Table 1 The eligibility criteria

The inclusion criteria

 Patients

Children with IS and low BMD

 Exposure

Studies on BMD, bone metabolism, or bone morphology

 Comparison

Children with IS and normal BMD, or healthy people

 Outcomes

(1) BMD measured by DXA, HR-pQCT, quantitative ultrasound or other quantitative instruments. And

(2) Genetic/endocrine/lifestyle-related factors linked to bone metabolism

 Research types

Observational studies or randomized controlled studies

The exclusion criteria

 Patients

(1) Children without IS; (2) Average age above 18

 Comparison

Average age above 18

 Outcomes

Studies that do not measure BMD and bone metabolism

 Research types

Case studies, or animal studies