Researchers from Germany recently studied 209 elderly patients with “low energy” fracture of the hip, meaning these fractures were not a result of a high impact injury, such as a fall. Low energy fractures occur spontaneously because the bones are weak. The authors obtained baseline 25(OH)D levels and then followed the patients for one year to see if there was a difference in death rates and post-operative medical complications in subjects with low vitamin D levels.
Fakler JK, Grafe A, Dinger J, Josten C, Aust G. Perioperative risk factors in patients with a femoral neck fracture – influence of 25-hydroxyvitamin D and C-reactive protein on postoperative medical complications and 1-year mortality. BMC Musculoskelet Disord. 2016 Feb 1;17(1):51.
Higher 25(OH)D status was associated with fewer medical complications. The total post-operative complications are list below:
- Postoperative medical complications (total) 20 %
- cardiovascular 6 %
- thromboembolic 1 %
- pulmonary infection 3 %
- extra-pulmonary infections 4 %
- other (i.e. delirium) 6 %
- 30-day mortality 13 %
- 1-year mortality 23 %
The inverse relationship between 25(OH)D and mortality was significant (p = 0.027) before adjustment. Dividing 25(OH)D levels into quartiles also showed significant results with a mortality rate of 6 % in the highest, 23 % and 24 % in the intermediate quartiles and 34 % in the lowest quartile (p = 0.014). No patient with a 25(OH)D level of >30 ng/ml died, but their findings on mortality and 25(OH)D did not prove statistically significant. See the graph below.
Systemic inflammation has been reported linked to lower circulating 25(OH)D. Some experts conclude that patients with a marked inflammation might be falsely identified as vitamin D deficient because, they hypothesize, inflammation lowers 25(OH)D. In fact, this study demonstrated an inverse association between 25(OH)D and CRP, an established indicator of systemic inflammation. However, exclusion of CRP in the multivariable regression model did not alter the role of 25(OH)D, demonstrating that CRP had no independent association with 25(OH)D as would be expected if inflammation lowered 25(OH)D.
The researchers stated,
“This lack of association indicates low 25(OH)D is not a byproduct of inflammation. Postoperative fluid shifts also represent a potential confounder of 25(OH)D measurements. However, in our study, most of the blood samples for analysis of 25(OH)D were taken preoperatively. Additionally, pre and postoperative analysis of 25(OH)D samples in the same patients did not differ significantly in our study.”
While the unadjusted mortality rates are shown on the graph below, there were not enough patients with levels above 30 ng/ml to make the findings statistically significant. That said, the graph is pretty spectacular.
This study found the average low energy hip fracture patient in Germany has a 25(OH)D of about 9 ng/ml! Obviously the physicians in Germany taking care of the elderly have a lot of work to do.