Association between protein-bound sialic acid and high-sensitivity C-reactive protein in essential hypertension: a possible indication of underlying cardiovascular risk

Neuraminidases-Key Players in the Inflammatory Response after Pathophysiological Cardiac Stress and Potential New Therapeutic Targets in Cardiac Disease

Glycoproteins and glycolipids on the cell surfaces of vertebrates and higher invertebrates contain α-keto acid sugars called sialic acids, terminally attached to their glycan structures. The actual level of sialylation, regulated through enzymatic removal of the latter ones by NEU enzymes, highly affects protein-protein, cell-matrix and cell-cell interactions. Thus, their regulatory features affect a large number of different cell types, including those of the immune system. Research regarding NEUs within heart and vessels provides new insights of their involvement in the development of cardiovascular pathologies and identifies mechanisms on how inhibiting NEU enzymes can have a beneficial effect on cardiac remodelling and on a number of different cardiac diseases including CMs and atherosclerosis. In this regard, a multitude of clinical studies demonstrated the potential of N-acetylneuraminic acid (Neu5Ac) to serve as a biomarker following cardiac diseases. Anti-influenza drugs i.e., zanamivir and oseltamivir are viral NEU inhibitors, thus, they block the enzymatic activity of NEUs. When considering the improvement in cardiac function in several different cardiac disease animal models, which results from NEU reduction, the inhibition of NEU enzymes provides a new potential therapeutic treatment strategy to treat cardiac inflammatory pathologies, and thus, administrate cardioprotection.

The association of total sialic acid and malondialdehyde levels with metabolic and anthropometric variables in obesity

Serum sialic acid levels are abnormally high in pathological states that exhibit tissue destruction, tissue proliferation or inflammation. We measured total serum sialic acid levels in 139 women and 125 men. Subjects were divided into quartiles according to their body mass index (BMI): Q1 (18-24.9 kg/m(2)), Q2 (25-29.9 kg/m(2)), Q3 (30-39.9 kg/m(2)) and Q4 (> 40 kg/m(2)). The patients in Q1 constituted the control group. Serum sialic acid levels of subjects in Q2, Q3 and Q4 were significantly higher than those in Q1. Higher BMI quartiles also were associated with higher levels of serum glucose, insulin, total cholesterol, LDL-cholesterol, triglycerides, high-sensitivity C-reactive protein, malondialdehyde levels, waist circumference, blood pressure and homeostasis model assessment of insulin resistance in both women and men. Lower BMI quartiles were associated with higher levels of serum HDL-cholesterol levels in both women and men. We found positive associations among serum sialic acid levels, BMI and oxidative stress. Serum sialic acid also is related to some conventional cardiovascular risk factors including elevated lipid profile, increased blood pressure, increased serum glucose and insulin levels, and insulin resistance in obese people.

Hyperhomocysteinemia, Insulin Resistance and High HS- CRP Levels in Prehypertension

BACKGROUND

Pre-hypertension refers to blood pressure in the range of 120 to 139 mm of Hg / 80 to 89 mm of Hg and its prevalence is increasing in India. Previous studies have documented the increase in homocysteine, C-reactive protein and insulin resistance and their role in the development of hypertension. In recent years much attention has been focused on subjects with prehypertension, as the risk for development of cardiovascular disease is higher in these subjects compared to those with normal blood pressure.

OBJECTIVES

To evaluate the serum homocysteine, hs-CRP level and insulin resistance in subjects with prehypertension.

MATERIALS AND METHODS

Sixty prehypertensives and 32 normotensives were recruited according to Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of blood pressure (JNC 7) guidelines. Serum homocysteine, vitamin B12, folate, insulin, hs-CRP and lipid profile were analysed. Independent t-test was carried out to compare two groups and pearson correlation analyses were carried out between various parameters with systolic blood pressure (SBP) and diastolic blood pressure (DBP).

RESULTS

Cardiovascular risk factors like serum homocysteine, insulin resistance and inflammatory marker hs-CRP were significantly increased in prehypertensives. Total cholesterol, TG, LDL-C and VLDL-C were significantly increased when compared to normotensives. Serum homocysteine correlated positively and vitamin B12 and folate negatively with Systolic Blood Pressure.

CONCLUSION

The present study concludes that the established cardiovascular risk factors, homocysteine, insulin resistance, and hs-CRP which have roles in the etiopathogenesis of hypertension, were elevated in subjects with prehypertension. Thus, early detection and life style modification may reduce the risk or delay the onset of hypertension and other cardiovascular complications.

Rosuvastatin, inflammation, C-reactive protein, JUPITER, and primary prevention of cardiovascular disease--a perspective

The major public health concern worldwide is coronary heart disease, with dyslipidemia as a major risk factor. Statin drugs are recommended by several guidelines for both primary and secondary prevention. Rosuvastatin has been widely accepted because of its efficacy, potency, and superior safety profile. Inflammation is involved in all phases of atherosclerosis, with the process beginning in early youth and advancing relentlessly for decades throughout life. C-reactive protein (CRP) is a well-studied, nonspecific marker of inflammation which may reflect general health risk. Considerable evidence suggests CRP is an independent predictor of future cardiovascular events, but direct involvement in atherosclerosis remains controversial. Rosuvastatin is a synthetic, hydrophilic statin with unique stereochemistry. A large proportion of patients achieve evidence-based lipid targets while using the drug, and it slows progression and induces regression of atherosclerotic coronary lesions. Rosuvastatin lowers CRP levels significantly. The Justification for Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) trial was designed after the observation that when both low density lipoprotein and CRP were reduced, patients fared better than when only LDL was lowered. Advocates and critics alike acknowledge that the benefits of rosuvastatin in JUPITER were real. After a review, the US Food and Drug Administration extended the indications for rosuvastatin to include asymptomatic JUPITER-eligible individuals with one additional risk factor. The American Heart Association and Centers of Disease Control and Prevention had previously recognized the use of CRP in persons with "intermediate risk" as defined by global risk scores. The Canadian Cardiovascular Society guidelines went further and recommended use of statins in persons with low LDL and high CRP levels at intermediate risk. The JUPITER study focused attention on ostensibly healthy individuals with "normal" lipid profiles and high CRP values who benefited from statin therapy. The backdrop to JUPITER during this period was an increasing awareness of a rising cardiovascular risk burden and imperfect methods of risk evaluation, so that a significant number of individuals were being denied beneficial therapies. Other concerns have been a high level of residual risk in those who are treated, poor patient adherence, a need to follow guidelines more closely, a dual global epidemic of obesity and diabetes, and a progressively deteriorating level of physical activity in the population. Calls for new and more effective means of reducing risk for coronary heart disease are intensifying. In view of compelling evidence supporting earlier and aggressive therapy in people with high risk burdens, JUPITER simply offers another choice for stratification and earlier risk reduction in primary prevention patients. When indicated, and in individuals unwilling or unable to change their diet and lifestyles sufficiently, the benefits of statins greatly exceed the risks. Two side effects of interest are myotoxicity and an increase in the incidence of diabetes.