This study innovatively examines, within a Chinese elderly cohort, how Pulmonary Function mediates the association between grip strength and depressive symptoms. The study data, spanning a three-year follow-up period, reveal a clear association between initial grip strength levels and subsequent depression severity. Importantly, our findings support the initial hypothesis that Pulmonary Function indeed exerts a partial mediating effect in the relationship between grip strength and the observed depression levels over the follow-up. In recent years, the relationship between grip strength and depression in the elderly population has increasingly become a focus of research. Our findings align with previous studies, revealing a significant negative correlation between grip strength and depressive symptoms. For instance, Yeqing Gu et al. (Gu et al., 2021), in a study involving a large adult sample, employed a combination of grip strength measurements and the Self-Rating Depression Scale (SDS) to delve into the intrinsic connection between grip strength and mental health, discovering that lower grip strength levels correlate with more pronounced depressive symptoms, with this association being particularly strong in women. Additionally, some studies, through the analysis of large prospective cohort datasets, especially in elderly populations in India, have not only confirmed the negative correlation between grip strength and depressive mood but also illuminated the complex interplay mechanisms between grip strength, depressive symptoms, and systemic inflammatory markers (such as cortisol levels) (García-Sanz and González-Barcala, 2021; Stevens et al., 2021; Wang et al., 2022). Notably, Jae Won Oh and colleagues' multinational study (Oh et al., 2023), spanning across the US, UK, Europe, Israel, South Korea, China, and Brazil, consistently revealed an association between weak grip strength and a higher risk of depression through analyzing six multi-country databases, a conclusion that stood firm in both individual database analyses and pooled analyses. This research underscores the role of grip strength as a powerful indicator of overall health status and predictor of future health risks in the elderly population, while also unraveling the intricate web of interactions between grip strength and mental health, further cementing the significance of grip strength assessment in geriatric medicine.
In recent years, scientific research has increasingly uncovered novel and significant connections between grip strength and Pulmonary Function, with particular importance emerging in the realm of mental health. Our latest study demonstrates a close correlation between the decline in grip strength and a reduction in Pulmonary Function. Notably, a study focusing on individuals with mental disorders, through an integrative analysis of physiological stress indices, mental health status, and objective measurements of bodily functions, revealed a significant association between lower body grip strength (BCRP = -0.21, SE = 0.06, p < .001) and impaired Pulmonary Function (BCRP = -2.07, SE = 0.66, p = .002) with the severity of patients' conditions(Lever-van et al., 2020). Previous research has established correlations between the severity of depressive and anxiety disorders and various physical function indicators, with the strong link between grip strength and Pulmonary Function standing out, emphasizing their unique significance in mental health evaluations. While these findings suggest a profound and intricate network of relationships among grip strength, Pulmonary Function, and mental disorders (specifically depression and anxiety), the underlying mechanisms await comprehensive elucidation. To address this gap, our research actively contributes by meticulously examining and exploring the multi-level interactions among these three factors, striving to illuminate the specific pathways of their reciprocal influences. Moreover, existing literature further solidifies the connection between diminished cardiorespiratory endurance and reduced grip strength metrics with an augmented risk of common mental disorders, powerfully affirming the fundamental role of physiological fitness in preserving mental health(Kandola et al., 2020). These discoveries not only deepen our comprehension of the physiological foundations of mental health but also furnish new perspectives and grounds for the development of interdisciplinary intervention strategies.
This study uncovers a pivotal finding: Pulmonary Function acts as a mediator in the relationship between grip strength and the severity of depression, with poor Pulmonary Function forecasting a heightened risk for depression development, underscoring its importance as a predictive marker in depression prognosis assessments(Orea-Tejeda et al., 2023). This implies that enhancing an individual's grip strength may effectively alleviate depressive symptoms by positively impacting Pulmonary Function. Cognitive Behavioral Therapy (CBT) has demonstrated remarkable efficacy in the management of Chronic Obstructive Pulmonary Disease (COPD), not only improving patients' Pulmonary Function but also reducing anxiety and depression, enhancing treatment adherence, and improving quality of life, further validating the effectiveness of mind-body interventions(Chen et al., 2024). Through a large-scale, long-term prospective study spanning over 13 years, we observed a significant association between declining Pulmonary Function and an increased risk of depression, suggesting potential value in monitoring physical function for prognostic evaluation in depression and anxiety disorder patients (Hu et al., 2024b). Existing literature further supports that abnormalities in Pulmonary Function are closely tied to changes in various biomarkers (such as liver and kidney function, red blood cell indices, inflammatory markers, and circulating metabolites), which are also intimately linked to the pathogenesis of depression(Du W et al., 2023; Li et al., 2023; Ma et al., 2023; Pan et al., 2021; Park et al., 2021) Collectively, cardiovascular and pulmonary fitness, along with muscle strength, represent not only vital modifiable factors for mental health but also, in conjunction, grip strength and physical fitness assessments can serve as early warning signals for mental health risks. Therefore, targeted enhancement of individuals' physical fitness and grip strength levels emerges as a promising strategy for reducing the incidence of common mental disorders.
Our study makes significant theoretical contributions to the alleviation of depressive symptoms and the prevention of depression in the elderly population. By uncovering for the first time the mediating effect of Pulmonary Function in the relationship between grip strength and depression, we lay the groundwork for developing innovative assessment tools and establishing early warning systems. This discovery enables the routine monitoring of grip strength and Pulmonary Function in older adults, allowing for timely interventions at the onset of depressive tendencies, thereby effectively curbing the progression of depression. Practically, we advocate for seniors to engage in moderate-intensity aerobic exercises such as brisk walking, slow jogging, swimming, and cycling, which can significantly enhance cardiovascular endurance and lung capacity. Incorporating breathing exercises and enjoyable singing activities not only boosts the efficiency of the respiratory system and improves gas exchange but also adds a layer of psychological pleasure, achieving dual benefits for both the mind and body. Furthermore, integrating resistance training tailored to individual health conditions to build muscle strength is crucial for maintaining overall health and preventing chronic diseases, particularly for the elderly, where preservation of muscle mass significantly reduces postoperative complications, shortens hospital stays, enhances physical function, and improves quality of life(Strasser et al., 2018) (Fyfe et al., 2022). By comprehensively improving the Pulmonary Function and grip strength of the elderly, we aim to construct a holistic health management strategy that simultaneously bolsters their physical and mental wellbeing. Lastly, our research transcends disciplines including medicine, psychology, and exercise science, fostering interdisciplinary collaboration and deep academic discourse.