Socioeconomic differences in bone mass in pediatric populations: A systematic review.

To summarize the available evidence regarding differences in bone mineral density (BMD) and content (BMC) according to socioeconomic indicators in the young population. A systematic review was performed on five electronic databases. Studies should have used central dual-energy X-ray absorptiometry to assess bone mass in children and adolescents. Of the 16,893 articles identified, only eight were included. Lower whole-body BMD was identified among those whose parents/guardians had a lower level of education in two of the three studies that investigated this topic. Similarly, lower femoral BMD was verified in all eight results from one study that analyzed this association. For BMC, one of seven possible results showed that a lower parental/guardian education level was related to lower whole-body BMC values. However, no relationship was identified between the educational level of parents/guardians and BMC of femoral regions (in three possible results) and lumbar spine (in one possible result). Associations between bone mass and other socioeconomic indicators (e.g., level of education, region of residence, marital status, economic level, and social class) were investigated by a very limited number of studies (≤ 2 studies), preventing a robust synthesis. Although the evidence points to a potential direct relationship between parental education and whole-body and femoral BMD, this relationship appears to be an indirect effect, likely mediated by factors such as fat mass. For BMC, no consistent relationship with parental education was found. The scarcity of evidence for all other socioeconomic indicators highlights a significant gap in the current literature.