Decreased bone density and the breakdown of bone microarchitecture are the hallmarks of osteoporosis, a systemic skeletal disease that raises the risk of fractures dramatically and decreases bone mass (1–3). As the world’s population ages more rapidly, osteoporosis is becoming a serious global public health problem (4, 5). Osteoporosis is particularly prevalent among postmenopausal elderly women, primarily due to estrogen deficiency (6, 7). The World Health Organization (WHO) estimates that 200 million men and women worldwide suffer from osteoporosis (8). In addition to severely lowering patients’ quality of life, osteoporosis places a financial strain on healthcare systems (9, 10). The incidence of osteoporosis and fractures can be decreased by early identification and management.

Currently, dual-energy X-ray absorptiometry (DXA) is the gold standard for diagnosing osteoporosis. However, its application in large-scale screening is limited due to its high cost, equipment requirements, and low accessibility (11). Additionally, traditional risk assessment tools, such as the Fracture Risk Assessment Tool (FRAX), can predict fracture risk but remain controversial regarding their accuracy and applicability (12). Therefore, identifying an economical, convenient, and widely applicable biomarker for early screening and risk assessment of osteoporosis holds significant clinical value.

The Lipid Accumulation Product (LAP) is a novel indicator of fat accumulation that integrates waist circumference and serum triglyceride levels, providing a more accurate reflection of an individual’s fat distribution and metabolic status (13–15). BMI and body fat percentage cannot differentiate the effects of different fat types on bone health (16). Previous studies have demonstrated a stronger association between visceral fat and bone metabolism. Moreover, LAP has been validated as a predictive marker for metabolic syndrome-related diseases, including diabetes, non-alcoholic fatty liver disease, and hypertension (17–20), suggesting its potential value in osteoporosis screening. However, systematic studies on the relationship between LAP and osteoporosis remain limited, particularly with regard to epidemiological evidence in the U.S. adult population.

This study utilizes data from the National Health and Nutrition Examination Survey (NHANES) to systematically assess the relationship between LAP and osteoporosis prevalence, aiming to explore the feasibility of LAP as a potential biomarker for early osteoporosis screening (21–23). Because hormones and cytokines secreted by visceral adipose tissue, such as leptin, may promote bone formation by stimulating osteoblasts (24), and a moderate increase in fat mass may enhance skeletal loading, thereby stimulating bone remodeling and increasing bone density (25). We hypothesize that LAP is significantly associated with bone mineral density (BMD), with higher LAP levels potentially correlating with a lower risk of osteoporosis. By further investigating this association, we aim to provide new theoretical insights for osteoporosis screening and prevention, as well as support future clinical practice and public health policies.

This study used data from the NHANES database to examine the relationship between the prevalence of osteoporosis and LAP. The findings demonstrated a strong inverse relationship between osteoporosis and LAP. An increase in LAP considerably decreased the incidence of osteoporosis in the lower range of LAP; however, this protective impact progressively diminished when LAP above a certain threshold. These findings suggest that moderate fat distribution may positively impact bone health by increasing mechanical loading on bones and promoting the secretion of bone-forming factors.

LAP is an indicator of fat accumulation that combines waist circumference and triglyceride levels, effectively reflecting an individual’s visceral fat level (26, 27). Compared to the traditional BMI, LAP has higher accuracy and sensitivity in assessing metabolic health and cardiovascular disease risk (28, 29). In line with certain other research findings, we discovered a strong negative connection between LAP and osteoporosis in our study. Similarly, in a study of the Visceral Adiposity Index (VAI) in adults over 20 years of age, those with high VAI scores also had high total femur BMD, suggesting that those with higher levels of visceral adiposity had a lower risk of fracture (30). Another study suggests that moderate weight gain protects bone density by increasing the mechanical load on bone through adipose tissue and by promoting bone formation through the secretion of several hormones and cytokines (31). In addition, the accumulation of visceral fat may have a positive effect on bone health by promoting the secretion of hormones such as leptin, which inhibits osteoclast activity (32, 33).

On the other hand, excessive fat buildup may be detrimental to bone health (34). High fat impaired bone mass and some trabecular microstructures in older mice in an experimental study of older mice (35). In another mechanistic study, the obesity-related adipose tissue secretes hormones and inflammatory substances such TNF-α and interleukin-6 (IL-6), which can raise the risk of osteoporosis by accelerating bone resorption and preventing the production of new bone (36–38). Excess fat may lead to adverse effects such as chronic inflammation, oxidative stress, and insulin resistance, ultimately accelerating bone loss (39). Particularly at higher LAP levels, these negative effects might outweigh the positive ones, leading to an increased risk of osteoporosis. Therefore, the nonlinear relationship between LAP and osteoporosis observed in this study suggests that the protective effect of fat accumulation on bone health diminishes or even disappears when fat accumulation reaches a certain level.

We carried out several more studies to confirm the consistency and robustness of our findings. First, we used restricted cubic spline (RCS) analysis to look at the dose–response relationship between LAP and osteoporosis (40, 41). The results showed that the risk of osteoporosis was significantly reduced for each unit increase in LAP when LAP <29 (OR = 0.95, 95% CI = 0.93–0.97, p < 0.001); however, this protective effect gradually diminished when LAP >29. Additionally, we conducted a subgroup analysis to explore the potential influence of variables such as age, sex, race, physical activity, smoking, diabetes, chronic kidney disease, and hypertension on the relationship between LAP and osteoporosis. The results indicated a consistent negative correlation between LAP and osteoporosis across different populations, suggesting that LAP may serve as an independent protective factor. This phenomenon may be attributed to the fact that LAP more directly reflects the metabolic status of visceral fat.

In assessing the connection between LAP and osteoporosis risk in adult Americans, this study identified LAP as a stand-alone protective factor against osteoporosis. The large sample size enhances the accuracy of our conclusions. Additionally, LAP outperforms traditional BMI in assessing individual fat distribution. Moreover, we adjusted for various confounding variables based on demographic characteristics and chronic diseases to minimize confounding bias, ensuring the broad applicability of the findings and enhancing both the internal and external validity of the study. In order to further understand the connection between LAP and osteoporosis in various groups, we lastly performed stratified subgroup analyses. These results highlight the necessity for more targeted osteoporosis preventive measures. There are many restrictions on this study. First of all, it is hard to establish a direct correlation between LAP and osteoporosis due to the cross-sectional nature of the study. Subsequent long-term investigations are required to confirm these results and investigate the possible utility of LAP in osteoporosis care and prevention. Secondly, this study used DXA to measure BMD and defined osteoporosis based on WHO criteria. Although DXA is considered the “gold standard” for osteoporosis diagnosis, it only assesses bone mineral density and does not evaluate bone quality or microarchitecture. Since fracture risk is also influenced by factors such as trabecular structure and cortical thickness, relying solely on BMD may underestimate the fracture risk in some patients. Due to the limitations of DXA, this study could not further explore the impact of LAP on bone microarchitecture. Future studies may integrate HR-pQCT or bone turnover markers to optimize osteoporosis risk assessment. Finally, as a novel body composition indicator, LAP requires further research to support its clinical application. This study found that LAP may be an independent protective factor against osteoporosis, as moderate fat distribution benefits bone health, while obesity may have adverse effects. LAP, being simple and practical, holds promise for osteoporosis prevention and early detection. Future studies should validate its applicability across different populations and its value in osteoporosis risk assessment.

According to this study, there is a substantial negative relationship between adult prevalence of osteoporosis in America and LAP. LAP is an easy-to-use and practical indication that may be very helpful in osteoporosis prevention and early detection.