Statistical analysis

Data were entered into a database created in Microsoft Excel 2016 for subsequent descriptive analysis with the Epi Info 7 software using absolute frequencies and percentages.

Ethical considerations

The study took into consideration the ethical principles for medical research involving human subjects established by the Declaration of Helsinki¹⁷ and was approved on August 2, 2017, by the Bioethics and Research Involving Human Subjects Committee of the Universidad Regional Autónoma de los Andes by means of Minutes No. 23-08/2017_CBISH-UNIANDES. Also, the informed consent of each participant was obtained to collect the data.

Sex

In the present study, HBP was slightly more prevalent in women than in men (59.17% vs. 40.83%). This is consistent with the findings of Sánchez Seco Higuera et al.,¹⁸ who found that 53.5% of women and 46.5% of men in a sample of 662 subjects over the age of 65 from Horche (Guadalajara, Spain) had high blood pressure. It should be noted that women have protective mechanisms against CVD, but they partially lose such protection when they reach menopause, making them more susceptible to developing this type of disease.^16,19

In spite of the above, it is noteworthy that the percentage of male participants classified as high-risk was significantly higher than that of females (79.59% vs. 45.07%), which may be influenced by tobacco use, as it was more frequent in males.

Diabetes mellitus type 2

The percentage of patients with DM2 found in the present study (15%) is considerably low, which coincides with an epidemiological study conducted in Japan, where approximately 20% of patients with high blood pressure had this disease.²⁰ This is relevant because, according to research conducted in Ethiopia by Akalu & Belsti,²¹ a one-year increase in the duration of DM2 increases the likelihood of developing HBP by 16% (aOR: 1.16, 95%CI: 1.08-1.25).

Smoking history

The patients who reported smoking accounted for a small percentage of the study population (13.33%, n=16), although most of them (n=13) were classified as high-risk for CVD; therefore, it could be concluded that this habit, although rare, implies a higher CVR compared to non-smokers. However, in the study by Petermann et al.²² carried out in Chile, no association between these variables was identified in men, but it was found that the risk decreases in female smokers (OR: 0.67 95%CI: 0.520.86, p=0.,002) and in former female smokers (OR: 0.77 95%CI: 0.60-0-99, p=0.040). This result contradicts most research in this matter, as few studies describe a decrease in blood pressure in smokers. ^23,24

With respect to this variable, it should be noted that Akalu & Belsti²¹ assessed smoking in 378 patients with DM2 and a mean age of 56 years, finding that this population is 3.9 times more likely to develop HBP than those without this condition.

Similarly, Arboleda-Carvajal & García-Yanés,²⁵ in a study of 249 people from a general population of the Amazon region of Morona Santiago (Ecuador), found that the main factor for CVR was smoking (48.6%), followed by overweight (40.2%) and low HDL-C (10.4%), which correlates with the findings of this research.

It is important to bear in mind that the present study did not evaluate the number of cigarettes smoked per day, but rather the presence or absence of consumption.

High-density total and lipoprotein cholesterol

Most (60.8%) of the participants had TC levels within the normal range and only a small percentage (16.6%) did not have an optimal result, which is similar to what has been reported by Sánchez Seco Higuera et al.,¹⁸ who found that 23.3% of participants had hypercholesterolemia.

Regarding HDL-C levels, 30% of participants had results below the optimal value, 68.33% had normal values, and only 1.67% had optimal values, which is relevant because, according to a study performed in 35 patients with metabolic syndrome by Mendoza-Romo et al.,²⁶ individuals with optimal HDL-C values experience a significant beneficial change by lowering their blood pressure and therefore their CVR, whereas the latter increases in those with a decrease in HDL-C levels

The measurement of these variables is of great importance because it is possible to establish adequate diets and nutritional recommendations focused at preventing possible cardiovascular events when determining CVR in patients using the FRS 2008.²⁷

Antihypertensive therapy

A large percentage of the participants in the sample analyzed were on antihypertensive treatment (82.5%). Of the 21 patients who reported not taking antihypertensive medication (17.5%), about half (47.61%; n=10) were classified as high-risk, which is concerning given that treatment is essential to avoid complications in these patients.

In this regard, Tang et al.,²⁸ in a cohort study of 2 199 patients aged 65 years or older in Canada comparing adherence rates and associations with mortality using different adherence definitions and various methods of managing concurrent drug use, found that 24.1% to 90.5% and 71.2% to 92.7% of the patients were considered adhering when using fixed interval and prescription-based interval measurement possession ratios respectively, depending on how concurrent medications were handled. This situation shows a large fluctuation that is concerning because of the lack of homogenization in the level of awareness regarding treatment.

Likewise, Tan et al.²⁹ conducted a systematic review that evaluated the effectiveness of educational interventions to improve medication adherence in adult patients diagnosed with hypertension, hyperlipidemia, and/or diabetes, and concluded that health literacy is improved through health education, improving medication adherence as well.

Age

In the present study, the predominant age range was 70 to 74 years (n=42), in which high CVR prevailed (n=33), which was to be expected given the increased number of physiological changes associated with aging that could influence this aspect.

With respect to this variable, Akalu & Belsti²¹ found in their study that people over the age of 50 are more likely to have HBP, which can be attributed to the vascular changes that occur during aging and that trigger greater stiffness and thickening of the arteries. This is supported by different studies that report that the prevalence of HBP increases with age.^21,30

Systolic blood pressure

When assessing SBP, it was found that in most participants the values were above 130 mmHg (72.49%), with a higher prevalence among older patients and in those who reported not being on antihypertensive treatment.

Based on the findings, it is confirmed that age is a factor of CVR, since SBP is more prevalent in patients over 60 years of age and is also associated with diseases such as stroke, cardiovascular disease, and increased mortality.^16,31

Overall cardiovascular risk in the study population

When determining overall CVR according to the FRS 2008, in the present study most of the study population (59.17%) was classified as high risk; about a quarter (29.17%) was classified as moderate risk; and a small percentage (11.67%) was classified as low risk. These findings markedly differ from those found by De La Noval-Garcia et al.,³² who reported a low risk (<10% according to the WHO risk classification proposal) in 93.6% of participants in a study of 1 287 people (randomly selected) between 40 and 70 years in Havana, Cuba. It should be noted, however, that this difference is most likely due, on the one hand, to the fact that each study used a different tool for risk assessment (FRS 2008 vs. WHO classification proposal) and, on the other, to sampling differences in population size and type, since the present study included a specific sample (patients with HBP) that was 10 times smaller, whereas the study of Nova-García et al.³² analyzed the general population.

Furthermore, the finding of the present study in terms of global CVR also differs from the results obtained by Muñoz-Gualan & Muñoz³³ in a study carried out in 2015 in 80 apparently healthy military personnel of the 62^nd Jungle Battalion "Zamora" (Ecuador), in which CVR was evaluated using the Framingham score, finding that 60% of the population was at low risk and 33.75% at moderate risk. The differences between the present study and the latter may be influenced by the physical fitness and systematic training that military participants received, which contributes to better overall health and, as a result, lower CVR.

It is also worth noting that the study by Giraldo-Trujillo et al.,³⁴ carried out in 138 Colombian workers of both sexes, found that 28.6% of men were classified as low risk and 53.5% as medium risk with the Framingham-Grundy scale, which contrasts with the present study in that most participants were classified as high risk.

It is also noteworthy that, compared with the studies described above, the overall CVR was significantly higher in the present study, which may be due to the fact that these studies were performed in populations different from the FHS (Caucasians aged between 30 and 60 years). This heightens debates over the FRS 2008's utility in different ethnic groups, particularly among young patients.^30,35

On the other hand, in a study carried out in 2014 with 208 women between 35 and 74 years old from Havana, Rodríguez-Blanco et al.³⁶ found that the most frequent factors of overall CVR were smoking (44.71%) and SBP≥140 mmHg (28.36%),³⁶ results that differ from those of the present research.

In general, the findings of this study are consistent with those reported in the literature; however, even though the population analyzed here presents with a large number of risk factors, they are not the ones that predispose it to high CVR, but rather the association of some of them in the same patient. In addition, the changes that the body goes through over time, both structural and functional, predispose to the development of CVD,³⁰ indicating the importance of taking preventive measures and conducting a comprehensive follow-up of patients.

Final remarks

In 2018, the ESC/ESH guidelines recommended using the SCORE scale in European and North American populations to assess CVR in patients without known CVD with a 10-year risk estimate, for which it is important to know the hypertension-mediated organ damage.¹² Thus, the stratification of CVR according to this tool can help detect patients who require timely comprehensive management, eliminating the predictors of death. This is considered a substantial contribution to Ecuador's national primary health care program.

It is essential to bear in mind that although CVR prediction equations are widely accepted, there is evidence showing that they cannot be applied directly to all populations; therefore, defining the most suitable model to use in the Ecuadorian population is a priority. To this end, the study by Muñoz et al.,³⁷ in which external validation of the Framingham and PROCAM models was performed in 1 013 Colombian patients aged 30 to 74 years and free of cardiovascular events at the time of enrollment to the cohort (1984 to 1996), can be used as a guide. In that study, the authors concluded that the FRS 2008 should be used with caution in low- and intermediate-risk Colombian populations with no previous history of CVD because it overestimated the risk and demonstrated a low capacity for discrimination between low- and high-risk patients.

Similarly, it should be noted that in Ecuador, the Ministry of Public Health¹ recommended using the Globorisk tool to assess CVR in the country because it was developed in a multi-ethnic population, Latin Americans (Mexico) being representative; it allows calculation without laboratory values, makes an estimate for 11 countries, and is free of charge. However, the FRS 2008 calibrated by Muñoz et al.³⁷continues to be used since it has been widely disseminated in recent years, the health personnel is familiar with its use,³⁸ and has been endorsed by 2 consensuses of the Colombian Society of Cardiology, as reported by Muñoz et al.³⁹ This model should be calibrated for use in the Ecuadorian population with local epidemiological data, which would pave the way for future studies determining the most appropriate scale for usage in the country.

Limitations

One of the limitations of this study is that different age ranges, the standardization approach, and the lack of cross-validation of laboratory tests make it difficult to compare the results obtained with those of other studies of similar characteristics in the absence of standardization.

Another limitation is that it is unknown whether the FRS 2008 is the most suitable instrument for estimating the CVR in Ecuador since the epidemiological characteristics of Ecuadorians are different from those of Americans, the population for which this instrument was designed, and absolute CVD mortality is higher in the USA.^7,38

Finally, while FRS 2008 is a valuable tool for predicting CVD risk, it has numerous limitations that must be noted before applying its results, such as the fact that it is an estimation algorithm rather than a medical examination. In addition, the original cohort did not include a young population, making it an inaccurate tool in this age group, and, finally, it does not include other possible factors of CVR.

Moreover, the cross-sectional nature of the present study makes it difficult to better address the direction of causality between variables,^35,40,41 so it is suggested to conduct additional studies by delving into the relational and explanatory levels of research within the CVR line of research.