Hypertension continues to be one of the most common modifiable risk factors for cardiovascular morbidity and mortality globally. Historically, the major method of diagnosis and monitoring has been office-based blood pressure (BP) measurement, but a growing body of evidence documents that traditional office measurements have limitations in the ability to capture true blood pressure profiles accurately. One such phenomenon that has received a lot of attention in recent years is masked hypertension (MH)—a condition where patients have normotensive readings in the clinic but increased blood pressure during daily life, as recorded by ambulatory blood pressure monitoring (ABPM) or home BP monitoring.

Masked hypertension is especially worrying because it is silent and has a strong link with increased cardiovascular risk, target organ damage, and long-term mortality. Actually, research has revealed that patients with MH can possess risk profiles equivalent to or even higher than those with persistent hypertension but remain undiagnosed and untreated because of their normal office BP levels (Bertram et al., 2024) [1] (Ghazi et al., 2020) [3]. This difference highlights the need for integrating out-of-office BP monitoring, particularly ABPM, into daily clinical assessment, especially among high-risk groups like working adults who could subjectively face occupational stress and abnormal routines that affect BP levels.

ABPM provides a thorough evaluation by recording 24-hour BP variability, including nocturnal and exertional periods, thus offering a better reflection of cardiovascular risk. Evidence suggests that ABPM has stronger prognostic value for cardiovascular events compared to office-based measurements (Böhm et al., 2024) [6] (Conen et al., 2014) [8]. Furthermore, automated office blood pressure (AOBP) methods—both attended and unattended—have demonstrated better agreement with ABPM than traditional auscultatory techniques (Andreadis et al., 2018) [2]. Unattended AOBP, in particular, has shown potential in reducing white-coat effects and minimizing observer bias, thereby improving diagnostic precision (Seeman et al., 2021) [4] (Palomba et al., 2019) [5].

Recent research has also investigated the impact of AOBP in lessening the white-coat effect and more sensitively identifying MH. For example, the SPRINT ABPM ancillary study found that intensive office-based approaches to treat hypertension did not lower masked uncontrolled hypertension substantially, confirming the importance of ABPM in management decision-making (Ghazi et al., 2020) [3]. Additionally, a study comparing traditional, AOBP, and smart assist BP systems discovered that more recent technologies possess variable accuracy, while ABPM remains the gold standard for identifying masked hypertension, particularly in primary care (Ma et al., 2024) [7].

In spite of these advancements, the epidemiology and cardiovascular risk patterns of masked hypertension in working adults—a population increasingly subjected to lifestyle stressors, sedentary lifestyle, and subclinical cardiovascular alterations—have been understudied, particularly in everyday practice employing ABPM. Prevailing literature focuses on the heterogeneity in MH prevalence across age, sex, ethnicity, and BP assessment methodology (Conen et al., 2014)[8] (Bertram et al., 2024) [1]. Thus, a targeted study on working-age adults with ABPM can provide useful insights into early diagnosis, risk stratification, and focused interventions for this underappreciated but significant condition.

This research will evaluate the prevalence of masked hypertension in employed adults with ABPM and the cardiovascular risk profile associated with it. By closing present gaps in knowledge and applying validated BP measurement methods, this study hopes to facilitate more accurate hypertension management and preventive cardiology.

Study Design and Population

The study was a cross-sectional observational analysis done over a one-year duration in a tertiary care medical facility. The population targeted were adults aged between 25 and 55 years who were actively working in different professional sectors like education, healthcare, finance, and corporate services. Recruitment was done through health screening camps and outpatient clinic referrals. Inclusion criteria were normal office blood pressure measurements (systolic <140 mmHg and diastolic <90 mmHg), lack of history of antihypertensive drug use, and willingness to be subjected to 24-hour ambulatory blood pressure monitoring (ABPM). Exclusion criteria were a known cardiovascular disease diagnosis, chronic kidney disease, secondary hypertension, and pregnancy.

Office Blood Pressure Measurement

Office blood pressure (OBP) was recorded with both traditional auscultatory sphygmomanometers and automated office blood pressure (AOBP) machines. Measurements were made in sitting position following a five-minute rest, and three readings were taken at one-minute intervals. The mean of the last two readings was utilized for analysis. AOBP readings were taken in a quiet room without the presence of a healthcare provider, which permitted unattended measurement conditions. Both attended and unattended approaches were utilized to assess their reliability compared with ABPM readings.

Ambulatory Blood Pressure Monitoring

Patients were subjected to 24-hour ABPM with validated oscillometric monitors. Blood pressure was measured every 15 minutes between 6:00 AM and 10:00 PM and every 30 minutes between 10:00 PM and 6:00 AM. The patients went about their usual activities and noted sleep times, physical activity, and symptoms in a diary received at enrollment. A tracing was valid if it contained ≥70% of the potential readings, with ≥14 daytime and ≥7 nighttime readings. Masked hypertension was diagnosed as elevated mean daytime blood pressure on ABPM (≥135/85 mmHg) with normal OBP values.

Data Collection and Variables

Structured interviews and clinical assessments provided extensive data. This involved demographic data such as age, gender, occupation, and lifestyle factors such as smoking, alcohol consumption, and physical activity. Anthropometric measures like height, weight, and body mass index (BMI) were recorded. Laboratory tests involved fasting blood glucose, lipid profile, and serum creatinine. The main outcome was the prevalence of masked hypertension in the study population. Secondary outcomes were the detection of correlations between masked hypertension and known cardiovascular risk factors.

Statistical Analysis

All data obtained were entered into a secure electronic database and analyzed with statistical software. Continuous variables were reported as means with standard deviations, and categorical variables were reported as frequencies and percentages. Comparisons between groups were conducted using independent t-tests for continuous variables and chi-square tests for categorical variables. Multivariable logistic regression analysis was used to determine independent predictors of masked hypertension. Statistical significance was determined by a p-value of less than 0.05. Office and ambulatory blood pressure agreement was assessed through correlation coefficients and represented graphically using Bland-Altman plots.

Participant Characteristics

A total of 300 working adults were initially screened, of which 250 participants met the eligibility criteria and completed the study protocol, including valid ABPM recordings. The mean age of participants was 39.8 ± 8.2 years, with a nearly equal gender distribution (51.6% male, 48.4% female). The average body mass index (BMI) was 26.4 ± 3.7 kg/m². Among the participants, 21.2% were smokers, 17.6% reported regular alcohol consumption, and 38.4% reported low levels of physical activity. A family history of hypertension was present in 43.2% of the study population.

Table 1. Baseline Characteristics of Study Participants

Prevalence of Masked Hypertension

Of the 250 subjects with regular office BP measurements, 62 patients (24.8%) had daytime ABPM values indicative of masked hypertension. This group of patients had a mean daytime ABPM of 139.6 ± 5.8 mmHg systolic and 88.7 ± 4.3 mmHg diastolic. The normotensive group (n = 188) had a mean daytime ABPM of 123.4 ± 6.1 mmHg systolic and 78.2 ± 5.6 mmHg diastolic. Masked hypertension was more common in men (32.3%) than in women (16.5%).

Table 2. Comparison of ABPM Parameters Between Masked Hypertension and Normotensive Groups

Cardiovascular Risk Profile

Those diagnosed with masked hypertension had significantly increased markers of cardiovascular risk. Fasting blood glucose averaged 106.3 ± 11.7 mg/dL in the MH group, while that in normotensives was 98.1 ± 10.4 mg/dL. LDL and total cholesterol were increased in the MH group. According to the Framingham Risk Score, 45.2% of the MH group were in the moderate-to-high risk group for 10-year cardiovascular events, whereas only 18.1% belonged to the normotensive group.

Table 3. Cardiovascular Risk Parameters by Blood Pressure Category

Relationship Between Office and Ambulatory Blood Pressure

A moderate correlation was observed between office BP and ABPM values. However, Bland-Altman analysis revealed a consistent underestimation of BP in office readings, especially among participants with masked hypertension. The graph below illustrates the disparity in systolic BP between conventional OBP and daytime ABPM measurements across all participants.

Figure 1. Comparison of Systolic Blood Pressure: Office BP vs. Daytime ABPM

In the present study that examined the prevalence and cardiovascular risk profile of masked hypertension (MH) in working adults by the use of ambulatory blood pressure monitoring (ABPM), we discovered that approximately one in every four participants (24.8%) had MH even with normal office blood pressure (OBP) levels. This result corroborates with evidence to date which indicates that a large percentage of individuals with normal OBP are likely to have concealed hypertension upon out-of-office measurements. The reported MH prevalence in our population is similar to prior real-world investigations employing ABPM and unattended automated office blood pressure (AOBP) techniques, which have uniformly reported MH prevalence rates between 15% and 30% based on the population being studied and BP measurement protocol employed.

Our results also emphasize the insufficiency of using OBP measurements alone in everyday practice, especially in quite young, employed populations who do not necessarily express overt clinical manifestations. The divergence between OBP and ABPM measurements in our population is consistent with the observations of Bauer et al. [9], who pointed out that OBP measurements—especially those that are attended—can potentially underestimate actual BP levels when compared to ABPM, especially in real-life clinical practice. They highlighted the advantage of unobserved AOBP in reducing observer bias and white-coat effects, as also supported by our research where daytime ABPM systolic measurements remained higher than office values in all MH individuals (Bauer et al., 2018) [9].

Comparative findings from the India ABPM study also lend support to the concept that ABPM uncovers higher and more precise BP burdens in various age groups. In this study, Kaul et al. [10] observed that hypertension as defined by ABPM rose with increasing age, but a high percentage of young adults also had raised ambulatory levels despite normal OBP—a trend that is similar to our results in a largely middle-aged, working population(Kaul et al., 2019) [10].

The elevated cardiovascular risk markers observed among individuals with MH in our study—such as higher fasting glucose, cholesterol levels, and Framingham risk scores—highlight the silent but significant burden posed by this condition. This finding aligns with evidence from the CKD population, where Iimuro et al. found that ABPM-based hypertension was a better predictor of target organ damage than OBP, even in early stages of kidney disease (Iimuro et al., 2013) [13]. Likewise, Korogiannou et al. showed that in kidney transplant recipients, MH identified through ABPM was strongly related to left ventricular hypertrophy and proteinuria, further supporting the importance of early detection and intervention (Korogiannou et al., 2021) [11].

Our findings also mirror wider evidence from meta-analyses highlighting the diagnostic superiority of unattended AOBP and ABPM over conventional attended techniques. For instance, Andreadis et al. demonstrated that unattended AOBP was in closer agreement with ABPM and yielded more uniform BP classification, especially in contexts of white-coat and masked phenomenon avoidance (Andreadis et al., 2019) [12]. This is applicable to our research, whereby usage of ABPM allowed for the detection of vulnerable persons who would otherwise remain undetected using only clinic measurements.

Notably, recent research in other clinical populations—like rheumatoid arthritis or organ transplant patients—also favors the use of unattended and out-of-office blood pressure measurement strategies. Bartoloni et al. found that unattended AOBP had lower, more reliable readings than conventional approaches in rheumatoid arthritis patients and hinted at wider use of such techniques in conditions with cardiovascular relevance (Bartoloni et al., 2021) [15]. Equivalently, Nguyen et al. noted that unattended AOBP in kidney transplant donors provided similar accuracy as ABPM for diagnosing MH, endorsing the trend towards fewer observer-dependent measurement methods(Nguyen et al., 2021) [14].

Overall, our results confirm the clinical utility of ABPM for detecting masked hypertension in working adults and its relationship with elevated cardiovascular risk. They also reflect increasing agreement that unsupervised and ambulatory BP measurement provides a more accurate reflection of an individual's actual BP burden than office measurements. These findings indicate wider use of ABPM in standard health check-ups—especially among workers—may improve earlier detection and control of hypertension and consequently lower long-term cardiovascular risk.

In summary, this research demonstrates a high incidence of masked hypertension in working populations, underscoring the shortfalls of traditional office blood pressure measurements in correctly identifying those at risk. The application of ambulatory blood pressure monitoring was found to be superior in identifying increased blood pressure and related cardiovascular risk factors that would otherwise go undetected during standard clinical practice. These results support the inclusion of out-of-office BP monitoring, especially ABPM, in routine health evaluations for early detection and treatment of masked hypertension. Active detection by ABPM may be a key to avoiding long-term cardiovascular disease in apparently normotensive subjects.

1. Bertram S, Bauer F, Shadi R, et al. Prevalence of masked hypertension in attended versus unattended office blood pressure measurement. J Clin Hypertens (Greenwich). 2024;26(6):615-623. doi:10.1111/jch.14798
2. Andreadis EA, Geladari CV, Angelopoulos ET, Savva FS, Georgantoni AI, Papademetriou V. Attended and Unattended Automated Office Blood Pressure Measurements Have Better Agreement With Ambulatory Monitoring Than Conventional Office Readings. J Am Heart Assoc. 2018 Apr 7;7(8):e008994. doi: 10.1161/JAHA.118.008994. PMID: 29627767; PMCID: PMC6015428.
3. Ghazi L, Cohen LP, Muntner P, Shimbo D, Drawz PE. Effects of Intensive Versus Standard Office-Based Hypertension Treatment Strategy on White-Coat Effect and Masked Uncontrolled Hypertension: From the SPRINT ABPM Ancillary Study. Hypertension. 2020 Oct;76(4):1090-1096. doi: 10.1161/HYPERTENSIONAHA.120.15300. Epub 2020 Aug 24. PMID: 32829666; PMCID: PMC7484232.
4. Seeman T, Staněk K, Slížek J, Filipovský J, Feber J. Unattended automated office blood pressure measurement in children. Blood Press. 2021 Dec;30(6):359-366. doi: 10.1080/08037051.2021.1963666. Epub 2021 Sep 25. PMID: 34565278.
5. Palomba C, Donadio S, Canciello G, Losi MA, Izzo R, Manzi MV, De Pisapia F, Mancusi C, De Luca N. Unattended Automated Office Blood Pressure Measurement and Cardiac Target Organ Damage, A Pilot Study. High Blood Press Cardiovasc Prev. 2019 Oct;26(5):383-389. doi: 10.1007/s40292-019-00337-1. Epub 2019 Aug 23. PMID: 31444783.
6. Böhm M, de la Sierra A, Mahfoud F, Schwantke I, Lauder L, Haring B, Vinyoles E, Gorostidi M, Segura J, Williams B, Staplin N, Ruilope LM. Office measurement vs. ambulatory blood pressure monitoring: associations with mortality in patients with or without diabetes. Eur Heart J. 2024 Aug 16;45(31):2851-2861. doi: 10.1093/eurheartj/ehae337. PMID: 38847237; PMCID: PMC11328865.
7. Ma J, Tang X, Zhao J, Zhang J, Wang Q, Wang Y, Yang Q, Shi Y, Cheng M, Wang Y, Zhu D. Intelligent Assist Office Blood Pressures (IOBP) versus awake ambulatory monitoring and conventional auscultatory office readings in Chinese primary medical institutions. Hypertens Res. 2024 Jul;47(7):1822-1830. doi: 10.1038/s41440-024-01687-7. Epub 2024 Apr 26. PMID: 38671216.
8. Conen D, Aeschbacher S, Thijs L, et al. Age-specific differences between conventional and ambulatory daytime blood pressure values. Hypertension. 2014;64(5):1073-1079. doi:10.1161/HYPERTENSIONAHA.114.03957
9. Bauer F, Seibert FS, Rohn B, et al. Attended Versus Unattended Blood Pressure Measurement in a Real Life Setting. Hypertension. 2018;71(2):243-249. doi:10.1161/HYPERTENSIONAHA.117.10026
10. Kaul U, Omboni S, Arambam P, et al. Blood pressure related to age: The India ABPM study. J Clin Hypertens (Greenwich). 2019;21(12):1784-1794. doi:10.1111/jch.13744
11. Korogiannou M, Sarafidis P, Theodorakopoulou MP, et al. Diagnostic Performance of Office versus Ambulatory Blood Pressure in Kidney Transplant Recipients. Am J Nephrol. 2021;52(7):548-558. doi:10.1159/000517358
12. Andreadis EA, Thomopoulos C, Geladari CV, Papademetriou V. Attended Versus Unattended Automated Office Blood Pressure: A Systematic Review and Meta-analysis. High Blood Press Cardiovasc Prev. 2019;26(4):293-303. doi:10.1007/s40292-019-00329-1
13. Iimuro S, Imai E, Watanabe T, et al. Clinical correlates of ambulatory BP monitoring among patients with CKD. Clin J Am Soc Nephrol. 2013;8(5):721-730. doi:10.2215/CJN.06470612
14. Nguyen MN, Skov K, Pedersen BB, Buus NH. Unattended automated office blood pressure in living donor kidney transplant recipients. Blood Press. 2021;30(6):386-394. doi:10.1080/08037051.2021.1991778
15. Bartoloni E, Angeli F, Marcucci E, et al. Unattended compared to traditional blood pressure measurement in patients with rheumatoid arthritis: a randomised cross-over study. Ann Med. 2021;53(1):2050-2059. doi:10.1080/07853890.2021.1999493