Glucose: A Biomarker in Acute Myocardial Infarction Ready for Prime Time?

Quantifying cardiovascular disease risk factors in patients with psoriasis: a meta-analysis

BACKGROUND

In a previous meta-analysis on categorical data we found an association between psoriasis and cardiovascular disease and associated risk factors.

OBJECTIVES

To quantify the level of cardiovascular disease risk factors in order to provide additional data for the clinical management of the increased risk.

METHODS

This was a meta-analysis of observational studies with continuous outcome using random-effects statistics. A systematic search of studies published before 25 October 2012 was conducted using the databases Medline, EMBASE, International Pharmaceutical Abstracts, PASCAL and BIOSIS.

RESULTS

We included 59 studies with up to 18 666 cases and 50 724 controls. Psoriasis cases had a higher total cholesterol [weighted mean difference 8·83 mg dL(-1) , 95% confidence interval (CI) 2·94-14·72, P = 0·003 (= 0·23 mmol L(-1) )], higher low-density lipoprotein cholesterol [9·90 mg dL(-1) , 95% CI 1·56-18·20, P = 0·020 (= 0·25 mmol L(-1) )], higher triglyceride [16·32 mg dL(-1) , 95% CI 12·02-20·63, P < 0·001 (= 0·18 mmol L(-1) )], a higher systolic blood pressure (4·77 mmHg, 95% CI 1·62-7·92, P = 0·003), a higher diastolic blood pressure (2·99 mmHg, 95% CI 0·60-5·38, P = 0·014), higher body mass idex (0·73 kg m(-2) , 95% CI 0·37-1·09, P < 0·001), higher waist circumference (3·61 cm, 95% CI 2·12-5·10, P < 0·001), higher fasting glucose [3·52 mg dL(-1) , 95% CI 0·64-6·41, P = 0·017 (= 0·20 mmol L(-1) )], higher nonfasting glucose [11·70 mg dL(-1) , 95% CI 11·24-12·15, P < 0·001 (= 0·65 mmol L(-1) )] and a higher HbA1c [1·09 mmol mol(-1) , 95% CI 0·87-1·31, P < 0·001 (= 2·2%)].

CONCLUSIONS

From a preventive medicine perspective, the weighted mean differences between cases and controls are significant, and therefore relevant to the clinical management of patients with psoriasis.

Ultra-acute increase in blood glucose during prehospital phase is associated with worse short-term and long-term survival in ST-elevation myocardial infarction

BACKGROUND

The current study was to investigate the blood glucose changes in ultra-acute phase in patients with ST-elevation myocardial infarction (STEMI) and its associations with patient outcome.

METHODS

This study was a retrospective population-based observational study utilizing prospectively collected registry data complemented with laboratory data. All adult patients with STEMI treated by emergency medical services (EMS) in the city of Helsinki from January 2006 to December 2010 were included in the study. Both prehospital and hospital admission glucose values were available from 152 (32%) of all STEMI patients (n = 469).

RESULTS

Change in blood glucose from prehospital phase to emergency department admission was significantly higher in non-survivors within 30 days compared to survivors (+1.2 ± 5.1 vs. -0.3 ± 2.4 mmol/l [mean ± SD], P = 0.03). Furthermore, the 3-year survival rate was significantly lower in patients with an evident (≥2 mmol/l) rise in blood glucose (P = 0.02). In patients with impaired left ventricle function (best ejection fraction < 40%), blood glucose increased more compared to patients without it (1.2 ± 2.9 vs. 0.4 ± 2.7 mmol/l, P = 0.01). Increase in glucose was correlated with peak myocardial creatinine kinase (r = 0.17, P = 0.04) as a marker of increased size of infarct, but not with glycosylated haemoglobin A1C as a marker of chronic hyperglycaemia (r = -0.12, P = 0.27).

CONCLUSIONS

In patients with STEMI, ultra-acute hyperglycaemia during prehospital phase is associated with increased mortality, impaired cardiac function and increased size of infarct.

Differences in myocardial PTEN expression and Akt signalling in type 2 diabetic and nondiabetic patients undergoing coronary bypass surgery

OBJECTIVE

Patients with diabetes experience increased cardiovascular complications after cardiac surgery. Hyperglycaemia predicts increased mortality after myocardial infarction and may influence cardiovascular risk in humans. Impaired prosurvival phosphatase and tensin homologue on chromosome 10 (PTEN)-Akt signalling could be an important feature of the diabetic heart rendering it resistant to preconditioning. This study was designed to evaluate for differences and relationships of myocardial PTEN-Akt-related signalling and baseline glycaemic control marker in type 2 diabetic and nondiabetic patients undergoing coronary artery bypass surgery.

METHODS

Right atrial biopsies and coronary sinus blood were obtained from 18 type 2 diabetic and 18 nondiabetic patients intraoperatively. Expression and phosphorylation of Akt, endothelial nitric oxide synthase (eNOS), Bcl-2 and PTEN were evaluated by Western blot. Plasma 15-F(2t) -isoprostane concentrations were evaluated by liquid chromatography-mass spectrometry.

RESULTS

PTEN expression and 15-F(2t) -isoprostane concentrations were significantly higher in diabetic patients. Increased fasting blood glucose levels correlated with increased coronary sinus plasma 15-F(2t) -isoprostane concentrations. Increased cardiac 15-F(2t) -isoprostane generation was highly correlated with myocardial PTEN expression. Bcl-2 expression and eNOS phosphorylation were significantly lower in diabetic compared with nondiabetic patients. Akt phosphorylation tended to be lower in diabetic patients; however, this tendency failed to reach statistical significance.

CONCLUSION

The current results suggest that prosurvival PTEN-Akt signalling is impaired in the diseased diabetic myocardium. Hyperglycaemia and increased oxidative stress may contribute to this phenomenon. These findings strengthen the understanding of the underlying biologic mechanisms of cardiac injury in diabetic patients, which could facilitate development of new treatments to prevent cardiovascular complications in this high-risk population.

Usefulness of changes in fasting glucose during hospitalization to predict long-term mortality in patients with acute myocardial infarction

Stress hyperglycemia is a complex phenomenon that incorporates the cumulative effects of multiple factors. Rapid changes in blood glucose may reflect neurohormonal and homodynamic events that affect patient outcome. We prospectively studied the relation between changes in fasting glucose (FG) during a hospital course and long-term mortality in 1,467 nondiabetic patients with acute myocardial infarction. FG was obtained at admission and later during the hospital course and classified at each time point as normal (<100 mg/dl), impaired (100 to 125 mg/dl), or diabetic range (>or=126 mg/dl). The relation between measurements of FG and mortality (median follow-up 30 months) was assessed using Cox models. FG classification improved in 426 (29.0%) and worsened in 248 patients (16.9%) during hospitalization. Mean FG was a better predictor of mortality than baseline or final FG levels alone (C-index 0.670, 0.656, and 0.645, respectively). Changes in FG during hospitalization were strongly associated with changes in mortality risk. Compared to patients with persistent normal FG, the adjusted hazard ratio (HR) for mortality was 2.6 (95% confidence interval [CI] 1.0 to 7.2) for patients in whom FG increased to the diabetic range; the HR was 6.3 (95% CI 4.0 to 10.4) in patients with persistent FG in the diabetic range but decreased substantially when FG normalized during hospitalization (HR 2.7, 95% CI 1.3 to 5.1). In conclusion, persistent increase of FG during hospitalization for acute myocardial infarction has greater prognostic effect than baseline FG. Changes in FG during hospitalization are simple and sensitive indicators of dynamic changes in risk.