N-terminal pro-B-type natriuretic peptide: an independent marker for coronary artery disease in asymptomatic diabetic patients

Relationship between the circulating N-terminal pro B-type natriuretic peptide and the risk of carotid artery plaque in different glucose metabolic states in patients with coronary heart disease: a CSCD-TCM plus study in China

OBJECTIVE

Circulating N-terminal pro B-type natriuretic peptide (NT-proBNP) is a marker for heart failure in patients with coronary heart disease (CHD) and associated with glycemic abnormalities. Studies on the association and diagnostic value of NT-proBNP in carotid plaques (CAP) in patients with CHD are limited.

METHODS

The relationships between NT-proBNP and the risk of CAP in different glucose metabolic states, sexes, and age categories were also examined using 5,093 patients diagnosed with CHD. The NT-proBNP tertiles were used to divide patients into three groups in which the NT-proBNP levels, blood glucose levels, the occurrence of CAP, and the number and nature of CAP were measured using normoglycemic (NG), prediabetes (Pre-DM), and diabetes mellitus (DM) glucose metabolic statuses. Logistic regression analyses were used to compare the relationship between NT-proBNP and the risk of CAP occurrence and the number and nature of CAP. The diagnostic value of NT-proBNP for CAP risk was measured using receiver operating characteristic (ROC) curves.

RESULTS

We found a 37% relative increase in the correlation between changes in NT-proBNP per standard deviation (SD) and the incidence of CAP. After adjusting for potential confounders, NT-proBNP at the T3 level was found to be associated with an increased CAP odds ratio (OR) when T1 was used as the reference. This relationship was also present in males, patients aged > 60 years, or both pre-DM and DM states. NT-proBNP was more likely to present as hypoechoic plaques at T1 and as mixed plaques at T3. We also measured the diagnostic accuracy of CAP for NT-proBNP in patients with CHD, with an AUC value of 0.627(95% CI 0.592-0.631), sensitivity of 50.7%, and specificity of 68.0%.

CONCLUSION

An increase in NT-proBNP was significantly associated with the risk of CAP in patients with CHD, especially in males and patients aged > 60 years, and exhibited specific characteristics under different glucose metabolism states. Trial registration The study was approved by the Ethics Committee of Tianjin University of Traditional Chinese Medicine (Approval number TJUTCM-EC20210007) and certified by the Chinese Clinical Trials Registry on April 4, 2022 (Registration number ChiCTR2200058296) and March 25, 2022 by ClinicalTrials.gov (registration number NCT05309343).

Guanylyl cyclase/natriuretic peptide receptor-A: Identification, molecular characterization, and physiological genomics

The natriuretic peptides (NPs) hormone family, which consists mainly of atrial, brain, and C-type NPs (ANP, BNP, and CNP), play diverse roles in mammalian species, ranging from renal, cardiac, endocrine, neural, and vascular hemodynamics to metabolic regulations, immune responsiveness, and energy distributions. Over the last four decades, new data has transpired regarding the biochemical and molecular compositions, signaling mechanisms, and physiological and pathophysiological functions of NPs and their receptors. NPs are incremented mainly in eliciting natriuretic, diuretic, endocrine, vasodilatory, and neurological activities, along with antiproliferative, antimitogenic, antiinflammatory, and antifibrotic responses. The main locus responsible in the biological and physiological regulatory actions of NPs (ANP and BNP) is the plasma membrane guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA), a member of the growing multi-limbed GC family of receptors. Advances in this field have provided tremendous insights into the critical role of Npr1 (encoding GC-A/NPRA) in the reduction of fluid volume and blood pressure homeostasis, protection against renal and cardiac remodeling, and moderation and mediation of neurological disorders. The generation and use of genetically engineered animals, including gene-targeted (gene-knockout and gene-duplication) and transgenic mutant mouse models has revealed and clarified the varied roles and pleiotropic functions of GC-A/NPRA in vivo in intact animals. This review provides a chronological development of the biochemical, molecular, physiological, and pathophysiological functions of GC-A/NPRA, including signaling pathways, genomics, and gene regulation in both normal and disease states.

Serum copeptin and NT-proBNP is associated with central aortic stiffness and flow hemodynamics in adolescents with type 1 diabetes: A pilot study

AIMS

Cardiovascular disease (CVD) is the major cause of mortality in type 1 diabetes (T1D). Biomarkers, N-terminal pro-brain natriuretic peptide (NT-proBNP) and copeptin have been linked with measures of CVD, but their relationship in adolescents with T1D remains incompletely understood. Accordingly, we examined the associations between NT-proBNP and copeptin and hemodynamic markers of central aortic stiffness in adolescents with T1D.

METHODS

In this pilot study, forty-nine pubertal adolescents with T1D (mean age 17 ± 2 years, median [Q1-Q3] Tanner Stage 5 [5, 5] and HbA1c 8.5 ± 1.5%), from the EMERALD study, were assessed for copeptin and NT-proBNP, and indices of central aortic stiffness non-invasively assessed by MRI. Pearson correlations and generalized linear regression models, adjusting for confounders, were applied to examine the relationships between biomarkers and vascular measures.

RESULTS

Copeptin correlated independently with both ascending aortic (AA) (β ± SE: -4.28 ± 1.87, p = 0.03) and descending aortic (DA) relative area change (RAC) (-3.41 ± 1.55, p = 0.04). NT-proBNP was independently associated with DA time-averaged wall shear stress (WSSTA) (0.87 ± 0.25, p = 0.001) and DA maximum wall shear stress (WSSmax) (2.45 ± 1.00, p = 0.02).

CONCLUSIONS

Serum copeptin and NT-proBNP may be associated with central aortic stiffness and elevated WSS in youth with T1D, potentially offering a non-invasive way to identify and monitor the development of early CVD in an at-risk population.

The plasma levels of atrial natriuretic peptide and brain natriuretic peptide in type 2 diabetes treated with sodium-glucose cotransporter-2 inhibitor

PURPOSE

The aim of this study was to determine the levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) after treatment with sodium-glucose cotransporter-2 (SGLT2) inhibitor or dipeptidyl peptidase-4 (DPP4) inhibitor in patients with type-2 diabetes inadequately controlled by insulin, and to determine whether variation in ANP levels can explain favorable cardiovascular outcome.

METHODS

We enrolled 56 patients, aged 18-80years, with type-2 diabetes inadequately controlled by insulin: i.e., HbA1c level 7.5-10.5% despite at least 8weeks' injectable insulin at a stable mean dose of 20-150IU daily, with or without no more than two oral antidiabetic agents.

FINDINGS

The 56 patients were randomized between 3 treatment groups: SGLT2 inhibitor (n=18), DPP4 inhibitor (n=19) and placebo (n=19). Patients who received SGLT2 inhibitor or DPP4 inhibitor treatment all showed significantly lower HbA1c levels, fasting blood glucose (FBG) levels and systolic blood pressure at 24weeks than controls. SGLT2 inhibitor treatment decreased ANP levels, BNP levels, systolic blood pressure and weight compared with placebo. Compared to those receiving DPP4 inhibitor, patients receiving SGLT2 inhibitor showed lower HbA1c levels (7.01 vs. 7.58%; P=0.03), ANP levels (28.41 vs. 43.03 pg/mL; P=0.00) and weight (66.14 vs. 71.76 kg; P=0.04) at 24weeks after adjusting for baseline values. The SGLT2 inhibitor group showed higher sodium concentrations than the placebo and DPP4 inhibitor groups (145.89 vs. 143.89 and 144.79 mmol/L, respectively; P=0.00 and P=0.04) at 24 weeks. ANP and BNP levels did not significantly correlate with HbA1c and blood glucose levels.

IMPLICATIONS

These results indicated that SGLT2 inhibitors may be superior to DPP4 inhibitors in reducing risk of cardiovascular disease in diabetic patients. The major study limitation was the small number of patients per group, which should be enlarged in further research.

Issues for the management of people with diabetes and COVID-19 in ICU

In the pandemic “Corona Virus Disease 2019” (COVID-19) people with diabetes have a high risk to require ICU admission. The management of diabetes in Intensive Care Unit is always challenging, however, when diabetes is present in COVID-19 the situation seems even more complicated. An optimal glycemic control, avoiding acute hyperglycemia, hypoglycemia and glycemic variability may significantly improve the outcome. In this case, intravenous insulin infusion with continuous glucose monitoring should be the choice. No evidence suggests stopping angiotensin-converting-enzyme inhibitors, angiotensin-renin-blockers or statins, even it has been suggested that they may increase the expression of Angiotensin-Converting-Enzyme-2 (ACE2) receptor, which is used by “Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to penetrate into the cells. A real issue is the usefulness of several biomarkers, which have been suggested to be measured during the COVID-19. N-Terminal-pro-Brain Natriuretic-Peptide, D-dimer and hs-Troponin are often increased in diabetes. Their meaning in the case of diabetes and COVID-19 should be therefore very carefully evaluated. Even though we understand that in such a critical situation some of these requests are not so easy to implement, we believe that the best possible action to prevent a worse outcome is essential in any medical act.

Association Between Uric Acid and N-Terminal Pro-B-Type Natriuretic Peptide in Patients With Unstable Angina Pectoris

BACKGROUND

The association between uric acid and N-Terminal Pro-B-Type Natriuretic Peptide (NT-proBNP) in patients with unstable angina pectoris (UAP) is unclear.

METHODS

We recruited 260 patients with UAP admitted to the first affiliated Hospital of Guangxi Medical University from February 2018 to August 2018. According to the level of uric acid, patients were divided into 4 groups (Q1 = 48.00-305.00 μmol/L; Q2 = 310.00-405.00 μmol/L; Q3 = 408.00-513.00 μmol/L; Q4 = 514.00-4330.00 μmol/L). The differences of NT-proBNP between groups and the relationship with cardiac function were compared.

RESULTS

The average age of the 260 patients enrolled was 75.04 years. The NT-proBNP of the 4 groups showed an increasing trend, and there were significant differences between the 4 groups (<0.001). On the other hand, with the increase of cardiac function (New York Heart Association), the levels of NT-proBNP and uric acid also showed an upward trend (all P < 0.05). Pearson correlation analysis showed that there was a positive correlation between uric acid log10 transform and NT-proBNP log10 transform (r = 0.272, P < 0.001). After adjusting the potential confounding factors, elevated uric acid was still significantly related to the increase of NT-proBNP (Q2 versus [vs.] Q1: OR = 469.64, 95%CI -1396.77 to 2336.05; Q3 vs. Q1: OR = 1166.53, 95%CI -726.12 to 3059.18; Q4 vs. Q1: OR = 3204.78, 95%CI 1240.86-5168.70). In subgroup analysis, the relationship between uric acid and NT-proBNP was significant in males, but no difference was observed in females.

CONCLUSIONS

In male patients with UAP, elevated uric acid is related to the increase of NT-proBNP, but this phenomenon is not obvious in female patients.

Predictive value of N-terminal-Pro brain natriuretic peptide in the detection of coronary artery disease in patients with positive myocardial perfusion imaging

Background: N-terminal pro-brain natriuretic peptide (NT-ProBNP) increases during myocardial ischemia and has a potential for the diagnosis of patients with coronary artery disease (CAD). We aimed to determine the incremental diagnostic value of NT-ProBNP in the selection of patients with positive myocardial perfusion imaging (MPI) for coronary angiography. We also tested the association between the level of NT-ProBNP and severity of CAD based on the vessel score and Gensini score.

Methods: In this cross-sectional study, stable angina patients with positive MPI who were assessed by coronary angiography in Imam Khomeini Hospitalwere enrolled. After the collection of demographic and clinical data, NT-ProBNP was measured in all patients on the day of coronary angiography, and its association with the presence of CAD, vessel score and Gensini score was tested.

Results: We enrolled 170 patients (mean age61.2±10.1 years, 86 males (50.6%)). Seventy-two (42.3%) patients had at least one stenotic vessel. NT-Pro BNP was significantly higher in the CAD-positive group (OR=1.01, 95% CI: 1.00-1.02; p=0.008) and could independently predict the presence of CAD at a cut-off point of 69.5, with a sensitivity of 55.6%, specificity of 82.5% and diagnostic accuracy of 61.7%. The Gensini score had a modest correlation with NT-Pro BNP (r=0.60, p<0.001). The combination of MPI result and NT-Pro BNP could predict the presence of CAD (OR=14.57, 95% CI: 4.28, 49.56; p<0.001).

Conclusion: Serum level of NT-Pro BNP alone and its combination with the results of MPI can significantly predict the presence of CAD and therefore, highlights the need for performing coronary angiography.

Predictive Properties of Biomarkers GDF-15, NTproBNP, and hs-TnT for Morbidity and Mortality in Patients With Type 2 Diabetes With Nephropathy

OBJECTIVE

Although patients with type 2 diabetes (T2D) with nephropathy are at high risk for renal and cardiovascular complications, relevant biomarkers have been poorly identified. Because renal impairment may increase biomarker levels, this potentially confounds associations between biomarker levels and risk. To investigate the predictive value of a biomarker in such a setting, we examined baseline levels of growth differentiation factor-15 (GDF-15), N-terminal prohormone of B-type natriuretic peptide (NTproBNP), and high-sensitivity troponin T (hs-TnT) in relation to renal and cardiovascular risk in T2D patients with nephropathy.

RESEARCH DESIGN AND METHODS

Eight hundred sixty-one T2D patients from the sulodexide macroalbuminuria (Sun-MACRO) trial were included in our post hoc analysis. Prospective associations of baseline serum GDF-15, NTproBNP, and hs-TnT with renal and cardiovascular events were determined by Cox multiple regression and C-statistic analysis. Renal base models included albumin-to-creatinine ratio (ACR), serum creatinine, hemoglobin, age, and sex. Cardiovascular base models included diastolic blood pressure, ACR, cholesterol, age, and sex.

RESULTS

The mean (±SD) estimated glomerular filtration rate was 33 ± 9 mL/min/1.73 m², and the median serum concentration for GDF-15 was 3,228 pg/mL (interquartile range 2,345-4,310 pg/mL), for NTproBNP was 380 ng/L (155-989 ng/L), and for hs-TnT was 30 ng/L (20-47 ng/L). In multiple regression analysis, GDF-15 (hazard ratio [HR] 1.83, P = 0.04), NTproBNP (HR 2.34, P = 0.004), and hs-TnT (HR 2.09, P = 0.014) were associated with renal events, whereas NTproBNP (HR 3.45, P < 0.001) was associated with cardiovascular events. The C-statistic was improved by adding NTproBNP and hs-TNT to the renal model (0.793 vs. 0.741, P = 0.04). For cardiovascular events, the C-statistic was improved by adding NTproBNP alone (0.722 vs. 0.658, P = 0.018).

CONCLUSIONS

Biomarkers GDF-15, NTproBNP, and hs-TnT associate independently with renal risk, whereas NTproBNP independently predicts cardiovascular risk.

Sodium-glucose co-transporter-2 inhibitors suppress atrial natriuretic peptide secretion in patients with newly diagnosed Type 2 diabetes

AIMS

To observe changes in atrial natriuretic peptide levels after treatment with sodium-glucose co-transporter-2 inhibitors in patients with newly diagnosed type 2 diabetes.

METHODS

A total of 28 patients with newly diagnosed Type 2 diabetes and HbA_1c levels of 58 -91 mmol/mol (7.5-10.5%) were randomly selected to receive sodium-glucose co-transporter-2 inhibitor treatment (n = 18) or placebo (n = 10) for 24 weeks. We analysed atrial natriuretic peptide concentrations, using an enzyme-linked immunosorbent assay. In addition, sodium and HbA_1c levels were measured at baseline, 12 weeks and 24 weeks and blood lipid levels and insulin sensitivities at baseline and 24 weeks.

RESULTS

Compared with patients treated with placebo, patients who received sodium-glucose co-transporter-2 inhibitor treatment exhibited lower atrial natriuretic peptide levels (36.74 vs 56.90 pg/ml in the placebo group; P < 0.05) and higher sodium levels (144.3 vs 141.4 mmol/l in the placebo group; P < 0.01) at 24 weeks, after adjusting for baseline values. HbA_1c levels were lower after sodium-glucose co-transporter-2 inhibitor treatment compared with placebo (51 vs 60 mmol/mol; P < 0.01). No correlation was found between atrial natriuretic peptide and HbA_1c levels. Homeostatic model assessment of β-cell function values and lipid profiles were generally similar after 24 weeks of treatment with placebo or sodium-glucose co-transporter-2 inhibitor.

CONCLUSIONS

This study shows the ability of sodium-glucose co-transporter-2 inhibitors to lower atrial natriuretic peptide levels and improve glycaemic control, which may benefit the cardiovascular system.

The role of mineral and bone disorders in the development and progression of cardiac and renal pathology in patients with type 1 diabetes mellitus of long duration

AIMS

The objective of our study was to evaluate the role of mineral and bone metabolism disorders associated with chronic kidney disease (MBD-CKD) in the development and progression of cardiac and renal pathology in patients with type 1 diabetes mellitus (T1DM) of long duration.

METHODS

We investigated 96 patients with T1DM of long duration, with CKD at different stages (0-5), including patients on hemodialysis (HD) and with kidney transplantation (KT). Along with overall clinical examination, we assessed markers of MBD (calcium, phosphorus, parathormone, vitamin D, fibroblast growth factor (FGF) 23) and levels of cardiac injury marker (atrial natriuretic peptide, NT-proBNP). Multispiral computer tomography with Agatston index calculation was also included.

RESULTS

Decreased kidney function was associated with increased of levels phosphorus, parathormone, FGF 23, and vitamin D deficiency, with the highest deviation from the reference ranges seen in patients on HD with a very high risk of cardiovascular events. In KT patients with satisfactory graft function, these parameters were at the same levels as in patients with CKD stages 0-4. Progression of cardiovascular pathology was accompanied by elevation of NT-proBNP levels as CKD duration increased, decreased glomerular filtration rate, and were correlated with the main parameters of mineral homeostasis. The severity of coronary arteries calcification was associated with patient age and duration of T1DM and arterial hypertension.

CONCLUSIONS

Development and progression of kidney dysfunction is accompanied by MBD, a significant factor in progression of cardiac pathology, which remains a major cause of mortality in this patient population.

Natriuretic peptides, heart, and adipose tissue: new findings and future developments for diabetes research

Natriuretic peptides (NPs) play a key role in cardiovascular homeostasis, counteracting the deleterious effects of volume and pressure overload and activating antibrotic and antihypertrophic pathways in the heart. N-terminal B-type NP (NT-proBNP) also is a promising biomarker of global cardiovascular risk in the general population, and there is increasing interest on its potential use in diabetic patients for screening of silent cardiovascular abnormalities, cardiovascular risk stratification, and guided intervention. Recently, both atrial NP (ANP) and B-type NP (BNP) have emerged as key mediators in the control of metabolic processes including the heart in the network of organs that regulate energy usage and metabolism. Epidemiological studies have shown that ANP and BNP are reduced in people with obesity, insulin resistance, and diabetes, and this deficiency may contribute to enhance their global cardiovascular risk. Moreover, ANP and BNP have receptors in the adipose tissue, enhance lipolysis and energy expenditure, and modulate adipokine release and food intake. Therefore, low ANP and BNP levels may be not only a consequence but also a cause of obesity, and recent prospective studies have shown that low levels of NT-proBNP and midregional proANP (MR-proANP) are a strong predictor of type 2 diabetes onset. Whether ANP and BNP supplementation may result in either cardiovascular or metabolic benefits in humans remains, however, to be established.

Flow-mediated-paradoxical vasoconstriction is independently associated with asymptomatic myocardial ischemia and coronary artery disease in type 2 diabetic patients

BACKGROUND

To investigate whether flow-mediated dilation (FMD) impairment, which precedes overt atherosclerosis, is associated with silent myocardial ischemia (SMI) and asymptomatic coronary artery disease (CAD) in type 2 diabetes.

METHODS

Forearm FMD was measured by ultrasonography in 25 healthy control, 30 non-diabetic overweight or obese patients and 118 asymptomatic type 2 diabetic patients with a high cardiovascular risk profile. SMI (abnormal stress myocardial scintiscan and/or stress dobutamine echocardiogram) and CAD (coronary angiography in the patients with SMI) were assessed in the diabetic cohort.

RESULTS

FMD was lower in diabetic patients (median 0.61% (upper limits of first and third quartiles -1.22;3.2)) than in healthy controls (3.95% (1.43;5.25), p < 0.01) and overweight/obese patients (4.25% (1.74;5.56), p < 0.01). SMI was present in 60 diabetic patients, including 21 subjects with CAD. FMD was lower in patients with SMI than in those without (0.12% (-2.3;1.58) vs 1.64% (0;3.69), p < 0.01), with a higher prevalence of paradoxical vasoconstriction (50.0% vs 29.3%, p < 0.05). FMD was also lower in patients with than without CAD (-1.22% (-2.5;1) vs 1.13% (-0.4;3.28), p < 0.01; paradoxical vasoconstriction 61.9% vs 34.4%, p < 0.05). Logistic regression analyses considering the parameters predicting SMI or CAD in univariate analyses with a p value <0.10 showed that paradoxical vasoconstriction (odds ratio 2.7 [95% confidence interval 1.2-5.9], p < 0.05) and nephropathy (OR 2.6 [1.2-5.7], p < 0.05) were independently associated with SMI; and only paradoxical vasoconstriction (OR 3.1 [1.2-8.2], p < 0.05) with CAD. The negative predictive value of paradoxical vasoconstriction to detect CAD was 88.7%.

CONCLUSIONS

In diabetic patients, FMD was independently associated with SMI and asymptomatic CAD.

TRIAL REGISTRATION

Trial registration number NCT00685984.

Decreased stroke volume−brachial pulse pressure ratio in patients with type 2 diabetes over 50 years: the role of peripheral neuropathy

BACKGROUND AND AIMS

To document the stroke volume to pulse pressure ratio (SV/PP, an index of total arterial compliance) and its correlates in patients with type 2 diabetes (T2DM) aged over 50 years whose peripheral neuropathy and silent myocardial ischemic (SMI) status were known.

METHODS AND RESULTS

A total of 360 patients with T2DM aged ≥ 50 years, without cardiac history or symptom, left ventricular systolic dysfunction, dilatation and hypokinesia, were retrospectively enrolled. The SV/PP was calculated from echocardiographic left ventricular measurements and brachial blood pressure at rest. Peripheral neuropathy was defined as the presence of any two or more of the following: neuropathic symptoms, decreased distal sensation, or decreased or absent ankle reflexes. SMI was defined as an abnormal stress myocardial scintigraphy and/or stress echocardiography. A low SV/PP ratio (<0.53 ml/m²/mmHg, first tertile) was associated with age, creatinine clearance, 24 h urinary albumin excretion rate, peripheral neuropathy, hypertension, serum total cholesterol and triglycerides levels (p < 0.05-0.0001). In multivariate analysis, age (OR 1.1 [1.0-1.2], p < 0.01), triglycerides (OR 1.5 [1.2-2.0], p = 0.01) and peripheral neuropathy (OR 2.2 [1.2-3.9], p = 0.009) were independently associated with a low SV/PP. The patients with peripheral neuropathy had lower SV (p < 0.01) and higher PP (p < 0.05) than those without, and only lower SV after adjustment for age and nephropathy. Similar results were obtained in the patients with and without SMI.

CONCLUSION

Peripheral neuropathy was independently associated with decreased SV/PP, mainly through decreased SV, in patients with T2DM over 50 years.

Glycation gap is associated with macroproteinuria but not with other complications in patients with type 2 diabetes

OBJECTIVE

We investigated whether glycation gap (G-Gap), an index of intracellular glycation of proteins, was associated with diabetes complications.

RESEARCH DESIGN AND METHODS

We measured concomitantly HbA1c and fructosamine in 925 patients with type 2 diabetes to calculate the G-Gap, defined as the difference between measured HbA1c, and fructosamine-based predicted HbA1c. Patients were explored for retinopathy, nephropathy, peripheral neuropathy, cardiac autonomic neuropathy (n = 512), and silent myocardial ischemia (n = 506).

RESULTS

Macroproteinuria was the only complication that was associated with G-Gap (prevalence in the first, second, and third tertile of G-Gap: 2.9, 6.2, and 11.0%, respectively; P < 0.001). The G-Gap was higher in patients with macroproteinuria than in those without (1.06 ± 1.62 vs. 0.03 ± 1.30%; P < 0.0001). Because HbA1c was associated with both G-Gap (HbA1c 7.0 ± 1.4, 7.9 ± 1.4, and 10.1 ± 1.8% in the first, second, and third G-Gap tertile, respectively; P < 0.0001) and macroproteinuria (HbA1c 8.8 ± 2.2% if macroproteinuria, 8.3 ± 2.0% if none; P < 0.05), and because it could have been a confounder, we matched 54 patients with macroproteinuria and 200 patients without for HbA1c. Because macroproteinuria was associated with lower serum albumin and fructosamine levels, which might account for higher G-Gap, we calculated in this subpopulation albumin-indexed fructosamine and G-Gap; macroproteinuria was independently associated with male sex (odds ratio [OR] 3.2 [95% CI 1.5-6.7]; P < 0.01), hypertension (2.9 [1.1-7.5]; P < 0.05), and the third tertile of albumin-indexed G-Gap (2.3 [1.1-4.4]; P < 0.05) in multivariate analysis.

CONCLUSIONS

In type 2 diabetic patients, G-Gap was associated with macroproteinuria, independently of HbA1c, albumin levels, and confounding factors, suggesting a specific role of intracellular glycation susceptibility on kidney glomerular changes.

Impact of the look AHEAD intervention on NT-pro brain natriuretic peptide in overweight and obese adults with diabetes

Look AHEAD (Action for Health in Diabetes) is a randomized trial determining whether intensive lifestyle intervention (ILI) aimed at long-term weight loss and increased physical fitness reduces cardiovascular morbidity and mortality in overweight and obese individuals with type 2 diabetes compared to control (diabetes support and education, DSE). We investigated the correlates of N-terminal pro-brain natriuretic peptide (NT-proBNP), a biomarker associated with heart failure (HF) risk, in a subsample from 15 of 16 participating centers and tested the hypothesis that ILI decreased NT-proBNP levels. Baseline and 1-year blood samples were assayed for NT-proBNP in a random sample of 1,500 without, and all 628 with, self-reported baseline CVD (cardiovascular disease) (N = 2,128). Linear models were used to assess relationships that log-transformed NT-proBNP had with CVD risk factors at baseline and that 1-year changes in NT-proBNP had with intervention assignment. At baseline, the mean (s.d.) age, BMI, and hemoglobin A(1c) (HbA(1c)) were 59.6 (6.8) years, 36.0 kg/m(2) (5.8), and 7.2% (1.1), respectively. Baseline geometric mean NT-proBNP was not different by condition (ILI 53.3 vs. DSE 51.5, P = 0.45), was not associated with BMI, and was inversely associated with HbA(1c). At 1 year, ILI participants achieved an average weight loss of 8.3% compared to 0.7% in DSE. At 1 year, NT-proBNP levels increased to a greater extent in the intervention arm (ILI +21.3% vs. DSE +14.2%, P = 0.046). The increased NT-proBNP associated with ILI was correlated with changes in HbA(1c), BMI, and body composition. In conclusion, among overweight and obese persons with diabetes, an ILI that reduced weight was associated with an increased NT-proBNP.

Cardiovascular risk prediction is improved by adding asymptomatic coronary status to routine risk assessment in type 2 diabetic patients

OBJECTIVE

To evaluate if silent myocardial ischemia (SMI) and silent coronary artery disease (CAD) provide significant additional value to routine cardiovascular risk assessment in type 2 diabetic patients.

RESEARCH DESIGN AND METHODS

We followed up to a first cardiovascular event 688 subjects (322 men, aged 59 ± 8 years) out of 731 consecutive asymptomatic type 2 diabetic patients with ≥1 additional risk factor who had been prospectively screened between 1992 and 2006 for SMI by stress myocardial scintigraphy and for silent CAD by coronary angiography.

RESULTS

SMI was found in 207 (30.1%) patients and CAD in 76 of those with SMI. Of the patients, 98 had a first cardiovascular event during a 5.4 ± 3.5 (range: 0.1-19.2) year follow-up period. Cox regression analysis considering parameters predicting events but not SMI and CAD ("routine assessment") showed in univariate analyses that macroproteinuria (hazard ratio [HR] 3.33 [95% CI 1.74-6.35]; P < 0.001), current multifactorial care (0.27 [0.15-0.47]; P < 0.001), and peripheral/carotid occlusive arterial disease (PCOAD; 4.33 [2.15-8.71]; P < 0.001) independently predicted cardiovascular events. When added into the model, SMI (HR 1.76 [1.00-3.12]; P = 0.05) and CAD (2.28 [1.24-4.57]; P < 0.01) were also independently associated with events. SMI added to the prediction of an event in the following 5 years above and beyond routine assessment risk prediction (c statistic with or without SMI 0.788 [0.720-0.855] and 0.705 [0.616-0.794], respectively).

CONCLUSIONS

Although screening for SMI and silent CAD should not be systematic, these complications are predictive of cardiovascular events in type 2 diabetic patients in addition to routine risk predictors, especially represented by PCOAD, macroproteinuria, and nonintensive management.

Meta-analysis of B-type natriuretic peptide's ability to identify stress induced myocardial ischemia

Studies in victims of sudden cardiac death and those surviving a cardiac arrest have confirmed that extent of coronary artery disease is similar in those with and without angina, suggesting that it is the presence of myocardial ischemia rather than associated symptoms that determine the prognosis. Experimental models show that hypoxic myocardial tissue results in production of extra B-type natriuretic peptide (BNP), suggesting that BNP could potentially serve as a biomarker of myocardial ischemia. We performed a meta-analysis of the studies that link BNP to inducible myocardial ischemia as indicated by noninvasive stress tests. Values of true positive, false positive, true negative, and false negative were calculated from the reported sensitivity, specificity, disease prevalence, and total number of patients studied. Sixteen studies reporting data on 2,784 patients across 14 study populations were included in the final analysis. Mean age of participants was 55 to 69 years and 55% to 90% were men. Pooled sensitivity and specificity of BNP for detection of stress-induced myocardial ischemia were 71% (95% confidence interval [CI] 68 to 74) and 52% (95% CI 52 to 54), respectively. Pooled diagnostic odds ratio was 3.5 (95% CI 2.46 to 5.04) and summary receiver operating characteristic curve revealed an area under the curve of 0.71 ± 0.02 (mean ± SE). In conclusion, this meta-analysis suggests that an increased BNP level can identify inducible ischemia as detected by standard noninvasive stress tests. This raises the possibility of a whole new role for BNP in the diagnosis and management of myocardial ischemia.

N-terminal fragment of pro-brain natriuretic peptide (NT-proBNP) for predicting silent myocardial ischaemia in type 2 diabetes mellitus independent of microalbuminuria

BACKGROUND

In the early identification of cardiovascular risk, it is essential to establish a biological marker for cardiac complications that is comparable to albuminuria for nephropathy. We tested the hypothesis that N-terminal pro-brain natriuretic peptide (NT-proBNP) might be a marker for silent myocardial ischaemia in diabetes.

METHODS

In forty consecutively recruited subjects without evident coronary artery disease, serum NT-proBNP was measured together with multi-slice computed tomography. With patients suspected of having significant coronary artery stenosis by multi-slice computed tomography, coronary angiography was performed. Silent myocardial ischaemia was defined as the presence of significant coronary artery stenosis with more than 50% luminal narrowing by angiography.

RESULTS

Thirteen patients (32.5%) had silent myocardial ischaemia. NT-proBNP levels were significantly higher in these patients (181.1 ± 43.8 versus 55.2 ± 9.7 pg/mL, p < 0.005) but HbA(1c), lipid profiles, and creatinine were similar in the two groups. Moreover, log NT-proBNP was identified as an independent predictor of silent myocardial ischaemia (R(2) = 0.502, p < 0.05) after adjustment for HbA(1c), creatinine, albuminuria, hypertension, hyperlipidaemia, or smoking. After stratifying patients by NT-proBNP, the upper tertile compared to the lowest tertile was significantly associated with silent myocardial ischaemia (odds ratio: 26.7, p < 0.05). Receiver operation characteristics analysis with a cut-off value of 52 pg/mL showed 92% sensitivity and 75% specificity for predicting silent myocardial ischaemia (positive predictive value 64.7%, negative predictive value 94.3%).

CONCLUSIONS

The outstandingly high negative predictive value of NT-proBNP enables us to focus on diabetic patients with occult coronary disease, independently of microalbuminuria.