Changes in bone mineral density in women before critical illness: a matched control nested cohort study.
The contribution of premorbid bone health to accelerated bone loss following critical illness is unknown. This study compared bone density in women before critical illness to women who did not become critically ill. Overall bone density was similar, although femoral neck bone mass increased immediately prior to critical illness.


PURPOSE
The relative contribution of acute and chronic factors to accelerated loss of bone mineral density (BMD) following critical illness is unknown. This study compared the BMD trajectory of women before critical illness to the BMD trajectory of women who did not become critically ill.


METHODS
This prospective, nested, age- and medication-matched, case-control study compared trajectory of BMD in women in the Geelong Osteoporosis study (GOS) requiring admission to an Australian Intensive Care Unit (ICU) between June 1998 and March 2016, to women not admitted to ICU. The main outcome was age and medication use adjusted change in BMD.


RESULTS
A total of 52 women, with a mean age of 77 ± 9 years were admitted to ICU, predominantly post-surgery (75%), during the study period. A greater age-adjusted annual rate of decline was observed for pre-ICU women compared to no-ICU women for AP spine BMD (-0.010 ± 0.002 g/cm2 vs -0.005 ± 0.002 g/cm2, p = 0.01) over the 15-year study period. In participants with multiple BMDs 2 years before critical illness, a significantly greater increase in femoral neck BMD compared to age- and medication-matched controls was observed (difference in BMD, ICU vs no-ICU = 0.037 ± 0.013 g/cm2, p = 0.006).


CONCLUSION
In a cohort of women with predominantly surgical ICU admission, bone health prior to critical illness was comparable to age- and medication-matched controls, with a relative increase in femoral neck bone mass immediately prior to critical illness. These findings suggest critical illness-related bone loss cannot be entirely explained as a continuation of pre-morbid bone trajectory.
['Orford|Neil R|NR|', 'Bailey|Michael|M|', 'Bellomo|Rinaldo|R|', 'Pasco|Julie A|JA|', 'Cooper|David J|DJ|', 'Kotowicz|Mark A|MA|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D001315:Australia D015519:Bone Density D016022:Case-Control Studies D016638:Critical Illness D005260:Female D005272:Femur Neck D006304:Health Status D006801:Humans D007362:Intensive Care Units D008875:Middle Aged D010024:Osteoporosis D011446:Prospective Studies D013131:Spine D013997:Time Factors
Bone mineral density Critical illness Bone loss Osteoporosis Fracture Long-term outcomes