Journal Article

A combination of low serum concentrations of vitamins K1 and D is associated with increased risk of hip fractures in elderly Norwegians: a NOREPOS study

Tell, G. S., Samuelsen, S. O., Gjesdal, C., Finnes, T. E., Lofthus, C. M., Grimnes, G., Holvik, K., Søgaard, A. J., Schei, B., Blomhoff, R., Meyer, H. E., Apalset, E. M.

2016

Overview

Summary The present study investigated the risk of incident hip fractures according to serum concentrations of vitamin K 1 and 25-hydroxyvitamin D in elderly Norwegians during long-term follow-up. The results showed that the combination of low concentrations of both vitamin D and K 1 provides a significant risk factor for hip fractures. Introduction This case-cohort study aims to investigate the associations between serum vitamin K 1 and hip fracture and the possible effect of 25-hydroxyvitamin D (25(OH)D) on this association. Methods The source cohort was 21,774 men and women aged 65 to 79 years who attended Norwegian community-based health studies during 1994–2001. Hip fractures were identified through hospital registers during median follow-up of 8.2 years. Vitamins were determined in serum obtained at baseline in all hip fracture cases ( n  = 1090) and in a randomly selected subcohort ( n  = 1318). Cox proportional hazards regression with quartiles of serum vitamin K 1 as explanatory variable was performed. Analyses were further performed with the following four groups as explanatory variable: I: vitamin K 1  ≥ 0.76 and 25(OH)D ≥ 50 nmol/l, II: vitamin K 1  ≥ 0.76 and 25(OH)D < 50 nmol/l, III: vitamin K 1  < 0.76 and 25(OH)D ≥ 50 nmol/l, and IV: vitamin K 1  < 0.76 and 25(OH)D < 50 nmol/l. Results Age- and sex-adjusted analyses revealed an inverse association between quartiles of vitamin K 1 and the risk of hip fracture. Further, a 50 % higher risk of hip fracture was observed in subjects with both low vitamin K 1 and 25(OH)D compared with subjects with high vitamin K 1 and 25(OH)D (HR 1.50, 95 % CI 1.18–1.90). The association remained statistically significant after adjusting for body mass index, smoking, triglycerides, and serum α-tocopherol. No increased risk was observed in the groups low in one vitamin only. Conclusion Combination of low concentrations of vitamin K 1 and 25(OH)D is associated with increased risk of hip fractures.

• Publisher: Springer London
• Subject: Aged / Cohort Studies / Endocrinology / Female / Follow-Up Studies / Hip Fractures - blood / Hip Fractures - epidemiology / Hip Fractures - etiology / Humans / Male / Medicine / Medicine & Public Health / Norway - epidemiology / Original Article / Orthopedics / Rheumatology / Risk Factors / Vitamin D - analogs & derivatives / Vitamin D - blood / Vitamin D Deficiency - blood / Vitamin D Deficiency - complications / Vitamin D Deficiency - epidemiology / Vitamin K 1 - blood / Vitamin K Deficiency - blood / Vitamin K Deficiency - complications / Vitamin K Deficiency - epidemiology