The COVID-19 pandemic led to a state of emergency in Japan, potentially increasing stress levels, particularly in chronically ill patients. Previous studies have shown that natural disasters increase stress and cardiovascular events in Japan. This study hypothesized that the state of emergency would induce stress, alter BP profiles, and pose health hazards. Given the high prevalence of hypertension in Japan (approximately 43 million patients), understanding the impact of stress on BP management is crucial for general practitioners. However, evidence on the pandemic's influence on BP management during the state of emergency was limited, prompting this investigation.

Prior research indicates a strong link between stress caused by natural disasters (like earthquakes and typhoons) and adverse cardiovascular outcomes in Japan. Studies following the Hanshin-Awaji earthquake in 1995 reported changes in hypertension status and increased heart disease events [1, 2]. The East Japan Earthquake in 2011 also showed a worsening of home blood pressure in patients near the affected area [3]. These findings established the concept of disaster-related diseases, including stress-related cardiomyopathy. The importance of managing hypertension-related diseases during and after disasters has been highlighted [4]. While the COVID-19 pandemic differs from typical natural disasters, concerns remain about the potential for increased stress and its impact on patient health, particularly in managing conditions like hypertension.

This retrospective study included 748 outpatients with chronic diseases treated by the Sagamihara Physicians Association during the first COVID-19 state of emergency (April 7 – May 31, 2020). Patients had BP data from before (January-March 2020) and during the emergency, and completed a questionnaire on stress levels. Office and home BP measurements were compared. Patients were categorized into four groups based on office and home BP: controlled, masked, white coat, and sustained hypertension. Changes in BP, age, sex, body weight, serum creatinine, HbA1c, urinary protein, NT-proBNP, and estimated salt intake were recorded. A nine-question survey assessed stress levels related to COVID-19, diet, exercise, sleep, and medication adherence. Statistical analysis included paired t-tests, Wilcoxon signed-rank tests, McNemar's test, repeated measures ANOVA, Cochran Q test, chi-square test, multiple linear regression, ROC analysis, and ANCOVA. The study was approved by the Special Ethics Committee of the Kanagawa Medical Association.

Office systolic and diastolic BP significantly increased during the state of emergency compared to the pre-emergency period (p<0.001 and p=0.03, respectively). Conversely, home systolic and diastolic BP significantly decreased (p<0.001 and p=0.01, respectively). The rate of white coat hypertension increased significantly (p<0.001). 58% of patients worried about hypertension's impact on COVID-19, 39% reported decreased exercise, and 17% reported worsened diets. Multiple linear regression analysis revealed that pre-emergency office MAP, mineralocorticoid receptor agonist use, worsened diet, and medication non-adherence were associated with changes in office MAP. For home MAP, pre-emergency home MAP, body weight, and worsened sleep quality were associated with changes. ROC analysis indicated a total stress score cutoff of 3.0 for an increased office MAP. Patients with a total stress score ≥3 had significantly higher office SBP, office MAP, home DBP, and home MAP than those with a score <3.

The study's findings indicate that the stress induced by the COVID-19 state of emergency significantly impacted BP measurements. The increase in office BP, coupled with a decrease in home BP, highlights the prominence of the white coat phenomenon during this stressful period. The significant increase in white coat hypertension suggests heightened stress response in this population. Patients' concerns about COVID-19's impact on hypertension, alongside lifestyle changes (reduced exercise, poorer diet), likely contributed to these BP changes. The association of certain factors with changes in both office and home MAP underscores the complexity of BP regulation under stress. The results emphasize the need for heightened awareness and tailored management strategies for hypertension during periods of widespread stress.

This study demonstrates that the COVID-19 state of emergency significantly influenced BP profiles in Japanese outpatients with chronic diseases, largely due to increased stress. General practitioners should prioritize BP management during such events and consider factors like stress levels, lifestyle modifications, and medication adherence. Further research could explore long-term cardiovascular outcomes and the effectiveness of targeted interventions to mitigate stress-related BP changes.

This study's retrospective design and reliance on self-reported data introduce potential biases. The specific stress assessment method may not fully capture the multifaceted impact of the state of emergency. The study population was limited to patients of the Sagamihara Physicians Association, which may limit the generalizability of the findings. Further research with larger, more diverse populations and different stress assessment tools is needed.