One-hour postload plasma glucose levels and diastolic function in hypertensive patients

Investigation of crucial genes and mitochondrial function impairment in diabetic cardiomyopathy

BACKGROUND

Diabetic cardiomyopathy (DCM) is a special type of cardiovascular disease, termed as a situation of abnormal myocardial structure and function that occurs in diabetic patients. However, the most fundamental mechanisms of DCM have not been fully explicated, and useful targets for the therapeutic strategies still need to be explored.

METHODS

In the present study, we combined bioinformatics analysis and in vitro experiments throughout the process of DCM. Differentially Expressed Genes (DEGs) analysis was performed and the weighted gene co-expression network analysis (WGCNA) was constructed to determine the crucial genes that were tightly connected to DCM. Additionally, Functional enrichment analysis was conducted to define biological pathways. To identify the specific molecular mechanism, the human cardiomyocyte cell line (AC16) was stimulated by high glucose (HG, 50 mM D-glucose) and used to imitate DCM condition. Then, we tentatively examined the effect of high glucose on cardiomyocytes, the expression levels of crucial genes were further validated by in vitro experiments.

RESULTS

Generally, NPPA, IGFBP5, SERPINE1, and C3 emerged as potential therapeutic targets. Functional enrichment analysis performed by bioinformatics indicated that the pathogenesis of DCM is mainly related to heart muscle contraction and calcium (Ca2+) release activation. In vitro, we discovered that high glucose treatment induced cardiomyocyte injury and exacerbated mitochondrial dysfunction remarkably.

CONCLUSION

Our research defined four crucial genes, as well as determined that mitochondrial function impairment compromises calcium homeostasis ultimately resulting in contractile dysfunction is a central contributor to DCM progression. Hopefully, this study will offer more effective biomarkers for DCM diagnosis and treatment.

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.

Immuno-Mediated Inflammation in Hypertensive Patients with 1-h Post-Load Hyperglycemia

Inflammation plays a key role in the pathogenesis/progression of atherosclerosis, and inflammatory molecules contribute to the progression of cardiovascular disease. Subjects with normal post-load glucose tolerance and 1-h post-load plasma glucose >155 mg/dL have an increased risk of subclinical target organ damage and incident diabetes. We aimed to test possible differences in immune-mediated inflammatory parameters in newly-diagnosed hypertensives with or without 1-h post-load hyperglycemia. We enrolled 25 normotensives (NGT) and 50 hypertensives normotolerant on oral glucose tolerance test, further divided into two groups based on 1-h post-load plasma glucose: NGT 1-h ≥ 155 (n = 25) and NGT 1-h < 155 (n = 25). We measured toll-like receptor (TLR) 2, TLR4, nuclear factor kβ (NF-kβ), interleukin (IL)-1β, IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α. Hypertensives showed significantly worse metabolic and lipid profiles, and higher values of body mass ass index (BMI), creatinine, and inflammatory parameters, compared to controls. NGT 1-h ≥ 155 had a worse glycometabolic profile and higher values of TLR2 (9.4 ± 4.2 vs. 5.9 ± 2.6 MFI), TLR4 (13.1 ± 3.9 vs. 7.8 ± 2.3 MFI), NF-kβ (0.21 ± 0.07 vs. 0.14 ± 0.04), IL-1β (6.9 ± 3.4 vs. 3.2 ± 2.1 pg/mL), IL-6 (10.8 ± 2.6 vs. 4.1 ± 1.6 pg/mL), IL-8 (27.6 ± 9.3 vs. 13.3 ± 5.6 pg/mL), TNF-α (6.4 ± 2.9 vs. 3.3 ± 1.4 pg/mL), and high-sensitivity C-reactive protein (hs-CRP) (4.8 ± 1.5 vs. 2.7 ± 1.0 mg/dL) in comparison with NGT 1-h < 155. Matsuda-index and 1-h post-load glycemia were retained as major predictors of TLRs and NF-kβ. These results contribute to better characterizing cardiovascular risk in hypertensives.

Depressed myocardial mechano-energetic efficiency in subjects with dysglycemia

AIMS

Evidence indicate that 1 h post-load glucose levels (1hPG) ≥ 155 mg/dl identify amongst subjects with normal glucose tolerance (NGT) a new category of prediabetes (NGT 1 h-high). A compromised myocardial mechano-energetic efficiency (MEE) is associated with type 2 diabetes and predicts adverse cardiovascular outcomes. Herein, we explored the association between prediabetes conditions such as NGT 1 h-high, impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) and a decreased MEE.

METHODS

MEE was assessed by an echocardiography-derived measure in 1467 non-diabetic individuals subdivided according to their glucose tolerance: NGT and 1-hPG < 155 mg/dl (NGT 1 h-low, n = 617), NGT 1 h-high (n = 210), isolated IFG (n = 237), and IGT (n = 403).

RESULTS

Subjects with NGT 1 h-high, isolated IFG, and IGT displayed a higher myocardial oxygen consumption, and a decreased MEE in comparison to NGT 1 h-low group. MEE was inversely related to male sex, age, body mass index, total cholesterol, triglycerides, fasting and post-load glucose and insulin, C reactive protein, and positively correlated with insulin sensitivity estimated by the Matsuda index. In a stepwise multivariate linear regression model including several cardio-metabolic risk factors, 1hPG was the major predictor of MEE.

CONCLUSIONS

Subjects with NGT 1 h-high, isolated IFG, and IGT have a raised myocardial oxygen consumption and a reduced MEE.

Impact of type 2 diabetes mellitus on left ventricular diastolic function in patients with essential hypertension: evaluation by volume-time curve of cardiac magnetic resonance

Background

Essential hypertension and type 2 diabetes mellitus (T2DM) are two common chronic diseases that often coexist, and both of these diseases can cause heart damage. However, the additive effects of essential hypertension complicated with T2DM on left ventricle (LV) diastolic function have not been fully illustrated. This study aims to investigate whether T2DM affects the diastolic function of the LV in patients with essential hypertension using the volume-time curve from cardiac magnetic resonance (CMR).

Methods

A total of 124 essential hypertension patients, including 48 with T2DM [HTN(T2DM +) group] and 76 without T2DM [HTN(T2DM-) group], and 52 normal controls who underwent CMR scans were included in this study. LV volume-time curve parameters, including the peak ejection rate (PER), time to peak ejection rate (PET), peak filling rate (PFR), time to peak filling rate from end-systole (PFT), PER normalized to end-diastolic volume (PER/EDV), and PFR normalized to EDV (PFR/EDV), were measured and compared among the three groups. Multivariate linear regression analyses were performed to determine the effects of T2DM on LV diastolic dysfunction in patients with hypertension. Pearson correlation was used to analyse the correlation between the volume-time curve and myocardial strain parameters.

Results

PFR and PFR/EDV decreased from the control group, through HTN(T2DM −), to HTN(T2DM +) group. PFT in the HTN(T2DM-) group and HTN(T2DM +) group was significantly longer than that in the control group. The LV remodelling index in the HTN(T2DM −) and HTN(T2DM +) groups was higher than that in the normal control group, but there was no significant difference between the HTN(T2DM −) and HTN(T2DM +) groups. Multiple regression analyses controlling for covariates of systolic blood pressure, age, sex, and heart rate demonstrated that T2DM was independently associated with PFR/EDV (β = 0.252, p < 0.05). The volume-time curve method has good repeatability, and there is a significant correlation between volume-time curve parameters (PER/EDV and PFR/EDV) and myocardial peak strain rate, especially circumferential peak strain rate, which exhibited the highest correlation (r = − 0.756 ~ 0.795).

Conclusions

T2DM exacerbates LV diastolic dysfunction in patients with essential hypertension. The LV filling model changes reflected by the CMR volume-time curve could provide more information for early clinical intervention.

Sex-specific differences in left ventricular mass and myocardial energetic efficiency in non-diabetic, pre-diabetic and newly diagnosed type 2 diabetic subjects

Background

Women with type 2 diabetes (T2DM) have a higher excess risk for cardiovascular disease (CVD) than their male counterparts. However, whether the risk for CVD is higher in prediabetic women than men is still debated. We aimed to determine whether sex-related differences exist in left ventricular mass index (LVMI), and myocardial mechano-energetic efficiency (MEEi) in with normal glucose tolerant (NGT), pre-diabetic and newly diagnosed type 2 diabetic subjects.

Methods

Sex-related differences in LVMI and myocardial MEEi, assessed by validated echocardiography-derived measures, were examined among 1562 adults with NGT, prediabetes, and newly diagnosed T2DM, defined according to fasting glucose, 2-h post-load glucose, or HbA1c.

Results

Worsening of glucose tolerance in both men and women was associated with an increase in age-adjusted LVMI and myocardial MEEi. Women with newly diagnosed T2DM exhibited greater relative differences in LVMI and myocardial MEEi than diabetic men when compared with their NGT counterparts. Prediabetic women exhibited greater relative differences in myocardial MEEi, but not in LVMI, than prediabetic men when compared with their NGT counterparts. The statistical test for interaction between sex and glucose tolerance on both LVMI (P < 0.0001), and myocardial MEEi (P < 0.0001) was significant suggesting a sex-specific association.

Conclusions

Left ventricle is subject to maladaptive changes with worsening of glucose tolerance, especially in women with newly diagnosed T2DM. The sex-specific increase in LVM and decrease in MEEi, both being predictors of CVD, may have a role in explaining the stronger impact of T2DM on the excess risk of CVD in women than in men.

Association of prediabetes with impaired left atrial contractility in patients with never-treated hypertension

AIM

Prediabetes defined by HbA1c 5.7-6.4 has been shown to be associated with left ventricular (LV) hypertrophy and diastolic dysfunction in hypertensive patients. We hypothesized HbA1c prediabetes may be related to the alterations of LA contractility or volume in nondiabetic hypertension.

METHODS

Nondiabetic individuals on sinus rhythm were enrolled; 107 patients with never-treated hypertension, 134 patients with treated hypertension, and 71 normotensive subjects. Participants were classified as normal glucose tolerance (NGT, HbA1c<5.7), prediabetes (HbA1c 5.7-6.4) according to the ADA criteria. They underwent echocardiography to measure left atrial (LA) phasic volumes and functions, as well as mitral E/e' and mitral e'.

RESULTS

In nondiabetic patients with never-treated hypertension, prediabetes saw lower LA total emptying fraction (53.7 ± 8.2 vs. 48.3 ± 9.9*) and mitral e' (7.38 ± 2.18 vs. 6.17 ± 1.50*) than NGT, implicating that the association of prediabetes with reduced LA contractility and LV stiffness. On the other hand, in nondiabetic patients with treated hypertension, prediabetes saw higher maximum LA volume/BSA (29.7 ± 7.1 vs. 32.9 ± 6.2* ml/mm²) and mitral E/e' (10.72 ± 3.08 vs. 12.37 ± 3.35*) than NGT, suggesting the relationship of prediabetes with increased LA preload.

CONCLUSION

Prediabetes may be involved in the progression of LA structural and functional alterations in nondiabetic hypertensive patients.

Nonalcoholic fatty liver disease is associated with a decreased myocardial mechano-energetic efficiency

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is linked to a raised risk of cardiovascular diseases (CVD), although the underlying mechanisms are not completely known. A reduced myocardial mechano-energetic efficiency (MEE) has been found to be an independent predictor of CVD.

OBJECTIVE

To evaluate the association between NAFLD and a compromised MEE.

METHODS

Myocardial MEE was assessed by a validated echocardiography-derived measure in 699 nondiabetic individuals subdivided into two groups according to ultrasonography defined presence of NAFLD.

RESULTS

Subjects with NAFLD displayed higher levels of systolic (SBP) and diastolic blood pressure (DBP), triglycerides, fasting and postload glucose, high-sensitivity C-reactive protein (hsCRP), insulin resistance (IR) estimated by HOMA-IR and liver IR index, and lower values of high-density lipoprotein (HDL) in comparison with those without NAFLD. Presence of NAFLD was associated with increased levels of myocardial oxygen demand and reduced values of MEE. MEE was negatively correlated with male sex, age, BMI, waist circumference, SBP, DBP, total cholesterol, triglycerides, fasting and postload glucose, HOMA-IR and liver IR index, hsCRP and positively with HDL levels. In a multivariable regression analysis, presence of NAFLD was associated with MEE regardless of several cardio-metabolic risk factors such as age, gender, waist circumference, SBP, DBP, total and HDL cholesterol, triglycerides, glucose tolerance and hsCRP (β = -0.09, P = 0.04), but not independently of IR estimates.

CONCLUSION

Ultrasound-defined presence of NAFLD is associated with a decreased MEE, a predictor of adverse cardiovascular events. The relationship between NAFLD and a compromised MEE is dependent of IR.

Prediabetes, heart mechanics, and echocardiography: A narrative review

Prediabetes is a dysglycemic state that affects many around the world and is a known risk factor for the occurrence of type 2 diabetes mellitus in the future, accompanied by vascular complications. Evidence abounds regarding myocardial involvement in prediabetes. We herein review studies having applied tissue Doppler imaging or speckle-tracking echocardiography to evaluate myocardial function in subjects with prediabetes to depict a picture of cardiac mechanics in individuals with prediabetes in comparison with patients suffering from diabetes mellitus and individuals in the normoglycemic state. Finally, we present the detrimental effects of prediabetes on cardiac mechanics.

Reduction in Global Myocardial Glucose Metabolism in Subjects With 1-Hour Postload Hyperglycemia and Impaired Glucose Tolerance

OBJECTIVE

Impaired insulin-stimulated myocardial glucose uptake has occurred in patients with type 2 diabetes with or without coronary artery disease. Whether cardiac insulin resistance is present remains uncertain in subjects at risk for type 2 diabetes, such as individuals with impaired glucose tolerance (IGT) or those with normal glucose tolerance (NGT) and 1-h postload glucose ≥155 mg/dL during an oral glucose tolerance test (NGT 1-h high). This issue was examined in this study.

RESEARCH DESIGN AND METHODS

The myocardial metabolic rate of glucose (MRGlu) was measured by using dynamic ¹⁸F-fluorodeoxyglucose positron emission tomography combined with a euglycemic-hyperinsulinemic clamp in 30 volunteers without coronary artery disease. Three groups were studied: 1) those with 1-h postload glucose <155 mg/dL (NGT 1-h low) (n = 10), 2) those with NGT 1-h high (n = 10), 3) and those with IGT (n = 10).

RESULTS

After adjusting for age, sex, and BMI, both subjects with NGT 1-h high (23.7 ± 6.4 mmol/min/100 mg; P = 0.024) and those with IGT (16.4 ± 6.0 mmol/min/100 mg; P < 0.0001) exhibited a significant reduction in global myocardial MRGlu; this value was 32.8 ± 9.7 mmol/min/100 mg in subjects with NGT 1-h low. Univariate correlations showed that MRGlu was positively correlated with insulin-stimulated whole-body glucose disposal (r = 0.441; P = 0.019) and negatively correlated with 1-h (r = -0.422; P = 0.025) and 2-h (r = -0.374; P = 0.05) postload glucose levels, but not with fasting glucose.

CONCLUSIONS

This study shows that myocardial insulin resistance is an early defect that is already detectable in individuals with dysglycemic conditions associated with an increased risk of type 2 diabetes, such as IGT and NGT 1-h high.

1 h Postload Glycemia Is Associated with Low Endogenous Secretory Receptor for Advanced Glycation End Product Levels and Early Markers of Cardiovascular Disease

We investigated the correlation of the soluble receptor for advanced glycation end products (sRAGE) and endogenous secretory RAGE (esRAGE) with markers of cardiovascular disease in subjects with normal glucose tolerance (NGT) and 1 h postload glucose ≥155 mg/dL after an oral glucose tolerance test. We stratified 282 subjects without a previous diagnosis of diabetes into three groups: 123 controls (NGT and 1 h postload glycemia <155 mg/dL), 84 NGT and 1 h postload glycemia ≥155 mg/dL (NGT 1 h high), and 75 subjects with impaired fasting glucose and/or impaired glucose tolerance (IFG/IGT). NGT 1 h high subjects exhibited lower esRAGE (0.36 ± 0.18 vs. 0.4 5 ± 0.2, p < 0.05) and higher S100A12 levels than controls (5684 (3193.2–8295.6) vs. 3960.1 (2101.8–7419), p < 0.05). Furthermore, they showed an increased pulse wave velocity (PWV) and intima–media thickness (IMT). No differences were found between the NGT 1 h high group and the IFG/IGT group regarding cardiometabolic profiles. After multiple regression analyses, esRAGE was associated with glycated hemoglobin (HbA_1c) and high-sensitivity C-reactive protein (hs-CRP). Age, HbA_1c, and esRAGE were the determinants of IMT, whereas S100A12 and systolic pressure were the determinants of PWV. The NGT 1 h high group exhibited low esRAGE levels and an altered cardiometabolic profile. HbA_1c, S100A12, and hs-CRP were associated with these alterations. In conclusion, subjects with NGT are not a homogeneous population, and they present different cardiovascular and glycometabolic risks.

Elevated 1-h post-load plasma glucose is associated with right ventricular morphofunctional parameters in hypertensive patients

PURPOSE

Emerging data demonstrate that type 2 diabetes mellitus (T2DM) is associated with right ventricular (RV) dysfunction. A cutoff point of 155 mg/dL for the 1-hour (h) post-load plasma glucose, during oral glucose tolerance test (OGTT), identifies patients with normal glucose tolerance (NGT) at high risk to develop T2DM and cardiovascular (CV) disease. We investigated if 1-h post-load glucose may affect RV geometry and function in a group of never-treated hypertensive individuals.

METHODS

We enrolled 446 Caucasian newly diagnosed hypertensive outpatients. All patients underwent an OGTT and a standard echocardiography. The tricuspid annular plane systolic excursion (TAPSE) and the RV fractional area change (RVFAC) were measured together with systolic pulmonary arterial pressure (s-PAP) and pulmonary vascular resistances (PVR). Insulin sensitivity was evaluated using the Matsuda index.

RESULTS

Among all partecipants, 296 had NGT, 100 impaired glucose tolerance (IGT), and 50 T2DM. Considering the cutoff point of 155 mg/dl for 1-h glucose, NGT subjects were stratified into two groups: NGT < 155 (n = 207), NGT ≥ 155 (n = 89). Subjects NGT ≥ 155 presented a worse metabolic and inflammatory profile than NGT < 155. RV functional parameters (TAPSE, RVFAC, TAPSE/s-PAP, and TAPSE/PVR) were significantly reduced in NGT ≥ 155 subjects compared with NGT < 155 patients. On the contrary, s-PAP and PVR were significantly higher. At multiple regression analysis, 1-h glucose was the strongest predictor of TAPSE in NGT ≥ 155, IGT, and T2DM.

CONCLUSIONS

The presence of RV impairment in hypertensive NGT ≥ 155 subjects further complicates their CV burden and it may, at least in part, justify the worse clinical outcome in this setting of patients.

Metabolic and vascular effects of silybin in hypertensive patients with high 1-h post-load plasma glucose

Hypertensive patients with normal glucose tolerance (NGT) but 1-h post-load plasma glucose ≥ 155 mg/dl (1-h high), during an oral glucose tolerance test (OGTT), show higher insulin resistance and multiple target organ damages. Experimental and clinical studies demonstrate that silybin presents anti-inflammatory and metabolic effects, improving insulin resistance and endothelial dysfunction. This study aims to evaluate the effects of the complex silybin-vitamin E and phospholipids on inflammatory, metabolic and vascular parameters in NGT 1-h high hypertensive patients. This is a pilot, single arm, interventional, longitudinal study enrolling 50 Caucasian NGT 1-h high hypertensive outpatients, 27 men and 23 women, age range 42-60 years (mean + SD = 52 ± 7). After 6 months of silybin intake, there is a significant improvement in metabolic profile. The glucose response during OGTT significantly improves (AUCglucose_0-120 309.6 ± 63.4 at baseline vs 254.6 ± 35.5 at the follow-up, ∆ = - 55, 95% CI from - 67 to - 43, p < 0.0001), so as insulin response (AUCinsulin_0-120 238.2 ± 99.1 vs 159.3 ± 44.9, ∆ = - 78.9, 95% CI from - 100.0 to - 57.8, p < 0.0001), in accordance with the increase of insulin sensitivity index Matsuda. Silybin intake is associated with a significant reduction of both clinical and central systolic blood pressure, with betterment in clinical and central pulse pressure and reduction of arterial stiffness parameters. In conclusion, this study demonstrates that silybin may improve the metabolic aspect and vascular damage in NGT 1-h high hypertensive patients who are at higher metabolic and cardiovascular risk. Thus, in these patients, silybin might strengthen the effect of antihypertensive drugs giving further cardiovascular protection.

Petition to replace current OGTT criteria for diagnosing prediabetes with the 1-hour post-load plasma glucose ≥ 155 mg/dl (8.6 mmol/L)

Many individuals with prediabetes, as presently defined, will progress to diabetes (T2D) despite the considerable benefit of lifestyle modification. Therefore, it is paramount to screen individuals at increased risk with a more sensitive method capable of identifying prediabetes at an even earlier time point in the lengthy trajectory to T2D. This petition reviews findings demonstrating that the 1-hour (1-h) postload plasma glucose (PG) ≥ 155 mg/dl (8.6 mmol/L) in those with normal glucose tolerance (NGT) during an oral glucose tolerance test (OGTT) is highly predictive for detecting progression to T2D, micro- and macrovascular complications and mortality in individuals at increased risk. Furthermore, the STOP DIABETES Study documented effective interventions that reduce the future risk of T2D in those with NGT and a 1-h PG ≥ 155 mg/dl (8·6 mmol/L). The 1-h OGTT represents a valuable opportunity to extend the proven benefit of diabetes prevention to the sizeable and growing population of individuals at increased risk of progression to T2D. The substantial evidence provided in this petition strongly supports redefining current diagnostic criteria for prediabetes with the elevated 1-h PG level. The authors therefore advocate a 1-h OGTT to detect prediabetes and hence, thwart the global diabetes epidemic.

One-Hour Postload Hyperglycemia: Implications for Prediction and Prevention of Type 2 Diabetes

CONTEXT

Recently, a value of 1-hour postload glucose concentration (1-h-PG) ≥155 mg/dL (8.6 mmol/L) in individuals with normal glucose tolerance (NGT) has been found to be associated with an increased risk for future type 2 diabetes mellitus (T2DM). In this review, we analyze the implication of 1-h-PG determination in prediction of T2DM and cardiovascular disease.

DESIGN

A literature search was performed using MEDLINE. We included all English studies published up to February 2018 in peer-reviewed journals that examined the relationship between 1-h-PG and diabetes, cardiometabolic alterations, organ damage, and cardiovascular disease.

RESULTS

Several longitudinal studies have consistently shown that 1-h-PG ≥155 mg/dL can recognize individuals at increased risk for future T2DM among subjects with NGT. Additionally, we describe the pathophysiological abnormalities associated with 1-h-PG ≥155 mg/dL including impaired insulin sensitivity, β-cell dysfunction, and increased glucose intestinal absorption, which are known to be involved in T2DM pathogenesis. Importantly, numerous studies have demonstrated that a value of 1-h-PG ≥155 mg/dL in individuals with NGT is not only linked to an increased risk for future T2DM, but also able to identify those having a worse cardiovascular phenotype and an increased risk of adverse cardiovascular outcomes.

CONCLUSIONS

Although 1-h-PG determination is not currently recommended by the American Diabetes Association for identifying high-risk individuals, the available evidence indicates that a value of 1-h-PG ≥155 mg/dL may be a useful tool to recognize, among subjects with NGT, those at increased risk of T2DM and cardiovascular disease.

One-hour and two-hour postload plasma glucose concentrations are comparable predictors of type 2 diabetes mellitus in Southwestern Native Americans

AIMS/HYPOTHESIS

Elevated 2-h plasma glucose concentration (2 h-PG) during a 75 g OGTT predict the development of type 2 diabetes mellitus. However, 1-h plasma glucose concentration (1 h-PG) is associated with insulin secretion and may be a better predictor of type 2 diabetes. We aimed to investigate the association between 1 h-PG and 2 h-PG using gold standard methods for measuring insulin secretion and action. We also compared 1 h-PG and 2 h-PG as predictors of type 2 diabetes mellitus.

METHODS

This analysis included adult volunteers without diabetes, predominantly Native Americans of Southwestern heritage, who were involved in a longitudinal epidemiological study from 1965 to 2007, with a baseline OGTT that included measurement of 1 h-PG. Group 1 (n = 716) underwent an IVGTT and hyperinsulinaemic-euglycaemic clamp for measurement of acute insulin response (AIR) and insulin-stimulated glucose disposal (M), respectively. Some members of Group 1 (n = 490 of 716) and members of a second, larger, group (Group 2; n = 1946) were followed-up to assess the development of type 2 diabetes (median 9.0 and 12.8 years follow-up, respectively).

RESULTS

Compared with 2 h-PG (r = -0.281), 1 h-PG (r = -0.384) was more closely associated with AIR, whereas, compared with 1 h-PG (r = -0.340), 2 h-PG (r = -0.408) was more closely associated with M. Measures of 1 h-PG and 2 h-PG had similar abilities to predict type 2 diabetes, which did not change when both were included in the model. A 1 h-PG cut-off of 9.3 mmol/l provided similar levels of sensitivity and specificity as a 2 h-PG cut-off of 7.8 mmol/l; the latter is used to define impaired glucose tolerance, a recognised predictor of type 2 diabetes mellitus.

CONCLUSIONS/INTERPRETATION

The 1 h-PG was associated with important physiological predictors of type 2 diabetes and was as effective as 2 h-PG for predicting type 2 diabetes mellitus. The 1 h-PG is, therefore, an alternative method of identifying individuals with an elevated risk of type 2 diabetes mellitus.

Targeting One-Hour Postmeal Glucose: Is It Time for a Paradigm Switch in Diabetes Management?

In the management of diabetes, postprandial glycemia (PPG) is usually targeted 2 h after the start of meal. Recent evidences, however, suggest that the value of glycemia at 1 h during an oral glucose tolerance test (OGTT) is a stronger predictor for developing diabetes than the value at 2 h and that it is an independent risk factor for cardiovascular disease. Studies in cells, animals, and humans suggest that 1-h high glucose is a sufficient stimulus for increasing several cardiovascular risk factors, such as inflammation, thrombosis, and endothelial dysfunction, with oxidative stress generation as the possible pathogenetic factor. One-hour glucose might be more dangerous than that at 2 h simply because glycemia is higher at 1 h, during an OGTT and postmeal. The new drugs, able to target better 1 h glycemia and the new noninvasive technologies for glucose monitoring, nowadays may help to change the therapeutic paradigm of targeting PPG at 2 h.

One-hour post-load plasma glucose levels associated with decreased insulin sensitivity and secretion and early makers of cardiometabolic risk

PURPOSE

Obese adults with normal glucose tolerance (NGT) but with 1-hour post-load plasma glucose (1hPG) ≥ 155 mg/dl are at higher risk of developing type 2 diabetes (T2D) and cardiometabolic complications. Little information is available for the pediatric population, where recently, a lower cutoff, 132.5 mg/dl, has been suggested as being more sensitive to identify subjects at risk of T2D. Our aim was to assess whether obese Caucasian youth with 1hPG ≥ 132.5 mg/dl have worse insulin sensitivity and secretion and a worse cardiometabolic profile compared to obese youth with 1hPG < 132.5 mg/dl.

METHODS

Medical records of 244 (43% male; age: 11.1 ± 2.7years) overweight/obese children and adolescents, who had undergone an oral glucose tolerance test (OGTT), were retrieved. Anthropometric and biochemical data were collected from the hard copy archive. Indexes of insulin resistance (HOMA-IR), insulin sensitivity (WBISI), and insulin secretion (Insulinogenic Index, Disposition Index) were calculated.

RESULTS

Of the 244 records analyzed, 215 fulfilled criteria for NGT and had complete biochemical data. Among NGT patients, 42 (19.5%) showed 1hPG ≥ 132.5 mg/dL (high-NGT), while the remaining had 1hPG < 132.5 mg/dL (low-NGT). The high-NGT group showed a higher male prevalence (59.5 vs 37%), lower Disposition Index (0.54 [0.39-0.71] vs 0.79 [0.47-1.43]), and WBISI (0.24 [0.18-0.35] vs 0.33 [0.23-0.50]) than the low-NGT group. High-NGT subjects also showed a trend towards lower HDL-cholesterol and higher triglycerides/HDL-cholesterol ratio (2.13 [1.49-3.41] vs 1.66 [1.24-2.49]).

CONCLUSIONS

In overweight/obese NGT Caucasian youth a 1hPG ≥ 132.5 mg/dL was able to identify those with impaired insulin sensitivity and secretion and a trend towards a worse cardio-metabolic profile, a group likely at risk for future T2D.

High salt intake does not aggravate glucose dysregulation and dyslipidemia induced by estrogen-progestin oral contraceptive

BACKGROUND

Estrogen-progestogen combined oral contraceptive (OC) use has been associated with increased cardiometabolic risk factors, including glucose dysregulation, dyslipidemia, hypertension, and pro-inflammatory state. However, the effect of a high-salt diet on these risk factors during OC use is not yet investigated. We therefore hypothesized that a high-salt diet would increase cardiometabolic risk factors in female rats treated with a combination of OC steroids, levonorgestrel (L) and ethinylestradiol (EE), and that elevated plasma levels of pro-inflammatory markers are associated with the cardiometabolic effects.

METHODS

Female Wistar rats were given (p.o.) vehicle, high-dose (1.0μg EE plus 5.0μgL) or low-dose (0.1μg EE plus 0.5μgL) OC with or without a high-salt diet (8%) daily for 8 weeks. Insulin resistance (IR) was estimated using the homeostatic model of assessment (HOMA).

RESULTS

Results showed that OC treatment or high salt diet led to significant increases in insulin resistance, plasma insulin, total cholesterol (TC), triglyceride (TG), TC/HDL-cholesterol, uric acid levels, and decreased glucose tolerance. OC treatment but not a high-salt diet resulted in increased plasma C-reactive protein and TG/HDL-cholesterol. However, a high-salt diet did not aggravate the effects of OC treatment.

CONCLUSION

The results from the present study indicate that glucose dysfunction and dyslipidemia induced by OC use, but not those induced by increased dietary salt are associated with elevated plasma C-reactive protein. Besides, increased dietary salt does not worsen abnormal cardiometabolic impact of OC use.

Metabolic profile of normal glucose-tolerant subjects with elevated 1-h plasma glucose values

AIM

The aim of this study was to compare the metabolic profiles of subjects with normal glucose tolerance (NGT) with and without elevated 1-h postglucose (1HrPG) values during an oral glucose tolerance test (OGTT).

METHODOLOGY

The study group comprised 996 subjects without known diabetes seen at tertiary diabetes center between 2010 and 2014. NGT was defined as fasting plasma glucose <100 mg/dl (5.5 mmol/L) and 2-h plasma glucose <140 mg/dl (7.8 mmol/L) after an 82.5 g oral glucose (equivalent to 75 g of anhydrous glucose) OGTT. Anthropometric measurements and biochemical investigations were done using standardized methods. The prevalence rate of generalized and central obesity, hypertension, dyslipidemia, and metabolic syndrome (MS) was determined among the NGT subjects stratified based on their 1HrPG values as <143 mg/dl, ≥143-<155 mg/dl, and ≥155 mg/dl, after adjusting for age, sex, body mass index (BMI), waist circumference, alcohol consumption, smoking, and family history of diabetes.

RESULTS

The mean age of the 996 NGT subjects was 48 ± 12 years and 53.5% were male. The mean glycated hemoglobin for subjects with 1HrPG <143 mg/dl was 5.5%, for those with 1HrPG ≥143-<155 mg/dl, 5.6% and for those with 1HrPG ≥155 mg/dl, 5.7%. NGT subjects with 1HrPG ≥143-<155 mg/dl and ≥155 mg/dl had significantly higher BMI, waist circumference, systolic and diastolic blood pressure, triglyceride, total cholesterol/high-density lipoprotein (HDL) ratio, triglyceride/HDL ratio, leukocyte count, and gamma glutamyl aminotransferase (P < 0.05) compared to subjects with 1HrPG <143 mg/dl. The odds ratio for MS for subjects with 1HrPG ≥143 mg/dl was 1.84 times higher compared to subjects with 1HrPG <143 mg/dl taken as the reference.

CONCLUSION

NGT subjects with elevated 1HrPG values have a worse metabolic profile than those with normal 1HrPG during an OGTT.

One-hour post-load hyperglycemia combined with HbA1c identifies pre-diabetic individuals with a higher cardio-metabolic risk burden

BACKGROUND AND AIMS

Evidence suggests that combining 1-hour plasma glucose ≥155 mg/dl during an oral glucose tolerance test (OGTT) with glycosylated hemoglobin (HbA1c) significantly increases their predictive power for incident diabetes, while their individual and joint associations with cardio-metabolic risk factors remain undefined. Herein, we evaluated whether 1-hour post-load plasma glucose ≥155 mg/dl combined with HbA1c may identify pre-diabetic individuals with a higher cardio-metabolic risk.

METHODS

Anthropometric and metabolic characteristics, insulin sensitivity and insulin secretion assessed by OGTT-derived indexes, carotid intima-media thickness (IMT), pulse pressure, and rate pressure product were evaluated in 1495 individuals.

RESULTS

As compared with subjects with 1-hour post-load glucose <155 mg/dl, individuals with 1-hour post-load glucose ≥155 mg/dl exhibited a significantly worse cardio metabolic profile, both in the group with HbA1c <5.7%, and in the group with prediabetes (HbA1c 5.7-6.4%). Specifically, in both groups, subjects with 1-hour post-load glucose ≥155 mg/dl had higher fasting and 2-h post-load glucose (p < 0.0001 for all in both groups), higher HOMA-IR (p < 0.0001 in both groups), and carotid IMT (p = 0.05 in the group with HbA1c <5.7% and p = 0.03 in the group HbA1c 5.7-6.4%), as well as lower Matsuda index, insulinogenic index and disposition index (p < 0.0001 in both groups), and lower insulin-stimulated glucose disposal (p < 0.0001 in the group with HbA1c <5.7% and p = 0.03 in the group HbA1c 5.7-6.4%).

CONCLUSIONS

Hyperglycemia at 1-hour during an OGTT may be a useful tool to identify a subset of individuals within HbA1c-defined glycemic categories at higher risk of developing type 2 diabetes and cardiovascular disease.

Sympathovagal balance and 1-h postload plasma glucose in normoglucose tolerant hypertensive patients

AIMS

Normoglucose tolerant (NGT) subjects with a 1-h postload plasma glucose (PLPG) value ≥155 mg/dL have an increased risk of type-2 diabetes and subclinical organ damage. Heart rate variability (HRV) reflects cardiac autonomic balance, frequently impaired in course of diabetes. At this time, no data support the association between 1-h PLPG and HRV; thus, we investigated the possible association between 1-h PLPG and HRV.

METHODS

We enrolled 92 never-treated hypertensive subjects (56 women, 36 men), aged 55 ± 9.8 years. During OGTT, the patients underwent electrocardiographic recordings to evaluate HRV in the time domain (SDNN). Insulin sensitivity was assessed by Matsuda index.

RESULTS

Among participants, 56 were NGT, 20 had impaired glucose tolerance (IGT), and 16 had type-2 diabetes. According to the 1-h PLPG cutoff point of 155 mg/dL, we divided NGT subjects into: NGT < 155 (n = 38) and NGT ≥ 155 (n = 18). Glucose tolerance status was associated with a significant (P < 0.0001) increase in PLPG and insulin and the reduction in Matsuda index. In all groups, the SDNN values significantly (P < 0.0001) decreased during the first hour of OGTT. A complete recovery in NGT groups was observed at the end of the second hour; in IGT and type-2 diabetes, SDNN remained significantly lower with respect to baseline values. At multiple regression analysis, Matsuda index resulted in the only determinant of SDNN modification, explaining the 12.3 % of its variability.

CONCLUSIONS

Our data demonstrate that during OGTT, sympathovagal balance is acutely affected by both glucose and insulin modifications. Particularly, NGT ≥ 155 subjects behave in the same way of IGT and type-2 diabetes patients.

One-Hour Postload Hyperglycemia Is a Stronger Predictor of Type 2 Diabetes Than Impaired Fasting Glucose

CONTEXT

Subjects with normal glucose tolerance (NGT) but 1-h postload glucose ≥ 155 mg/dL (NGT-1h-high) exhibit an intermediate cardiometabolic risk profile between individuals with NGT and impaired glucose tolerance (IGT).

OBJECTIVE

This study aimed to evaluate whether NGT-1h-high subjects have different cardiometabolic characteristics and an increased risk of type 2 diabetes compared with individuals with isolated impaired fasting glucose (IFG).

SETTING, DESIGN, AND PATIENTS

A cross-sectional analysis was performed on 595 nondiabetic subjects who underwent an oral glucose tolerance test and an euglycemic hyperinsulinemic clamp in an ambulatory care setting. In addition, a longitudinal analysis was performed on 392 individuals, who were reexamined after a followup of 5.2 ± 0.9 y.

MAIN OUTCOME MEASURES

Insulin sensitivity, beta-cell function, and risk of developing diabetes were measured.

RESULTS

Subjects with NGT-1h-high have a significant reduction of peripheral insulin sensitivity and beta-cell function, assessed by the disposition index, compared with either 1-h postload glucose < 155 mg/dL (NGT-1h-low) or IFG individuals, but not compared with IGT. Among the 392 subjects studied in the longitudinal analysis the incidence rate of type 2 diabetes over the follow-up period was 2.9, 16.7, 12.5, and 31.4% for subjects with NGT-1h-low, NGT-1h-high, IFG, and IGT, respectively. In a Cox proportional hazard regression analysis the risk of developing diabetes for NGT-1h-high subjects was 4.02 (95% confidence interval [CI] 1.06-15.26); an even higher risk (6.67; 95% CI, 2.09-21.24) was observed in subjects with IGT, but not in the isolated IFG group (1.91; 95% CI, 0.44-8.29).

CONCLUSIONS

NGT-1h-high subjects exhibit a higher risk of developing diabetes than those with IFG or NGT-1h-low, likely due to decreased insulin sensitivity and beta-cell function.

Elevated 1-h post-load plasma glucose levels in subjects with normal glucose tolerance are associated with unfavorable inflammatory profile

Glucose tolerant subjects with 1-h post-load glucose ≥155 mg/dl (NGT-1 h-high) are at increased risk for type 2 diabetes (T2DM). Prospective studies showed that chronic subclinical inflammation is a predictor of T2DM. In this study, we aimed to evaluate the inflammatory profile in NGT-1 h-high subjects as compared with individuals with 1-h post-load glucose <155 mg/dl (NGT-1 h-low). To this end, an oral glucose tolerance tests (OGTT) were performed in 1,099 nondiabetic whites. Cardio-metabolic risk factors including high-sensitivity C-reactive protein (hsCRP), erythrocyte sedimentation rate (ESR), fibrinogen, and complement C3 (C3) were determined. Of the 1,099 subjects examined, 497 had NGT-1 h-low, 154 had NGT-1 h-high, 158 had isolated impaired fasting glucose (IFG), and 290 had impaired glucose tolerance (IGT). As compared with NGT-1 h-low, NGT-1 h-high and IGT subjects exhibited significantly higher hsCRP, ESR, fibrinogen, and C3 levels. Notably, hsCRP, ESR, and C3 were also significantly higher as compared with IFG individuals. In a logistic regression analysis adjusted for age and gender, NGT-1 h-high and IGT subjects had a 1.8-fold increased risk of having the highest value of the Inflammatory Score. These data suggest that a value of a 1-h OGTT glucose ≥155 mg/dl may be helpful to identify a subset of normal glucose tolerance individuals at risk for chronic subclinical inflammation, a predictor of T2DM, and cardiovascular diseases.

Urinary type IV collagen is related to left ventricular diastolic function and brain natriuretic peptide in hypertensive patients with prediabetes

AIM

Urinary type IV collagen is an early biomarker of diabetic nephropathy. Concomitant prediabetes (the early stage of diabetes) was associated with left ventricular (LV) diastolic dysfunction and increased brain natriuretic peptide (BNP) in hypertensive patients. We hypothesized that urinary type IV collagen may be related to these cardiac dysfunctions.

METHODS

We studied hypertensive patients with early prediabetes (HbA1c <5.7% and fasting glucose >110, n=18), those with prediabetes (HbA1c 5.7-6.4, n=98), and those with diabetes (HbA1c>6.5 or on diabetes medications, n=92). The participants underwent echocardiography to assess left atrial volume/body surface area (BSA) and the ratio of early mitral flow velocity to mitral annular velocity (E/e'). Left ventricular diastolic dysfunction (LVDD) was defined if patients had E/e'≥15, or E/e'=9-14 accompanied by left atrial volume/BSA≥32ml/mm(2). Urinary samples were collected for type IV collagen and albumin, and blood samples were taken for BNP and HbA1c.

RESULTS

Urinary type IV collagen and albumin increased in parallel with the deterioration of glycemic status. In hypertensive patients with prediabetes, subjects with LVDD had higher levels of BNP and urinary type IV collagen than those without LVDD. In contrast, in hypertensive patients with diabetes, subjects with LVDD had higher urinary albumin and BNP than those without LVDD. Urinary type IV collagen correlated positively with BNP in hypertensive patients with prediabetes, whereas it correlated with HbA1c in those with diabetes.

CONCLUSIONS

In hypertensive patients with prediabetes, urinary type IV collagen was associated with LV diastolic dysfunction and BNP.

Glycemic variability in normal glucose regulation subjects with elevated 1-h postload plasma glucose levels

Subjects with normal glucose regulation (NGR), whose 1-h postload plasma glucose is ≥8.6 mmol/L (155 mg/dL, NGR 1 h ≥ 8.6) during 75-g oral glucose tolerance test (OGTT), have an increased risk of type 2 diabetes and subclinical organ damage. And, the deficiency in islet β cell function is responsible for glycemic disorders. The purpose of this study is to investigate glycemic variability in NGR subjects with elevated 1-h postload plasma glucose levels and its association with islet β cell function. The 29 NGR subjects with 1-h postload plasma glucose ≥8.6 mmol/L (NGR 1 h ≥ 8.6) and 29 age- and sex-matched NGR subjects with 1-h postload plasma glucose <8.6 mmol/L (NGR 1 h < 8.6) were recruited in the study. Insulin sensitivity (Matsuda index, ISI), insulin secretion (insulinogenic index ΔI30/ΔG30), and integrated β cell function measured by the oral disposition index (ΔI30/ΔG30 multiplied by the ISI) were derived from OGTT. All subjects were monitored using the continuous glucose monitoring system for consecutive 72 h. The multiple parameters of glycemic variability included the standard deviation of blood glucose (SDBG), mean blood glucose (MBG), mean of daily differences (MODD), and mean amplitude of glycemic excursions (MAGE). MAGE is considered as a gold standard of glycemic variability. Glycemic variability parameters SDBG, MBG, MODD, and MAGE in NGR 1 h ≥ 8.6 group were higher than those in NGR 1 h < 8.6 group (p < 0.05), and oral disposition index in NGR 1 h ≥ 8.6 group was lower than that in NGR 1 h < 8.6 group (p < 0.05). SDBG, MBG, MODD, MAGE, and 1-h postload plasma glucose all negatively associated with oral disposition index in the separate group (p < 0.05) and in the whole subjects (p < 0.05). After multivariate regression analysis, oral disposition index was the strongest independent contributor to MAGE and 1-h postload plasma glucose in the separate group (p < 0.05) and in the whole subjects (p < 0.05). It is concluded that NGR 1 h ≥ 8.6 group had higher glycemic variability and lower oral disposition index, compared with NGR 1 h < 8.6 group. Increased glycemic variability parameters and elevated 1-h postload plasma glucose consistently associated with declined oral disposition index in subjects from NGR 1 h < 8.6 to NGR 1 h ≥ 8.6 group.

Dietary patterns and 1-h post-load glucose in essential hypertension

BACKGROUND AND AIMS

Normoglucosetolerants (NGT) are considered at low risk, even if a 1-h post-load glucose (PLG) value ≥ 155 mg dl(-1) identifies NGTs at high risk of type-2 diabetes (T2D) and sub-clinical organ damage. Specific dietary factors may affect insulin sensitivity and the risk of T2D. However, it is unknown whether dietary components affect 1-h PLG in hypertensive NGT. Therefore, we investigate the effect of dietary patterns on 1-h PLG.

METHODS AND RESULTS

We selected 188 subjects (94 NGTs < 155 mg dl(-1) and 94 NGTs ≥ 155 mg dl(-1) PLG), well matched for age, gender and body mass index (BMI). Insulin sensitivity was evaluated using the Matsuda index. Dietary intake was quantified by a semiquantitative food frequency questionnaire (FEQ) validated in the European Investigation into Cancer and Nutrition (EPIC) study. The NGT ≥ 155 group had significantly reduced insulin sensitivity (40.3 ± 19.8 vs. 73.3 ± 28.8; P < 0.0001). With the exclusion of total calories, lipids, alcohol and fiber consumption we observed a significant difference, between groups, in starch (214.1 ± 52.4 vs. 268.8 ± 71.8 g; P < 0.0001), saturated (27.4 ± 8.7 vs. 24.1 ± 8.5 g; P = 0.009), monounsaturated (45.5 ± 8.9 vs. 48.8 ± 10.7 g; P = 0.023) and polyunsaturated fatty acids (FAs) (14.5 ± 4.0 vs. 16.8 ± 4.7 g; P < 0.0001), fructose (14.5 ± 5.3 vs. 11.2 ± 4.8 g; P < 0.0001), and oligosaccharides (103.2 ± 26.6 vs. 89.9 ± 29.2 g; P = 0.001) consumption. In the whole population, starch was the major predictor of 1-h PLG, explaining 23.2% of variation (P < 0.0001). In the NGT < 155 group, fructose was the strongest predictor, accounting for 15.4% of the variation; BMI, gender and polyunsaturated FAs added another 6.6%, 3.6% and 3.2%, respectively. In the NGT ≥ 155 group, saturated and polyunsaturated FAs were retained as the major predictors of 1-h PLG, explaining 18.2% and 11.4% of the variation.

CONCLUSIONS

The present data demonstrate that dietary patterns affect 1-h PLG, remarking the importance of both quantitative and qualitative composition of a diet.

Vitamin D and 1-hour post-load plasma glucose in hypertensive patients

Background

A plasma glucose value ≥155 mg/dl for 1-hour post-load plasma glucose during an oral glucose tolerance test (OGTT) is able to identify subjects with normal glucose tolerance (NGT) at high-risk for type-2 diabetes and with subclinical organ damage. We designed this study to address if 25-hydroxyvitamin D [25(OH)D] circulating levels are associated with glucose tolerance status, and in particular with 1-hour post-load plasma glucose levels.

Methods

We enrolled 300 consecutive Caucasian hypertensive never-treated outpatients (160 men and 140 women, aged 52.9 ± 9.2 years). Subjects underwent OGTT and measurements of 25(OH)D and standard laboratory tests. Estimated glomerular filtration rate (e-GFR) was calculated by CKD-EPI formula and insulin sensitivity was assessed by Matsuda-index.

Results

Among participants, 230 were NGT, 44 had impaired glucose tolerance (IGT) and 26 had type-2 diabetes. According to 1-h post-load plasma glucose cut-off point of 155 mg/dL, we divided NGT subjects into: NGT < 155 (n = 156) and NGT > 155 mg/dL (n = 74).

NGT ≥ 155 had higher significant fasting and post-load glucose and insulin, parathyroid hormone and hs-CRP levels than NGT < 155. On the contrary, Matsuda-index, e-GFR, and 25(OH)D were significantly lower in NGT ≥ 155 than NGT < 155 subjects. In the multiple regression analysis, 25(OH)D levels resulted the major determinant of 1-h post-load plasma glucose in all population and in the four groups of glucose tolerance status. In the whole population, Matsuda-index, hs-CRP and e-GFR explained another 12.2%, 6.7% and 1.7% of its variation.

Conclusions

Our data demonstrate a significant and inverse relationship between 25(OH)D levels and glucose tolerance status, particularly with 1-h post-load glucose.

Elevated 1 h postload plasma glucose levels identify adults with normal glucose tolerance but increased risk of non-alcoholic fatty liver disease

OBJECTIVE

To determine the ability of the proposed diagnostic value of a 1-h OGTT glucose ≥155mg/dL to identify individuals with non-alcoholic fatty liver disease (NAFLD) diagnosed by ultrasonography in a cohort of adult white individuals.

DESIGN

The study group comprised 710 white individuals participating to the CATAnzaro MEtabolic RIsk factors (CATAMERI) Study, a cross-sectional study assessing cardio-metabolic risk factors in individuals carrying at least one risk factor including dysglycemia, overweight/obesity, hypertension, dyslipidemia. a 75 g oral Oral Glucose Tolerance Test (OGTT) was performed with 0, 30, 60, 90 and 120 min sampling for plasma glucose and insulin measurements. Cardio-metabolic risk factors including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT) were assessed in the whole cohort.

RESULTS

Of the 710 participants examined, 295 had normal glucose tolerance (NGT) with 1-hour post-load plasma glucose <155 mg/dL (NGT 1h-low), 109 individuals had NGT 1h-high, 104 had isolated impaired fasting glucose (IFG), and 202 had impaired glucose tolerance (IGT). As compared with NGT 1h-low, NGT 1h-high and IGT subjects exhibited significantly higher body mass index (BMI), triglycerides, high sensitivity C reactive protein, ALT, GGT, and hepatic insulin resistance (IR), assessed by the liver IR index, as well as lower high density lipoprotein, and insulin-like growth factor-1 (IGF-1) levels. In a logistic regression analysis adjusted for age, gender, and BMI, NGT 1h-high participants had a 1.5-fold increased risk of having NAFLD and an even increased risk was observed in subjects with IGT (1.8-fold), but not in the isolated IFG group (1.01-fold).

CONCLUSIONS

These data suggest that the value of a 1-hour OGTT glucose ≥155 mg/dL may be helpful to identify a subset of NGT individuals at risk for NAFLD.

Plasma glucose levels and left ventricular diastolic function in nondiabetic hypertensive patients

BACKGROUND

Changes in left ventricular (LV) diastolic filling anticipate diastolic heart failure and are frequently detected in patients with hypertension or diabetes. We tested the hypothesis that increased fasting and postload glucose levels are associated with diastolic dysfunction as assessed by tissue Doppler imaging (TDI) in hypertensive patients.

METHODS

In 104 untreated, nondiabetic, hypertensive patients free of cardiovascular complications, we measured glucose and insulin at fast and after an oral glucose load, calculated the Homeostatic Model Assessment (HOMA) index, and performed electrocardiogram (ECG), conventional echocardiography, and TDI.

RESULTS

Thirty-one patients who had impaired fasting glucose/impaired glucose tolerance had more frequent LV strain at ECG and worse TDI markers of diastolic function than patients with normal plasma glucose but no differences in variables LV mass, LV geometry, systolic function, and early-/late-wave transmitral diastolic velocity. TDI detected diastolic dysfunction in 46 patients who were older and had greater body mass index, blood pressure, fasting and postload glucose, insulin, HOMA index, LV mass, and left atrial diameter than patients with preserved diastolic function. Variables of diastolic function measured at TDI were significantly related with age, body mass index, LV mass, and fasting and postload plasma glucose. Stepwise regression analysis showed that the relationship of markers of diastolic dysfunction with both fasting and postload glucose levels was independent of possible confounders.

CONCLUSIONS

Initially abnormal fasting and postload glucose levels are associated with more prominent diastolic impairment in uncomplicated hypertensive patients, suggesting that hyperglycemia might increase the risk of diastolic heart failure even in the absence of diabetes.

Decreased insulin clearance in individuals with elevated 1-h post-load plasma glucose levels

Reduced insulin clearance has been shown to predict the development of type 2 diabetes. Recently, it has been suggested that plasma glucose concentrations ≥8.6 mmol/l (155 mg/dl) at 1 h during an oral glucose tolerance test (OGTT) can identify individuals at high risk for type 2 diabetes among those who have normal glucose tolerance (NGT 1 h-high). The aim of this study was to examine whether NGT 1 h-high have a decrease in insulin clearance, as compared with NGT individuals with 1-h post-load glucose <8.6 mmol/l (l (155 mg/dl, NGT 1 h-low). To this end, 438 non-diabetic White individuals were subjected to OGTT and euglycemic-hyperinsulinemic clamp to evaluate insulin clearance and insulin sensitivity. As compared with NGT 1 h-low individuals, NGT 1 h-high had significantly higher 1-h and 2-h post-load plasma glucose and 2-h insulin levels as well as higher fasting glucose and insulin levels. NGT 1 h-high exhibited also a significant decrease in both insulin sensitivity (P<0.0001) and insulin clearance (P = 0.006) after adjusting for age, gender, adiposity measures, and insulin sensitivity. The differences in insulin clearance remained significant after adjustment for fasting glucose (P = 0.02) in addition to gender, age, and BMI. In univariate analyses adjusted for gender and age, insulin clearance was inversely correlated with body weight, body mass index, waist, fat mass, 1-h and 2-h post-load glucose levels, fasting, 1-h and 2-h post-load insulin levels, and insulin-stimulated glucose disposal. In conclusion, our data show that NGT 1 h-high have a reduction in insulin clearance as compared with NGT 1 h-low individuals; this suggests that impaired insulin clearance may contribute to sustained fasting and post-meal hyperinsulinemia.

The relationship between coronary risk factors and elevated 1-h postload plasma glucose levels in patients with established coronary heart disease

OBJECTIVE

Recent studies have shown that an elevated 1-h postload plasma glucose (1hPG) is able to identify subjects with normal glucose tolerance (NGT) at high risk for future type 2 diabetes and atherosclerotic cardiovascular disease. However, clinical studies about the characteristics of coronary heart disease (CHD) patients with elevated 1hPG are lacking. The aim of this study was to analyse the 1hPG level in CHD patients with NGT.

METHODS

A total of 204 CHD patients with NGT were recruited. Subjects underwent an oral glucose tolerance test, echocardiography and coronary angiography. Demographic data were recorded and blood samples obtained. According to the 1hPG cut-off point of 8.6 mm, patients were divided into two groups: 1hPG ≥ 8.6 mm (n = 65) and 1hPG < 8.6 mm (n = 139).

RESULTS

Compared with the 1hPG < 8.6 mm group, subjects with 1hPG ≥ 8.6 mm had a worse metabolic profile, exhibiting significantly higher body mass index, systolic blood pressure, triglyceride level and lower HDL-cholesterol level. Plasma high-sensitivity CRP (hsCRP) levels were higher in the 1hPG ≥ 8.6 mm group than in the 1hPG < 8.6 mm group. Coronary angiography revealed that single-vessel changes were more frequent in the 1hPG < 8.6 mm group, but there were no significant differences in the Gensini score.

CONCLUSIONS

Patients with CHD with 1hPG ≥ 8.6 mm have a worse metabolic profile, higher levels of hsCRP and multi-vessel coronary atherosclerosis. These findings suggest that, in patients with CHD, elevated 1hPG increases coronary risk factors and may be a marker for early-stage glucose intolerance.

One-hour post-load plasma glucose and IGF-1 in hypertensive patients

BACKGROUND

In normoglucose-tolerant subjects (NGT), 1-h post-load plasma glucose value ≥155 mg/dL, during an oral glucose tolerance test (OGTT), is associated with an increased risk of type-2 diabetes (T2D) and subclinical organ damage. Insulin-like growth factor-1 (IGF-1) is involved in the pathogenesis of insulin resistance (IR) and T2D. Moreover, hypertensives have different degrees of IR and different levels of IGF-1. Actually, there are no data supporting the association between post-load glucose and IGF-1; thus, the aim of the study was to investigate this relationship.

MATERIALS AND METHODS

We enrolled 1126 never-treated hypertensive subjects who underwent an OGTT and clinical characterization. Insulin sensitivity was assessed by the Matsuda index. IGF-1 was measured by a sensitive immunoradiometric assay.

RESULTS

Among participants, 764 had NGT, 263 had impaired glucose tolerance (IGT) and 99 had T2D. According to the 1-h post-load plasma glucose cut-off point of 155 mg/dL, we divided NGT subjects into NGT < 155 mg/dL and NGT ≥ 155 mg/dL. NGT ≥ 155 in comparison with NGT < 155 had significantly reduced insulin sensitivity and IGF-1 levels. At multiple regression analysis, IGF-1 was the major determinant of 1-h post-load glucose in NGT ≥ 155 subjects, IGT and diabetics, accounting for 20·9%, 17·7% and 15·5% of its variation in the respective models.

CONCLUSIONS

In hypertensive NGT ≥ 155 subjects, IGF-1 results strongly associated with 1-h post-load glucose, similarly to that observed in IGT and diabetics. This finding has clinical relevance because both low IGF-1 levels and 1-h post-load glucose in NGT subjects are associated with subclinical organ damage, an independent predictor of cardiovascular events.

Association between one-hour post-load plasma glucose levels and vascular stiffness in essential hypertension

Objectives

Pulse wave velocity (PWV) is a surrogate end-point for cardiovascular morbidity and mortality. A plasma glucose value ≥155 mg/dl for the 1-hour post-load plasma glucose during an oral glucose tolerance test (OGTT) is able to identify subjects with normal glucose tolerance (NGT) at high-risk for type-2 diabetes (T2D) and for subclinical organ damage. Thus, we addressed the question if 1-hour post-load plasma glucose levels, affects PWV and its central hemodynamic correlates, as augmentation pressure (AP) and augmentation index (AI).

Methods

We enrolled 584 newly diagnosed hypertensives. All patients underwent OGTT and measurements of PWV, AP and AI. Insulin sensitivity was assessed by Matsuda-index.

Results

Among participants, 424 were NGT and 160 had impaired glucose tolerance (IGT). Of 424 NGT, 278 had 1-h post-load plasma glucose <155 mg/dl (NGT<155) and 146 had 1-h post-load plasma glucose ≥155 mg/dl (NGT≥155). NGT≥155 had a worse insulin sensitivity and higher hs-CRP than NGT<155, similar to IGT subjects. In addition, NGT ≥155 in comparison with NGT<155 had higher central systolic blood pressure (134±12 vs 131±10 mmHg), as well as PWV (8.4±3.7 vs 6.7±1.7 m/s), AP (12.5±7.1 vs 9.8±5.7 mmHg) and AI (29.4±11.9 vs 25.1±12.4%), and similar to IGT. At multiple regression analysis, 1-h post-load plasma glucose resulted the major determinant of all indices of vascular stiffness.

Conclusion

Hypertensive NGT≥155 subjects, compared with NGT<155, have higher PWV and its hemodynamic correlates that increase their cardiovascular risk profile.

Insulin sensitivity, β-cell function, and incretin effect in individuals with elevated 1-hour postload plasma glucose levels

OBJECTIVE

Individuals with normal glucose tolerance (NGT), whose 1-h postload plasma glucose is ≥155 mg/dL (NGT 1h-high), have an increased risk of type 2 diabetes. The purpose of this study was to characterize their metabolic phenotype.

RESEARCH DESIGN AND METHODS

A total of 305 nondiabetic offspring of type 2 diabetic patients was consecutively recruited. Insulin secretion was assessed using both indexes derived from oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (IVGTT). Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp.

RESULTS

Compared with individuals with a 1-h postload plasma glucose <155 mg/dL (NGT 1h-low), NGT 1h-high individuals exhibited lower insulin sensitivity after adjustment for age, sex, and BMI. Insulin secretion estimated from the OGTT did not differ between the two groups of individuals. By contrast, compared with NGT 1h-low individuals, the acute insulin response during an IVGTT and the disposition index were significantly reduced in NGT 1h-high individuals after adjustment for age, sex, and BMI. Incretin effect, estimated as the ratio between total insulin responses during OGTT and IVGTT, was higher in NGT 1h-high individuals compared with NGT 1h-low individuals.

CONCLUSIONS

NGT 1h-high individuals may represent an intermediate state of glucose intolerance between NGT and type 2 diabetes characterized by insulin resistance and reduced β-cell function, the two main pathophysiological defects responsible for the development of type 2 diabetes. Postload hyperglycemia is the result of an intrinsic β-cell defect rather than impaired incretin effect.

Serum uric acid and 1-h postload glucose in essential hypertension

OBJECTIVE

Subjects who are normal glucose tolerant (NGT) are considered at low risk, even if a plasma glucose value ≥155 mg/dL for the 1-h postload plasma glucose during an oral glucose tolerance test (OGTT) is able to identify NGT subjects at high risk for type 2 diabetes and subclinical organ damage. Hyperuricemia is associated with several risk factors for cardiovascular diseases such as hypertension, insulin resistance, and diabetes. However, it is unknown whether uric acid (UA) is able to affect 1-h postload plasma glucose in hypertensive NGT subjects.

RESEARCH DESIGN AND METHODS

From a cohort of ∼1,200 uncomplicated hypertensive outpatients who underwent OGTT, we selected 955 subjects (548 men and 407 women) aged 45.6 ± 10.1 years. Laboratory evaluations were performed, and estimated glomerular filtration rate was assessed by using the new equation proposed by investigators in the Chronic Kidney Disease Epidemiology Collaboration.

RESULTS

Considering different stepwise multivariate linear regression models, UA was the major predictor of 1-h postload glucose in the entire population, with NGT ≥155 subjects, impaired glucose tolerant, and type 2 diabetic patients accounting for 26.0% (P < 0.0001), 25.3% (P < 0.0001), 13.5% (P < 0.0001), and 13.5% (P = 0.003) of its variation in the respective models.

CONCLUSIONS

We documented that in hypertensive NGT ≥155 subjects, UA is strongly associated with 1-h postload glucose, similarly to what is observed in impaired glucose tolerant and diabetic patients.