Cardiovascular risk assessment

Modifiable risk factors are those for which we have pharmacological resources or lifestyle modification so that they can be mitigated.

• Smoking: is associated with the development of atherosclerosis and consequently, with an increase in blood pressure and 2 to 4 times, with the development of cardiovascular diseases. It is the leading cause of preventable death and is the cause of 20% of deaths from coronary heart disease. It is responsible for 80% of cases of chronic obstructive pulmonary disease and 75 to 80% of cases of chronic bronchitis. It is the cause of 25 to 30% of all cancers and 90% of lung cancer cases. The impact of smoking cessation on human health is very important. At age 5, the risk of esophageal cancer is reduced by half. At 10 years, the risk of lung cancer is also reduced by half and at 15 years, the risk of cardiovascular disease is similar to that of non-smokers, of the same gender and the same age. The cardiovascular risk of people exposed to tobacco smoke (passive smoker) also increases.

• Obesity and overweight: the most common method for defining obesity is by calculating the BMI (Body Mass Index, which is the result of dividing the weight by the square of the height). If the BMI is less than 18.5 kg/m2, it corresponds to low weight (if it is <15 kg/m2, it is associated with a risk of death). If it is between 18.5 and 24.9 kg/m2, we are talking about normal weight. Between 25 and 29.9 kg/m2, we are talking about excess weight (the cardiovascular risk is increased, but not significantly. If the BMI is between 27 and 29.9 kg/m2 and if other risk factors are present, such as diabetes or high blood pressure, then the cardiovascular risk is already significantly increased). Regardless of the presence or absence of other risk factors, for a BMI >30 kg/m2, cardiovascular risk is already significantly increased and will increase further as BMI increases. Obesity is defined as having a BMI >30 kg/m2. If the BMI is 30 to 34.9 kg/m2, the obesity is type I. If it is 35 to 39.9 kg/m2, it is type II and if it is =>40 kg/m2, it is type III. For some authors, BMI =>50 kg/m2 is classified as type IV or extreme or morbid obesity. Calculating BMI is important for classifying obesity. However, if we take into account central or android obesity, the measurement of the abdominal perimeter is more important than the BMI. In men, a measurement <94 cm is associated with low cardiovascular risk. If the measurement is between 94 and 101.9 cm, the risk is increased and if it is =>102 cm, the risk is greatly increased. In women, the values ​​are, respectively, <80 cm (some authors consider 83 cm), from 80 to 87.9 cm and =>88 cm. There is a direct relationship between obesity and other cardiovascular risk factors. 78% of type 2 diabetics have a BMI >25 kg/m2. 60% of hypertensive patients are obese. There is a direct relationship between BMI and mortality from cardiac causes and, regardless of BMI, increased abdominal perimeter is always associated with increased cardiovascular risk.

• Diabetes mellitus: is one of the most important cardiovascular risk factors. Diabetic patients, particularly those with poorer control, have a significantly increased risk of suffering from myocardial infarction, cerebral thrombosis or peripheral arterial disease. This conclusion was reported for the first time in a scientific article published by Haffner and collaborators in 1998. They concluded that in relation to cardiovascular risk, diabetes was equivalent to the patient being in secondary prevention, that is, the risk of a diabetic patient suffering from a myocardial infarction, even if he had not had any previous episode, was similar to that of another non-diabetic patient who had already suffered a myocardial infarction.

• High blood pressure: high blood pressure is one of the most common and important cardiovascular risk factors. It is associated with a higher risk of stroke (thrombotic or hemorrhagic), coronary heart disease and peripheral arterial disease. It is estimated that 27% of the adult population in Portugal is hypertensive. Of these, only 50% know they have high blood pressure, only 25% are taking medication and only 11% have their blood pressure under control. A blood pressure value lower than 120/70 mmHg is considered normal. If the systolic (“maximum”) blood pressure is between 120 and 140 mmHg and the diastolic (“minimum”) blood pressure is between 70 and 90 mmHg, it is considered that blood pressure is high or pre-hypertension. If the value is >140/90 mmHg it is called arterial hypertension.

• Dyslipidemia: abnormalities in lipid metabolism, whether cholesterol, triglycerides or apolipoproteins, are associated with an increased cardiovascular risk, in particular coronary disease. Cholesterol is essentially formed by three lipoproteins: HDL (High Density Lipoproteins); LDL (Low Density Lipoproteins; Lp(a). HDL is the so-called “good” cholesterol. It protects against coronary disease, which is why its high value is associated with a reduction in cardiovascular risk. Values ​​>60 mg/dl are considered protective. However, sometimes even very high values ​​(>80 mg/dl) may not be protective because they are dysfunctional HDL. LDL is considered “bad” cholesterol. It represents the cholesterol that is deposited on the walls of the arteries and causes atherosclerosis and the consequent increase in cardiovascular risk. In individuals without other risk factors, a value <115mg/dl is accepted. If other risk factors are present, the normal value should be <100 mg/dl or even <70 mg/dl. However, in relation to LDL, there is a consensus that the lower the value, the better. Lp(a) is a lipoprotein similar to LDL, with the difference that it is made up of an apolipoprotein B100 linked to the apoilipoprotein a. A high Lp(a) value is also associated with an increased cardiovascular risk. Regarding total cholesterol, the value considered normal is <180 mg/dl. However, various scientific studies, such as the Framingham Heart Study, indicate that the normal value should be <150 mg/dl. Triglycerides (TG) are a fat and represent the most important form of how it is stored in the human body. They are supplied by food and synthesized in the liver. Excess calories ingested are transformed into TG, which are stored in adipose tissue as an energy reserve. In the event of a lack of energy supply, TG are mobilized from adipose tissue and converted into glucose in the liver through a process called neoglucogenesis. High TG levels are associated with increased cardiovascular risk and very high levels are associated with risk of pancreatitis. The normal level is <150 mg/dl. Between 150 and 199 mg/dl is considered to be a value at the upper limit of normal. Between 200 and 499 mg/dl is considered a high value and above 500 mg/dl, a very high value.

• Sedentary lifestyle: associated with increased cardiovascular risk, in particular, myocardial infarction, cerebral thrombosis, heart failure and sudden cardiac death. It is also associated with an increased prevalence of obesity, high blood pressure, type 2 diabetes mellitus and obstructive sleep apnoea syndrome. Physical activity can be done while taking advantage of everyday tasks. If more intense physical activity is performed, it must follow certain rules to minimize any risks. Heart rate should be monitored by measuring the pulse or using some equipment that can take the measurement. You should start by calculating the Maximum Theoretical Frequency (MTF) to be achieved. The MTF is the result of subtracting age from 220. The maximum heart rate to be achieved with the activity should be between 60 and 75% of the MTF. In a scientific study carried out by the University of Cambridge and published in the American Journal of Clinical Nutrition, 334,000 Europeans were monitored, during 12 years, their physical activity and mortality were analysed, concluding that 7.3% of them were due to a sedentary lifestyle.

• Unhealthy diet: This is associated with an increased risk of cardiovascular disease, particularly if the diet is rich in saturated fats, trans fats, salt and sugar and poor in fiber and essential nutrients. On the contrary, a diet based on the Mediterranean diet, rich in fruits, vegetables, whole grains, fish, poultry and olive oil, significantly reduces cardiovascular risk.

• Chronic stress: is associated with increased blood pressure and accelerated heart rate and consequently the risk of events such as myocardial infarction and cerebral thrombosis.