diabetes (T2DM) are major causes of chronic kidney disease (CKD) and identification of predictors of CKD onset is advisable. We aimed to assess whether dynamic renal resistive index (DRIN), as well as other markers of systemic vascular damage, are able to predict albuminuria onset and estimated glomerular filtration rate (eGFR) decline in patients with T2DM or EH.

METHODS

In this prospective observational cohort study, 27 T2DM and 43 EH patients, free of CKD at baseline, were followed-up for 4.1 ± 0.6 years. Resistive Index (RI), endothelium-dependent (FMD) and independent vasodilation in the brachial artery (after glyceryl trinitrate - GTN - 25 μg s.l.), carotid-femoral Pulse Wave Velocity (PWV), Augmentation Index (AIx), DRIN (%RI change after GTN 25 μg s.l.) were evaluated.

RESULTS

Patients developing microalbuminuria were older, more frequently T2DM, with higher UACR at baseline, and showed higher DRIN (-2.8 ± 6.7 vs -10.6 ± 6.4 %, p = 0.01) and PWV (9.9 ± 1.3 vs 7.9 ± 1.5 m/s, p = 0.004) at baseline. The best predictors of microalbuminuria onset were DRIN > -5.16 % in T2DM (sensitivity 0.83, specificity 0.80) and PWV > 8.6 m/s in EH (sensitivity 0.96, specificity 1.00). Individuals whose eGFR declined (n = 27) had higher eGFR at baseline, but similar vascular characteristics; however in EH showing eGFR decline, baseline DRIN and PWV were higher. PWV showed a steeper progression during follow-up in patients developing albuminuria (Visit-outcome interaction: p = 0.01), while DRIN was early compromised but no further impaired (Visit-outcome interaction: p = 0.04).

CONCLUSIONS

PWV and DRIN are able to predict microalbuminuria onset in newly diagnosed EH and T2DM. DRIN is early compromised in T2DM patients developing microalbuminuria.

Chronic kidney disease in type 2 diabetes: lessons from the Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicentre Study

The Renal Insufficiency And Cardiovascular Events (RIACE) Italian Multicentre Study is an ongoing observational survey that examines the role of estimated glomerular filtration rate (eGFR) as an independent predictor of cardiovascular and renal outcomes in 15,773 Italian subjects with type 2 diabetes. The analysis of data collected at the enrollment visit provided a picture of chronic kidney disease (CKD) and its association with other complications, risk factors for cardiovascular disease (CVD) and treatments in a large contemporary cohort. Main results of this analysis were that (a) non-albuminuric renal impairment is the predominant clinical phenotype in patients, particularly women, with reduced eGFR; (b) concordance between CKD and diabetic retinopathy is low, with only a minority of patients with renal dysfunction presenting with any or advanced retinal lesions; (c) the non-albuminuric form is associated with a significant prevalence of CVD, especially at the level of the coronary vascular bed; (d) CKD is associated with hemoglobin (Hb) A1c variability more than with average HbA1c, whereas retinopathy and CVD are not; (e) in elderly individuals with moderate-to-severe eGFR reduction, use of agents which are not recommended, such as sulphonylureas and metformin, is still frequent; and (f) though complications are generally more prevalent in men (except non-albuminuric renal impairment) women show a less favorable CVD risk profile and achieve therapeutic targets to a lesser extent than men, despite the fact that treatment intensity is not lower. These data update existing information on the natural history of CKD in patients with type 2 diabetes.

Impact of mild to moderate reductions of glomerular filtration rate on coronary artery disease severity

BACKGROUND & AIMS

The bases of the link between reduced glomerular filtration rate (GFR) and coronary artery disease (CAD) are complex and to some extent still unclear. We performed this observational, single referral center, cohort study to evaluate whether mild to moderate GFR reduction is associated with more severe CAD and/or with a worse cardiac prognosis independently of proteinuria, diabetes and traditional risk factors.

METHODS AND RESULTS

In 1752 consecutive non-diabetic patients without proteinuria or moderate/severe kidney disease undergoing a clinically driven coronary angiography, coronary arteries lesions, myocardial function and hypertrophy and 10-yrs incidence of cardiac events and death were evaluated in relation to classes of estimated GFR defined according the lowest eGFR value (105+, 90+, 75+, 60+, 45+). A reduced eGFR was independently associated with hypertension, myocardial hypertrophy and stress induced ischemia, while the excess coronary lesions and the worse myocardial systolic function were both largely explained by age and cardiovascular risk factors. When compared to subjects 75+, both the risk of cardiac death (1.67[1.10-2.57] and 3.06[1.85-5.10]) and non-fatal myocardial infarction (2.58[1.12-6.49] and 2.73[1.31-6.41]) adjusted for age and comorbidities were higher in eGFR 60+ and 45+ patients.

CONCLUSIONS

A mild-moderate reduction of eGFR is closely associated to higher rates of stress-induced ischemia, myocardial hypertrophy and higher risk of fatal and non-fatal cardiac events. The associations of reduced eGFR with coronary atherosclerosis and myocardial systolic dysfunction are both largely explained by age and traditional risk factors.

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.

The P2X7 receptor-inflammasome complex has a role in modulating the inflammatory response in primary Sjögren's syndrome

OBJECTIVE

Innate and adaptive immunity may contribute to gland dysfunction in patients with primary Sjögren's syndrome (pSS). The P2X7 receptor (P2X7 R)-NLRP3 inflammasome complex modulates the release of the inflammatory cytokines IL-1β and IL-18. The presence of P2X7 R in salivary glands suggests an interesting scenario for the initiation and amplification of the innate immune response in pSS. Therefore, the aim of this study was to assess the role of the P2X7 R-NLRP3 inflammasome in pSS.

SUBJECTS AND METHODS

Twenty-one consecutive patients with pSS according to the American-European Consensus Group criteria and 15 patients with sicca syndrome (i.e. without Sjögren's syndrome, non-SS) were enrolled in this study, together with six control (CTL) subjects. Expression of the P2X7R-NLRP3 platform and IL-18 was determined by real-time PCR and western blotting in gland specimens and peripheral lymphomonocytes; data were related to patients\x92 clinical, serological and histopathological characteristics. The presence of IL-18 was determined in gland and saliva samples.

RESULTS

P2X7 R expression was significantly higher in salivary glands from individuals with pSS than in those from non-SS and CTL subjects. Accordingly, the gene expression levels of the inflammasome components NLRP3, ASC and caspase-1 were significantly higher in pSS gland specimens, and this was paralleled by an increased expression of mature IL-18 in pSS saliva samples. The expression of both the P2X7 R and the inflammasome components was a marker of disease-related glandular involvement, being increased in patients with anti-Ro/SSA positivity and correlated with focus score.

CONCLUSION

The results of this study suggest an involvement of the P2X7 R-inflammasome-caspase-1-IL-18 axis in the development of pSS exocrinopathy. This finding provides the basis for studying the complex mechanisms underlying pSS, as well as for developing novel potential therapeutic strategies.

Gender differences in cardiovascular disease risk factors, treatments and complications in patients with type 2 diabetes: the RIACE Italian multicentre study

OBJECTIVES

Poorer control of risk factors for cardiovascular disease (CVD) has been reported in diabetic women, as compared with diabetic men. It has been proposed that this finding is due to gender disparities in treatment intensity. We investigated this hypothesis in a large contemporary cohort of subjects with type 2 diabetes.

DESIGN

Observational, cross-sectional study.

SUBJECTS AND SETTING

Consecutive patients with type 2 diabetes from the Renal Insufficiency And Cardiovascular Events (RIACE) Italian multicentre study (n = 15 773), attending 19 hospital-based diabetes clinics in 2007-2008.

MAIN OUTCOME MEASURES

Traditional CVD risk factors, macro- and microvascular complications and current glucose-, lipid- and blood pressure (BP)-lowering treatments were assessed.

RESULTS

Although CVD was more prevalent in men, women showed a less favourable CVD risk profile and worse performance in achieving treatment targets for haemoglobin A1c , LDL, HDL and non-HDL cholesterol, systolic blood pressure (BP) and in particular obesity [body mass index (BMI) and waist circumference], but not for triglycerides and diastolic BP. However, women were more frequently receiving pharmacological treatment for hypertension and to a lesser extent hyperglycaemia and dyslipidaemia than men, and female gender remained an independent predictor of unmet therapeutic targets after adjustment for confounders such as treatments, BMI, duration of diabetes and, except for the systolic BP goal, age.

CONCLUSIONS

In women with type 2 diabetes from the RIACE cohort, a more adverse CVD risk profile and a higher likelihood of failing treatment targets, compared with men, were not associated with treatment differences. This suggests that factors other than gender disparities in treatment intensity are responsible.

Dynamic evaluation of renal resistive index in normoalbuminuric patients with newly diagnosed hypertension or type 2 diabetes

AIM/HYPOTHESIS

Renal resistive index is a useful measure for quantifying alterations in renal blood flow. In the present study we evaluated resistive index at baseline and after vasodilation induced by nitroglycerine in normoalbuminuric patients with type 2 diabetes or essential hypertension, relating the values to indices of systemic vascular dysfunction.

METHODS

Newly diagnosed treatment-naïve type 2 diabetic (n = 32) and hypertensive patients (n = 49) were compared with 27 age- and sex-matched healthy controls. Renal resistive index was obtained by duplex ultrasound at baseline and after 25 μg sublingual nitroglycerine. Endothelium-dependent (flow-mediated dilation) and -independent (response to nitroglycerine) vasodilation in the brachial artery was assessed by computerised edge detection system. Carotid-femoral pulse-wave velocity and augmentation index were assessed by applanation tonometry. Nitrotyrosine levels, an index of oxidative stress, were also measured.

RESULTS

Resistive index was higher in diabetic than in hypertensive patients and controls (p < 0.001), while changes in resistive index induced by nitroglycerine were lower in hypertensive patients compared with controls (p < 0.01), and were further reduced in type 2 diabetic patients. Hypertensive and diabetic patients showed significantly increased arterial stiffness, nitrotyrosine levels and reduced endothelial function than controls (p < 0.05). Changes in resistive index induced by nitroglycerine were independently related to serum glucose, reactive hyperaemia and aortic pulse-wave velocity in the overall population.

CONCLUSIONS/INTERPRETATION

These results support the dynamic evaluation of renal resistive index as an early detector of renal vascular alterations in the presence of type 2 diabetes and hypertension, even before the onset of microalbuminuria.

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.

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 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.

High glucose and homocysteine synergistically affect the metalloproteinases-tissue inhibitors of metalloproteinases pattern, but not TGFB expression, in human fibroblasts

AIMS/HYPOTHESIS

Atherosclerosis is particularly aggressive in patients with diabetes. Hyperhomocysteinaemia causes oxidative stress and cytokine secretion: its atherogenic effect is mediated by an enhanced inflammatory response. Matrix metalloproteinases (MMPs) regulate extracellular matrix degradation and remodelling, and contribute to the vulnerability of the atherosclerotic lesion. Fibroblasts contribute to collagen biosynthesis and participate in plaque remodelling via expression and release of MMP2 and MMP9. To explore the role of hyperhomocysteinaemia in cellular pathways involved in plaque growth and stability in diabetic patients, we studied the effect of hyperhomocysteinaemia in human fibroblasts grown in the presence of normal or high glucose concentrations.

MATERIALS AND METHODS

In fibroblasts of five normal subjects, grown at 5.5 or 22 mmol/l glucose and treated with homocysteine, we determined: (1) MMP2, MMP9 and tissue inhibitor of metalloproteinases (TIMP)-1 (an MMP inhibitor) production by western blot analysis; (2) their activity by zymography; (3) TGFB1 expression by real-time PCR; and (4) TGFB, fibronectin and IL6 release by ELISA.

RESULTS

Hyperhomocysteinaemia increased the production and enzymatic activity of MMP2 and MMP9, the effect being more pronounced in high glucose. Conversely, TIMP1 production was reduced by hyperhomocysteinaemia in both conditions, especially in high glucose. Hyperhomocysteinaemia also stimulated IL6 release, at least in part through nuclear factor-kappaB activation. TGFB1 expression was not affected by hyperhomocysteinaemia either in normal or in high glucose.

CONCLUSIONS/INTERPRETATION

Homocysteine upregulates the MMP-TIMP pathway and IL6 release, the effect being stronger in the presence of high glucose. These actions of homocysteine may contribute to the increased atherogenesis observed in diabetic patients with poor metabolic control.

Acute vascular events and electrolytes variations in elderly patients

Alterations in electrolyte balance have been claimed to play a role in the pathophysiology of coronary heart disease; however, the relationship between the electrolyte pattern and other clinical variables immediately after an acute vascular event is unclear. The aim of the present study was to test whether electrolyte and microelement changes characterize the acute phase in patients with different degrees of glucose tolerance admitted to the hospital shortly after an acute cardiovascular or cerebrovascular ischemic event. Two hundred consecutive patients with either myocardial infarction or stroke (SP group), stratified by degree of glucose tolerance, were studied within six hours of admission, and compared against 125 patients admitted for conditions other than acute vascular ischemia (CP). Routine laboratory parameters and serum Na, K, Cl, Mg and Ca concentrations were determined in all patients and compared to those recorded within six months before the admission. Relative to CP and independently of confounding factors including glucose tolerance status, the SP group showed significantly higher plasma glucose and insulin concentrations, higher creatinine and a modified serum electrolyte pattern characterized by significantly lower potassium and magnesium levels and by hypercalcemia and hyperphosphatemia. Irrespective of glucose tolerance, the first hours following an acute vascular event are characterized by marked insulin resistance with a consistent shift in the serum electrolyte pattern. This pattern is the physiological consequence of the attendant compensatory hyperinsulinemia. Its significance for the evolution of ischemic damage remains to be established.

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.

Lipoprotein lipase gene variants and progression of nephropathy in hypercholesterolaemic patients with type 2 diabetes

OBJECTIVE

Recent prospective studies have identified hyperlipidaemia as an independent determinant of diabetic nephropathy. Lipoprotein lipase (LPL) is a key enzyme in the postprandial processing of triglycerides and VLDL. Among a number of common sequence variants of the LPL, HindIII has been associated with coronary heart disease and, more recently, with microalbuminuria in type 2 diabetes. We evaluated the progression of renal disease in hypercholesterolaemic type 2 diabetic patients in relation to this polymorphism.

DESIGN AND SUBJECTS

We followed up for 4 years 65 consecutively enrolled microalbuminuric patients with type 2 diabetes; of whom 28 had hypercholesterolaemia (6.62 +/- 0.9 mmol L(-1), group A) and 37 were normocholesterolaemic (4.68 +/- 0.5 mmol L(-1), group B).

MAIN OUTCOME MEASURES

After performing the genetic analyses, albumin excretion rate (AER) and estimated glomerular filtration rate (GFR), calculated by the simplified equation of the MDRD Study Group, were repeated every year.

RESULTS

In group A, AER increased more (deltaAER: 11 [38] vs. 4 [18] microg min(-1) per year in group B, P < 0.0001) while GFR declined faster (-3.5 +/- 2.1 vs. -2.0 +/- 1.4 mL min(-1) per year, P < 0.02). Patients homozygous for the allele + of HindIII showed a significantly faster decline of GFR and a higher increase of AER (both P = 0.0001) even after adjustment for cholesterol levels and anthropometric variables.

CONCLUSIONS

In hypercholesterolaemic type 2 diabetic patients with microalbuminuria, the renal disease has an accelerated course, particularly in those carrying the H+/H+ genotype of the HindIII polymorphism at the LPL locus.

Effect of metabolic control on homocysteine levels in type 2 diabetic patients: a 3-year follow-up

OBJECTIVES

Hyperhomocysteinaemia has emerged as a novel risk factor for cardiovascular disease. The determinants of total homocysteine (tHcy) levels in type 2 diabetic patients (D2p) have not been studied in detail. We examined prospectively the effect of different degrees of metabolic control on plasma tHcy in D2p with preserved kidney function. SUBJECTS AND MAIN OUTCOME MEASUREMENTS: Ninety-five D2p were studied. Clinical parameters, fasting plasma glucose, HbA1c, serum lipids, blood urea nitrogen (BUN) and creatinine, vitamin B12 and folate and tHcy were measured at the baseline and after 36 months. The methylentetrahydrofolate reductase (MTHFR) C677T polymorphism was also determined. Subjects were categorized according to deltaHbA1c into group A (+/-1 point), B (>1 point increase) or C (>1 point decrease).

RESULTS

Total homocysteine was reduced in subjects whose HbA1c decreased with time, whilst patients showing a worsened metabolic control had an increased tHcy in respect to baseline. A larger response to the improved metabolic control in terms of tHcy reduction was noted in wild type patients versus those homozygous for the mutation. A multivariate analysis revealed MTHFR polymorphism and HbA1c as strong determinants of changes in tHcy with time.

CONCLUSIONS

The findings suggest that in D2p tHcy decreases even with modest improvement of glycaemic control; moreover patients homozygous for the MTHFR C677T mutation show the largest changes in tHcy levels with concomitant changing of HbA1c. These results define a further mechanism through which hyperglycaemia might promote cardiovascular damage in diabetic patients.

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.

Atorvastatin improves metabolic control and endothelial function in type 2 diabetic patients: a placebo-controlled study

Several pieces of evidence support a role of inflammatory processes in the pathogenesis of atherosclerosis; it is also known that endothelial dysfunction is the initial lesion of the atherosclerotic process. Among other markers of endothelial dysfunction, some adhesion molecules seem to play an interesting role. The aim of the present study was to evaluate the effect of atorvastatin vs placebo on some indexes of leukocytes adhesion in a group of Type 2 diabetic patients. Twenty-five Type 2 diabetic patients free from microangiopathic complications and with LDL-cholesterol lower than 180 mg/dl were randomized to receive either atorvastatin (T2DA) or placebo (T2Dp) for twelve months. BMI, fasting plasma glucose, glycated hemoglobin (HbA1c), albumin excretion rate (AER), lipid profile, and serum concentrations of vascular cell adhesion molecule-1 (VCAM1), E-selectin and cadherin-5 were measured at baseline and at the end of the follow-up. At T0 E-selectin was 16 +/- 6 ng/ml in T2DA and 17 +/- 13 in T2Dp; VCAM1 was 413 +/- 112 ng/ml in T2DA and 411 +/- 112 in T2Dp. At T12 VCAM1 and E-selectin did not vary in T2Dp, while a significant reduction was observed in T2DA (VCAM1 275 +/- 104 ng/ml and E-selectin 8 +/- 3 ng/ml; p < 0.001 and p < 0.01, respectively). T2DA also showed a reduction of total and LDL cholesterol and an improved glycemic control respect to T2Dp. Hypolipidemic therapy was the strongest independent predictor of the cytokines variations along the time. These results confirm the role of statins in modulating endothelial function also in Type 2 diabetes, outlining a therapeutic role of these molecules probably independent from the hypolipidemic effect.

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.

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.

ACE genotype and endothelium-dependent vasodilation of conduit arteries and forearm microcirculation in humans

The ACE gene is a candidate gene for cardiovascular disease. Endothelial dysfunction is considered an intermediate phenotype in the pathogenesis of hypertension and atherosclerosis. We evaluated the role of ACE gene polymorphism in endothelial function of young healthy humans. We assessed ACE genotype (deletion [D]/insertion [I] polymorphism) in 92 young healthy individuals. In 88 of them, endothelium-dependent (flow-mediated) vasodilation and endothelium-independent (nitroglycerin-induced) vasodilation were measured in the common femoral artery and in the brachial (n=84) artery by echo Doppler technique. In 35 subjects, we also applied the forearm perfusion technique to quantify the responses of the forearm vascular bed to 3 increasing doses of 2 endothelium-dependent vasodilators (acetylcholine and bradykinin) and 1 endothelium-independent vasodilator (sodium nitroprusside). The D allele of the ACE gene was associated with a significant blunting (Delta approximately 26%) of endothelium-dependent vasodilation in the femoral artery (P=0.02) but not in the brachial artery (P=0.55) or in the forearm microcirculation (P=0.70 to 0.80). Endothelium-independent vasodilation was unaffected by the ACE genotype. In young healthy humans, the D allele of the ACE gene is associated with selective endothelial dysfunction of the femoral artery. It remains to be determined whether this association discloses a causal role in vascular, particularly peripheral artery, disease.

Plasma homocysteine, methylenetetrahydrofolate reductase mutation and carotid damage in elderly healthy women

Plasma homocysteine (Hcy) is an independent vascular risk factor. Its remethylation to methionine is regulated by the activity of the enzyme 5,10-methylene tetrahydrofolate reductase (MTHFR). A C-to-T substitution at nucleotide 677 of the MTHFR gene is frequently associated to hyperhomocysteinemia. In this study, we evaluated the relationship among MTHFR C677T polymorphism, Hcy and some ultrasonographic parameters at the level of carotid arteries in 120 elderly women with normal ECG, normal blood pressure values, total cholesterol <250 mg/dl, normal glucose tolerance, normal albumin excretion rate. In all subjects, we measured Hcy by HPLC, MTHFR mutation by polymerase chain reaction followed by HinfI digestion and intima-media thickness (IMT), peak velocity of the systolic flow (SP(V)), end-diastolic velocity (ED(V)) and resistance and pulsatility indexes of intracranial circulation (RI and PI) by ultrasound imaging. Twenty-eight women were homozygotes for the wild type allele (Ala/Ala), 72 were heterozygotes (Ala/Val) and 20 were homozygotes for the mutation (Val/Val). Groups were comparable for age, blood pressure values and plasma lipid levels. Hcy was higher in Val/Val group; moreover, after adjustment for confounding factors, Val/Val had significantly greater IMT and ED(V) (P<0.001 and P<0.05, respectively). Logistic analysis revealed that Val/Val genotype was the strongest risk factor for IMT (OR 30.8, 95% CI 2.82-335.6). Our results show that, in elderly healthy women, Val/Val homozygosity for C677T mutation in MTHFR gene could identify subjects at risk for asymptomatic carotid atherosclerotic impairment.

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.

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.

The relationship of plasma glucose and electrocardiographic parameters in elderly women with different degrees of glucose tolerance

Plasma glucose has been regarded as a risk factor for macrovascular complications in diabetes, but less is known about its role in the development of cardiac impairment other than coronary heart disease (CHD). The aim of our study was to determine the relationship between basal and post-OGTT (Oral Glucose Tolerance Test) plasma glucose levels and some ECG parameters in a group of elderly women with normal or impaired glucose tolerance (IGT). One-hundred and one women with normal fasting glucose (<6.0 mmol/L) and no familial history or clinical signs of CHD and diabetes underwent an OGTT and a resting ECG. Based on the degree of glucose tolerance, we identified 24 women with a diagnostic OGTT for either IGT or diabetes; the 77 women (age range 52-88 years) with normal glucose tolerance were further divided into two groups according to their post-OGTT area under the curve (AUCG): below and above the median value (32 and 45 women, respectively). Basal plasma glucose and insulin levels, as well as lipid profile and percent of hypertensive patients were similar in the three groups. Mean corrected QT (QTc) was prolonged as a function of progressive worsening of glucose tolerance even after adjustment for possible confounding factors (p=0.03). A similar relationship was apparent when post-OGTT plasma glucose peak (GP) was considered. In a multiple regression analysis, AUCG and GP were the only factors independently related to both QTc and Sokolow index. Our observations suggest that, even in the presence of a normal glucose tolerance, plasma glucose concentrations during an OGTT are associated with peculiar ECG signs potentially combined with an increased risk of sudden death, arrhythmias, or cardiovascular mortality.

The surgical treatment of thoracic and lumbar fractures by posterior approach

A review of large case series, biomechanical studies and the development of surgical approaches and various types of instrumentation have led to different orientations in the surgical treatment of vertebral fractures. The authors present their experience in 67 cases treated by posterior approach using segmental fixation for the instability of the lesion and the possible association of neurologic deficit (Magerl A in 35 cases, B in 25, C in 7; Frankel A in 21 cases, B in 15, C in 9, D in 6). At a mean follow-up of 3 years, treatment by posterior approach allowed us to suitably treat most of the vertebral fractures observed with clinically satisfactory results, but without observing a definite correlation between neurologic recovery and quality of the reduction. The overall realignment of the spine with extension synthesis and adequate geometry and the development of good bone callus allowed us to obtained a stable spine, protecting consolidation of the fractured metamere.

Polymorphisms of angiotensin-converting enzyme and angiotensinogen genes in type 2 diabetic sibships in relation to albumin excretion rate

Familial clustering of altered albumin excretion and nephropathy risk has been described in both type 1 and type 2 diabetes; moreover, an association of micro-macroalbuminuria and diabetic retinopathy has been recently reported in a large number of white families with type 2 diabetes. Conflicting reports, mainly comparing affected with unaffected unrelated subjects, have suggested a possible role of some genotypes of the renin-angiotensin system in conferring nephropathy risk in type 2 diabetes. To examine the role of genetic factors in influencing albuminuria in families, we studied the relation of angiotensin-converting enzymes (ACE) and angiotensinogen (AGN) genotypes with albumin excretion rate in a population of affected siblings of type 2 diabetic probands. We determined ACE insertion/deletion polymorphism and two polymorphisms of the AGN gene (T174M and M235T) in 160 families with at least one affected member. Defining proband as the patient with the longest known duration of diabetes, we compared the allelic distribution in diabetic probands with and without altered albumin excretion and in their siblings. Allelic distribution of these polymorphisms was similar in the two groups of probands, as well as in their siblings. Identity-by-State (IBS) analysis showed a link between AGN locus and arterial hypertension in these siblings, which was independent from the degree of renal involvement. Thus, our findings suggest that in white families with type 2 diabetes, there is no linkage between the degree of albumin excretion and ACE and AGN polymorphisms, whereas the latter is related to arterial hypertension, as previously found in patients without diabetes but with essential hypertension.

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.

Elevated PC-1 content in cultured skin fibroblasts correlates with decreased in vivo and in vitro insulin action in nondiabetic subjects: evidence that PC-1 may be an intrinsic factor in impaired insulin receptor signaling

Membrane glycoprotein PC-1 inhibits insulin receptor (IR) tyrosine kinase activity and subsequent cellular signaling. PC-1 content is elevated in muscle and adipose tissue from insulin-resistant subjects, and its elevation correlates with in vivo insulin resistance. To determine whether elevated PC-1 content is a primary cause of insulin resistance, we have now measured PC-1 content in cultured skin fibroblasts from nonobese nondiabetic insulin-resistant subjects and found that 1) PC-1 content was significantly higher in these cells when compared with cells from insulin-sensitive subjects (6.7 +/- 0.9 vs. 3.1 +/- 0.6 ng/0.1 mg protein, mean +/- SE, P < 0.01); 2) PC-1 content in fibroblasts was highly correlated with PC-1 content in muscle tissue (r = 0.95, P = 0.01); 3) PC-1 content in fibroblasts negatively correlated with both decreased in vivo insulin sensitivity and decreased in vitro IR autophosphorylation; and 4) in cells from insulin-resistant subjects, insulin stimulation of glycogen synthetase was decreased. These studies indicate, therefore, that the elevation of PC-1 content may be a primary factor in the cause of insulin resistance.

The surgical treatment of cervical metastases

Vertebral instability and the neuroaggressiveness produced by the occurrence of cervical metastasis in a neoplastic patient during remission or quiescence of the disease is rare, but it may negatively influence the prognosis of the patient and drastically reduce his or her life expectancy. The authors describe their experience with conservative or surgical treatment in 151 patients affected with cervical metastases.

Giant cell tumor of the spine. Surgical findings

The authors report 5 cases of giant cell tumor surgically treated. After a mean follow-up of 7 years posterior stabilization alone in the latent form, and wide intralesional curettage in the four aggressive forms allowed for suitable treatment of the lesion, with remission of symptoms leaving stability of the spine intact. Radiation therapy was used successfully in only 1 case of local recurrence occurring 4 months after surgical treatment. Unlike localizations of giant cell tumor in other skeletal segments, whether or not margins are left intact does not seem to influence clinical results.

Derangements in protein metabolism induced by type I diabetes mellitus

In poorly controlled diabetics, the whole-body protein flux is increased by 20-30% in comparison to well-controlled type I diabetes (IDDM) and normal subjects. Intensive insulin administration completely reverses these abnormalities. In poorly controlled IDDM, the primary effect of insulin administration is to reduce the increased protein catabolic rate by suppressing the accelerated rate of protein breakdown. Studies in humans have demonstrated that the increased rate of protein synthesis observed in these patients is the consequence of elevated plasma amino acid levels. When IDDM subjects develop renal complications, a protein-restricted diet may be recommended to preserve the remnant kidney function. However, it has been demonstrated that in IDDM patients, metabolic adaptation to protein restriction is incomplete because suppression of endogenous proteolysis is impaired. Since this component of protein metabolism is very sensitive to insulin action, maintaining strict metabolic control during the protein restriction regimen has been suggested. The major studies on the effects of amino acid and insulin on protein metabolism in patients with diabetes mellitus are reviewed.