Association of peripheral nerve conduction in diabetic neuropathy with subclinical left ventricular systolic dysfunction

Development and validation of a prediction model of left ventricular systolic dysfunction in type 2 diabetes mellitus

Background

Left ventricular longitudinal myocardial systolic dysfunction (LVSD) represents a critical risk factor for diabetes-related cardiovascular events. This study aimed to develop a well-calibrated and convenient risk prediction model to investigate early predictive risk of LVSD in type 2 diabetes mellitus (T2DM) patients with preserved left ventricular ejection fraction (LVEF), and to evaluate its performance.

Methods

A total of 310 patients with T2DM from June 2020 to October 2021 at the Second Affiliated Hospital of Nanchang University were prospectively enrolled and randomly assigned to a training set (n=217) and a validation set (n=93) at a 7:3 ratio. Basic characteristics, laboratory tests, echocardiographic parameters, two-dimensional global longitudinal strain (GLS) parameters, and medication use were collected. LVSD in patients with T2DM with preserved LVEF was defined as an absolute value of GLS <18%. The least absolute shrinkage and selection operator (LASSO) regression was applied to optimize the screening variables, followed by multivariate logistic regression to identify independent risk factors for predicting LVSD, and a nomogram was established. The receiver operating characteristic (ROC) curves, area under the curve (AUC) values, calibration plot, and decision curve analysis (DCA) were used to verify and evaluate the nomogram's discrimination, calibration, and clinical validity.

Results

A total of 8 independent risk predictors of LVSD in T2DM were extracted and incorporated into the nomogram, as evaluated using LASSO regression analysis and multivariate logistic regression analysis, including body mass index (BMI), T2DM duration, blood urea nitrogen (BUN), left ventricular (LV) mass index, E/e', diabetic retinopathy, diabetic peripheral neuropathy, and diabetic nephropathy. The nomogram indicated excellent prediction properties with AUC values of 0.922 and 0.918 for the training set and validation set, respectively. Further, the predictive nomogram demonstrated outstanding consistency between the predicted probability and the actual probability in terms of the calibration plots. DCA showed also that the predicted nomogram was clinically beneficial.

Conclusions

This study identified independent risk factors for LVSD in patients with T2DM and developed a predictive nomogram. It allows for clinical decision-making to timely intervene or delay the occurrence of LVSD.

The role of Cardiotrophin-1 and echocardiography in early detection of subclinical diabetic cardiomyopathy in children and adolescents with type 1 diabetes mellitus

OBJECTIVES

To assess the role of Cardiotrophin-1 (CT-1) and echocardiography in early detection of subclinical Diabetic Cardiomyopathy (DCM) in children with type 1 Diabetes Mellitus (T1D).

METHODS

This case-control study included two groups of children and adolescents aged between 7 and 18. Group (1) included forty patients with T1D (duration > 5 years) regularly followed at the children's hospital of Cairo University, and Group (2) included forty age and sex-matched healthy subjects as a control group. The serum level of CT-1 was measured, and conventional echocardiography, tissue Doppler imaging (TDI), and 2D speckle tracking echocardiography were performed.

RESULTS

The level of CT-1 in the cases ranged from 11 to 1039.4 pg/ml with a median (IQR) of 19.4 (16.60-25.7) pg/ml, while its level in the control group ranged from 10.8 to 162.6 pg/ml with a median (IQR) of 20.2 (16.2-24.8) pg/ml. CT-1 levels showed no statistically significant difference between cases and controls. Patients had significantly higher mean left ventricle E/E' ratio (p<0.001), lower mean 2D global longitudinal strain (GLS) of the left ventricle (LV) (p<0.001), and lower mean GLS of the right ventricle (RV) (p<0.001) compared to controls. Ofpatients with diabetes, 75 % had LV diastolic dysfunction, 85 % had RV diastolic dysfunction, 97.5 % had LV systolic dysfunction, and 100 % had RV systolic dysfunction.

CONCLUSIONS

Non-conventional echocardiography is important for early perception of subclinical DCM in patients with T1D. CT-1 was not specific for early detection of DCM.

Left ventricular systolic dyssynchrony: a novel imaging marker for early assessment of myocardial damage in Chinese type 2 diabetes mellitus patients with normal left ventricular ejection fraction and normal myocardial perfusion

OBJECTIVES

Myocardial damage is the important cause of heart failure (HF) in type 2 diabetes mellitus (T2DM), which is difficult to early diagnose, especially in T2DM with normal left ventricular ejection fraction (LVEF) and normal myocardial perfusion. The goal was to evaluate myocardial damage in T2DM with normal LVEF and normal myocardial perfusion by detecting left ventricular systolic dyssynchrony (LVSD), and find out the risk factors associated with LVSD.

METHODS

This study included 95 T2DM with normal LVEF, normal myocardial perfusion. 69 consecutive individuals without T2DM and CAD were enrolled as the control group with age-, sex- and BMI-matched. All participants underwent stress/rest 99mtechnetium-sestamibi (99mTc-MIBI) gated myocardial perfusion imaging (GMPI) and two-dimensional echocardiography within 1 week. Clinical data including age, gender, BMI, duration of diabetes, chronic diabetic complications, glycated haemoglobin A1c (HbA1c), fast blood glucose (FBG) and Brain Natriuretic Peptide (BNP) were collected from medical records. Left ventricular synchrony parameters were acquired, including phase standard deviation (PSD) and phase histogram bandwidth (PBW) by rest GMPI.

RESULTS

PSD and PBW in T2DM group were significantly higher than control group (P < .05). LVSD was detected in 20 (21%) T2DM patients. Compared to non-LVSD T2DM group, LVSD T2DM group had higher BMI, higher prevalence of BNP [Formula: see text] 35 pg/mL and chronic diabetic complications (P < .05). BNP [Formula: see text] 35 pg/mL had mild positive association with LVSD (r = 0.318, P = .004). In multivariate logistic regression, chronic diabetic complications and high BMI (> 23.4 kg/m2) were independent risk factors of LVSD (OR 5.64, 95% CI 1.58-20.16, P = .008; OR 6.77, 95% CI 1.59-28.89, P = .010).

CONCLUSIONS

LVSD existed in T2DM patients with normal LVEF and normal myocardial perfusion. Chronic diabetic complications and high BMI (> 23.4 kg/m2) were the independent risk factors of LVSD. LVSD based on GMPI can be the novel imaging marker to early assess myocardial damage in T2DM patients.

Association of peripheral neuropathy with subclinical left ventricular dysfunction in patients with type 2 diabetes

OBJECTIVES

The impacts of diabetic peripheral neuropathy (DPN) on clinical manifestations of left ventricular (LV) function in patients suffering from type 2 diabetes mellitus (T2DM) and the preserved LV ejection fraction (LVEF) lack a full evaluation. This study was carried out to investigate the correlation of peripheral neuropathy with subclinical LV systolic dysfunction, accompanied by the exploration of the relevant clinical features of peripheral neuropathy in these patients.

METHODS

A retrospective analysis was conducted depending on the data of 101 consecutive inpatients with T2DM and preserved LVEF (all ≥ 50 %), without coronary artery disease and other histories of heart disease. All subjects received both a nerve conduction assessment and a speckle-tracking echocardiography examination. Global longitudinal strain (GLS) was conducted to assess the subclinical LV systolic function.

RESULTS

Forty-six (46 %) patients were diagnosed as DPN according to electrophysiological examination and clinical assessment. A significant difference was revealed in GLS between patients with and without DPN (16.5 ± 2.8 vs. 19.3 ± 3.4, p < 0.001). Multiple logistic regression analysis indicated GLS as one of the independent determinative factors for DPN (odds ratio, 0.68; P < 0.001). In addition, motor-sensory nerve conduction exhibited a significant positive correlation with GLS, which may not be revealed between the types of peripheral nerve damage.

CONCLUSIONS

Despite the preserved LVEF, the subclinical LV myocardial dysfunction may have occurred in T2DM patients with DPN. Peripheral nerve conduction was significantly correlated with GLS. An early assessment of nerve conduction may exert a dual warning significance for the progression of subclinical LV dysfunction in asymptomatic patients with T2DM.

Diabetic microvascular complications are associated with left atrial structural alterations in asymptomatic type 2 diabetes patients: A cross-sectional study

AIMS

We used 4D-Auto LAQ to quantitatively evaluate the morphological and functional changes of left atrium in patients with asymptomatic type 2 diabetes mellitus (T2DM), and explored its correlations with diabetic microvascular complications (MICRO).

METHODS

This study included 319 patients with asymptomatic T2DM. According to the occurrence of MICRO, these patients were divided into 3 groups: patients with no complication, 1 complication, and 2-3 complications. 4D-Auto LAQ was used to evaluate left atrial volume (LAVImin, LAVImax, LAVIpre) and calculate the left atrial function (DEI, PEI, AEI) in different phases. Multiple linear regression was used to analyze the correlation between changes in left atrial volume and function and the number of MICROs in DM patients.

RESULTS

A total of 279 patients with asymptomatic T2DM were included in this study. (1) The ultrasound data of the three T2DM groups showed that there was no significant difference in left ventricular size and function among the three groups; (2) with the increase of MICRO number, the left atrial volume (LAVImin, LAVImax, LAVIpre) progressively increased, the left atrial storage function index (DEI) gradually decreased, and the differences were significant (P < 0.05). (3) Multiple linear regression analysis showed that: with the increase of MICRO number (no complication→1 complication→2-3 complications), the left atrial volume (LAVImin, LAVIpre) showed an increasing trend (both P < 0.05).

CONCLUSION

In asymptomatic T2DM patients, MICRO number showed a significant positive correlation with LAVImin and LAVIpre (P < 0.05). Therefore, the increase in left atrial volume can dynamically reflect the severity of microvascular lesions in patients with asymptomatic T2DM.

Association of left ventricular longitudinal myocardial function with subclinical right ventricular dysfunction in type 2 diabetes mellitus

Background

Left ventricular (LV) involvement in diabetic cardiomyopathy has been reported; however, only limited data exist on right ventricular (RV) involvement. Therefore, our purpose was to investigate RV systolic dysfunction and its association with LV longitudinal myocardial dysfunction in patients with type 2 diabetes mellitus (T2DM) and preserved LV ejection fraction (LVEF).

Methods

We studied 177 T2DM patients with preserved LVEF and 79 age-, sex-, and LVEF-matched healthy volunteers. LV longitudinal myocardial function was assessed as global longitudinal strain (GLS), and RV systolic function was assessed as RV free-wall strain, and predefined cutoff values for subclinical dysfunction were set at GLS < 18% and RV free-wall strain < 20%, respectively.

Results

RV free-wall strain in T2DM patients was significantly lower than that in normal controls (19.3% ± 4.8% vs. 24.4% ± 5.1%; P < 0.0001). RV free-wall strain in T2DM patients and LV longitudinal dysfunction was similar compared to that in T2DM patients without (19.0 ± 4.5% vs. 19.6 ± 5.0%, P = 0.40). Furthermore, multivariate logistic regression analyses showed that GLS was independently associated with RV systolic dysfunction as well as mitral inflow E and mitral e′ annular velocities ratio (odds ratio, 1.16; 95% confidence interval: 1.03–1.31; P < 0.05). Sequential logistic models evaluating the association of RV systolic dysfunction in T2DM patients showed an improvement in clinical variables (χ² = 6.2) with the addition of conventional echocardiographic parameters (χ² = 13.4, P < 0.001) and a further improvement with the addition of GLS (χ² = 20.8, P < 0.001).

Conclusion

RV subclinical systolic dysfunction was observed in T2DM patients with preserved LVEF and was associated with LV longitudinal myocardial dysfunction. Our findings may provide additional findings for the management of T2DM patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01404-5.

Diabetic microvascular complications are associated with reduced global longitudinal strain independent of atherosclerotic coronary artery disease in asymptomatic patients with diabetes mellitus: a cross-sectional study

Background

Reduced left ventricular function, assessed by global longitudinal strain (GLS), is sometimes observed in asymptomatic patients with diabetes mellitus (DM) and is often present in patients with diabetes-related microvascular complications. Our aim was to assess the association between microvascular complications, coronary artery plaque burden (PB) and GLS in asymptomatic patients with DM and non-obstructive coronary artery disease (CAD).

Methods

This cross-sectional study included patients with DM without any history, symptoms or objective evidence of obstructive CAD. All patients were identified in the outpatient Clinic of Endocrinology at Odense University Hospital Svendborg. An echocardiography and a coronary computed tomography angiography were performed to assess GLS and the degree of CAD, respectively. A coronary artery stenosis < 50% was considered non-obstructive. A linear regression model was used to evaluate the impact of potential confounders on GLS with adjustment of body mass index (BMI), mean arterial pressure (MAP), microvascular complications, type of diabetes, tissue Doppler average early diastolic mitral annulus velocity (e’) and PB.

Results

Two hundred and twenty-two patients were included, of whom 172 (77%) had type 2 DM and 50 (23%) had type 1 diabetes. One hundred and eleven (50%) patients had microvascular complications. GLS decreased as the burden of microvascular complications increased (P-trend = 0.01): no microvascular complications, GLS (− 16.4 ± 2.5%), 1 microvascular complication (− 16.0 ± 2.5%) and 2–3 microvascular complications (− 14.9 ± 2.8%). The reduction in GLS remained significant after multivariable adjustment (β 0.50 [95% CI 0.11–0.88], p = 0.01). BMI (β 0.12 [95% CI 0.05–0.19]) and MAP (β 0.05 [95% CI 0.01–0.08]) were associated with reduced GLS. In addition, an increased number of microvascular complications was associated with increased PB (β 2.97 [95% CI 0.42–5.51], p = 0.02) in a univariable linear regression model, whereas there was no significant association between PB and GLS.

Conclusions

The burden of microvascular complications was associated with reduced GLS independent of other cardiovascular risk factors in asymptomatic patients with DM and non-obstructive CAD. In addition, the burden of microvascular complications was associated with increasing PB, whereas PB was not associated with GLS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02063-w.

Effect of heart rate on left ventricular longitudinal myocardial function in type 2 diabetes mellitus

BACKGROUND

Left ventricular (LV) longitudinal myocardial dysfunction is considered a marker of preclinical LV dysfunction in patients with type 2 diabetes mellitus (T2DM). High heart rate (HR) is associated with cardiovascular outcomes, but the effect of HR on LV longitudinal myocardial function in T2DM patients is uncertain.

METHODS

We studied 192 T2DM patients with preserved LV ejection fraction (LVEF), and 81 age-, sex-, and LVEF-matched healthy volunteers. HR was measured as the average HR during echocardiography, and high HR was defined as resting HR ≥ 70 beats/minute. LV longitudinal myocardial function was assessed as global longitudinal strain (GLS). The predefined cutoff for subclinical LV dysfunction was set at GLS < 18%.

RESULTS

GLS in T2DM patients with high HR was significantly lower than that in T2DM patients with low HR (16.3% ± 4.2% vs. 17.8% ± 2.8%; P = 0.03), whereas GLS in normal subjects with high and low HR was similar (20.3 ± 1.7% vs. 20.3 ± 2.0%; P = 0.99). Multivariable logistic regression analysis showed that high HR (odds ratio: 1.04; 95% confidence interval: 1.01-1.07; P = 0.01) was independently associated with GLS < 18% in T2DM patients as well as HbA1c, T2DM duration, LVEF, body mass index, and mitral inflow E and mitral e' annular velocity ratio. One sequential logistic model evaluating the associations between GLS < 18% and clinical variables in T2DM patients showed an improvement with the addition of LVEF and E/e' (P < 0.001) and a further improvement with the addition of high HR (P < 0.001).

CONCLUSION

Compared with normal subjects, resting HR was associated with LV longitudinal myocardial function in asymptomatic T2DM patients with preserved LVEF. Our findings provide new insights on the management of T2DM patients.

Impact of diabetes mellitus on left ventricular longitudinal function of patients with non-ischemic dilated cardiomyopathy

Background

Left ventricular (LV) longitudinal dysfunction has been identified in type 2 diabetes mellitus (T2DM) patients with preserved LV ejection fraction (LVEF). However, the impact of T2DM on LV longitudinal function or the association of LV longitudinal function with outcome for dilated cardiomyopathy (DCM) remains unclear.

Methods

We retrospectively studied 206 patients with non-ischemic DCM, mean age of 59 ± 17 years and LVEF of 31 ± 8% (all < 45%). All patients underwent a standard echocardiographic examination, and LV longitudinal function was assessed in terms of global longitudinal strain (GLS). Long-term outcomes were assessed, with a median follow-up period of 6.2 years, as primary endpoints of death from or hospitalization for deteriorating heart failure.

Results

GLS of DCM patients with T2DM (n = 55) was significantly lower than that in DCM patients without T2DM (n = 151) in spite of similar conventional LV function (7.0 ± 2.0% vs. 7.8 ± 2.2%, p = 0.03). Kaplan–Meier curves indicated that long-term outcomes for DCM patients without T2DM were better than for those with T2DM (log-rank p = 0.001). Subdividing the two groups into four with by using the median value of GLS (7.9%) showed long-term outcome was worst for DCM patients with T2DM and low GLS. Cox proportional hazards analyses demonstrated an independent association of T2DM, GLS and left atrial volume index with long-term outcome. Moreover, multiple regression analysis for the association of GLS showed that T2DM was the independent determinant parameter for GLS as well as for LVEF and left atrial volume index.

Conclusion

Management of DCM patients with T2DM may be improved by using GLS guidance.

Positive effect of dapagliflozin on left ventricular longitudinal function for type 2 diabetic mellitus patients with chronic heart failure

BACKGROUND

The effect of sodium glucose cotransporter type 2 (SGLT2) inhibitor on left ventricular (LV) longitudinal myocardial function in type 2 diabetes mellitus (T2DM) patients with heart failure (HF) has remained unclear.

METHODS

We analyzed data from our previous prospective multicenter study, in which we investigated the effect of the SGLT2 inhibitor dapagliflozin on LV diastolic functional parameters of T2DM patients with stable HF at five institutions in Japan. Echocardiography was performed at baseline and 6 months after administration of dapagliflozin. LV diastolic function was defined as the ratio of mitral inflow E to mitral e' annular velocities (E/e'). LV longitudinal myocardial function was assessed as global longitudinal strain (GLS), which in turn was determined as the averaged peak longitudinal strain from standard LV apical views.

RESULTS

E/e' significantly decreased from 9.3 to 8.5 cm/s 6 months after administration of dapagliflozin (p = 0.020) as previously described, while GLS showed significant improvement from 15.5 ± 3.5% to 16.9 ± 4.1% (p < 0.01) 6 months after administration of dapagliflozin. Furthermore, improvement of GLS in HF with preserved ejection fraction patients was more significant from 17.0 ± 1.9% to 18.7 ± 2.0% (p < 0.001), compared to that in HF with mid-range ejection fraction and HF with reduced ejection fraction patients from 14.4 ± 2.4% to 15.5 ± 1.8% (p = 0.06) and from 8.1 ± 1.5% to 7.8 ± 2.1% (p = 0.44), respectively. It was noteworthy that multiple regression analysis showed that the change in GLS after administration of dapagliflozin was the only independent determinant parameters for the change in E/e' after administration of dapagliflozin.

CONCLUSION

Dapagliflozin was found to be associated with improvement of LV longitudinal myocardial function, which led to further improvement of LV diastolic function of T2DM patients with stable HF. GLS-guided management may thus lead to improved management of T2DM patients with stable HF.

Association between Circulating B-Type Natriuretic Peptide and Diabetic Peripheral Neuropathy: A Cross-Sectional Study of a Chinese Type 2 Diabetic Population

Cardiovascular disease which is associated with cardiac dysfunction, usually measured with circulating levels of B-type natriuretic peptide (BNP), has been associated with incidence and progression of diabetic peripheral neuropathy (DPN). The potential relationship of circulating physiological levels of BNP with DPN, however, has not been reported. Circulating levels of BNP were measured in 258 patients with type 2 diabetes mellitus (T2DM), and participants were divided into a DPN group (n = 61) and no DPN group (n = 197). The relationship between circulating physiological levels of BNP and DPN and other parameters was analyzed. Circulating levels of BNP were significantly elevated in T2DM patients with DPN compared to those without (P = 0.001). Circulating levels of BNP were significantly and positively associated with systolic blood pressure (P = 0.035), neutrophil-to-lymphocyte ratio (P = 0.007), creatinine (P = 0.030), vibration perception threshold values (P = 0.021), and the prevalence of diabetic foot ulceration (P = 0.039), peripheral arterial disease (P = 0.013), DPN (P = 0.032), and diabetic nephropathy (P = 0.020) and negatively with lymphocyte count (P = 0.003) and ankle-brachial index (P = 0.038), irrespective of age, sex, and body mass index. Moreover, circulating levels of BNP was an independent decisive factor for the presence of DPN after multivariate adjustment (odds ratio, 1.044; 95% confidence interval, 1.006-1.084; P = 0.024). Additionally, the higher quartiles of circulating BNP were related significantly to an increased risk of DPN compared to the lowest quartile (P = 0.003). Last but most importantly, the analysis of receiver operating characteristic curves revealed that the best cutoff value for circulating levels of BNP to predict DPN was 15.18 pg/mL (sensitivity 78.7% and specificity 48.2%). These findings suggest that high circulating physiological levels of BNP may be associated with the development of DPN and may be a potential biomarker for DPN in patients with T2DM.

Comparação entre pico de torque e flexibilidade dos membros inferiores de indivíduos com e sem diabetes mellitus tipo 2

RESUMO O objetivo deste trabalho foi comparar o pico de torque e flexibilidade dos membros inferiores de indivíduos com e sem diabetes mellitus tipo 2 (DM2). O método foi o estudo com grupos expostos e não expostos ao DM2. Foram incluídos indivíduos com diagnóstico médico de DM2, encaminhados para eletroneuromiografia, e não expostos ao DM2. Foram excluídos da pesquisa indivíduos com idade superior a 70 anos ou que, por algum motivo, não conseguiram realizar um ou dois dos testes. A amostra foi não probabilística, composta por 64 indivíduos: 34 (53,1%) expostos ao DM2 e 30 não expostos; 50 (78,1%) eram do sexo feminino, a idade média era de 60,7±7,1 anos, e o membro inferior dominante era o direito em 57 (89,1%) dos indivíduos. Comparando indivíduos com e sem diagnóstico de DM2, observou-se redução do torque de flexão à esquerda, em velocidade angular de 120° (25,94±2,26 vs. 33,79±2,4nm, p=0,027, respectivamente). Relatou-se menor valor do torque de dorsiflexão à direita, em velocidade angular de 60°, dos diabéticos em relação aos não diabéticos (10,95±0,89 vs. 13,95±0,96nm, p=0,033, respectivamente). Ao comparar indivíduos com DM2, com e sem diagnóstico de neuropatia diabética periférica (NDP), notou-se maior déficit de flexão entre os indivíduos neuropatas em comparação com não neuropatas (46,57±9,47 vs. 11,63±13,85nm, p=0,049, respectivamente). Não foram encontradas diferenças estatisticamente significativas ao comparar os grupos de expostos e não expostos ao DM2 e diabéticos neuropatas e não neuropatas.

Sensory Neuropathy Affects Cardiac miRNA Expression Network Targeting IGF-1, SLC2a-12, EIF-4e, and ULK-2 mRNAs

Background: Here we examined myocardial microRNA (miRNA) expression profile in a sensory neuropathy model with cardiac diastolic dysfunction and aimed to identify key mRNA molecular targets of the differentially expressed miRNAs that may contribute to cardiac dysfunction. Methods: Male Wistar rats were treated with vehicle or capsaicin for 3 days to induce systemic sensory neuropathy. Seven days later, diastolic dysfunction was detected by echocardiography, and miRNAs were isolated from the whole ventricles. Results: Out of 711 known miRNAs measured by miRNA microarray, the expression of 257 miRNAs was detected in the heart. As compared to vehicle-treated hearts, miR-344b, miR-466b, miR-98, let-7a, miR-1, miR-206, and miR-34b were downregulated, while miR-181a was upregulated as validated also by quantitative real time polymerase chain reaction (qRT-PCR). By an in silico network analysis, we identified common mRNA targets (insulin-like growth factor 1 (IGF-1), solute carrier family 2 facilitated glucose transporter member 12 (SLC2a-12), eukaryotic translation initiation factor 4e (EIF-4e), and Unc-51 like autophagy activating kinase 2 (ULK-2)) targeted by at least three altered miRNAs. Predicted upregulation of these mRNA targets were validated by qRT-PCR. Conclusion: This is the first demonstration that sensory neuropathy affects cardiac miRNA expression network targeting IGF-1, SLC2a-12, EIF-4e, and ULK-2, which may contribute to cardiac diastolic dysfunction. These results further support the need for unbiased omics approach followed by in silico prediction and validation of molecular targets to reveal novel pathomechanisms.

Left atrial, ventricular and atrio-ventricular strain in patients with subclinical heart dysfunction

Arterial hypertension (AH) and diabetes mellitus (DM) are the most common causes of heart deterioration because of their high prevalence in the population. The aim of this study was to evaluate peak left atrial (LA), longitudinal strain (PALS), left ventricular (LV), longitudinal  strain (LS) and global atrial-ventricular strain (GAVS), by speckle-tracking echocardiography (STE), in asymptomatic patients with AH or/and DM and normal LA, LV size and ejection fraction (EF), to analyze their capability to detect early subclinical dysfunction. We enrolled 162 patients affected by AH and/or DM with normal indexed LA volume, LV end-diastolic diameter and a LVEF > 52% (females) or > 54% (males) (60 hypertensives, 52 diabetics and 50 both) and 60 healthy controls. All subjects underwent standard and advanced STE. PALS, LS and GAVS were measured. GAVS was calculated as the algebraic sum of absolute PALS and LS values in four- and two-chambers views. LS, although with lower values in hypertensives, diabetics and both, did not show significant differences between groups. PALS and GAVS were significantly reduced in AH (31.9 ± 10.3% and 49.7 ± 11.2%, respectively) and DM (26.2 ± 7.1% and 42.6 ± 9.8%) compared to controls, and even more if the two coexisted (20.4 ± 6.5% and 37.1 ± 8.4%). PALS had the highest statistical significance and was able to identify subclinical damage independently from LS value. PALS was reduced in patients with AH and/or DM without alteration of standard echo indexes. The value of PALS was independent from LS and was sufficient to identify heart dysfunction in an earlier stage.

Utility of strain imaging in conjunction with heart failure stage classification for heart failure patient management

The American College of Cardiology Foundation/American Heart Association (ACCF/AHA) classification, based on structural changes and symptoms, classifies stages of heart failure (HF) development as Stages A-D. This HF classification emphasizes the development and progression of the disease and can be used to describe individuals and populations. Since HF is considered a progressive disorder that can be represented as a clinical continuum, individuals at a particular HF stage require specific management with the long-term goal of avoiding HF development and progression. Although early detection of subclinical left ventricular (LV) dysfunction is essential for delaying progression to HF, the assessment of such dysfunction can be challenging. While echocardiography plays a pivotal role in the quantification and early detection of LV structural findings, two-dimensional speckle-tracking echocardiographic parameters, especially global longitudinal strain (GLS), have recently been reported to be sensitive markers of early subtle abnormalities of LV myocardial performance. They are thus helpful for prediction of outcomes for various cardiac diseases, and superior to conventional echocardiographic indices such as LV ejection fraction, mitral inflow E and mitral e' annular velocities ratio. Strain imaging, especially GLS-guided management for patients at a particular stage of HF, may therefore have the potential to prevent progression to later HF stages and may offer new insights into the management of HF patients. This article reviews the utility of strain imaging, especially GLS in conjunction with HF stage classification, and future perspectives for HF patient management.

Association of left ventricular myocardial dysfunction with diabetic polyneuropathy

BACKGROUND

The pathogenesis of left ventricular (LV) dysfunction in diabetes has been attracting attention. It has been reported that LV longitudinal systolic myocardial function determined by speckle tracking echocardiography (STE) is associated with diabetic polyneuropathy (DPN). However, the relationship between the severity of peripheral neuropathy and LV myocardial dysfunction is unknown. This study examined the relationship between the severity of DPN and echocardiographic parameters as well as clinical features.

METHODS

The subjects were 166 patients (57 ± 14 years old) with diabetes who had a normal LV ejection fraction (≥ 55%). To assess LV longitudinal systolic function, global longitudinal strain (GLS) was calculated by two-dimensional STE as the average peak strain of 18 LV segments in three standard apical views. A nerve conduction study (NCS) was performed in each subject to assess the severity of neuropathy based on the NCS Baba Classification (Grade 0: no apparent abnormalities-Grade IV: abolition). Three nerves in the lower extremity were examined: tibial nerve (F-wave latency, motor nerve conduction velocity, and amplitude), sural nerve (sensory conduction velocity and amplitude), and peroneal nerve (motor nerve conduction velocity and amplitude).

RESULTS

Of the 166 subjects, 112 subjects (67.5%) were confirmed to have DPN, and all the subjects were divided into two groups according to the presence/absence of DPN. When multivariate analysis was performed using significant factors from univariate logistic regression analysis as explanatory variables, GLS was found to be an independent determinant of DPN (odds ratio: 0.55, p < 0.001). In multivariate analysis of NCS data, F-wave latency was the most important determinant of DPN (odds ratio: 1.43, p < 0.001). There was a significant negative correlation between F-wave latency and GLS (r = - 0.43, p < 0.001). Regarding the relation between GLS and the severity of DPN, GLS was significantly lower in patients with Grade I or higher DPN than in patients without DPN, but showed no significant difference between the grades of neuropathy. In addition, GLS was significantly lower when 2-3 lower extremity nerves were affected by DPN than in patients without DPN.

CONCLUSION

Patients with diabetes may already have subclinical LV myocardial dysfunction when DPN is Grade I. Assessment of LV longitudinal systolic function by GLS may be important in diabetic patients with DPN.

Future Perspectives for Management of Stage A Heart Failure

Patients with Stage A heart failure (HF) show no HF symptoms but have related comorbid diseases with a high risk of progressing to HF. Screening for comorbid diseases warrants closer attention because of the growing interest in addressing Stage A HF as the best means of preventing eventual progression to overt HF such as Stages C and D. The identification of individuals of Stage A HF is potentially useful for the implementation of HF-prevention strategies; however, not all Stage A HF patients develop left ventricular (LV) structural heart disease or symptomatic HF, which lead to advanced HF stages. Therefore, Stage A HF requires management with the long-term goal of avoiding HF development; likewise, Stage B HF patients are ideal targets for HF prevention. Although the early detection of subclinical LV dysfunction is, thus, essential for delaying the progression to HF, the assessment of subclinical LV dysfunction can be challenging. Global longitudinal strain (GLS) as assessed by speckle-tracking echocardiography has recently been reported to be a sensitive marker of early subtle LV myocardial abnormalities, helpful for the prediction of the outcomes for various cardiac diseases, and superior to conventional echocardiographic indices. GLS reflects LV longitudinal myocardial systolic function, and can be assessed usually by means of two-dimensional speckle-tracking. This article reviews the importance of the assessment of subclinical LV dysfunction in Stage A HF patients by means of GLS, and its current potential to prevent progression to later stage HF.

Impact of overweight on left ventricular function in type 2 diabetes mellitus

Background

Coexistence of left ventricular (LV) longitudinal myocardial systolic dysfunction with LV diastolic dysfunction could lead to heart failure with preserved ejection fraction (HFpEF). Diabetes mellitus (DM) is known as a significant factor associated with HFpEF. Although the mechanisms of DM-related LV myocardial injury are complex, it has been postulated that overweight contributes to the development of LV myocardial injury in type 2 diabetes mellitus (T2DM) patients. However, the precise impact of overweight on LV longitudinal myocardial systolic function in T2DM patients remains unclear.

Methods

We studied 145 asymptomatic T2DM patients with preserved LV ejection fraction (LVEF) without coronary artery disease. LV longitudinal myocardial systolic function was assessed by global longitudinal strain (GLS), which was defined as the average peak strain of 18-segments obtained from standard apical views. Overweight was defined as body mass index (BMI) ≥ 25 kg/m². Ninety age-, gender- and LVEF-matched healthy volunteers served as controls.

Results

GLS of overweight T2DM patients was significantly lower than that of non-overweight patients (17.9 ± 2.4% vs. 18.9 ± 2.6%, p < 0.05), whereas GLS of both overweight and non-overweight controls was similar (19.8 ± 1.3% vs. 20.4 ± 2.1%, p = 0.38). Furthermore, multiple regression analysis revealed that for T2DM patients, BMI was the independent determinant parameters for GLS as well as LV mass index.

Conclusions

Overweight has a greater effect on LV longitudinal myocardial systolic function in T2DM patients than on that in non-DM healthy subjects. Our finding further suggests that the strict control of overweight in T2DM patients may be associated with prevention of the development of HFpEF.

Diagnostic approaches for diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a cardiac dysfunction which affects approximately 12% of diabetic patients, leading to overt heart failure and death. However, there is not an efficient and specific methodology for DCM diagnosis, possibly because molecular mechanisms are not fully elucidated, and it remains asymptomatic for many years. Also, DCM frequently coexists with other comorbidities such as hypertension, obesity, dyslipidemia, and vasculopathies. Thus, human DCM is not specifically identified after heart failure is established. In this sense, echocardiography has been traditionally considered the gold standard imaging test to evaluate the presence of cardiac dysfunction, although other techniques may cover earlier DCM detection by quantification of altered myocardial metabolism and strain. In this sense, Phase-Magnetic Resonance Imaging and 2D/3D-Speckle Tracking Echocardiography may potentially diagnose and stratify diabetic patients. Additionally, this information could be completed with a quantification of specific plasma biomarkers related to related to initial stages of the disease. Cardiotrophin-1, activin A, insulin-like growth factor binding protein-7 (IGFBP-7) and Heart fatty-acid binding protein have demonstrated a stable positive correlation with cardiac hypertrophy, contractibility and steatosis responses. Thus, we suggest a combination of minimally-invasive diagnosis tools for human DCM recognition based on imaging techniques and measurements of related plasma biomarkers.

Myocardial dysfunction identified by three-dimensional speckle tracking echocardiography in type 2 diabetes patients relates to complications of microangiopathy

BACKGROUND

The clinical effect of diabetic microangiopathy on left ventricular (LV) function is still uncertain. The purpose of this study was to assess the relation between diabetic microvascular complications and comprehensive myocardial deformation measurements using three-dimensional (3D) speckle tracking echocardiography.

METHODS

Seventy-seven asymptomatic patients with type 2 diabetes mellitus (DM) and 35 age-matched healthy control subjects underwent 3D echocardiography. Patients with coronary artery disease or LV ejection fraction <50% were excluded. Presence of proliferative retinopathy, microalbuminuria as nephropathy, and decreased coefficient of variation of R-R intervals (CVRR) <3% as cardiac autonomic neuropathy were defined as diabetic microvascular complications.

RESULTS

LV ejection fraction, LV mass index, and global radial strain did not differ between control and DM patients. However, global longitudinal and circumferential strain and endocardial area change ratio were lower in patients with DM than in the controls (-12.0±3.0% vs. -16.2±1.9%, -27.7±7.1% vs. 32.2±5.7%, -37.6±7.6% vs. 44.0±6.2%, respectively, p<0.001). In DM patients, longitudinal strain is related to CVRR (R=0.58, p<0.001), retinopathy stage, and nephropathy stage.

CONCLUSIONS

Diabetic microangiopathy and its accumulated effects significantly related to subclinical LV dysfunction are characterized by impaired longitudinal shortening.

Xanthine Oxidase Activity in Type 2 Diabetes Mellitus Patients with and without Diabetic Peripheral Neuropathy

This study investigated the relationship between serum xanthine oxidase (XOD) activity and the occurrence of diabetic peripheral neuropathy (DPN) in type 2 diabetes mellitus (T2DM) patients. Serum XOD activity, ischemia-modified albumin (IMA), uric acid (UA), albumin, glycated hemoglobin (HbA1c), advanced glycation end products (AGE), total free thiols, atherogenic index of plasma (AIP), and body mass index (BMI) were measured in 80 T2DM patients (29 with and 51 without DPN), and 30 nondiabetic control subjects. Duration of diabetes, hypertension, medication, and microalbuminuria was recorded. Serum XOD activities in controls, non-DPN, and DPN were 5.7 ± 2.4 U/L, 20.3 ± 8.6 U/L, and 27.5 ± 10.6 U/L (p < 0.01), respectively. XOD activity was directly correlated to IMA, UA, BMI, HbA1c, and AGE, while inversely correlated to serum total free thiols. A multivariable logistic regression model, which included duration of diabetes, hypertension, AIP, HbA1c, UA, and XOD activity, revealed HbA1c [OR = 1.03 (1.00-1.05); p = 0.034] and XOD activity [OR = 1.07 (1.00-1.14); p = 0.036] as independent predictors of DPN. Serum XOD activity was well correlated to several other risk factors. These results indicate the role of XOD in the development of DPN among T2DM patients.