High levels of C-reactive protein with low total cholesterol concentrations additively predict all-cause mortality in patients with coronary artery disease

BACKGROUND

This study aimed to investigate independent and additive predictive effects of raised C-reactive protein (CRP) levels and decreased total cholesterol levels on mortality in patients with chronic coronary artery disease (CAD). Low total cholesterol (TC) levels are associated with worsened survival in chronic and acute diseases. Elevated CRP level is an important predictor of vascular events and mortality in patients with CAD. Potential inhibition of immune activation by circulating lipoproteins could be a link between cholesterol and inflammatory markers.

MATERIALS AND METHODS

A group of 387 patients (median age 59 years) with CAD and with or without severe heart failure (HF) were followed for a median of 5.06 years. Serum total cholesterol and CRP concentrations were measured at enrollment.

RESULTS

The relationship between lipoproteins, CRP and survival was explored. High CRP concentrations were in significant association with severity of HF and predicted worsened survival in patients with CAD (hazard ratio 5.214, 95% CI 1.762-15.427). The association between CRP levels and mortality was independent of potential confounding factors such as age, body-mass index, severity of HF, smoking habits, hypertension and TC levels. The prediction of mortality by low TC levels was significant (hazard ratio 2.932, 95% CI 1.021-8.422). Furthermore, patients with increased CRP and decreased TC (additive predictive effect) phenotype had 11.714-times higher risk (95% CI 2.619-52.385) of being nonsurvivors than patients with low CRP/high TC.

CONCLUSIONS

High CRP levels and low TC concentrations are independent and additive predictors of mortality in patients with CAD. Our data indicate that joint analysis of circulating lipoproteins and inflammatory biomarkers may improve prediction of survival in patients with CAD.

Changes of enzyme activity in T-cells during induced maternal behaviour in rats

Continuous exposure to foster pups elicits specific behavioural patterns in adult naive female or male rats. The first exposure induces active avoidance of young. By day 2 or 3 adults show neutral behaviour. Next day complete maternal behaviour begins to develop; e.g. retrieving of pups, nursing and crouching. The avoidance reaction activates stress mechanisms, and the developed maternal behaviour is associated with moderate prolactin release. The question is raised whether pup-induced catecholamine and prolactin release is able to alter enzyme activity in T-cells. Using Arg-Pro-; Leu-Pro; and Pro-Pro-4-nitroanilide as substrates the activity of a marker enzyme dipeptidyl peptidase IV, DP IV, EC. 3.4.14.5., was measured in T-cell suspension prepared from the thymi of adrenalectomized female and male Wistar rats. We found that changes of DP IV activity during the pup-induced avoidance phase could be prevented by propranolol pretreatment indicating the role of catecholamines in this phenomenon. Prolactin released during artificial maternal behaviour in female rats resulted in an elevation of DP IV activity which failed to develop, if they were given daily injections of bromocriptine or apomorphine. It is concluded that pup-exposure is the most physiological way to influence hormonal mechanisms and immune functions, which are highly responsive to sensory stimuli.

Changes of dipeptidyl peptidase (DP IV) activity in the T lymphocytes of rats following administration of ACTH, dexamethasone and opiates

The aim of the work was to study the effect of glucocorticoids, opiates and stressful stimuli on dipeptidyl peptidase IV (DP IV, EC 3.4.14.5) activity of T lymphocytes prepared from the thymus of intact and adrenalectomized rats. Four week old male rats of Wistar strain were used. The in vivo administration of ACTH, dexamethasone and morphine treatment resulted in an increase of DP IV activity in the cell suspension. In adrenalectomized rats ACTH treatment failed to modify the enzyme activity, however, pain or emotional stress resulted in an elevated DP IV activity. Morphine and D-Met2-Pro5-enkephalinamide resulted in a dose dependent activation of DP IV in T cells, an effect which could be modified by naloxone pretreatment. Our findings show that DP IV mechanisms in T cells are highly sensitive to exogenous and endogenous steroids, opiates and biologically active substances released in response to stress in rats.

Comparative analysis of enzyme activity in human colostrum, milk, and serum

Changes of enzyme activity in the colostrum, milk, and serum samples of 14 mothers were followed. For the enzyme assay, the colostrum and the milk samples were diluted, 1:10 and 1:5, respectively. The activity of the following enzymes were measured: lactate dehydrogenase (LDH); gammaglutamyl transpeptidase (GGT); aspartate aminotransferase (ASAT); alanine aminotransferase (ALAT); cholinesterase; alkaline, and acid phosphatase. Milk, LDH, ASAT, and ALAT activities did not change during the first four days of lactation, yet were significantly higher than the corresponding activities of serum. The activity of GGT and alkaline and acid phosphatase in milk showed a marked decrease by day 4 postpartum; however, the GGT stayed much higher than that of serum, while the activity of the other two enzymes decreased to the level of the serum. By contrast, as compared to the colostrum, the cholinesterase activity in the breast milk showed a significant increase.