This study investigated the trajectory of BP using longitudinal data collected from a uniquely vulnerable population, the Palestinian adults living in Gaza Strip, 64% of them are refugees. They have faced adverse and challenging living conditions, including war trauma. Our findings show that exposure to frequent traumatic events is linked to chronic disease risks, as indicated by elevated BP over time. In our trajectory analyses of SBP and DBP measurements (2013-2019), 22.4% and 21.4% of participants had CVH SBP (>160 mmHg) and DBP (>95 mmHg). The war-related traumatic events were positively associated with adverse BP trajectories.
This study provides evidence of the ongoing hypertension burden and the particular difficulties this vulnerable population faces. Because of exposure to war-related traumatic events might cause a double or triple burden in many families in Gaza, or perhaps more. One may find people from the same family have been injured or killed or even exposed to violence due to the bombing of their houses and others. The burden of the presence of all these events caused by wars might increase the frequency of developing hypertension or lead to worsening the levels of systolic and diastolic BP more and more. The Palestinians in Gaza are greatly affected by events surrounding oscillating stability and cumulative traumatic life (25). We believe that living in a situation of ongoing trauma may lead to further suffering in an agitated environment, leaving them vulnerable to developing hypertension.
The high affliction of war-related traumatic events indicates a significant association of war-related traumatic events, which are: injury of any family member, exposure to violence due to house bombing, and living in debt, with the highest trajectory change 'CVH' of SBP and DBP, where this trajectory characterized with a rapid gain of BP values, throughout the follow-up (2013-2019), within a constant high level of SBP and DBP. The relatively high proportion of 'CVH' trajectory change (22.4%) in SBP and (21.4%) in DBP confirm that large numbers of hypertension patients could be affected by the war-related traumatic events, which is a significant concern and should be taken into consideration in the prevention/management of NCDs.
The Palestinian people have been facing four wars in the past 14 years, besides the post-war repercussions of low living standards, poverty, and livelihood in debt In 2019, Gaza Strip residents' poverty rate was 86% (33% severe poverty) (25, 26). Perhaps living at this poverty level among Gazans would make them live their daily lives dependent on others' debts. Meanwhile, life for the average Palestinian in Gaza is getting more and more wretched (27).
We found injury due to wars was positively associated with adverse BP trajectories. The finding is in line with another study, which reported that initial injury severity was independently associated with hypertension (28). Another study conducted in Iraq and Afghanistan veterans reported that the severity of combat injury was associated with the subsequent development of hypertension, coronary artery disease, diabetes mellitus, and chronic kidney disease (29).
Moreover, Gaza Strip is a complicated environment with structural challenges such as the lack of medicines, low salaries, and specialized training abroad (30). It challenges the health system's capacity to respond to the populations' basic needs (31). There is a noticeable shortage of medicines for cancer and chronic diseases due to those wars' repercussions. According to the Ministry of Health in Gaza, over 50% of the essential medications for chronic diseases were unavailable (32). In light of those mentioned earlier, the presence of 24.4% of the diagnosed hypertension to be non-compliant to antihypertensive medication in our study is reasonable; these findings support the figures of a survey that was undertaken at the outpatient clinics of the Ministry of Health in West Bank, Palestine (n=450), which indicated that more than half of the hypertension patients (54.2%) had poor adherence with medications, where one of the reasons for the low-adherence to medications was cost and unavailability of these medications at the healthcare centers (33).
Various potential risk factors, including psychosocial factors and stressful experiences in war life in Gaza, may play a role in developing hypertension (34). Frequent exposure to stressful events is thought to be one of the most common environmental causes of hypertension on a physiological basis (35). Studies have shown that those stressful events induce various neurochemical, neurotransmitter, and hormonal changes, predominantly by triggering the sympathetic nervous system (SNS) and hypothalamic-pituitary-adrenal (HPA) axes (36). SNS and HPA axes are woken up to release chemical mediators to protect the body from stress (37). This is in line with a cohort study of 122.816 adults aged ≥30 years, with a different cultural and socioeconomic setting population in France, where perceived stress was significantly associated with high BP (38).
More future research will help explain the biological mechanisms for the effect of war events on BP. There is research suggest that the body creates a surge of hormones in a stressful environment, which then causes the heart to beat faster and blood vessels to narrow (39). Stability and living in peace without wars can help people with hypertension trigger the relaxation response and reduce stress. Thus, reducing the risk of CVDs.
The major strengths of this study are targeting a uniquely vulnerable population, the Palestinian adults, who face adverse and challenging living conditions and war trauma. It is the first study to investigate the longitudinal trajectory of SBP and DBP in Gaza, a very special place in the world. This study involved both cross-sectional and historical longitudinal designs with repeated SBP and DBP measurements for a representative population, enabling us to perform the trajectory analyses.
This study has limitations. First, the study design cannot prove causal relationships. Second, the sociodemographic and the war-related traumatic events were collected in 2019 using a survey questionnaire. Third, we cannot rule out selection bias as only those who regularly visited the primary healthcare centers in Gaza Strip were enrolled in the study. In addition, the sample size and study duration are limited.
Future efforts are needed to enhance implementing care models to improve NCD management, including hypertension, health education, and medication services in Gaza Strip. In addition, an in-depth trauma care system evaluation is needed in Gaza's health system. Therefore, a comprehensive intervention towards war-related traumatic events should be provided to the people in Gaza Strip.
In conclusion, this study provides evidence that the burden of war-related traumatic events among Palestinians living in Gaza Strip is high. Such war-related traumatic events are positively associated with adverse BP trajectory. Efforts and sustainable programs are needed to enhance health care services to improve health education and medication services and for NCD prevention and management, including hypertension, mental health, and other prevalent health conditions in Gaza Strip.