Cardiovascular Test EXPERT

What are the main causes of cardiovascular disease?

The presence of risk factors associated with cardiovascular diseases elevates the likelihood of their development. WHO describes 7 major causes and risk factors [3-4]:

• hypertension
• smoking
• increased cholesterol levels in the blood
• overweight and obesity
• lack of physical activity
• low dietary intake of vegetables and fruits
• excessive alcohol consumption

What´s measured

What does the Cardiovascular Test EXPERT include? 

Test of cardiovascular risk is a specialised test package designed to evaluate the risk of cardiovascular diseases stemming from disorders related to fat metabolism, diabetes, and kidney function. It encompasses screening for impaired glucose metabolism and glycated hemoglobin HBA1c, insulin, insulin resistance (HOMA-IR), lipid metabolism (cholesterol, triglycerides, LDL cholesterol, HDL cholesterol, non-HDL cholesterol, sd LDL cholesterol, and fatty acid profile). 

Additionally, it provides information on atherogenicity through the determination of small dense LDL particles, ApoB/ApoA1 ratio, lipoprotein (a), atherogenic index of plasma (AIP), LDL/HDL (AI1) and CHOL/HDL (AI2) indices. Renal function assessment is conducted by determining glomerular filtration rate (GF-CKD EPI), serum creatinine, microalbuminuria, and other metabolism-related parameters including ALT, GGT, uric acid, homocysteine, hs-CRP, TSH, fibrinogen, D-dimer, and blood count with a differential count.

Glucose

Blood glucose concentration (=glycaemia) depends on the balance between uptake (food, supply from the liver between meals—glycogenolysis, gluconeogenesis) and its utilisation by cells, as well as on its hormonal regulation: insulin decreases glycaemia, while glucagon, adrenaline, cortisol, and growth hormone increase it.

Glycated haemoglobin (HBA1c)

Glycated haemoglobin is produced in the body through the non-enzymatic binding of glucose to haemoglobin. The level of glycated haemoglobin is influenced by both glucose concentration and the lifespan of erythrocytes. Glycated haemoglobin concentration provides a reflection of glucose levels over the entire lifespan of erythrocytes, which is approximately 120 days. It is utilised to evaluate the management of diabetes over the preceding 6 to 8 weeks before the examination. 

Insulin

Insulin is a peptide hormone with anabolic effects in the body and represents the main regulator of glucose homeostasis. The biosynthesis of the hormone occurs within the β‐cells of the islets of Langerhans, where it is being secreted into the circulation as proinsulin. 

HOMA-IR

Insulin resistance refers to a state where a physiologically normal amount of insulin produces an inadequate biological response, necessitating higher insulin concentrations to achieve the desired effect. The HOMA index is used to quantify insulin resistance.

ALT

ALT is a crucial enzyme frequently utilised in diagnosing hepatocellular injury, often alongside AST. It catalyses the transfer of an amino group of alanine to ketoglutaric acid. Unlike AST, ALT is predominantly found in the liver and is exclusively located in the cytosol.

Uric acid

Uric acid is a nitrogenous compound produced in humans as an end product of purine metabolism. In individuals with good health, it serves as a potent antioxidant, effectively scavenging free oxygen radicals. It is also included as one of the biomarkers in the metabolic syndrome panel.

GGT

GGT, in literature also referred to as GMT, is an enzyme predominantly found in the liver, with the highest concentration therein. It is positioned near the surface (membrane) of liver cells, making it among the first enzymes to be released in cases of liver and bile duct disorders.

Cholesterol

Cholesterol is an essential component of every cell in the body and serves several vital functions. It exists in the human body either from exogenous sources (obtained from outside through food) or endogenously (produced within the body).

LDL

LDL cholesterol refers to the cholesterol carried within LDL particles. LDL particles are categorised within the apoB family of lipoprotein particles, known to be atherogenic. The apoprotein B100 remains within the LDL envelope and serves as both a structural and ligand apoprotein. LDL cholesterol is a significant marker of cardiovascular risk. It is targeted in the evaluation of cardiovascular risk and the monitoring of pharmacological treatments for hypercholesterolemia.

HDL

HDL cholesterol refers to the cholesterol carried within HDL particles. HDL particles are created from the surplus phospholipids of the VLDL envelope, along with a variable number of apoprotein A molecules during the metabolism of VLDL to LDL. The concentration of serum HDL cholesterol indirectly indicates the quantity of antiatherogenic HDL particles present.

Triglycerides

Triglycerides serve as a primary source of fatty acids for energy metabolism. They constitute approximately 95% of adipose tissue.

ApoA

The apolipoprotein A1 protein plays a crucial regulatory role in lipoprotein metabolism. It is synthesised in both the liver and intestine. Besides its role in structurally stabilising HDL particles, it performs other functions in lipoprotein metabolism. One of its key roles in atherogenesis is activating the lecithin-cholesterol acyltransferase (LCAT) enzyme, which is responsible for cholesterol esterification.

ApoB

Apolipoprotein B100 (apoB) serves as the principal structural apoprotein for the group of apolipoprotein B lipoprotein particles (including VLDL, IDL, LDL, and remnant particles). Each of these particles contains one apoB molecule, making its quantity a reliable indicator of the number of these particles in serum. Additionally, in relation to LDL cholesterol concentration, apoB serves as a marker for the proportion of atherogenic small dense (sdLDL) lipoprotein particles.

ApoB/ApoA1

It represents a ratio between atherogenic (apoB) and antiatherogenic (apoA1) plasma lipoprotein particles. It reflects cholesterol transport in lipoprotein particles and is a more accurate indicator of cardiovascular risk than other parameters of lipid metabolism.

sd LDL Cholesterol

The LDL particle population varies in size and metabolic activity. Large LDL particles primarily serve as cholesterol donors for cells requiring cholesterol as a substrate for metabolic activities. However, the cardiovascular risk is attributed to small LDL particles, as they possess the capability to penetrate into subendothelial spaces where they aggregate and undergo oxidation.

non-HDL cholesterol

non-HDL cholesterol is a way of expressing the content of lipoproteins that are involved in the development of atherosclerosis. This calculation parameter is one of the assessment criteria for estimating cardiovascular risk and is also part of several online calculators. At the same time, it is recommended as a secondary treatment target instead of LDL cholesterol in a defined group of patients.

Fatty acid profile

Fatty acids and glycerol are the main components of lipids or lipids. The fatty acid profile provides an overview of the representation of the ten saturated, monounsaturated (omega-9) and polyunsaturated (omega-6 and omega-3) fatty acids and their relative proportions of omega-6 and omega-3. Fatty acids are essential for the body, we get them from food and they play an important role in the development and functioning of the brain and nervous system, they boost immunity and they also have anti-inflammatory effects.

Blood count with differential

It helps in the assessment of the overall health status, can assist in detecting anemia (low red blood cell count), and thus impaired oxygen supply to tissues, as well as in determining the risk of infections, inflammations, immune disorders, or coagulation problems.

Atherogenic index of plasma

The calculated AIP takes into account not only the absolute values of the parameters from which it is calculated (TG and HDL cholesterol), but also the size of the lipoprotein particle subpopulations. The atherogenicity of lipoprotein particles depends on their composition and size.

CRP

C-reactive protein (CRP) is comprised of five identical unglycated globular subunits, each with a molecular mass of 25 kDa. These subunits are organised by non-covalent bonds into a single disc. It is classified as a pentraxin. It is synthesised in the liver in response to stimulation by cytokines, primarily IL-6, IL-13, and TNF-α. High-sensitivity CRP (hs-CRP) measurement is employed in assessing cardiovascular risk. The hs-CRP level correlates with the risk of developing metabolic syndrome, type 2 diabetes mellitus, and arterial hypertension.

TSH

Thyrotropic hormone is a glycoprotein synthesised in the anterior lobe of the pituitary gland. Its secretion varies throughout the day and is regulated by a negative feedback loop involving the hypothalamus-adenohypophysis-thyroid axis. TSH binds to specific receptors on the surface of thyroid follicular cells, stimulating the production of thyroid hormones.

Glomerular filtration rate (GFR)

The CKD-EPI calculation is used to assess and estimate glomerular filtration rate in adults based on serum creatinine concentration, age, sex, and race of the patient adjusted to a standard body surface area of 1.73 m3. It is derived based on data from 10 studies with 8,254 participants. As recommended by the KDIGO, the CKD-EPI equation is currently the preferred equation for calculating GF in adults.

CKD-EPI calculation

The CKD-EPI calculation is included in the result for each adult patient whose creatinine concentration has been determined.

Urea

Urea is the primary nitrogenous waste product of amino acid and protein metabolism. It is synthesised in the liver from ammonia produced as a result of deamination reactions during amino acid metabolism.

Urea is filtered by the kidneys and excreted into the urine through glomerular filtration.

Creatinine

Creatinine is produced in muscle tissue after the cleavage of phosphate from creatine phosphate, which acts as an energy source for muscles. It is primarily eliminated by the kidneys through glomerular filtration at a relatively consistent rate.

Microalbuminuria

Increased urinary albumin excretion serves as an early indicator of glomerular damage and is predictive of the progression of renal disease, particularly in individuals with diabetes and hypertension. Elevated levels of albuminuria also pose a risk factor for cardiovascular disease, even among individuals without diabetes, serving as a marker of endothelial dysfunction.

Fibrinogen

Fibrinogen, also known as coagulation factor I, is a glycoprotein found in relatively high concentrations in plasma compared to other coagulation factors. It is synthesised in the liver and megakaryocytes. As the final step in the coagulation cascade, fibrinogen is converted by thrombin to fibrin, which is a crucial component of the final red thrombus. This is facilitated by calcium and fibrin-stabilising factor XIII.

D-dimer

D-dimer is a highly sensitive marker that indicates activation of fibrinolysis. The most common manifestation of venous thromboembolism is deep vein thrombosis, or pulmonary embolism, which is directly related to an increase in blood D-dimer levels.

Homocysteine

Homocysteine (Hcy) is a sulfur-containing amino acid involved in methionine metabolism. Approximately 1–2% of homocysteine circulates in the blood in its free reduced form, some as disulfides, and 70–90% is bound to proteins. The measurement of homocysteine levels is important for assessing the risk of developing vitamin B12, B6, and folate deficiencies, as well as the risk of ischemic heart disease (IHD).