High-sensitive troponin T is associated with all-cause and cardiovascular mortality in stable outpatients with type 2 diabetes (ZODIAC-37)

BACKGROUND

We aimed to investigate whether high-sensitive cardiac troponin T (hs-cTnT) is associated with all-cause and cardiovascular mortality in stable type 2 diabetes (T2D) outpatients treated in primary care.

METHODS

Cardiac troponin T was measured with a high-sensitive assay at baseline in patients with T2D participating in the observational ZODIAC study. Cox proportional hazards models were used to investigate the relationship between hs-cTnT and mortality with adjustment for selected confounders. Risk prediction capabilities of hs-cTnT were assessed with Harrell C statistics.

RESULTS

Complete baseline data were available for 1,133 patients. During median follow-up of 11 (7-14) years, 513 (45%) patients died, of which 218 (42%) died of cardiovascular causes. Of the patients with undetectable hs-cTnT levels (<3 ng/L), only 23% died, compared with 58% with low detectable levels (3-14 ng/L) and 84% with raised levels (≥14 ng/L). Natural log hs-cTnT was significantly associated with all-cause mortality (hazard ratio 1.30, 95% CI 1.19-1.42) and cardiovascular mortality (hazard ratio 1.33, 95% CI 1.15-1.53), independent of potential confounders. The Harrell C statistic for the crude model of hs-cTnT was 0.72 (95% CI 0.70-0.75) for all-cause mortality and 0.74 (95% CI 0.71-0.77) for cardiovascular mortality.

CONCLUSIONS

Higher levels of hs-cTnT are associated with mortality in stable outpatients with T2D. The high crude Harrell C values and the excellent prognosis of patients with undetectable levels illustrate the strength of hs-cTnT as a potential marker for mortality.

Circulating Total Bilirubin and Risk of Incident Cardiovascular Disease in the General Population

Objective—

To assess the association of circulating total bilirubin and cardiovascular disease (CVD) risk in a new prospective study and to determine whether adding information on total bilirubin values to established cardiovascular risk factors is associated with improvement in prediction of CVD risk.

Approach and Results—

Circulating total bilirubin levels were measured at baseline in the PREVEND (Prevention of Renal and Vascular End-stage Disease) prospective study of 7222 participants and 773 incident CVD events. Total bilirubin was log-linearly associated with CVD risk. Age- and sex-adjusted hazard ratio (95% confidence interval) for CVD per 1-SD increase in log e total bilirubin was 0.82 (0.76 to 0.88; P <0.001), which was minimally attenuated to 0.89 (0.82 to 0.96; P =0.003) after further adjustment for established risk factors. In a meta-analysis of 12 population-based prospective studies involving 9378 incident CVD cases, the pooled multivariate-adjusted relative risk (95% confidence interval) for CVD was 0.93 (0.90 to 0.97; P <0.001) per 1-SD increase in total bilirubin levels. The corresponding pooled risks for coronary heart disease and stroke were 0.95 (0.92 to 0.99; P =0.018) and 0.93 (0.88 to 0.98; P =0.006), respectively. Addition of information on total bilirubin to a CVD risk prediction model containing established risk factors was associated with a C-index change of 0.0013 (−0.0004 to 0.0029; P =0.13).

Conclusions—

There is a log-linear inverse association between circulating total bilirubin level and CVD risk, which is independent of established risk factors. Nonetheless, inclusion of total bilirubin in the standard established risk factors panel provides no significant improvement in CVD risk prediction.

Clinical Risk Stratification Optimizes Value of Biomarkers to Predict New-Onset Heart Failure in a Community-Based Cohort

Background—

We aim to identify and quantify the value of biomarkers for incident new-onset heart failure (HF) in a community-based cohort and subgroups based on cardiovascular risk and evaluate the prognostic value of 13 biomarkers for HF with reduced and preserved ejection fraction.

Methods and Results—

Thirteen biomarkers reflecting diverse pathophysiologic domains were examined in 8569 HF-free participants in Prevention of Vascular and Renal Endstage Disease (mean age, 49 years; 50% men). Subjects were categorized in 2 risk groups based on cardiovascular history. Incremental value per biomarker was assessed using Harrell C-indices. One hundred sixty-eight subjects (2.4%) were diagnosed with new-onset HF in the low-risk group (n=6915; Framingham Risk Score, 5.9%) and 206 (12.2%) subjects in the high-risk group (n=1654; Framingham Risk Score, 18.6%). The association of natriuretic peptides, adrenomedullin, endothelin, and galectin-3 with new-onset HF was stronger in the high-risk group (all P <0.05). Troponin-T, high-sensitive C-reactive protein, urinary albumin excretion, and cystatin-C had similar risk for new-onset HF between both risk groups. The best model for new-onset HF included the combination of N-terminal pro-B-type natriuretic peptide, troponin-T, and urinary albumin excretion, increasing model accuracy to 0.81 (9.5%, P <0.001) in the high-risk group. Except for a modest effect of cystatin-C, no biomarker was associated with increased risk for HF with preserved ejection fraction.

Conclusions—

Risk stratification increases the incremental value per biomarker to predict new-onset HF, especially HF with reduced ejection fraction. We suggest that routine biomarker testing should be limited to the use of natriuretic peptides and troponin-T in patients with increased cardiovascular risk.

Long-Term Cardiovascular Mortality in Patients With Differentiated Thyroid Carcinoma: An Observational Study

Purpose

The primary aim was to study the risk of cardiovascular mortality in patients with differentiated thyroid carcinoma (DTC). Secondary aims were to evaluate all-cause mortality and explore the relation between thyroid-stimulating hormone (TSH; also known as thyrotropin) level and these outcome parameters.

Patients and Methods

Subjects from two cohorts were retrospectively compared by Cox regression analyses; 524 patients with DTC and 1,572 sex- and age-matched controls from a large population-based study in the same geographic region.

Results

Mean age plus or minus standard deviation was 49 ± 14 years. Median follow-up was 8.5 years (interquartile range [IQR], 4.1 to 15.9 years) for patients with DTC and 10.5 years (IQR, 9.9 to 10.9 years) for controls. One hundred patients with DTC (19.1%) died, 22 (4.2%) as a result of cardiovascular disease, 39 (7.4%) as a result of DTC, and 39 (7.4%) as a result of other/unknown causes. Eighty-five controls (5.4%) died, 24 (1.5%) as a result of cardiovascular disease and 61 (3.9%) as a result of other/unknown causes. Patients with DTC had an increased risk of cardiovascular and all-cause mortality (hazard ratios [HRs], 3.35 [95% CI, 1.66 to 6.74] and 4.40 [95% CI, 3.15 to 6.14], respectively, adjusted for age, sex, and cardiovascular risk factors). Within the DTC group, TSH level was predictive for cardiovascular mortality; the adjusted HR was 3.08 (95% CI, 1.32 to 7.21) for each 10-fold decrease in geometric mean TSH level.

Conclusion

The risk of cardiovascular and all-cause mortality is increased in patients with DTC, independent of age, sex, and cardiovascular risk factors. A lower TSH level is associated with increased cardiovascular mortality, supporting the current European Thyroid Association and the American Thyroid Association guidelines of tempering TSH suppression in patients with low risk of cancer recurrence. Furthermore, patients with DTC may benefit from assessment and treatment of cardiovascular risk factors.

Creatinine excretion rate and mortality in type 2 diabetes and nephropathy

OBJECTIVE

The creatinine excretion rate (CER) is inversely associated with mortality in the general and renal transplant population. The CER is a marker for muscle mass. It is unknown whether the CER is associated with outcome in diabetes. We therefore investigated whether the CER is a determinant of all-cause mortality in diabetic patients.

RESEARCH DESIGN AND METHODS

We used data from the combined Reduction of Endpoints in Non-insulin dependent diabetes mellitus with the Angiotensin II Antagonist Losartan (RENAAL) and Irbesartan Diabetic Nephropathy Trial (IDNT) studies. A total of 1,872 patients (58% of the overall population) with type 2 diabetes and nephropathy with valid 24-h urinary creatinine excretion data were included. The primary end point of the analyses was all-cause mortality.

RESULTS

Mean age was 60 ± 8 years and median CER was 1,407 (total range 400-3,406) mg/day. Body surface area, hemoglobin, black race, and albuminuria were positive independent determinants of the CER, whereas female sex and age were inverse independent determinants of the CER. During a median follow-up of 36 (29-45) months, 300 patients died. In a Kaplan-Meier analysis of sex-stratified tertiles of the CER, risk for all-cause mortality increased with decreasing CER (P < 0.001). In a multivariable Cox regression analysis, lower CER (as a continuous variable) was independently associated with increased risk for all-cause mortality (hazard ratio 0.39 [95% CI 0.29-0.52], P < 0.001). Adjustment for potential collection errors did not materially change these associations.

CONCLUSIONS

Lower CER was strongly associated with increased all-cause mortality in patients with type 2 diabetes and nephropathy. As the CER can be considered a proxy for muscle mass, this puts renewed emphasis on physical condition and exercise in this population.

Association of complement C3 gene variants with renal transplant outcome of deceased cardiac dead donor kidneys

Local renal complement activation by the donor kidney plays an important role in the pathogenesis of renal injury inherent to kidney transplantation. Contradictory results were reported about the protective effects of the donor C3F allotype on renal allograft outcome. We investigated the influence of the donor C3F allotype on renal transplant outcome, taking all different donor types into account. C3 allotypes of 1265 donor-recipient pairs were determined and divided into four genotypic groups according to the C3F allotype of the donor and the recipient. The four genotypic groups were analyzed for association with primary nonfunction (PNF), delayed graft function, acute rejection, death-censored graft survival and patient survival. Considering all donor types, multivariable analysis found no association of the donor C3F allotype with renal allograft outcome. Also, for living and deceased brain-dead donors, no association with allograft outcome was found. Post hoc subgroup analysis within deceased cardiac dead (DCD) donors revealed an independent protective association of donor C3F allotype with PNF. This study shows that the donor C3F allotype is not associated with renal allograft outcome after kidney transplantation. Subgroup analysis within DCD donors revealed an independent protective association of the donor C3F allotype with PNF, which is preliminary and warrants further validation.

N-glycosylation of carnosinase influences protein secretion and enzyme activity: implications for hyperglycemia

OBJECTIVE

The (CTG)(n) polymorphism in the serum carnosinase (CN-1) gene affects CN-1 secretion. Since CN-1 is heavily glycosylated and glycosylation might influence protein secretion as well, we tested the role of N-glycosylation for CN-1 secretion and enzyme activity. We also tested whether CN-1 secretion is changed under hyperglycemic conditions.

RESULTS

N-glycosylation of CN-1 was either inhibited by tunicamycin in pCSII-CN-1-transfected Cos-7 cells or by stepwise deletion of its three putative N-glycosylation sites. CN-1 protein expression, N-glycosylation, and enzyme activity were assessed in cell extracts and supernatants. The influence of hyperglycemia on CN-1 enzyme activity in human serum was tested in homozygous (CTG)(5) diabetic patients and healthy control subjects. Tunicamycin completely inhibited CN-1 secretion. Deletion of all N-glycosylation sites was required to reduce CN-1 secretion efficiency. Enzyme activity was already diminished when two sites were deleted. In pCSII-CN-1-transfected Cos-7 cells cultured in medium containing 25 mmol/l d-glucose, the immature 61 kilodaltons (kDa) CN-1 immune reactive band was not detected. This was paralleled by an increased GlcNAc expression in cell lysates and CN-1 expression in the supernatants. Homozygous (CTG)(5) diabetic patients had significantly higher serum CN-1 activity compared with genotype-matched, healthy control subjects.

CONCLUSIONS

We conclude that apart from the (CTG)(n) polymorphism in the signal peptide of CN-1, N-glycosylation is essential for appropriate secretion and enzyme activity. Since hyperglycemia enhances CN-1 secretion and enzyme activity, our data suggest that poor blood glucose control in diabetic patients might result in an increased CN-1 secretion even in the presence of the (CTG)(5) allele.