Psychosocial stress is an established risk factor for many chronic diseases, with mounting evidence suggesting that stress plays a role in osteoporotic fractures. With a growing aging population, osteoporotic fractures are increasingly seen among postmenopausal women despite medical advances. Although hormones thought to degrade bone mineral density (BMD) are activated when experiencing stress, few studies have examined this association. My colleagues and I set out to investigate whether social stress is associated with bone loss, independent of important behavioral and biological risk factors.

For a study published in Epidemiology & Community Health, we evaluated social stress and the change in BMD over 6 years in 11,020 postmenopausal women enrolled in the Women’s Health Initiative (WHI), a long-term US health study launched in 1993 to assess strategies for preventing chronic conditions, including fractures in postmenopausal women. The women completed a questionnaire at enrollment on psychosocial stress related to their social environment, specifically on social strain, social support, and social functioning. Participants’ BMD was measured at the femoral neck, lumbar spine, and total hip.

We found that social stress was associated with lower BMD over 6 years, after adjusting for confounders. Women with the most social strain experienced an average 1.3% greater rate of femoral neck bone loss over 6 years when compared with women with the lowest social strain. Each point higher in social strain was associated with 0.082% greater loss of femoral neck BMD, 0.108% greater loss of total hip BMD, and 0.069% greater loss of lumbar spine BMD. This rate of postmenopausal bone loss is comparable to cigarette smoking for 6 years, which is associated with 1.2% greater bone loss.

Our research recognizes bone loss as a biological expression of adverse social environments. The next research stage is linking these findings to fracture outcomes. As an observational study, we can’t determine a cause-and-effect relationship. However, we hope these findings lead to interventions to improve social environments as non-pharmaceutical and community-based bone loss prevention strategies, along with recommended guidelines.