Adolescents with poorly controlled type 1 diabetes (T1D) demonstrate reduced bone mineral density (BMD), yet the contribution of glycemic control and advanced glycation end-products (AGEs) remains uncertain.
This longitudinal study, published in BMJ Open Diabetes Research and Care, included 37 adolescents (48.6% female; mean age 14.3 years) with HbA1c >9% (85 mmol/mol). Dual-energy X-ray absorptiometry (DXA) was performed at baseline and 12 months. Glycemic control was monitored using HbA1c, CGM parameters, and glycemic load. Serum IGF-I and MG-HI, a specific AGE, were also measured.

At baseline, DXA-derived BMD z-scores were approximately 0.5 below reference values at all major skeletal sites (p = 0.005–0.04). During follow-up, only girls demonstrated significant improvement in proximal femur BMD. Across the cohort, increases in IGF-I were positively associated with BMD accrual, whereas changes in HbA1c, CGM time in range, or MG-HI showed no correlation. No vertebral fractures were identified during follow-up.

These findings suggest that IGF-I plays a key role in bone mineral accrual independent of glycemic control or MG-HI accumulation in adolescents with poorly controlled T1D. Further research using advanced bone imaging and broader AGE profiling is warranted to clarify mechanisms of skeletal fragility in this population.