The Diagnostic Value of 24-Hour Ambulatory Blood Pressure Monitoring in Family Medicine Clinics

    Authors

    Abstract

    Arterial hypertension is a leading public health problem and a risk factor for the development of cardiovascular and cerebrovascular diseases. Most patients suffering from hypertension are monitored by family medicine physicians that have the requisite knowledge and skills needed to diagnose and treat this disease. This is greatly facilitated by 24-hour ambulatory blood pressure monitoring (ABPM), which has more diagnostic value for arterial hypertension than clinical measurement of blood pressure (BP) values and is also used for monitoring disease management and deciding on the therapy of choice. This article assesses the utility of 24-hour ABPM in family medicine clinics for establishing the diagnosis of arterial hypertension and monitoring patients with a previously established diagnosis. We included 52 patients in a cross-sectional study over a period of 4 months. BP values measured using 24-hour ABPM were compared with values initially measured at the clinic on the examination date. The difference in the percentage of uncontrolled hypertension diagnosed by clinical BP measurement in comparison with 24-hour ABPM was tested by applying the χ 2 test. The association between BP values measured at the clinic and those measured by ABPM was tested using Spearman’s rank correlation coefficient. The study comprised 18 men and 34 women. The average age of the participants was 56.06 years. Average 24-hour systolic pressure was 156.13 mmHg, and average diastolic pressure was 89.81 mmHg. The average values of systolic and diastolic pressure measured in the clinic were 141.98 mmHg and 84.52 mmHg, respectively. Uncontrolled systolic pressure demonstrated by ABPM was found in 47/52 patients, while 36/52 patients had uncontrolled diastolic pressure. In clinical measurements, uncontrolled systolic and diastolic BP values were registered in 29/52 and 9/52 patients, respectively. The measurement results demonstrate a positive correlation between BP values measured at the clinic and those measured using 24-hour ABPM. The application of ABPM contributes to correctly establishing the diagnosis of arterial hypertension and improved BP management.

    Keywords

    arterial hypertension, 24-hours ambulatory blood pressure monitoring, family medicine

    DOI

    https://doi.org/10.15836/ccar2018.3

    Full Text

    ## Introduction Arterial hypertension is a global epidemic and the leading global risk factor for mortality and morbidity. According to the latest guidelines of the European Society of Hypertension (ESH) and the European Society of Cardiology (ESC) from 2013, arterial hypertension is defined as blood pressure (BP) values higher than 140/90 mmHg measured at the clinic using a calibrated BP monitor ( 1 ). According to these guidelines, the diagnosis of arterial hypertension should be based on multiple BP measurements in a given period, depending on its physiological variability. One of the more significant shortcomings of BP measurement at the clinic is that this method provides BP values only at a particular point in time. According to data from ESH/ESC guidelines, the prevalence of arterial hypertension in the general population is between 30% and 40% and increases significantly with age ( 1 ). Data from the World Health Organization (WHO) on its prevalence indicate that the frequency of hypertension rises with population growth, age, and risk factors (smoking, alcohol, insufficient physical activity, increased body mass) ( 2 ). Persons suffering from hypertension have a greater risk of developing heart, vascular, and kidney diseases. According to the Epidemiology of arterial hypertension in Croatia study (EH-UH), the prevalence of hypertension in Croatia is 37.5% and is higher in women (39.7%) than in men (35.2%) ( 3 ). Higher BP values in women are also caused by the following factors: higher body-mass index, lower income, and less physical activity in comparison with men ( 3 ). Despite that, women were more aware of their disease, received treatment more frequently, and achieved better BP control ( 3 ). Although arterial hypertension is associated with preventable risk factors and drugs for effective treatment are available, it is still poorly managed. In Croatia, only 58.6% of the population is aware of their arterial hypertension, of which only 48.4% receive treatment and only 14.8% have controlled BP values ( 4 ). Twenty-four-hour ambulatory blood pressure monitoring (ABPM) is a non-invasive method for automatic measurement of BP values over a period of 24 hours or longer and represents the “gold standard” in the diagnostics and monitoring of arterial hypertension ( 5 ). The diagnostic superiority of 24-hour ABPM is based on more precise determination of true BP values, taking measurements in a realistic setting, negligible placebo effect, and revealing white coat hypertension and masked hypertension ( 6 ). ABPM can improve cardiovascular risk assessment in patients and is indicated when there is significant variability in clinical BP, when high clinical BP values have been measured in persons with low cardiovascular risk, for significant deviations between home and clinical BP measurements, suspected hypotensive episodes, suspected resistant hypertension, and in pregnant women with elevated clinical BP and suspected preeclampsia. The largest study to date on the use of 24-hour ABPM in primary healthcare was conducted in Spain, where a national project to promote the use of ABPM in everyday practice was initiated ten years ago ( 7 ). The study showed that the use of ABPM allowed identification of patients who truly required antihypertensive therapy and significantly reduced the number of persons treated for hypertension ( 7 ). It was found that the use of ABPM lead to cost-reduction in the healthcare system and that the initial expenses investing in the purchase of the devices were compensated by savings from better and targeted treatment ( 8 ). Data collected by ABPM are average 24-hour values, average and maximal BP values during the day and the night, the total amount above normal values, pressure variability, heart frequency and its variability, and the nightly dip and morning rise in pressure values. The appropriate nightly dip in pressure is average nightly pressure values being 10-20% lower than average daytime values ( 9 ). A night pressure drop in the range of less than 10% (non-dipper patients) or an increase in nocturnal BP (inverse dipper patients) is associated with an increased risk of cardiovascular (CV) events, diastolic dysfunction and left ventricular hypertrophy, ventricular arrhythmia, and kidney disease progression, and is more common in patients with diabetes, obese patients, and older patients ( 9 ). Dipping pattern of nocturnal BP of more than 20% (extreme dipper) is associated with increased frequency of stroke and myocardial infarction ( 9 ). The curve of the 24-hour ABPM shows us whether there is a morning rise in pressure, which is the time when most CV and cerebrovascular events occur, likely due to the large increase in BP values while waking up, increased thrombocyte aggregation, reduced fibrinolytic activity, and sympathetic activation. “White coat” hypertension is present in 10% to 40% of patients, and 30-60% will develop permanent hypertension in the next 5 years ( 5 ). Masked hypertension is the reverse phenomenon, defined as normal BP in the clinic and elevated values when measured outside the clinic or using ABPM. This type of hypertension is present in 8-49% of the population ( 5 ). An ABPM device weighs approximately 0.5 kg, and the upper arm cuff allows continuous BP measurement during the day and the night, along with heart frequency measurements ( 6 ). The device is carried in a purse attached to the belt, and the cuff is placed on the non-dominant hand. During ABPM, the patient should avoid strenuous physical activities and lifting heavy objects with the hand on which the device is placed. All patients should be aware of the importance of keeping an activity diary where they note the time they go to sleep, the time they wake up, taking medication, and all health issues that may occur during the day or night ( 9 ). In order to avoid damaging the device, the patient may not take showers or baths, work with tools or objects that could damage the device, participate in sports due to the possibility of falling and damaging the device, and enter areas with increased electromagnetic radiation ( 9 ). At least 70% of measured values must be correct, or the measurement must be repeated ( 9 ). ABPM-related complications are rare. Bruising can appear on the skin under the cuff, and sleeping difficulties are possible due to night measurements. According to ESH/ESC guidelines, the normative values as measured by 24-hour ABPM are: daytime ≥135/85 mmHg, nighttime ≥120/70 mmHg, 24 hours ≥130/80 mmHg ( 1 ). ## Patients and Methods This cross-sectional study was conducted in the period from February 1, 2017 to May 31, 2017 in the specialist family medicine clinic in the city of Varazdin. The study comprised 52 consecutive patients older than 18 years of age. All patients gave informed consent to participating the study by signing an informed consent form. Before signing, the patients examined the form and received answers to all questions related to the study. Initially, the BP values of every patient were measured in the clinic after 10 minutes at rest in a seated position in a chair with a backrest. Blood pressure was measured on the non-dominant hand using a digital blood pressure monitor (Microlife AFIB) which calculated the median BP value on the basis of three measurements. After this, the 24-hour ABPM device (BTL Cardiopoint-ABPM) was placed on the patient’s non-dominant hand. All patients were advised to continue their usual daily activities while wearing the device and avoid more strenuous physical exertions. They were also given an activity diary in which they were instructed to input the time they took their medication, the activities they took part in, the time they went to sleep, and any other symptoms they considered relevant (e.g. elevated BP values). The device was programmed to measure BP every 30 minutes between 6:00 and 22:00 and every 60 minutes between 22.01 and 05.59. For the purposes of this study, we defined arterial hypertension as BP values measured in the clinic ≥140/90 mmHg and ≥130/80 mmHg measured by ABPM. Data input and analysis was conducted in the Excel 2013 program, and P values <0.05 were considered statistical significant. Data were analyzed with the application of descriptive statistics: quantitative data using arithmetic means and standard deviations (age and BP) as well as maximal, minimal, and median values, and qualitative data using absolute frequencies. Data analysis was used to calculate median BP values during 24-hour monitoring. We also calculated the percentage of patients with controlled and uncontrolled BP values measured at the clinic and with ABPM. The difference in frequency of uncontrolled hypertension diagnosed by ABPM and at the clinic was tested using the χ 2 test. The association between BP measured at the clinic and with ABPM was tested using Spearman’s rank correlation coefficient. ## Results Over a period of 4 months, 52 patients underwent BP monitoring with 24-hour ABPM. The measurements were technically correct, with an average percentage of correct measurements of 88%. The study included 34 women and 18 men, with an average age of 56.06±13.2; 47 patients were non-smokers. The average duration of hypertension in patients with a previously established diagnosis was 4.06 years, and their treatment included 1 to 3 antihypertensive drugs. Table 1 contains a more detailed list of the demographic and health characteristics of the patients. Almost all patients had an increased body mass index (BMI), as shown in Table 2 . The average BMI for all participants was 29.86±4.8 kg/m 2 . The average systolic and diastolic pressures measured over 24 hours were 156.13±27.16 mmHg and 89.81±15.45 mmHg, respectively. The average systolic and diastolic pressures measured in the clinic were 141.98±23.5 mmHg and 84.51±9.89 mmHg, respectively. Table 3 show the number of patients with controlled and uncontrolled systolic and diastolic BP values measured in the clinic and with ABPM. Uncontrolled systolic BP values demonstrated by ABPM were found in 47/52 patients, and diastolic in 36/52 patients. The number of patients with unregulated BP values based on measurements in the clinic was lower. Uncontrolled systolic values were found in 29/52 patients, and diastolic in 9/52. The results showed that there is no statistically significant difference between systolic pressure measured by ABPM and measured at the clinic (χ 2 = 0.065; P = 3.84) ( Table 4 ). The difference between diastolic pressure measured by ABPM and measured at the clinic was statistically significant (χ 2 = 6.776; P = 3.84) ( Table 5 ). ABPM showed normal values in 12 patients who had uncontrolled systolic values based on measurements in the clinic. A total of 8 patients with normal diastolic values as measured at the clinic had uncontrolled values when measured by ABPM. ABPM found normal values in 8 patients whose diastolic pressure values were unregulated when measured in the clinic. There was a positive correlation between systolic and diastolic pressure measured at the clinic and using ABPM (r = 0.703 and r = 0.771, respectively). ## Discussion Family medicine physicians have an important role in the monitoring and treatment of patients with arterial hypertension with the goal of achieving the best possible results in BP management. Twenty-four-hour ABPM is important for the evaluation of disease prognosis, reducing the number of false-positive diagnoses of arterial hypertension, and improved monitoring of disease management. Only measuring BP in the clinic can lead to misdiagnosing patients as well-regulated and cause physicians to miss establishing a timely diagnosis of arterial hypertension ( 10 - 15 ). Most studies conducted so far showed that participants had higher BP values measured at the clinic in comparison with ABPM. However, these studies were conducted in the general population, with participants who were not receiving antihypertensive therapy and were of a younger age ( 16 ). Lower BP values measured in the clinic could be a consequence of the fact that most patients took their antihypertensive medication before the examination. Twenty-four-hour ABPM reduces the effect of antihypertensive drugs. Numerous other factors can influence the differences in BP measured at the clinic and with ABPM, such as the number, times, and schedule of measurements ( 17 ). BP values measured in the clinic and using ABPM were higher in patients with previously diagnosed arterial hypertension, and similar results were described by other authors as well ( 18 ). In line with previously published studies, we found higher BP values measured both in the clinic and using ABPM in older patients ( 19 ). Given that systolic pressure values correlate with higher cardiovascular risk, monitoring these values is usually the focus when deciding changes and types of antihypertensive therapy. A review article published in 2011, which compared the diagnostic accuracy of BP measured at home and at the clinic with ABPM values, demonstrated that the establishment of the final diagnosis should not rely only on values of BP measured at home and at the clinic but should also be confirmed using 24-hour ABPM ( 20 ). In the observed group of patients, the average BP value was clearly above normal values. The BP values were unregulated, regardless of whether the patients were receiving antihypertensive therapy or not. This was described by other authors as well ( 19 ). Most participants in this study were receiving one to three antihypertensive drugs, so the elevated BP values can be at least partially explained by inadequate treatment regiments and lack of patient compliance in regularly taking the treatment to achieve target pressure values. The current study was limited by the small number of participants and the fact that it was conducted in a single center. The participants were older and had previously diagnosed arterial hypertension for which they were taking at least one antihypertensive drug. Measuring ABPM over 24 hours also depends on compliance to the rules on wearing the device and the behavior of the patient during the test. Depth of sleep, the patient’s psychological state, and physical activity during the day also influence BP values and have an effect on the reproducibility of the results, since these factors were not considered during their interpretation. ## Conclusion The results showed that there was a positive correlation between BP measurement at the clinic and with 24-hour ABPM. These data support the application of ABPM in the everyday practice of family physicians as part of their approach to patients with newly-diagnosed arterial hypertension, as well as in monitoring patients with an existing diagnosis. Comparing the two methods of blood pressure measurement, at the clinic and using ABPM, can facilitate correctly determining the type and cause of hypertension. Timely recognition and treatment of arterial hypertension is important for the prevention of cardiovascular and cerebrovascular complications and mortality in general. The application of ABPM can be successfully implemented in everyday practice, thereby raising the quality of care and treatment of patients with arterial hypertension.

    Cardiologia Croatica
    Back to search

    The Diagnostic Value of 24-Hour Ambulatory Blood Pressure Monitoring in Family Medicine Clinics

    Original Scientific Paper
    Issue1-2
    Published
    Pages3-10
    PDF via DOIhttps://doi.org/10.15836/ccar2018.3
    arterial hypertension
    24-hours ambulatory blood pressure monitoring
    family medicine

    Authors

    Tatjana Cikač*Varaždin, Croatia
    Kristina SambolVaraždin, Croatia

    Abstract

    Arterial hypertension is a leading public health problem and a risk factor for the development of cardiovascular and cerebrovascular diseases. Most patients suffering from hypertension are monitored by family medicine physicians that have the requisite knowledge and skills needed to diagnose and treat this disease. This is greatly facilitated by 24-hour ambulatory blood pressure monitoring (ABPM), which has more diagnostic value for arterial hypertension than clinical measurement of blood pressure (BP) values and is also used for monitoring disease management and deciding on the therapy of choice. This article assesses the utility of 24-hour ABPM in family medicine clinics for establishing the diagnosis of arterial hypertension and monitoring patients with a previously established diagnosis. We included 52 patients in a cross-sectional study over a period of 4 months. BP values measured using 24-hour ABPM were compared with values initially measured at the clinic on the examination date. The difference in the percentage of uncontrolled hypertension diagnosed by clinical BP measurement in comparison with 24-hour ABPM was tested by applying the χ 2 test. The association between BP values measured at the clinic and those measured by ABPM was tested using Spearman’s rank correlation coefficient. The study comprised 18 men and 34 women. The average age of the participants was 56.06 years. Average 24-hour systolic pressure was 156.13 mmHg, and average diastolic pressure was 89.81 mmHg. The average values of systolic and diastolic pressure measured in the clinic were 141.98 mmHg and 84.52 mmHg, respectively. Uncontrolled systolic pressure demonstrated by ABPM was found in 47/52 patients, while 36/52 patients had uncontrolled diastolic pressure. In clinical measurements, uncontrolled systolic and diastolic BP values were registered in 29/52 and 9/52 patients, respectively. The measurement results demonstrate a positive correlation between BP values measured at the clinic and those measured using 24-hour ABPM. The application of ABPM contributes to correctly establishing the diagnosis of arterial hypertension and improved BP management.

    Full Text

    ## Introduction Arterial hypertension is a global epidemic and the leading global risk factor for mortality and morbidity. According to the latest guidelines of the European Society of Hypertension (ESH) and the European Society of Cardiology (ESC) from 2013, arterial hypertension is defined as blood pressure (BP) values higher than 140/90 mmHg measured at the clinic using a calibrated BP monitor ( 1 ). According to these guidelines, the diagnosis of arterial hypertension should be based on multiple BP measurements in a given period, depending on its physiological variability. One of the more significant shortcomings of BP measurement at the clinic is that this method provides BP values only at a particular point in time. According to data from ESH/ESC guidelines, the prevalence of arterial hypertension in the general population is between 30% and 40% and increases significantly with age ( 1 ). Data from the World Health Organization (WHO) on its prevalence indicate that the frequency of hypertension rises with population growth, age, and risk factors (smoking, alcohol, insufficient physical activity, increased body mass) ( 2 ). Persons suffering from hypertension have a greater risk of developing heart, vascular, and kidney diseases. According to the Epidemiology of arterial hypertension in Croatia study (EH-UH), the prevalence of hypertension in Croatia is 37.5% and is higher in women (39.7%) than in men (35.2%) ( 3 ). Higher BP values in women are also caused by the following factors: higher body-mass index, lower income, and less physical activity in comparison with men ( 3 ). Despite that, women were more aware of their disease, received treatment more frequently, and achieved better BP control ( 3 ). Although arterial hypertension is associated with preventable risk factors and drugs for effective treatment are available, it is still poorly managed. In Croatia, only 58.6% of the population is aware of their arterial hypertension, of which only 48.4% receive treatment and only 14.8% have controlled BP values ( 4 ). Twenty-four-hour ambulatory blood pressure monitoring (ABPM) is a non-invasive method for automatic measurement of BP values over a period of 24 hours or longer and represents the “gold standard” in the diagnostics and monitoring of arterial hypertension ( 5 ). The diagnostic superiority of 24-hour ABPM is based on more precise determination of true BP values, taking measurements in a realistic setting, negligible placebo effect, and revealing white coat hypertension and masked hypertension ( 6 ). ABPM can improve cardiovascular risk assessment in patients and is indicated when there is significant variability in clinical BP, when high clinical BP values have been measured in persons with low cardiovascular risk, for significant deviations between home and clinical BP measurements, suspected hypotensive episodes, suspected resistant hypertension, and in pregnant women with elevated clinical BP and suspected preeclampsia. The largest study to date on the use of 24-hour ABPM in primary healthcare was conducted in Spain, where a national project to promote the use of ABPM in everyday practice was initiated ten years ago ( 7 ). The study showed that the use of ABPM allowed identification of patients who truly required antihypertensive therapy and significantly reduced the number of persons treated for hypertension ( 7 ). It was found that the use of ABPM lead to cost-reduction in the healthcare system and that the initial expenses investing in the purchase of the devices were compensated by savings from better and targeted treatment ( 8 ). Data collected by ABPM are average 24-hour values, average and maximal BP values during the day and the night, the total amount above normal values, pressure variability, heart frequency and its variability, and the nightly dip and morning rise in pressure values. The appropriate nightly dip in pressure is average nightly pressure values being 10-20% lower than average daytime values ( 9 ). A night pressure drop in the range of less than 10% (non-dipper patients) or an increase in nocturnal BP (inverse dipper patients) is associated with an increased risk of cardiovascular (CV) events, diastolic dysfunction and left ventricular hypertrophy, ventricular arrhythmia, and kidney disease progression, and is more common in patients with diabetes, obese patients, and older patients ( 9 ). Dipping pattern of nocturnal BP of more than 20% (extreme dipper) is associated with increased frequency of stroke and myocardial infarction ( 9 ). The curve of the 24-hour ABPM shows us whether there is a morning rise in pressure, which is the time when most CV and cerebrovascular events occur, likely due to the large increase in BP values while waking up, increased thrombocyte aggregation, reduced fibrinolytic activity, and sympathetic activation. “White coat” hypertension is present in 10% to 40% of patients, and 30-60% will develop permanent hypertension in the next 5 years ( 5 ). Masked hypertension is the reverse phenomenon, defined as normal BP in the clinic and elevated values when measured outside the clinic or using ABPM. This type of hypertension is present in 8-49% of the population ( 5 ). An ABPM device weighs approximately 0.5 kg, and the upper arm cuff allows continuous BP measurement during the day and the night, along with heart frequency measurements ( 6 ). The device is carried in a purse attached to the belt, and the cuff is placed on the non-dominant hand. During ABPM, the patient should avoid strenuous physical activities and lifting heavy objects with the hand on which the device is placed. All patients should be aware of the importance of keeping an activity diary where they note the time they go to sleep, the time they wake up, taking medication, and all health issues that may occur during the day or night ( 9 ). In order to avoid damaging the device, the patient may not take showers or baths, work with tools or objects that could damage the device, participate in sports due to the possibility of falling and damaging the device, and enter areas with increased electromagnetic radiation ( 9 ). At least 70% of measured values must be correct, or the measurement must be repeated ( 9 ). ABPM-related complications are rare. Bruising can appear on the skin under the cuff, and sleeping difficulties are possible due to night measurements. According to ESH/ESC guidelines, the normative values as measured by 24-hour ABPM are: daytime ≥135/85 mmHg, nighttime ≥120/70 mmHg, 24 hours ≥130/80 mmHg ( 1 ). ## Patients and Methods This cross-sectional study was conducted in the period from February 1, 2017 to May 31, 2017 in the specialist family medicine clinic in the city of Varazdin. The study comprised 52 consecutive patients older than 18 years of age. All patients gave informed consent to participating the study by signing an informed consent form. Before signing, the patients examined the form and received answers to all questions related to the study. Initially, the BP values of every patient were measured in the clinic after 10 minutes at rest in a seated position in a chair with a backrest. Blood pressure was measured on the non-dominant hand using a digital blood pressure monitor (Microlife AFIB) which calculated the median BP value on the basis of three measurements. After this, the 24-hour ABPM device (BTL Cardiopoint-ABPM) was placed on the patient’s non-dominant hand. All patients were advised to continue their usual daily activities while wearing the device and avoid more strenuous physical exertions. They were also given an activity diary in which they were instructed to input the time they took their medication, the activities they took part in, the time they went to sleep, and any other symptoms they considered relevant (e.g. elevated BP values). The device was programmed to measure BP every 30 minutes between 6:00 and 22:00 and every 60 minutes between 22.01 and 05.59. For the purposes of this study, we defined arterial hypertension as BP values measured in the clinic ≥140/90 mmHg and ≥130/80 mmHg measured by ABPM. Data input and analysis was conducted in the Excel 2013 program, and P values <0.05 were considered statistical significant. Data were analyzed with the application of descriptive statistics: quantitative data using arithmetic means and standard deviations (age and BP) as well as maximal, minimal, and median values, and qualitative data using absolute frequencies. Data analysis was used to calculate median BP values during 24-hour monitoring. We also calculated the percentage of patients with controlled and uncontrolled BP values measured at the clinic and with ABPM. The difference in frequency of uncontrolled hypertension diagnosed by ABPM and at the clinic was tested using the χ 2 test. The association between BP measured at the clinic and with ABPM was tested using Spearman’s rank correlation coefficient. ## Results Over a period of 4 months, 52 patients underwent BP monitoring with 24-hour ABPM. The measurements were technically correct, with an average percentage of correct measurements of 88%. The study included 34 women and 18 men, with an average age of 56.06±13.2; 47 patients were non-smokers. The average duration of hypertension in patients with a previously established diagnosis was 4.06 years, and their treatment included 1 to 3 antihypertensive drugs. Table 1 contains a more detailed list of the demographic and health characteristics of the patients. Almost all patients had an increased body mass index (BMI), as shown in Table 2 . The average BMI for all participants was 29.86±4.8 kg/m 2 . The average systolic and diastolic pressures measured over 24 hours were 156.13±27.16 mmHg and 89.81±15.45 mmHg, respectively. The average systolic and diastolic pressures measured in the clinic were 141.98±23.5 mmHg and 84.51±9.89 mmHg, respectively. Table 3 show the number of patients with controlled and uncontrolled systolic and diastolic BP values measured in the clinic and with ABPM. Uncontrolled systolic BP values demonstrated by ABPM were found in 47/52 patients, and diastolic in 36/52 patients. The number of patients with unregulated BP values based on measurements in the clinic was lower. Uncontrolled systolic values were found in 29/52 patients, and diastolic in 9/52. The results showed that there is no statistically significant difference between systolic pressure measured by ABPM and measured at the clinic (χ 2 = 0.065; P = 3.84) ( Table 4 ). The difference between diastolic pressure measured by ABPM and measured at the clinic was statistically significant (χ 2 = 6.776; P = 3.84) ( Table 5 ). ABPM showed normal values in 12 patients who had uncontrolled systolic values based on measurements in the clinic. A total of 8 patients with normal diastolic values as measured at the clinic had uncontrolled values when measured by ABPM. ABPM found normal values in 8 patients whose diastolic pressure values were unregulated when measured in the clinic. There was a positive correlation between systolic and diastolic pressure measured at the clinic and using ABPM (r = 0.703 and r = 0.771, respectively). ## Discussion Family medicine physicians have an important role in the monitoring and treatment of patients with arterial hypertension with the goal of achieving the best possible results in BP management. Twenty-four-hour ABPM is important for the evaluation of disease prognosis, reducing the number of false-positive diagnoses of arterial hypertension, and improved monitoring of disease management. Only measuring BP in the clinic can lead to misdiagnosing patients as well-regulated and cause physicians to miss establishing a timely diagnosis of arterial hypertension ( 10 - 15 ). Most studies conducted so far showed that participants had higher BP values measured at the clinic in comparison with ABPM. However, these studies were conducted in the general population, with participants who were not receiving antihypertensive therapy and were of a younger age ( 16 ). Lower BP values measured in the clinic could be a consequence of the fact that most patients took their antihypertensive medication before the examination. Twenty-four-hour ABPM reduces the effect of antihypertensive drugs. Numerous other factors can influence the differences in BP measured at the clinic and with ABPM, such as the number, times, and schedule of measurements ( 17 ). BP values measured in the clinic and using ABPM were higher in patients with previously diagnosed arterial hypertension, and similar results were described by other authors as well ( 18 ). In line with previously published studies, we found higher BP values measured both in the clinic and using ABPM in older patients ( 19 ). Given that systolic pressure values correlate with higher cardiovascular risk, monitoring these values is usually the focus when deciding changes and types of antihypertensive therapy. A review article published in 2011, which compared the diagnostic accuracy of BP measured at home and at the clinic with ABPM values, demonstrated that the establishment of the final diagnosis should not rely only on values of BP measured at home and at the clinic but should also be confirmed using 24-hour ABPM ( 20 ). In the observed group of patients, the average BP value was clearly above normal values. The BP values were unregulated, regardless of whether the patients were receiving antihypertensive therapy or not. This was described by other authors as well ( 19 ). Most participants in this study were receiving one to three antihypertensive drugs, so the elevated BP values can be at least partially explained by inadequate treatment regiments and lack of patient compliance in regularly taking the treatment to achieve target pressure values. The current study was limited by the small number of participants and the fact that it was conducted in a single center. The participants were older and had previously diagnosed arterial hypertension for which they were taking at least one antihypertensive drug. Measuring ABPM over 24 hours also depends on compliance to the rules on wearing the device and the behavior of the patient during the test. Depth of sleep, the patient’s psychological state, and physical activity during the day also influence BP values and have an effect on the reproducibility of the results, since these factors were not considered during their interpretation. ## Conclusion The results showed that there was a positive correlation between BP measurement at the clinic and with 24-hour ABPM. These data support the application of ABPM in the everyday practice of family physicians as part of their approach to patients with newly-diagnosed arterial hypertension, as well as in monitoring patients with an existing diagnosis. Comparing the two methods of blood pressure measurement, at the clinic and using ABPM, can facilitate correctly determining the type and cause of hypertension. Timely recognition and treatment of arterial hypertension is important for the prevention of cardiovascular and cerebrovascular complications and mortality in general. The application of ABPM can be successfully implemented in everyday practice, thereby raising the quality of care and treatment of patients with arterial hypertension.