Relatively low and moderate pre-fracture serum 25-hydroxyvitamin D levels associated with the highest survival in elderly hip fracture patients in Finland: a minimum 3-year follow-up

Abstract

Summary The association between serum 25-hydroxyvitamin D level and post-fracture mortality indicates beneficial relatively high serum 25-hydroxyvitamin D concentrations. A 1-year cohort study on 245 hip fracture patients in Finland indicated the lowest 3-year mortality and highest survival among patients with serum 25-hydroxyvitamin D level of 50–74 nmol/L. Purpose To explore pre-fracture serum 25-hydroxyvitamin D level as a factor associated with post-fracture survival among a cohort of hip fracture patients in Finland. Methods A prospectively collected cohort of hip fracture patients ( n = 245, 70% women) from two hospitals was followed for 3.2 post-hip fracture years. Serum 25-hydroxyvitamin D was measured in admission to the hospital and classified: < 50, 50–74, 75–99, and ≥ 100 nmol/L. Survival was analyzed with a Bayesian multivariate model. Relative survival was explored with the life table method according to serum 25-hydroxyvitamin D. Mortality according to serum 25-hydroxyvitamin D level and to the hospital was calculated. Results Mortality in the patients with serum 25-hydroxyvitamin D level of 50–74 nmol/L was significantly lower than in all other patients together at every post-fracture year. The most important factors for survival were age under 85 years; living in an actual/private home; serum 25-hydroxyvitamin D level of 50–74 nmol/L, followed by 75–99 nmol/L; ASA classes 1–2 and 3; and female sex. The mean age of patients with serum 25-hydroxyvitamin D level of 50–99 nmol/L was significantly higher than in other levels. Relative survival was highest in men, women, and patients in hospital B with serum 25-hydroxyvitamin D level of 50–74 nmol. Conclusion The highest 3-year survival and the lowest mortality in this cohort appeared in patients with pre-fracture serum 25-hydroxyvitamin D level of 50–74 nmol/L. This result differs from similar studies and is lower than the recommended level of 25-hydroxyvitamin D among hip fracture patients. The results should be examined in future research with larger data. Supplementary Information The online version contains supplementary material available at 10.1007/s00198-021-06094-z.

Impact of vitamin D deficiency on mortality in patients with hip fracture: A meta‐analysis

“…No relevant unpublished studies have been published to date. Ultimately, a total of nine studies were included in the meta‐analysis 7,15–22 …”

“…In general, there appears to be an inverse relationship; as vitamin D levels decrease, there is an increase in mortality incidence. For example, at a 30‐day follow‐up, studies consistently showed that higher mortality rates were associated with lower levels of vitamin D. Fakler et al reported a mortality incidence of 13.0% with an average vitamin D level of 8.4 ng/mL, 18 whereas Nurmi‐Lüthje et al reported a mortality incidence of 7.3% with an average vitamin D level of 28.3 ng/mL 21 . Similarly, at 1 year of follow‐up, the studies demonstrate that higher mortality rates are linked to lower levels of vitamin D. However, it is important to note that this correlation did not establish a direct causal relationship between vitamin D levels and mortality.…”

“…Different methods have been used to measure vitamin D levels in different study groups. Variations in vitamin D measurement methods have also been observed in different studies, including those that considered vitamin deficiency of <50 nmol/L 21 . Finally, patients with vitamin D deficiency may have received treatment, which could have led to eventual recovery and normalization of vitamin D levels.…”

Older adults and vitamin D hip fracture connections-what is the 2022 research base indicating?

“…This result thus differed from similar studies and is lower than the recommended level of 25-hydroxyvitamin D among hip fracture patients. 22 The authors suggested these results should be examined in future research with a larger data set.…”