Oxidative Stress and Left Ventricular Performance in Patients with Different Glycometabolic Phenotypes

International Diabetes Federation Position Statement on the 1-hour post-load plasma glucose for the diagnosis of intermediate hyperglycaemia and type 2 diabetes

Many individuals with intermediate hyperglycaemia (IH), including impaired fasting glycaemia (IFG) and impaired glucose tolerance (IGT), as presently defined, will progress to type 2 diabetes (T2D). There is confirmatory evidence that T2D can be prevented by lifestyle modification and/or medications, in people with IGT diagnosed by 2-h plasma glucose (PG) during a 75-gram oral glucose tolerance test (OGTT). Over the last 40 years, a wealth of epidemiological data has confirmed the superior value of 1-h plasma glucose (PG) over fasting PG (FPG), glycated haemoglobin (HbA1c) and 2-h PG in populations of different ethnicity, sex and age in predicting diabetes and associated complications including death. Given the relentlessly rising prevalence of diabetes, a more sensitive, practical method is needed to detect people with IH and T2D for early prevention or treatment in the often lengthy trajectory to T2D and its complications. The International Diabetes Federation (IDF) Position Statement reviews findings that the 1-h post-load PG ≥ 155 mg/dL (8.6 mmol/L) in people with normal glucose tolerance (NGT) during an OGTT is highly predictive for detecting progression to T2D, micro- and macrovascular complications, obstructive sleep apnoea, cystic fibrosis-related diabetes mellitus, metabolic dysfunction-associated steatotic liver disease, and mortality in individuals with risk factors. The 1-h PG of 209 mg/dL (11.6 mmol/L) is also diagnostic of T2D. Importantly, the 1-h PG cut points for diagnosing IH and T2D can be detected earlier than the recommended 2-h PG thresholds. Taken together, the 1-h PG provides an opportunity to avoid misclassification of glycaemic status if FPG or HbA1c alone are used. The 1-h PG also allows early detection of high-risk people for intervention to prevent progression to T2D which will benefit the sizeable and growing population of individuals at increased risk of T2D. Using a 1-h OGTT, subsequent to screening with a non-laboratory diabetes risk tool, and intervening early will favourably impact the global diabetes epidemic. Health services should consider developing a policy for screening for IH based on local human and technical resources. People with a 1-h PG ≥ 155 mg/dL (8.6 mmol/L) are considered to have IH and should be prescribed lifestyle intervention and referred to a diabetes prevention program. People with a 1-h PG ≥ 209 mg/dL (11.6 mmol/L) are considered to have T2D and should have a repeat test to confirm the diagnosis of T2D and then referred for further evaluation and treatment. The substantive data presented in the Position Statement provides strong evidence for redefining current diagnostic criteria for IH and T2D by adding the 1-h PG.

Association between non-dipping blood pressure pattern and different glucometabolic profile during oral glucose tolerance test

It is known that, a not physiological blood pressure (BP) circadian pattern has been associated with increased risk of organ damage and cardiovascular (CV) event. The aim of this study was to assess the association between circadian BP pattern and glucometabolic phenotypes occurring after oral glucose tolerance test (OGTT). We recruited 810 hypertensive Caucasian patients. All participants underwent to OGTT, laboratory test and 24-h ambulatory BP monitoring (ABPM). The analysis of collected data allowed classifying patients based on nocturnal BP profiles into four categories: dippers, non-dippers, extreme dippers, and reverse dippers. Considering the dipping pattern, the proportion of non-dippers in normal glucose tolerance patients with 1-h glucose ≥ 155 mg/dL (NGT ≥ 155) (36.4%) was higher than NGT < 155 (29.6%) and impaired glucose tolerance (IGT) (34.8%), but lower than type 2 diabetes group (T2DM) (52.6%) (p = 0.001). The proportion of dippers was lower in NGT ≥ 155 (47%) and T2DM (34.6%), when compared with NGT < 155 (53.8%) and IGT (51.2%) (p = 0.017). From logistic regression analysis, 1-h glucose ≥ 155 increased the risk of a pathological nocturnal drop in BP by 74%, (OR = 1.740, 95% CI 1.254-2.415, p < 0.0001). In addition, the improvement in 1 unit of Matsuda was responsible for a 3.5% risk decrease (OR = 0.965, 95% CI 0.958-0.971, p < 0.0001), while e-GFR determined a 0.9% risk reduction of nocturnal BP drop (OR = 0.991, 95% CI 0.984-0.999, p = 0.020). Our data demonstrated the existence, in newly diagnosed hypertensive patients, of an association between circadian BP profile and altered glycemic response during OGTT, in particular NGT ≥ 155 subjects are associated with a non-dipper BP pattern, this is clinically relevant because may explain, at least in part, the increased CV risk in this setting of patients.

Effects of canagliflozin on cardiac remodeling and hemodynamic parameters in patients with type 2 diabetes mellitus

Sodium-glucose cotransporter type 2 (SGLT2) inhibitors have demonstrated to reduce cardiovascular risk in patients with type 2 diabetes mellitus (T2DM) in large trials independent of glycemic control. The mechanisms of this cardioprotective property remain uncertain. Evidence suggests positive hemodynamic changes and favorable cardiac remodeling contributing to the clinical outcomes but results were conflicting. We aim to investigate the potential impact on hemodynamic parameters, cardiac structure and functions. This prospective observational study included T2DM patients receiving canagliflozin 100 mg per day in addition to their antidiabetic treatment. We analyzed hemodynamic parameters assessed by echocardiographic measurements and impedance cardiography (ICG) to evaluate systolic and diastolic functions from baseline to 24 weeks after treatment. A total of 47 patients (25 males and 22 females) averaging 64.6 ± 10.9 years had a significant reduction in HbA1c, body weight, and systolic blood pressure. Hematocrit increased significantly, while NT-proBNP remained unchanged. E/e', left atrium (LA) volume, and LA stiffness were reduced, while left ventricle (LV) global longitudinal strain (GLS) and LA strain rates increased at 24 weeks by conventional and speckle tracking echocardiography. LV mass and ejection fraction showed no differences. ICG suggested significant improvement in hemodynamic parameters with increased stroke volume index and cardiac output index and decreased systemic vascular resistance index at 12 and 24 weeks. Canagliflozin improved hemodynamic parameters and had a favorable impact on LA and LV reverse remodeling. These changes may explain the beneficial effect on cardiovascular outcomes in large clinical trials.

Impacts of obesity on global subclinical left cardiac function represented by CMR-derived myocardial strain, TyG index may be a predictor

Obesity is a recognized risk factor for heart failure. People with similar weights may have different metabolic health. Notably, insulin resistance is a hallmark of obesity and a feature of heart failure. We aimed to evaluate the effects of obesity and metabolic health status on subclinical left cardiac function. We also investigated whether insulin resistance (TyG index) plays a role in BMI-linked subclinical left cardiac dysfunction. The study involved 403 volunteers. Hierarchical multiple regression models were used to assess associations between obesity, metabolic health, and overall subclinical left cardiac function. Mediating analysis was used to explore the role of the TyG index in the association between BMI and left cardiac function. Finally, ROC analysis was performed to explore the predictive value of the TyG index in subclinical left cardiac dysfunction. The correlation analysis showed that metabolic unhealth increased the risk of subclinical left ventricular (LV) dysfunction; obesity was associated with an increased risk of global left cardiac dysfunction regardless of metabolic health status. The TyG index mediated 25% of the associations between BMI and Left atrial (LA) functional parameters. ROC analysis exhibited that the TyG index can be used as a predictor of LA dysfunction (AUC = 0.63), and the optimal cut-off point for the TyG index is 9.33. Even a "non-obese metabolically unhealthy" is a detrimental state of early LV function; obesity remains a major risk factor for global subclinical left cardiac dysfunction. Using the TyG index could allow early identification of individuals at high risk of subclinical left cardiac dysfunction.Registration number: ChiCTR2200057991; Date of registration: 2022-03-25. URL: http://www.chictr.org.cn/showproj.aspx?proj=162316 .

One-hour post-load glucose and subclinical left atrial myocardial dysfunction in hypertensive patients

BACKGROUND

Recently, studies demonstrated that normal glucose-tolerant subjects (NGT) with 1-h post-load plasma glucose value ≥155 mg/dL during oral glucose tolerance test (OGTT) (NGT ≥ 155) present an impaired cardio-metabolic profile, with subclinical myocardial damage. Atrial morphological and functional alterations, closely related to diastolic dysfunction, are important predictors of atrial fibrillation (AF), cardiovascular (CV) events and mortality in the entire population as well as in diabetic patients. The aim of our study was to evaluate subclinical atrial myocardial damage, assessed with speckle tracking echocardiography, in NGT≥155 mg/dL patients, comparing to NGT < 155 mg/dL subjects, impaired glucose tolerant (IGT) individuals and patients with newly diagnosed type 2 diabetes (T2DM).

METHODS

We enrolled 229 Caucasian patients. All subjects underwent anthropometrical and haemodynamic parameters evaluation, OGTT, advanced Colour-Doppler echocardiography with evaluation of main atrial and ventricular parameters.

RESULTS

As expected, from first to the fourth group there was a worsening of the metabolic profile as attested by fasting, 1- and 2-h post-load plasma glucose levels, during OGTT. Moreover, from NGT < 155 to T2DM group there was an impairment in reservoir and pump atrial function (PALS and PACS, respectively) (p < .0001).

CONCLUSION

Present data demonstrated for the first time that NGT≥155 subjects present subclinical atrial dysfunction. These results may be clinically relevant because they highlight how atrial myopathy occurs early in pre-diabetes stage regardless of fibrotic and morphological alterations of the ventricular myocardium.

New potential biomarkers for early chronic kidney disease diagnosis in patients with different glucose tolerance status

Background

The purpose of the present study was to investigate the role of oxidative stress, platelet activation, and endocan levels in renal dysfunction in normal glucose tolerance (NGT) patients with 1-h plasma glucose values ≥155 mg/dl (NGT ≥ 155), compared to NGT < 155, impaired glucose tolerance (IGT), and type 2 diabetes mellitus (T2DM) newly diagnosed subjects. We enlisted 233 patients subjected to an oral glucose tolerance test (OGTT).

Materials and methods

The serum levels of platelet activation (glycoprotein VI and sP-selectin), oxidative stress biomarkers (8-isoprostane and Nox-2), and endocan were evaluated using an ELISA test.

Results

Among NGT < 155 patients and the T2DM group, there was a statistically significant increase in 8-isoprostane (p < 0.0001), Nox-2 (p < 0.0001), glycoprotein VI (p < 0.0001), and sP-selectin (p < 0.0001) serum levels. Higher serum endocan levels were found with the worsening of metabolic profile (p < 0.0001); specifically, NGT ≥ 155 patients presented higher serum endocan values when compared to NGT < 155 patients (p < 0.0001). From the multivariate linear regression analysis, 1-h glucose resulted in the major predictor of estimated glomerular filtration rate (e-GFR) justifying 23.6% of its variation (p < 0.0001); 8-isoprostane and Nox-2 added respectively another 6.0% (p < 0.0001) and 3.2% (p = 0.001).

Conclusion

Our study confirmed the link between 1-h post-load glucose ≥155 mg/dl during OGTT and the possible increased risk for chronic kidney disease (CKD) in newly diagnosed patients. The novelty is that we demonstrated a progressive increase in oxidative stress, platelet activation, and serum endocan levels with the worsening of metabolic profile, which becomes evident early during the progression of CKD.

Effects of continuous positive airway pressure on comprehensive geriatric assessment and cognitive function in elderly patients with obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) can lead to cognitive impairment and depression affecting memory, attention, and executive functions. Continuous positive airway pressure (CPAP) treatment seems to be able to revert changes in brain networks and neuropsychological tests correlated to OSAS. The aim of the present study was to evaluate the effects of a 6-month treatment with CPAP on functional, humoral and cognitive parameters in a cohort of elderly OSAS patients with several comorbidities. We enrolled 360 elderly patients suffering from moderate to severe OSAS and indication for nocturnal CPAP. At baseline the Comprehensive Geriatric Assessment (CGA) revealed a borderline Mini-Mental State Examination (MMSE) score that improved after 6-month treatment with CPAP (25.3 ± 1.6 vs 26 ± 1.5; p < 0.0001), as well as the Montreal Cognitive Assessment (MoCA) showed a mild improvement (24.4 ± 2.3 vs 26.2 ± 1.7; p < 0.0001). Moreover, functionality activities increased after treatment, as documented by a short physical performance battery (SPPB) (6.3 ± 1.5 vs 6.9 ± 1.4; p < 0.0001). Reduction of the Geriatric Depression Scale (GDS) from 6.0 ± 2.5 to 4.6 ± 2.2 (p < 0.0001) was also detected. Changes of homeostasis model assessment (HOMA) index, oxygen desaturation index (ODI), sleep-time spent with saturation below 90% (TC90), peripheral arterial oxyhaemoglobin saturation (SpO2), apnea-hypopnea index (AHI) and estimation of glomerular filtration rate (eGFR), contributed, respectively, to 27.9%, 9.0%, 2.8%, 2.3%, 1.7% and 0.9% of MMSE variability for a total of 44.6% of MMSE variations. GDS score changes were due to the improvement of AHI, ODI and TC90, respectively, for 19.2%, 4.9%, 4.2% of the GDS variability, cumulative responsible for 28.3% of GDS modifications. The present real-world study shows that CPAP treatment is able to improve cognition and depressive symptoms in OSAS elderly patients.

Short-term effect of sacubitril/valsartan on endothelial dysfunction and arterial stiffness in patients with chronic heart failure

Heart failure (HF) is associated to endothelial dysfunction that promotes the increase of arterial stiffness thus augmenting myocardial damage. Sacubitril/Valsartan is used in the treatment of HF reduced ejection fraction (HFrEF) and has been proven effective in reducing cardiovascular disease (CVD) progression and all-cause mortality. The aim of this study was to evaluate the effect of Sacubitril/Valsartan on endothelial dysfunction, arterial stiffness, oxidative stress levels and platelets activation in patients with HFrEF, at baseline and after 6 months of treatment. We enrolled 100 Caucasian patients. Endothelial function was evaluated by the reactive hyperemia index (RHI) and arterial stiffness (AS) by the measurement of carotid-femoral pulse wave velocity (PWV), augmentation pressure (AP) and augmentation index (AI). At baseline, among enrolled outpatients, 43% showed a NYHA class II and 57% a NYHA class III. At 6 months, there was a significant improvement of several hemodynamic, clinical and metabolic parameters with a significant reduction in oxidative stress indices such as 8-isoprostane (p < 0.0001) and Nox-2 (p < 0.0001), platelets activity biomarkers such as sP-selectin (p < 0.0001) and Glycoprotein-VI (p < 0.0001), and inflammatory indices. Moreover, we observed a significant improvement in arterial stiffness parameters and in endothelial function indices. Our study demonstrated that 6 months treatment with Sacubitril/Valsartan, in patients with HFrEF, improves endothelial dysfunction and arterial stiffness, by reducing oxidative stress, platelet activation and inflammation circulating biomarkers, without adverse effects.

Endothelial Dysfunction Is Associated with Decreased Nitric Oxide Bioavailability in Dysglycaemic Subjects and First-Degree Relatives of Type 2 Diabetic Patients

Oxidative stress plays an important role in the pathogenesis of diabetes. We investigated oxidative stress and nitrite/nitrate concentrations at baseline and during postprandial hyperglycaemia in 40 first-degree relatives (FDRs) of diabetic patients with normal oral glucose tolerance test (OGTT) results, 40 subjects with abnormal OGTT results (dysglycaemic) and 20 subjects with normal OGTT results (normoglycaemic). Malondialdehyde (MDA), protein carbonyls (PCs), nitrite/nitrate plasma levels, the perfused boundary region (PBR—Glycocheck) of the sublingual microvessels, a marker of glycocalyx integrity, coronary flow reserve (CFR) and left ventricular global longitudinal strain (GLS) were assessed at 0 and 120 min of the OGTT. Insulin sensitivity was evaluated using Matsuda and the insulin sensitivity index (ISI). In all subjects, there were no significant changes in MDA or PC after the OGTT (p > 0.05). Compared with normoglycaemic subjects, FDRs and dysglycaemic subjects had significantly decreased nitrite/nitrate levels (−3% vs. −24% vs. −30%, respectively), an increased PBR and reduced CFR and GLS at 120 min (p < 0.05). The percent reduction in nitrite/nitrate was associated with abnormal Matsuda and ISI results, reversely related with the percent increase in PBR (r = −0.60) and positively related with the percent decrease in CFR (r = 0.39) and GLS (r = 0.48) (p < 0.05). Insulin resistance is associated with reduced nitric oxide bioavailability and coronary and myocardial dysfunction in FDRs and dysglycaemic subjects.