Promotion of healthy aging has become essential due to the rapid increase of aging in the Chinese population [1, 2]. Centenarians, representing the oldest segment of this demographic, serve as an ideal cohort for studying he dynamics of healthy aging due to their longevity [3, 4]. Notably, the incremental rise in blood pressure with advancing age has been observed in older adults [5], which correlates with an elevated prevalence of hypertension in this population. This trend exacerbates the risk of cardiovascular diseases [5, 6].

Previous studies established a significantly increase in the risk of cardiovascular disease among centenarians emphasizing the health challenges within this unique population [5, 6]. Notably, our analysis reveals pronounced disparities in hypertension risk based on both sex and geography. Specifically, female centenarians face a 1.624-fold higher risk of developing hypertension compared to their male counterparts, while individuals residing in the northern and central regions of the Hainan province are subject to a 0.625-fold higher risk than those in the eastern region [7]. To deepen our understanding of these disparities and other contributing risk factors, we utilized data from 2014 to 2016 to conduct a comprehensive epidemiological study on blood pressure levels within the centenarian population of Hainan, China. This study aims to elucidate critical factors influencing hypertension, thereby informing strategies for promoting healthy aging among the oldest adults.

The seventh National Population Census of China revealed a notable trend towards an aging society, with a significant correlation observed between aging and increased morbidity due to hypertension [10]. Among the older adult Chinese population, aged over 75 years, the rate of hypertension is expected to reach 60% [11]. Despite this, there is a scarcity of high-quality clinical studies targeting this population, inevitably adding to the difficulties in clinical decision making. In contrast, the Hainan province, often referred to as China’s ‘home of longevity’, reports a lower hypertension prevalence rate of 26.2% among adults—below the national average—possibly attributed to its unique natural environment and the dietary habits characterized by light flavors and low salt intake [12, 13]. Given these unique regional attributes, including centenarians from Hainan in this study offers a representative cross-section of the province’s diverse environments and genetic backgrounds, thereby providing valuable insights into the factors influencing hypertension in an aging population.

Numerous studies have established a robust link between obesity and hypertension, identifying BMI as a critical risk factor that influences both the likelihood and severity of hypertension [14, 15, 16]. Some studies suggest that maintaining an ideal BMI (20.0–23.9 kg/m${}^2$) and abdominal obesity (waist circumference $\ge$90 cm [male] and $\ge$85 cm [female]) are effective strategies for managing blood pressure [17, 18]. These findings are corroborated by our research, which demonstrates that individuals with a BMI below 18.5 kg/m${}^2$ were significantly less likely to progress from grade I to grade III hypertension, or from grade I to grade II hypertension compared to those with a normal BMI. However, our analysis did not reveal any significant differences in hypertension severity between individuals with a BMI $>$24 kg/m${}^2$ and those within the 18.5–24 kg/m${}^2$ range. This underscores the complex interplay between BMI and hypertension severity and highlights the need for further research to explore the thresholds at which BMI begins to significantly impact hypertension risk.

This study found that older adults with BMI below 18.5 kg/m${}^2$ had a lower risk of developing hypertension than those with a normal BMI, however no statistically significant differences were found in the hypertension rates between older adults with a normal BMI compared to older adults with an elevated BMI (Supplementary Table 2). The results indicate that the traditionally perceived “emaciated” status is a protective factor for centenarians with hypertension and severe hypertension grading. Our dataset indicates that individuals with a body mass index (BMI) less than 18.5 kg/m${}^2$ constitute 57.40% (551 individuals) of the sample (Supplementary Table 1), representing more than half of the centenarian population. Therefore, the traditional BMI classification may not be suitable for centenarians.

This study indicates that elevated LDL cholesterol substantially increases the risk of advancing to more severe hypertension stages among older adults. Specifically, individuals with elevated LDL levels and grade I hypertension were significantly more likely to progressing to grade III hypertension than that among those with normal LDL levels. This association between higher LDL levels and increased blood pressure supports existing literature [19]. Furthermore, LDL levels may be improved through physical exercise, maintaining a lower BMI, and increasing fiber intake [20].

Our study also revealed a role for ethnicity in hypertension. Particularly, the risk transitioning from grade I to grade II hypertension was significantly higher in the older population of Li ethnicity when compared to that of the Han ethnicity. This disparity may be influenced by lifestyle factors [21], particularly in the higher prevalence of smoking, alcohol consumption, and dietary preference for foods with high cholesterol and fat content [22]. Moreover, the lower educational attainment among older Li individuals often leads to inadequate attention to personal health and a lack of medical health knowledge, both of which contributes to the persistently elevated prevalence of chronic diseases such as hypertension [23].

There are researches and analysis of the factors influencing hypertension, found that female centenarians had a higher risk of hypertension [7]. This increased risk is thought to be associated with factors such as physiological hormone differences, cumulative lifestyle impacts, and sex-specific expression of longevity genes [1, 24, 25]. Notably, the decline in estrogen levels after menopause is believed to play a significant role [1, 24, 25]. Despite these findings, we did not identify a significant effect of sex on the severity grading of hypertension. This unexpected result suggests a complex interplay of factors at this advanced age and underscores the need for further research to elucidate the mechanisms behind these observations.

In this study analyzing factors influencing hypertension among 960 centenarians, we found the prevalence of hypertension among centenarians in the central and northern regions of the Hainan province was lower than that in other regions (Supplementary Table 2). This regional disparity may be attributed to environmental factors unique to these areas, such as higher altitude, dense forests, and large areas of tropical rainforests in the central and northern parts of Hainan which are thought to enrich atmospheric oxygen levels [26]. Such conditions could facilitate better regulation of blood pressure by the vasomotor center, potentially reducing the incidence of hypertension [26]. Despite these findings, we did not observe significant differences in hypertension classification by residential area. This suggests that other unexamined factors might influence the regional distribution of hypertension severity. Further investigation is needed to fully understand these dynamics and their implications for public health strategies.

Previous studies have consistently identified overweight and obese status, diabetes [27, 28], and lifestyle factors such as smoking, alcohol consumption, and lack of physical activity [8, 29] as primary risk factors for hypertension in adults. However, our findings did not establish a correlation between these traditional lifestyle factors—such as high BMI, diabetes, smoking, alcohol consumption, lack of exercise—and hypertension among centenarians. This discrepancy has been previously observed, and it has been suggested that the influence of traditional risk factors on hypertension may gradually decrease among centenarians [30, 31]. The phenomenon of aging itself could explain the attenuated relationship between these risk factors and hypertension, as it might modulate physiological responses [32]. Another possibility is that the longevity-survival effect evident in centenarian populations allows them to avoid or postpone the health impacts of risk factors and chronic diseases that lead to premature death, thus enabling this group to maintain good health and live longer lives [33]. Moreover, mental health factors, such as the association between diastolic dysfunction and depression identified by Tudoran et al. [34], may be relevant in certain cases. Therefore, the impact of psychological conditions on hypertension classification in centenarians deserves further investigation.

The elderly population is a unique group requiring distinct strategies for the prevention, diagnosis, evaluation, and treatment of hypertension, distinct from those used in the general population. Given their particular needs, it is crucial to tailor comprehensive hypertension management strategies for their needs, encompassing specific blood pressure targets, antihypertensive drug treatments, and lifestyle interventions. The STEP study underscores the effectiveness of hypertensive therapy, targeting a systolic blood pressure range of 110- to less than 130 mmHg, which significantly reduces the incidence of cardiovascular events in elderly hypertensive patients compared to standard therapy targeting a systolic blood pressure range of 130–150 mmHg [35]. This study provides important evidence-based support for future development of clinical management norms and guidelines for hypertension. However, there is currently insufficient evidence-based medical data specifically pertaining to centenarians. Given that most patients within this age group have poor overall health and multiple complications, individualized blood pressure control goals should be formulated based on their specific circumstances [36].

The prevalence of hypertension among centenarians in Hainan is notably high. Our findings indicate that the primary factors influencing hypertension classification in this population include a BMI below 18.5 kg/m${}^2$, elevated LDL levels, and ethnic differences. These insights suggest that maintaining a healthy weight to avoid emaciation, maintaining LDL cholesterol levels within normal ranges, and adopting dietary habits that emphasize a low-cholesterol and low-fat diet may have a positive impact on the management and prevention of hypertension.

This study is subject to several inherent limitations. First, all participants were recruited from the Hainan province, and although the dataset comprehensively represents this region, the results may not be generalized to centenarians nationwide or in other countries and territories. Second, the historical hypertension data and use of antihypertensive drugs were self-reported by the participants, introducing the potential for information bias. This could affect the accuracy of the data regarding hypertension prevalence and management.

The data that support the findings of this study are available from the corresponding authors upon reasonable request.

ML and YH designed the study. JL, JFB, SSW, SSY, SWY, SMC, KH, SDL, and QYJ participated in the data collection, analysis, and interpretation of the work. JL, JFB, SDL, QYJ, SMC, and KH wrote the manuscript. SSW, SSY, and SWY critically reviewed the statistical methods in the manuscript. ML and YH provided constructive suggestions for the manuscript and participated in its revision. All authors read and approved the final manuscript. All authors were fully involved in the work and agreed to be accountable for all aspects of the work.

All procedures performed in this study involving human participants were in accordance with the standards of the ethics committee of the Hainan Branch, General Hospital of Chinese PLA (approval number: 301hn11201601). A written informed consent was obtained from each patient.

This study thanks for all the subjects and staff in CHCCS.

This study was supported by the National Natural Science Foundation of China (Nos. 82173589 & 82173590), the National Key Research and Development Program of China (2022YFC2503605), the Capital’s Funds for Health Improvement and Research (Nos. 2022-2G-5031 & 2024-2G-5033).

The authors declare no conflict of interest.