Diagnostic Thresholds for Pre-Diabetes Mellitus and Diabetes Mellitus and Subclinical Cardiac Disease in the General Population: Data From the ACE 1950 Study

Distribution and prognostic value of high-sensitivity cardiac troponin T and I across glycemic status: a population-based study

BACKGROUND

Whether distributions and prognostic values of high-sensitivity cardiac troponin (hs-cTn) T and I are different across normoglycemic, prediabetic, and diabetic populations is unknown.

METHODS

10127 adult participants from the National Health and Nutrition Examination Survey 1999-2004 with determined glycemic status and measurement of at least one of hs-cTn assays were included, from whom healthy participants and presumably healthy diabetic and prediabetic participants were selected to investigate pure impacts of glycemic status on distributions of hs-cTn. The nonparametric method and bootstrapping were used to derive the 99th upper reference limits of hs-cTn and 95% CI. Participants with available follow-up and hs-cTn concentrations of all 4 assays were included in prognostic analyses. Associations of hs-cTn with all-cause and cardiac-specific mortality were modeled by Cox proportional hazard regression under the complex survey design. The incremental value of hs-cTn to an established risk score in predicting cardiac-specific mortality was assessed by the 10-year area under time-dependent receiver operating characteristic curve (AUC) using the Fine-Grey competing risk model.

RESULTS

Among 9714 participants included in prognostic analyses, 5946 (61.2%) were normoglycemic, 2172 (22.4%) prediabetic, and 1596 (16.4%) diabetic. Hyperglycemic populations were older than the normoglycemic population but sex and race/ethnicity were similar. During the median follow-up of 16.8 years, hs-cTnT and hs-cTnI were independently associated with all-cause and cardiac-specific mortality across glycemic status. In the diabetic population, adjusted hazard ratios per 1-standard deviation increase of log-transformed hs-cTnT and hs-cTnI (Abbott) concentrations were 1.77 (95% CI 1.48-2.12; P < .001) and 1.83 (95% CI 1.33-2.53; P < .001), respectively, regarding cardiac-specific mortality. In the diabetic but not the normoglycemic population, adding either hs-cTnT (difference in AUC: 0.062; 95% CI 0.038-0.086; P < 0.001) or hs-cTnI (Abbott) (difference in AUC: 0.071; 95% CI 0.046-0.097; P < 0.001) would significantly increase the discriminative ability of the risk score; AUC of the score combined with hs-cTnT would be further improved by incorporating hs-cTnI (0.018; 95%CI 0.006-0.029; P = 0.002). The 99th percentile of hs-cTnT of the presumably healthy diabetic population was higher than the healthy population and had no overlap in 95% CIs, however, for hs-cTnI 99th percentiles of the two populations were very close and 95% CIs extensively overlapped.

CONCLUSIONS

Hs-cTnT and hs-cTnI demonstrated consistent prognostic associations across glycemic status but incremental predictive values in hyperglycemic populations only. The susceptibility of hs-cTnT 99th percentiles to diabetes plus the additive value of hs-cTnI to hs-cTnT in diabetic cardiovascular risk stratification suggested hs-cTnI and hs-cTnT may be differentially associated with glycemic status, but further research is needed to illustrate the interaction between hyperglycemia and hs-cTn.

Early insulin resistance in normoglycemic low-risk individuals is associated with subclinical atherosclerosis

BACKGROUND

Elevated glycated hemoglobin (HbA1c) is associated with a higher burden of subclinical atherosclerosis (SA). However, the association with SA of earlier insulin resistance markers is poorly understood. The study assessed the association between the homeostatic model assessment of insulin resistance index (HOMA-IR) and SA in addition to the effect of cardiovascular risk factors (CVRFs) in individuals with normal HbA1c.

METHODS

A cohort of 3,741 middle-aged individuals from the Progression of Early Subclinical Atherosclerosis (PESA) study with basal HbA1c < 6.0% (< 42 mmol/mol) and no known CV disease underwent extensive imaging (multiterritorial vascular ultrasound and coronary artery calcium score, CACS) to assess the presence, burden, and extent of SA.

RESULTS

Individuals with higher HOMA-IR values had higher rates of CVRFs. HOMA-IR showed a direct association with the multiterritorial extent of SA and CACS (p < 0.001) and with global plaque volume measured by 3-dimensional vascular ultrasound (p < 0.001). After adjusting for key CVRFs and HbA1c, HOMA-IR values ≥ 3 were associated with both the multiterritorial extent of SA (odds ratio 1.41; 95%CI: 1.01 to 1.95, p = 0.041) and CACS > 0 (odds ratio 1.74; 95%CI: 1.20 to 2.54, p = 0.004), as compared with the HOMA-IR < 2 (the reference HOMA-IR category). In a stratified analysis, this association remained significant in individuals with a low-to-moderate SCORE2 risk estimate (75.6% of the cohort) but not in high-risk individuals.

CONCLUSIONS

The use of HOMA-IR identified low-risk individuals with a higher burden of SA, after adjusting for the effects of key traditional CVRFs and HbA1c. HOMA-IR is a simple measure that could facilitate earlier implementation of primary CV prevention strategies in clinical practice.

NT-proBNP and cardiovascular event risk in individuals with prediabetes undergoing cardiovascular evaluation

AIMS

Cardiovascular risk assessment beyond traditional risk factors in subjects with prediabetes is not well-established. Here, we evaluated the utility of N-terminal pro-B-type natriuretic peptide (NT-proBNP) in predicting incident adverse cardiovascular outcomes in prediabetic subjects.

METHODS

NT-proBNP was analyzed in 3,235 stable subjects with prediabetes undergoing cardiovascular risk evaluation and followed for both 3-year major adverse cardiac events (MACE; death, myocardial infarction, stroke), and 5-year all-cause mortality.

RESULTS

Using Cox proportional hazard models, we found that plasma NT-proBNP was associated with incident (3-year) MACE risk (Q4 vs Q1, HR 6.04 [95%CI 4.17-8.76], P < 0.001) and 5-year mortality risk (HR 8.64 [95%CI 5.78-12.9], P < 0.001). These associations remained significant after adjustments for traditional cardiovascular risk factors, multiple indices of glycemic control, cardiovascular disease (CVD), left ventricular ejection fraction (LVEF), and medication (e.g. diuretic) use (adjusted HR for 3-year MACE 2.65 [95% CI 1.16-6.05], P < 0.05; and adjusted HR for 5-year mortality 3.45 [95% CI 1.42-8.39], P < 0.01). NT-proBNP significantly improved the clinical prognostic value (C-statistic, NRI, IDI) for both 3-year MACE and 5-year death when added to models.

CONCLUSIONS

NT-proBNP independently predicts increased long-term MACE and mortality risks in prediabetic subjects, and may help identify those for whom more aggressive global preventive efforts are indicated.

Patterns of Cardiac Troponin I Concentrations as Risk Predictors of Cardiovascular Disease and Death: The Trøndelag Health Study

BACKGROUND

Concentrations of cardiac troponin predict risk of cardiovascular disease and death in the general population. There is limited evidence on changing patterns of cardiac troponin in the years preceding cardiovascular events.

METHODS

We analyzed cardiac troponin I (cTnI) with a high-sensitivity assay in 3272 participants in the Trøndelag Health (HUNT) Study at study visit 4 (2017-2019). Of these, 3198 had measurement of cTnI at study visit 2 (1995-1997), 2661 at study visit 3, and 2587 at all 3 study visits. We assessed the trajectories of cTnI concentrations in the years prior to cardiovascular events using a generalized linear mixed model, with adjustment for age, sex, cardiovascular risk factors, and comorbidities.

RESULTS

At HUNT4 baseline, median age was 64.8 (range 39.4-101.3) years, and 55% were women. Study participants who were admitted because of heart failure or died from cardiovascular cause on follow-up had a steeper increase in cTnI compared with study participants with no events (P < .001). The average yearly change in cTnI was 0.235 (95% confidence interval, 0.192-0.289) ng/L for study participants with heart failure or cardiovascular death, and -0.022 (95% confidence interval, -0.022 to -0.023) ng/L for study participants with no events. Study participants who experienced myocardial infarction, ischemic stroke, or noncardiovascular mortality exhibited similar cTnI patterns.

CONCLUSIONS

Fatal and nonfatal cardiovascular events are preceded by slowly increasing concentrations of cardiac troponin, independently of established cardiovascular risk factors. Our results support the use of cTnI measurements to identify at-risk subjects who progress to subclinical and later overt cardiovascular disease.

Peripapillary Retinal Nerve Fiber Layer Thickness and its Ocular and Systemic Determinants in an Elderly Population: A Population-Based Study

Purpose

To determine the distribution, ocular, and systemic determinants of peripapillary retinal nerve fiber layer thickness (pRNFLT) using spectral-domain optical coherence tomography (SD-OCT) in an elderly population.

Methods

This report is a part of the Tehran Geriatric Eye Study, a population-based cross-sectional study conducted in Tehran, the capital of Iran. The study population was all residents aged 60 years and above in Tehran. The sampling was performed using a multi-stage stratified random cluster sampling method. All study participants underwent ocular examination (including measurement of visual acuity, objective and subjective refraction, and slit-lamp biomicroscopy), anterior segment imaging using Pentacam HR, and ocular biometry using IOLMaster 500. The OCT imaging was performed for a random subsample (1307 individuals) using Spectralis SD-OCT.

Results

Two thousand two hundred and forty-six eyes of 1189 individuals were analyzed for this report. Of these, 691 (58.1%) were female, and the mean age of the participants was 67.3 ± 5.9 years (60-94 years). The mean overall pRNFLT was 98.6 μ (95% confidence interval [CI]: 98.0-99.3). There was a statistically significant difference in pRNFLT between different quadrants; the highest and lowest mean pRNFLT was related to inferior and temporal quadrants, respectively (P < 0.001). The multiple generalized estimating equation model showed that older age (coefficient: -0.15 [95% CI: -0.24 to -0.06], P = 0.001), diabetes (coefficient: -1.69 [95% CI: -2.82 to -0.55], P = 0.004), and longer axial length (coefficient: -0.52 [95% CI: -0.83 to -0.22], P < 0.001) were significantly associated with a decreased overall pRNFLT. Higher body mass index was significantly related to an increased overall pRNFLT (coefficient: 0.19 [95% CI: 0.07 to 0.30], P = 0.002).

Conclusions

The results of the present study can be used as a reference database for pRNFLT in the elderly population. Considering ocular and systemic determinants of pRNFLT is necessary for correct clinical interpretation of this parameter.

Diagnostic and prognostic biomarkers reflective of cardiac remodelling in diabetes mellitus: A scoping review

AIMS

The aim of this scoping review is to evaluate the current biomarkers used in the assessment of adverse cardiac remodelling in people with diabetes mellitus (DM) and in the diagnosis and prognosis of subsequent cardiovascular disease. We aim to discuss the biomarkers' pathophysiological roles as a reflection of the cardiac remodelling mechanisms in the presence of DM.

METHODS

We performed the literature search to include studies from 2003 to 2021 using the following databases: MEDLINE, Scopus, Web of Science, PubMed, and Cochrane library. Articles that met our inclusion criteria were screened and appraised before being included in this review. The PRISMA guidelines for Scoping Reviews were followed.

RESULTS

Our literature search identified a total of 43 eligible articles, which were included in this scoping review. We identified 15 different biomarkers, each described by at least two studies, that were used to determine signs of cardiac remodelling in cardiovascular disease (CVD) and people with DM. NT-proBNP was identified as the most frequently employed biomarker in this context; however, we also identified emerging biomarkers including hs-CRP, hs-cTnT, and Galectin-3.

CONCLUSION

There is a complex relationship between DM and cardiovascular health, where more research is needed. Current biomarkers reflective of adverse cardiac remodelling in DM are often used to diagnose other CVDs, such as NT-proBNP for heart failure. Hence there is a need for identification of specific biomarkers that can detect early signs of cardiac remodelling in the presence of DM. Further research into these biomarkers and mechanisms can deepen our understanding of their role in DM-associated CVD and lead to better preventative therapies.

The Africans in America study demonstrates that subclinical cardiovascular risk differs by etiology of abnormal glucose tolerance

Abnormal-glucose tolerance (Abnl-GT) is due to an imbalance between β-cell function and insulin resistance (IR) and is a major risk factor in cardiovascular disease (CVD). In sub-Saharan Africa, β-cell failure is emerging as an important cause of Abnl-GT (Abnl-GT-β-cell-failure). Visceral adipose tissue (VAT) volume and hyperlipidemia are major contributors to CVD risk when Abnl-GT is due to IR (Abnl-GT-IR). Yet, the CVD profile associated with Abnl-GT-β-cell failure is unknown. Therefore, our goals in 450 African-born Blacks (Male: 65%; Age: 39 ± 10 years; BMI 28 ± 5 kg/m²), living in America were to: (1) determine Abnl-GT prevalence and etiology; (2) assess by Abnl-GT etiology, associations between four understudied subclinical CVD risk factors in Africans: (a) subclinical myocardial damage (high-sensitivity troponin T (hs-cTnT)); (b) neurohormonal regulation (N-terminal pro-Brain-natriuretic peptide (NT-proBNP)); (c) coagulability (fibrinogen); (d) inflammation (high-sensitivity C-reactive protein (hsCRP)), as well as HbA_1c, Cholesterol/HDL ratio and VAT. Glucose tolerance status was determined by the OGTT. IR was defined by the threshold at the lowest quartile for the Matsuda Index (≤ 2.97). Abnl-GT-IR required both Abnl-GT and IR. Abnl-GT-β-cell-failure was defined as Abnl-GT without IR. VAT was assessed by CT-scan. For both the Abnl-GT-β-cell-failure and Abnl-GT-IR groups, four multiple regression models were performed for hs-cTnT; NT-proBNP; fibrinogen and hsCRP, as dependent variables, with the remaining three biomarkers and HbA_1c, Cholesterol/HDL and VAT as independent variables. Abnl-GT occurred in 38% (170/450). In the Abnl-GT group, β-cell failure occurred in 58% (98/170) and IR in 42% (72/170). VAT and Cholesterol/HDL were significantly lower in Abnl-GT-β-cell-failure group vs the Abnl-GT-IR group (both P < 0.001). In the Abnl-GT-β-cell-failure group: significant associations existed between hscTnT, fibrinogen, hs-CRP, and HbA_1c (all P < 0.05), and none with Cholesterol/HDL or VAT. In Abnl-GT-IR: hs-cTnT, fibrinogen and hsCRP significantly associated with Cholesterol/HDL (all P < 0.05) and NT-proBNP inversely related to fibrinogen, hsCRP, HbA_1c, Cholesterol/HDL, and VAT (all P < 0.05). The subclinical CVD risk profile differed between Abnl-GT-β-cell failure and Abnl-GT-IR. In Abnl-GT-β-cell failure subclinical CVD risk involved subclinical-myocardial damage, hypercoagulability and increased inflammation, but not hyperlipidemia or visceral adiposity. For Abnl-GT-IR, subclinical CVD risk related to subclinical myocardial damage, neurohormonal dysregulation, inflammation associated with hyperlipidemia and visceral adiposity. ClinicalTrials.gov Identifier: NCT00001853.

Correlation Between Glycated Hemoglobin (HbA1c) and Post-Systolic Index Measured by Speckle-Tracking Echocardiography in Patients with Non-apparent Coronary Artery Disease

Glycated hemoglobin (HbA1c) is a useful biomarker for the diagnosis of diabetes and also for determination of individuals with an increased risk of a severe disease. Some subtle changes in myocardial contractile function is measurable by post-systolic index (PSI) which is defined as late systolic shortening after aortic valve closure. The aim of our study was to determine the relationship between HbA1c and PSI in patients with non-apparent coronary artery disease (CAD) on angiograms. This study was a historical cohort study on 85 consecutive patients with a left ventricular ejection fraction ≥ 50% and non-apparent CAD on angiogram. Patients were divided into two groups based on their HbA1c levels, regardless of the diagnosis of diabetes in these patients, to patients with an HbA1c level of equal or higher than 5.7% and those with an HbA1c of less than 5.7%. A speckle-tracking echocardiography was performed for all patients and global longitudinal strain, PSI, left ventricular diameters, left atrial volume, pulsed-Doppler-derived transmitral early (E wave) and late (A wave) diastolic velocities, and tissue-Doppler-derived mitral annular early diastolic (e') and peak systolic (s') velocities were determined. PSI, E/e' ratio, and A wave were higher and e' velocity was lower in patients with HbA1c ≥ 5.7% than those with a level of < 5.7% (P value = 0.04, 0.001, 0.014, and 0.004, respectively). Other echocardiographic variables were not different between two groups. Multiple linear regression analysis showed the association between HbA1c and PSI was independent of other demographic, biochemical, and echocardiographic variables (B = 35.674, 95% CI 10.741-60.606, P value = 0.006). Our study showed PSI is more pronounced in individuals with an HbA1c > 5.7% than those with a lower value in the absence of CAD. Because PSI is an important indicator of adverse outcome and increased mortality, these data can underline the importance of an abnormal HbA1c level and its association with subtle cardiac dysfunction, irrespective of the diagnosis of diabetes in patients with non-apparent CAD.

Association between prediabetes and adverse outcomes in heart failure

AIMS

Patients with heart failure (HF) and with diabetes experienced significantly worse outcomes than those without diabetes. However, data on the prognostic impact of prediabetes in HF are inconclusive. This meta-analysis aimed to explore the association between prediabetes and the risk of all-cause mortality and adverse cardiac outcomes in patients with HF.

MATERIALS AND METHODS

We searched multiple electronic databases (PubMed, Embase and Google Scholar) for relevant studies up to 31 March 2021. Studies were included for analysis if multivariable adjusted relative risks of adverse outcomes were reported in patients with prediabetes and with HF compared with those with normoglycaemia. Random-effects models were used to calculate the pooled hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Twelve studies comprising 28 643 patients with HF reported the risk of all-cause mortality and cardiac outcomes associated with prediabetes. The prevalence of prediabetes ranged from 9.6% to 37.2%. After a median follow-up duration of 2.3 years, patients with HF and with prediabetes were associated with an increased risk of all-cause mortality (HR 1.29, 95% CI 1.06-1.58), cardiovascular mortality (HR 1.59, 95% CI 1.09-2.32), HF hospitalization (HR 1.33, 95% CI 1.09-1.61), all-cause mortality and/or HF hospitalization (HR 1.22, 95% CI 1.01-1.47), as well as cardiovascular mortality and/or HF hospitalization (HR 1.21, 95% CI 1.07-1.37).

CONCLUSIONS

Prediabetes is associated with a worse prognosis in patients with HF. Further risk stratification and effective treatment strategies are needed in patients with prediabetes and with HF to improve the prognosis.