Introduction: The weight-adjusted waist index (WWI) serves as an innovative obesity measure, seemingly surpassing body mass index (BMI) and waist circumference (WC) in evaluating lean and fat mass. This study aimed to explore the relationship between WWI and total bone mineral density (BMD) in US adolescents.Methods: This population-based study investigated adolescents aged 8–19 years with comprehensive WWI and total BMD data from the National Health and Nutrition Examination Survey (NHANES) 2011–2018. WWI was computed by dividing WC by the square root of body weight. Weighted multivariate linear regression and smoothed curve fitting were employed to examine linear and non-linear associations. Threshold effects were determined using a two-part linear regression model. Additionally, subgroup analyses and interaction tests were conducted.Results: Multivariate linear regression analysis revealed a significant negative association between WWI and total BMD in 6,923 US adolescents aged 8–19 years [β = -0.03, 95% CI: (-0.03, -0.03)]. This negative correlation remained consistent across all subcategories, with the exception of age, encompassing gender,ethnicity, and diabetes status subgroups. Furthermore, a non-linear relationship and saturation effect between WWI and total BMD were identified, with an inflection point at 9.88 cm/√kg.Conclusions: Our research demonstrated a notable negative relationship and saturation effect between WWI and total BMD among US adolescents.

Low back pain caused by intervertebral disc degeneration (IDD) has emerged as a significant global public health concern, with far-reaching consequences for patients' quality of life and healthcare systems. Although previous research have revealed that the mechanisms of intervertebral disc cell apoptosis, pyroptosis and necroptosis can aggravate IDD damage by mediating inflammation and promoting extracellular matrix degradation, but they cannot explain the connection between different cell death mechanisms and ion metabolism disorders. The latest study shows that cell death mechanisms such as cellular senescence, ferroptosis, and cuproptosis, and PANopotosis have similar roles in the progression of intervertebral disc degeneration, but not exactly the same damage mechanism. This paper summarizes the effects of various cell death patterns on the disease progression of IDD, related molecular mechanisms and signaling pathways, providing new perspectives and potential clinical intervention strategies for the prevention and treatment of IDD.

The treatment of bone defects remains a great clinical challenge. With the development of science and technology, bone tissue engineering technology has emerged, which can mimic the structure and function of natural bone tissues and create solutions for repairing or replacing human bone tissues based on biocompatible materials, cells and bioactive factors. Hydrogels are favoured by researchers due to their high water content, degradability and good biocompatibility. This paper describes the hydrogel sources, roles and applications. According to the different types of stimuli, hydrogels are classified into three categories: physical, chemical and biochemical responses, and the applications of different stimuli-responsive hydrogels in bone tissue engineering are summarised. Stimuli-responsive hydrogels can form a semi-solid with good adhesion based on different physiological environments, which can carry a variety of bone-enhancing bioactive factors, drugs and cells, and have a long retention time in the local area, which is conducive to a long period of controlled release; they can also form a scaffold for constructing tissue repair, which can jointly promote the repair of bone injury sites. However, it also has many defects, such as poor biocompatibility, immunogenicity and mechanical stability. Further studies are still needed in the future to facilitate its clinical translation.

Bone-related diseases caused by trauma, infection, and aging affect people’s health and quality of life. The prevalence of bone-related diseases has been increasing yearly in recent years. Mild bone diseases can still be treated with conservative drugs and can be cured confidently. However, serious bone injuries caused by large-scale trauma, fractures, bone tumors, and other diseases are challenging to heal on their own. Open surgery must be used for intervention. The treatment method also faces the problems of a long cycle, high cost, and serious side effects. Studies have found that hydrogels have attracted much attention due to their good biocompatibility and biodegradability and show great potential in treating bone-related diseases. This paper mainly introduces the properties and preparation methods of hydrogels, reviews the application of hydrogels in bone-related diseases (including bone defects, bone fracture, cartilage injuries, and osteosarcoma) in recent years. We also put forward suggestions according to the current development status, pointing out a new direction for developing high-performance hydrogels more suitable for bone-related diseases.

Original Article Current status and trends in quantitative MRI study of intervertebral disc degeneration: a bibliometric and clinical study analysis Shuang Chen, Daoxi Sun, Nan Wang, Xiaoyang Fang, Zhipeng Xi, Chenyu Wang, Heng Chen, Lin Xie