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A large-scale analysis of U.S. children and adolescents has uncovered a significant positive association between serum triglyceride (TG) levels and bone mineral density (BMD)—a finding that may reshape how clinicians view the relationship between lipid metabolism and skeletal health in young people.

The cross-sectional study, which analyzed data from 3,818 participants aged 12 to 19 years from the National Health and Nutrition Examination Survey (NHANES) 2011–2018, offers the first robust epidemiological evidence of its kind in the pediatric population.

While triglycerides are commonly viewed through the lens of cardiovascular risk, the new data suggest a more complex role—one that may support bone development under certain physiological conditions.

After adjusting for a wide range of demographic and biochemical covariates, TG levels were positively associated with pelvic BMD (β = 0.047, 95% CI: 0.032–0.062; P < .001). A similar, though more modest, association was found for trunk BMD (β = 0.015, 95% CI: 0.006–0.025; P = .002). Notably, the relationship between TG and lumbar BMD was statistically significant only at moderate TG levels, suggesting a potential threshold effect.

No association was observed between TG levels and head BMD, reinforcing the idea that the influence of TGs on bone may vary across skeletal sites.

The strength of the association was particularly evident among male adolescents and in higher TG quartiles, with a linear dose-response relationship visualized using smooth curve fitting.

Triglycerides represent the body’s primary form of stored fat and are widely recognized as a risk factor for cardiovascular disease and metabolic syndrome. But their role in bone metabolism is less well understood—and highly context-dependent.

Lipids account for as much as 70–90% of the bone marrow fat content, and osteoblasts—the bone-forming cells—depend on lipid signaling pathways for differentiation and function. Studies suggest that lipid-derived molecules influence bone growth through signaling mechanisms involving WNT/β-catenin and Notch pathways, both critical for skeletal development.

This study adds to emerging research indicating that lipid metabolism may directly impact bone strength, particularly during periods of rapid growth such as adolescence.

While obesity and elevated TGs often coexist, this study carefully adjusted for body mass index (BMI) and still found a significant association between TGs and BMD. That suggests the observed relationship is not merely a reflection of higher body weight loading the skeleton, but may involve metabolic or hormonal interactions unique to lipid-bone physiology.

The effect was more pronounced in male adolescents, possibly reflecting the influence of sex hormones, muscle mass, or pubertal development—factors that may modulate both lipid profiles and bone accrual. Interestingly, a nonlinear relationship was observed in female adolescents, raising questions about how estrogen or sex-specific fat distribution may alter lipid-bone dynamics.

Bone mass accrued during childhood and adolescence forms the foundation for skeletal health throughout life. Peak bone mass is typically achieved by the early twenties, and suboptimal development during these formative years is a known risk factor for osteoporosis and fractures in later life.

This study suggests that low TG levels may serve as an early warning sign for poor bone mineralization. As such, children with chronically low TG levels—due to malnutrition, restrictive diets, or metabolic disorders—may warrant closer monitoring of bone health, especially during key developmental windows.

Conversely, while moderate TG levels may be beneficial for BMD, excessively high TGs remain a known cardiovascular risk, highlighting the importance of balance in lipid metabolism.

Although the findings are statistically robust and drawn from a nationally representative dataset, the study’s cross-sectional design limits causal inference. Additionally, TG levels were measured at a single time point, and bone development is a dynamic, longitudinal process. Dietary intake, physical activity, and hormonal markers—key factors influencing both lipids and bone—were not fully captured.

Furthermore, the findings may not be generalizable to populations outside the United States or to children under 12, who were not included in the analysis.

Going forward, prospective cohort studies are needed to examine how changes in TG levels over time correlate with skeletal development and fracture risk. There’s also a need to better define the optimal TG range for supporting bone health in youth—balancing the metabolic benefits without tipping into cardiometabolic harm.

This study is the first to demonstrate a positive, concentration-dependent relationship between serum triglycerides and bone mineral density in U.S. children and adolescents, with site-specific effects most notably in the pelvis and trunk. The findings underscore the need to consider lipid status as part of comprehensive bone health assessments during the critical window of adolescent growth.

While more research is needed to define clinical thresholds and causality, these results support a nuanced view of triglycerides—not just as markers of metabolic risk, but potentially as modulators of skeletal development.