Osteoporosis, a skeletal disorder characterised by compromised bone strength, results in an increased fracture risk( Reference Yazdanpanah, Zilikens and Rivadeneira 1 ) with considerable costs to both patients and the health service. While vitamin D has a well established role in bone health, evidence is emerging to support a role for the B-vitamins, and the related metabolite homocysteine (Hcy), in bone health( Reference Gjesdal, Vollset and Ueland 2 , Reference Gjesdal, Vollset and Ueland 3 ). The aim of this study was to investigate homocysteine and related B-vitamin status as determinants of bone mineral density (BMD).
Existing data from a subset (n=1276) of participants recruited to the Trinity Ulster Department of Agriculture (TUDA) study, a large observational cohort study of older Irish adults, were examined. Blood samples were analysed for plasma Hcy, red cell folate (RCF), serum folate and vitamin B12 at Trinity College Dublin. BMD at the total hip, femoral neck (FN) and spine were measured using dual energy X-ray absorptiometry (DXA) scans (Lunar Prodigy, GE Healthcare, UK).
Of the general determinants of osteoporosis (defined as a T-Score of −2.5 sd or lower), the following were found to be significant predictors: age (β=0.077, p<0.001), female gender (β=1.153, p<0.001) and BMI (β=−0.165, p<0.001) (logistic regression). As expected, a higher incidence of osteoporosis was observed among women (25%) compared with men (9%). BMD values at the total hip and femoral neck were significantly higher in women with the highest red cell folate status compared to those with the lowest red cell folate status (Table).
Differences between groups were assessed using ANOVA with Tukey post-hoc test; different superscript letters denote significant differences between any 2 groups (p<0.05)
After adjustment for age, BMI, vitamin D and serum creatinine levels (a marker of renal function), a weak but significant association between Hcy and BMD at the FN (r=−0.081, p=0.035) and total hip (r=−0.100, p=0.009) was found in women. In conclusion, these preliminary findings add to the current body of evidence suggesting a potential protective role for folate and related B-vitamins in bone health. These relationships will be further explored in this cohort when the full set of data, including relevant genetic information, is available.
We would like to acknowledge the co-funding for this research from the Irish Department of Agriculture and the Northern Ireland Department for Employment and Learning through its “Strengthening the all-Island Research Base” initiative.
