Cognitive Decline in Older Women Could Signal Bone Loss, Increased Fracture Risk

Jacqueline Center, MBBS, PhD

Research from investigators in Australia suggests older women experiencing cognitive decline were at an increased risk of fracture.

Results of the study, which assessed data from the Canadian Multicentre Osteoporosis Study, found women 65 years and older who experienced significant cognitive decline had a 61% greater risk of fracture in the next decade than their counterparts without cognitive decline; however, this risk was not seen among men.

"Bone loss and cognitive decline are major public health issues, but both are 'silent diseases' that can go undetected and untreated for long periods, often until the conditions are severely progressed," said lead investigator Jacqueline Center, MBBS, PhD, Head of the Clinical Studies and Epidemiology lab at Garvan Institute of Medical Research and endocrinologist at St Vincent's Hospital, in a press release. “Our study has revealed a link between the two in women, which suggests that cognition should be monitored together with bone health, as a decline in one could mean a decline in the other. These findings may help refine best practice guidelines of how cognition and bone health are monitored in older age, to ensure appropriate treatment can be more effectively administered."

While many have speculated and prior evidence suggests a potential link between cognitive decline and osteoporosis, Center and colleagues point out there is little to no data on the longitudinal relationship between cognitive decline and fracture risk, independent of aging. With this in mind, investigators designed the current study with the specific intent of evaluating associations between cognitive decline and bone loss and clinically significant cognitive decline and fracture risk.

To do so, investigators leveraged data obtained from the Canadian Multicentre Osteoporosis Study, which included more than 2000 patients aged 65 years and older who were followed from 1997-2013. From the study, investigators identified 1741 women and 620 men for inclusion in their analyses. All patients included in the study completed baseline examinations, including assessment on the Mini Mental State Examination (MMSE). For the purpose of analysis, clinically significant cognitive decline was defined as a reduction of 3 points or more on the MMSE.

Investigators planned to assess associations between gentile decline and bone loss using mixed-effects models. Multivariable-adjusted Cox models were designed to assess associations between clinically significant cognitive decline over the first 5 years and subsequent fracture risk over the following decade.

Among those included in the investigators’ analyses, more than 95% had an MMSE score of 24 or greater at baseline. Initial analysis indicated the annual percentage change in MMSE was similar for both genders, with a mean decline of -0.33 (IQR, -0.70 to 0.00) among women and -0.34 (IQR, -0.99 to 0.01) among men.

In adjusted analyses, results indicated cognitive decline was associated with bone loss in women, with a 6.5% (95% CI, 3.2-9.9) increase in risk of bone loss for each percent decline in MMSE from baseline; however, investigators pointed out this effect was not observed among men.

Among the 2361 patients included in the study, 13% experienced clinically significant cognitive decline by year 5. Among women, experiencing significant cognitive decline was associated with a 1.61-fold (HR, 1.61; 95% CI, 1.11-2.34) increase in risk of fracture risk in the next 10 years. Due to the small number of men in this group, investigators were unable to assess subsequent fracture risk.

"While this study could not identify a causal link—whether a decline in cognitive function leads to a decline in bone loss, or vice versa—it suggests that cognitive decline should be monitored along with bone health, as a decline in one may signal the need for increased vigilance in the other," said Center.

This study, “Cognitive decline is associated with an accelerated rate of bone loss and increased fracture risk in women: a prospective study from the Canadian Multicentre Osteoporosis Study,” was published in the Journal of Bone and Mineral Research.