Association between socioeconomic status and bone mineral density in adults: a systematic review

For most causes of mortality and morbidity, a socioeconomic gradient exists; however, this systematic review identified limited evidence for the role of education on bone mineral density (BMD). Further research is required to build upon the current paucity of data examining influences of socioeconomic status (SES) on BMD, especially in men. For most causes of mortality and morbidity, a socioeconomic gradient exists, although little is understood of the relationship between BMD and SES. We systematically evaluated evidence of SES as a risk factor for low BMD at the clinically relevant sites of hip and spine in adults. We conducted a computer-aided search of Medline, EMBASE, CINAHL, and PsychINFO from January 1, 1966 until December 31, 2008. Reviewed studies investigated the relationship between SES parameters of income, education, and occupation, and the level of BMD. Studies were rated based on their methodological quality, and a best-evidence synthesis was used to summarise the results. One case-control and seven cross-sectional studies were identified for inclusion, of which four cross-sectional studies were high-quality. Best-evidence analysis identified consistent, yet limited, evidence for a positive association between educational attainment and BMD in women. No evidence was available regarding an association between income or occupation and BMD in either gender, or education and BMD in men. Limited good quality evidence exists for the role that education level may play in BMD levels. Cohort studies are required to examine the relationship between individual SES parameters and BMD in order to identify potential intervention targets.