This study was approved by the Ethics Committee of the First People's Hospital of Zunyi City (No. (2022) -1-25), and screening was conducted with written informed consent from the subjects or guardians. All procedures performed in studies involving human participant were in accordance with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.. Throughout the research, the ethical principles of voluntariness, informed consent, privacy and confidentiality, and non - maleficence were strictly adhered to. Before the study commenced, the research objectives, content, and procedures were thoroughly explained to participants and their caregivers. Written informed consent was obtained from participants or their legal guardians, and the consent form was signed prior to screening. Data were encrypted and stored exclusively for this study. Participants were informed that they could withdraw from the study at any time without prejudice.

This study reveals a moderate prevalence of activity of daily living (ADL) impairment (27.51%, 95% CI: 25.83–29.19) among older adults of the Gelao ethnic minority in China, positioning it between reported rates for other minority populations. While aligning with the national average for Chinese older adults [10], this rate exceeds those observed in home-dwelling older adults of the Ningxia Hui Autonomous Region (17.21%) [12] and the Qiannan Buyi-Miao Autonomous Prefecture [26], yet remains lower than rates documented in high-altitude ethnic minorities of Southwest China [25]. Such intermediate prevalence underscores the dual burden faced by the Gelao population: systemic socioeconomic challenges common to underdeveloped western regions and culturally mediated risks rooted in their unique geographic isolation, traditional dietary practices (e.g., daily salt intake > 10g [17]), and limited healthcare infrastructure.

This study identified significant gender disparities in ADL impairment, with females exhibiting a markedly higher prevalence than males (61.80% vs. 38.20%), consistent with prior epidemiological findings in ethnic minority populations [27]. A critical driver of this disparity lies in structural educational inequities: female illiteracy rates (68.9%) were 2.15-fold higher than males (32.1%), aligning with the established gradient where each educational attainment level reduces ADL/IADL impairment risk by 15–20% [28]. The observed age-related escalation in ADL impairment [12, 29] parallels rising illiteracy rates among older cohorts—a legacy of China’s historical educational deprivation, particularly pronounced in western ethnic minorities.At the same time, given that this region is one of the underdeveloped areas in China,compounded by long-standing historical factors and entrenched customs, women's access to education has been significantly constrained. Furthermore, as one of the provinces with the least developed economy and culture in China, the region exhibits a relatively low economic level. A substantial portion of the area consists of barren karst slopes. The older persons in these regions predominantly rely on an agricultural economy, with only one crop harvested annually. This leads to their monthly income being both meager and unstable. The traditional agricultural economic model forces families to adopt a gender-based prioritization strategy in educational investment. Then, this woman's early involvement in labor eventually causes a decline in their health management from generation to generation, capabilities eventually form a perpetuating vicious cycle of "illiterate motherless educated daughter." Moreover, the Gelao ethnic group primarily resides in mountainous or semi-mountainous areas of Guizhou Province. These villages are situated near mountains and rivers. However, medical resources are scarce in remote areas,and the rugged terrain severely restricts access to healthcare services. Due to their traditional family roles, women are more likely to delay seeking medical treatment.

Meanwhile, the risk of ADL impairment among older persons individuals living alone is significantly lower than that of those living with relatives, consistent with the functional maintenance theory of "use it or lose it." Older persons people living alone must independently perform tasks such as cooking, washing clothes, and managing medications,thereby objectively fostering continuous practice of their activities of daily living [30]. This protective effect is significantly influenced by the geographical environment. The interaction between "residential pattern-geographical environment" suggests that enhancing the accessibility of basic living facilities should be considered a prerequisite for promoting the maintenance of ADL among older persons individuals living alone.

This study identified occupational physical activity as a protective factor against ADL impairment among Gelao older adults. Shaped by the karst mountainous terrain, 68.3% of participants engaged in agricultural labor, which conferred biomechanical advantages through enhanced muscular endurance and joint flexibility[31, 32]. Notably, older adults engaging in ≥ 3 sessions/week of moderate-to-vigorous physical activity (MVPA) demonstrated 23.7% better preservation of basic ADL skills compared to sedentary peers [33].

The protective effect of social activities on ADL is achieved through the dual pathways of "social connection - biological regulation". This study shows that the ADL impairment rate of the older persons who participate in social activities every day is significantly lower than that of those who do not participate, which is consistent with the research conclusion that "social activities maintain function through cognitive stimulation and social support" [33, 34]. Group activities (market parties, playing mahjong) activate the prefrontal cortex area and delay cognitive decline [35]. Social interaction increases the level of oxytocin, reduces inflammatory markers related to functional decline, and indirectly improves the ability to perform daily living operations [36].

Chronic diseases have been widely recognized as significant risk factors for impaired Activities of Daily Living (ADL) in older persons populations, as evidenced by multiple studies [37]. Long-term pharmacological management of chronic conditions may trigger adverse drug reactions that cascade into multisystem effects, including visual impairment, altered consciousness, and psychiatric symptoms. These systemic repercussions not only contribute to cognitive decline but also directly compromise ADL performance through mechanisms such as neurotransmitter dysregulation [38]. Notably, our findings reinforce the bidirectional relationship between cognitive impairment and ADL dysfunction. This aligns with longitudinal evidence demonstrating that baseline ADL capacity in adulthood predicts subsequent cognitive deterioration [39], while impairments in instrumental activities of daily living (IADL), when independent of physical limitations, may serve as a specific prodromal marker of Alzheimer’s disease [40]. Regional epidemiological studies further substantiate these patterns. For instance, within the Yi ethnic older persons population of Yunnan Province, each unit decline in IADL performance corresponds to a significantly elevated risk of cognitive impairment [38].

At the neural mechanism level, autonomic nerve dysfunction warrants particular emphasis as a potential early biomarker for neurodegenerative disorders, including Alzheimer's disease (AD) [41]. This dysfunction initiates a multi-system cascade impairing activities of daily living (ADL) by disrupting critical physiological processes such as cardiovascular homeostasis, gastrointestinal absorption, and urogenital regulation [42]. Notably, beyond conventional risk factors, our investigation revealed that regional health behavior patterns exert a disproportionate influence on ADL trajectories. Epidemiological data indicate that over half of the older persons participants reported brushing their teeth no more than once daily, with nocturnal toothbrushing rates falling markedly below recommended hygiene standards. Such suboptimal oral care practices not only elevate cardiovascular risk through systemic inflammation [43] but also instigate a detrimental cycle of ADL decline via secondary complications. Specifically, dental caries and periodontal pathologies impair masticatory efficiency and nutritional intake, thereby exacerbating functional deterioration [44].

This longitudinal study revealed that older persons individuals with sleep disorders exhibit a 23% elevated risk of activities of daily living (ADL) impairment compared to their counterparts with normative sleep patterns. Chronic sleep deprivation manifestations - including prolonged sleep latency and frequent nocturnal awakenings-induce hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis, resulting in a 27.3% elevation in peak cortisol concentrations and subsequent neuroendocrine dysregulation [45]. The resultant chronic stress state precipitates prefrontal cortex neurotoxicity, critically impairing executive functions essential for complex ADL performance, such as medication management and meal preparation [46]. Concurrent with cognitive effects, sleep deprivation induces mitochondrial dysfunction in skeletal muscle tissue, disrupting adenosine triphosphate (ATP) synthesis pathways. This metabolic compromise reduces muscle endurance capacity and diminishes articular flexibility, clinically manifesting as gait velocity reduction and impaired postural stability - foundational deficits directly compromising basic ADL competencies, including ambulation and personal care [45]. Notably, our path analysis identified a triadic pathological relationship between circadian rhythm disruption, cognitive impairment, and autonomic dysfunction. Among sleep-disordered participants, 68.7% demonstrated concurrent mild cognitive impairment and reduced heart rate variability, with inflammatory markers mediating accelerated sarcopenia progression and degenerative joint changes [47]. These multifactorial mechanisms appear particularly exacerbated in older persons Gelao ethnic populations. Geographically specific factors, including nocturnal hypothermia and elevated ambient humidity in mountainous regions, correlate with increased sleep fragmentation. Moreover, circadian misalignment secondary to traditional agricultural practices significantly disrupts suprachiasmatic nucleus-mediated sleep-wake regulation [48].

Firstly, although the cross-sectional study design can reveal the variable associations, it cannot establish the causal relationship sequence among chronic diseases, cognitive function, and impaired ADL. In the future, the causal paths need to be verified through cohort studies. Secondly, although the research was strictly limited to the concentrated areas of the Gelao ethnic group to enhance cultural specificity, the geographical concentration of the samples might limit the validity of the conclusion to other ethnic groups or geographical regions. Subsequent studies need to include multi-ethnic control groups for verification. Furthermore, key variables such as health behaviors and disease history rely on self-reports of the subjects, which may introduce recall bias, especially when the insufficient primary medical resources may lead to missed diagnoses of chronic diseases. Subsequent studies should combine medical record verification and biomarker detection to improve data accuracy.

Based on a cross-sectional survey of the older persons of the Gelao ethnic group, this study found that their ADL impairment rate (27.51%) was slightly higher than the national average level and was interwoven and affected by multiple risk factors. Advanced age, sleep disorders, polymedication, abnormal autonomic nerve function, and cognitive impairment constitute independent risk factors, while educational level, economic status, and healthy behaviors play a significant protective role. Given the observational characteristics and regional specificity of this study, the research conclusion not only provides a quantitative basis for identifying the older persons health vulnerable population of the Gelao ethnic group, but also suggests that intervention needs to be advanced from the following dimensions. From the policy perspective, it is suggested that the government formulate a coordinated intervention policy of "health - education - economy" for ethnic minority areas in the central and western regions. Through special fiscal transfer payments, increase the coverage rate of age-friendly facilities, and rely on the "rural revitalization" strategy to improve the allocation of basic education resources, thereby enhancing the health literacy of the older persons population from the root.

This study was approved by the Ethics Committee of the First People's Hospital of Zunyi City (No. (2022) -1-25), and screening was conducted with written informed consent from the subjects or guardians. The clinical trial was registered at the Chinese Clinical Trial Registry (ChiCTR2400094722, http://www.chictr.org.cn/), with a registration date of 2024-12-26.

It was not appropriate or possible to involve patients or the public in the design, or conduct, or reporting, or dissemination plans of our research.

All data used in this study were anonymized during data collection and analysis. The manuscript does not contain any identifying images, personal details (e.g., name, hospital number, specific address), or clinical information that could compromise the anonymity of the participants. Therefore, "Consent for publication" is Not Applicable.

Competing interest statement: All authors have completed the Unified Competing Interest form (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years, no other relationships or activities that could appear to have influenced the submitted work.

The lead author (the manuscript’s guarantor) affirms that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned (and, if relevant, registered) have been explained.