European Journal of Cardiovascular Medicine

Hypertension is usually diagnosed based on elevated blood pressure (BP) measured in a clinical setting. However, a subset of individuals with normal clinic BP may exhibit hypertensive BP levels when measurements are obtained outside the clinic using home blood pressure monitoring or ambulatory blood pressure monitoring. This phenomenon is referred to as masked hypertension (MHT) [1]. Hypertension is one of the leading modifiable risk factors for cardiovascular diseases (CVD), including stroke, myocardial infarction, heart failure, and cardiovascular mortality. Accurate assessment of blood pressure (BP) is essential for the early detection and effective management of hypertension [2]. Traditionally, BP is measured in clinical settings using office blood pressure measurements; however, these measurements may not always reflect the patient’s true BP levels in daily life [3].

One important clinical phenomenon is masked hypertension, in which BP readings appear normal in the clinic but are elevated outside the clinical environment. This condition often remains undetected during routine clinical assessments and can delay appropriate treatment. Studies indicate that masked hypertension carries a cardiovascular risk similar to sustained hypertension, making its identification clinically important [4].

In recent years, home blood pressure monitoring (HBPM) has emerged as a valuable tool for detecting masked hypertension. HBPM allows repeated measurements in a patient’s usual living environment, thereby providing a more accurate representation of true blood pressure levels compared with single office readings. Large observational studies have demonstrated that HBPM improves the detection of abnormal BP patterns that are missed in clinical settings [5].

Recent evidence also suggests that masked hypertension detected through home BP monitoring is associated with increased cardiovascular risk. Studies have shown that individuals with masked hypertension have significantly higher risks of stroke and other cardiovascular events compared with normotensive individuals [6].

Furthermore, more recent investigations have demonstrated that masked nocturnal hypertension, identified through home BP monitoring, is also linked to a higher incidence of cardiovascular events, highlighting the prognostic importance of out-of-office BP measurements [7].

Despite growing evidence, the prognostic significance of masked hypertension in treated elderly hypertensive patients remains an important area of investigation. Understanding the cardiovascular risks associated with masked hypertension in this population may help improve hypertension management and reduce adverse cardiovascular outcomes.

This hospital-based observational study was conducted among 106 treated elderly hypertensive patients aged ≥60 years attending the Outpatient Department (OPD) and Inpatient Department (IPD) at RKDF Medical College Hospital and Research Centre. All eligible patients who fulfilled the study criteria and provided consent were included. Patients aged 60 years and above with a known diagnosis of hypertension and receiving treatment were included in the study. Patients younger than 60 years, newly diagnosed or untreated hypertensive individuals, those with incomplete clinical or blood pressure data, those unable to perform home blood pressure monitoring, and those unwilling to participate were excluded from the study. Demographic details such as age and gender were recorded for all participants. Blood pressure assessment was carried out using standard protocols, including both office blood pressure measurements and home blood pressure monitoring. Based on these readings, patients were classified into controlled hypertension, masked hypertension, sustained hypertension, and white coat hypertension. Mean systolic and diastolic blood pressure values were calculated for both office and home settings. Cardiovascular risk factors, including diabetes mellitus, dyslipidemia, smoking, obesity, and sedentary lifestyle, were evaluated in all participants. The patients were followed up for the occurrence of cardiovascular outcomes such as left ventricular hypertrophy, coronary artery disease, stroke/transient ischemic attack, and heart failure. Statistical analysis was performed to assess the association between blood pressure categories, home blood pressure levels, and cardiovascular outcomes, including the calculation of hazard ratios.

Table 1: Age Distribution of Participants

The age distribution of the study participants showed that the majority of patients belonged to the 60–64 years age group (32.1%), followed by 65–69 years (27.4%), 70–74 years (21.7%), and ≥75 years (18.9%). This indicates that most of the treated hypertensive elderly patients in the study were in the early elderly age group (60–69 years).

Table 2: Gender Distribution

The study population demonstrated a male predominance, with 64 males (60.4%) and 42 females (39.6%). This finding suggests that hypertension requiring treatment and monitoring in the elderly population was slightly more common among males in the present study.

Table 3: Blood Pressure Classification (Office vs Home BP)

Blood pressure classification based on office and home measurements revealed that controlled hypertension was present in 48 patients (45.3%), while masked hypertension was identified in 30 patients (28.3%). Additionally, sustained hypertension was observed in 20 patients (18.9%), and white coat hypertension was found in 8 patients (7.5%). These findings highlight that a considerable proportion of treated hypertensive patients had masked hypertension that was detectable only through home blood pressure monitoring.

Table 4: Mean Blood Pressure Measurements

Blood pressure classification based on office and home measurements revealed that controlled hypertension was present in 48 patients (45.3%), while masked hypertension was identified in 30 patients (28.3%). Additionally, sustained hypertension was observed in 20 patients (18.9%), and white coat hypertension was found in 8 patients (7.5%). These findings highlight that a considerable proportion of treated hypertensive patients had masked hypertension that was detectable only through home blood pressure monitoring.

Table 5: Cardiovascular Risk Factors

Among the cardiovascular risk factors evaluated in the study population, sedentary lifestyle was the most common (41.5%), followed by dyslipidemia (37.7%), diabetes mellitus (34.0%), obesity (26.4%), and smoking (22.6%). The presence of these risk factors indicates a significant burden of metabolic and lifestyle-related contributors to cardiovascular disease among elderly hypertensive patients.

Table 6: Cardiovascular Outcomes During Follow-up

During follow-up, cardiovascular outcomes were compared between patients with masked hypertension (n = 30) and those with controlled hypertension (n = 48). Left ventricular hypertrophy was observed in 33.3% of patients with masked hypertension compared to 12.5% in the controlled hypertension group, which was statistically significant (p = 0.01). Similarly, coronary artery disease was present in 26.7% of patients with masked hypertension compared to 12.5% in the controlled hypertension group (p = 0.04). Although stroke/TIA and heart failure were more frequent in the masked hypertension group, these differences were not statistically significant.

Table 7: Risk of Cardiovascular Events According to BP Category

The risk of cardiovascular events was analyzed according to blood pressure categories. Compared with controlled hypertension (reference group), masked hypertension showed a significantly increased hazard ratio of 2.05 (95% CI: 1.21–3.46; p = 0.01), indicating approximately two-fold increased risk of cardiovascular events. Similarly, sustained hypertension also showed elevated cardiovascular risk (HR 1.90; p = 0.02). In contrast, white coat hypertension was not significantly associated with increased cardiovascular risk (HR 1.15; p = 0.41).

Table 8: Association between Home BP and Cardiovascular Events

The association between home blood pressure levels and cardiovascular outcomes showed that each 10 mmHg increase in home systolic blood pressure was associated with a 17% increase in cardiovascular risk (HR 1.17, p < 0.001). Similarly, each 5 mmHg increase in home diastolic blood pressure increased cardiovascular risk by approximately 12% (HR 1.12, p = 0.002). These findings emphasize the prognostic significance of home blood pressure monitoring in predicting cardiovascular outcomes among treated elderly hypertensive patients.

In the present study, most of the participants belonged to the younger elderly age group (60–69 years), with a clear male predominance (60.4%). Similar findings have been reported by Fujiwara T et al. [3] (2018), where a higher proportion of males and early elderly individuals were observed in hypertensive populations. This pattern may be explained by higher cardiovascular risk and better healthcare-seeking behavior among this group.

The prevalence of masked hypertension in the present study was 28.3%, which is comparable to the findings of Kario K et al. [8] (2020) in the ANAFIE registry, where it was reported to be 23.4% among elderly patients. Although slightly lower than the present study, the similarity suggests that masked hypertension is fairly common in treated elderly individuals. Likewise, Shi X et al. [9] (2020) observed that patients with masked uncontrolled hypertension were more often older males with a higher burden of comorbidities, which supports the trend seen in our study population.

Another important finding of the present study was that home blood pressure readings were higher than office measurements (SBP 142.6 ± 10.3 mmHg vs. 134.8 ± 9.1 mmHg). This highlights the limitation of relying only on office BP. Similar observations have been reported in large datasets such as the International Database of Home Blood Pressure in Relation to Cardiovascular Outcome, which showed that home BP is a better predictor of cardiovascular outcomes. This emphasizes the importance of home BP monitoring in routine practice [10].

In our study, masked hypertension was significantly associated with target organ damage. Patients with masked hypertension had higher rates of left ventricular hypertrophy (33.3% vs. 12.5%) and coronary artery disease (26.7% vs. 12.5%). These findings are in agreement with the study by Huang Y et al. [11] (2024), which also demonstrated a strong association between masked hypertension and organ damage, especially LVH. This suggests that masked hypertension is not a benign condition and may lead to silent cardiovascular injury.

With respect to cardiovascular outcomes, the present study showed that masked hypertension was associated with a two-fold increase in cardiovascular risk (HR 2.05, p=0.01). Fujiwara T et al. [7] (2024) reported that office-masked nocturnal hypertension was also associated with increased cardiovascular events, further supporting the findings of the present study.

On the other hand, white coat hypertension in our study was not significantly associated with increased cardiovascular risk (HR 1.15, p=0.41). This is consistent with findings from the International Database of Home Blood Pressure in Relation to Cardiovascular Outcome, where white coat hypertension did not significantly increase cardiovascular events, indicating a relatively lower risk compared to masked hypertension.

Furthermore, the present study showed that even small increases in home BP had a significant impact on cardiovascular risk. A 10 mmHg increase in systolic BP increased the risk by 17%, while a 5 mmHg increase in diastolic BP increased the risk by 12%. Similar trends have been reported by Fujiwara T et al. [3] (2018), reinforcing that home BP is a strong predictor of cardiovascular outcomes.

Overall, the findings of the present study are in line with existing literature and clearly show that masked hypertension is common in elderly patients, often goes undetected in routine clinical practice, and is associated with increased cardiovascular risk and organ damage. Therefore, the use of home blood pressure monitoring should be encouraged for early detection and better management of such patients.

This study demonstrates that a significant proportion of elderly hypertensive patients have masked hypertension, which cannot be detected by office blood pressure measurements alone. Home blood pressure readings were higher and showed better association with cardiovascular risk. Masked and sustained hypertension was linked to increased cardiovascular events, while white coat hypertension was not significant. The presence of multiple risk factors further increased the disease burden. Overall, home blood pressure monitoring is essential for accurate diagnosis, risk assessment, and better management of hypertension in the elderly.

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