Atrophic gastritis is common among older adults and can lead to vitamin B12 depletion owing to the suppression of gastric acid, which is required for B12 absorption from foods(Reference Stabler1,Reference Hughes and McNulty2) . Emerging evidence supports a role for vitamin B12 in bone health(Reference Clarke, Ward and Strain3), but no previous study has investigated this association in relation to atrophic gastritis. This study aimed to examine the relationship of vitamin B12 with bone mineral density (BMD), osteoporosis risk and bone turnover markers (BTM) in older adults with atrophic gastritis. We hypothesized that atrophic gastritis has a detrimental effect on vitamin B12 status and, in turn, is negatively associated with BMD.
Eligible participants (n = 2620) not using B12 supplements were identified from the Trinity-Ulster and Department of Agriculture (TUDA) cohort, a study of community-dwelling adults ≥60 years recruited across Northern Ireland and the Republic of Ireland (2008–2012). Ethical approval was granted from relevant ethics committees in Northern Ireland (ORECNI; reference 08/NI/RO3113) and the Republic of Ireland. BMD was measured via dual energy X-ray absorptiometry (DXA) at three sites: femoral neck, total hip and lumbar spine (L1–L4). Atrophic gastritis was identified via ELISA using a pepsinogen I:II ratio <3. Vitamin B12 biomarkers (serum total B12; serum holotranscobalamin; plasma homocysteine) and BTM were measured.
Atrophic gastritis was associated with lower B12 status (all three biomarkers; P < 0.001) and a higher prevalence of deficiency (combined B12 index; 37% vs 17%; P < 0.001). The risk of osteoporosis (T-score ≤ -2.5) was examined by binary logistic regression. Age (OR = 1.05, 95% CI 1.02–1.07 P < 0.001), female sex (OR = 2.03, 95% CI 1.44–2.88 P < 0.001), BMI
(OR = 0.84, 95% CI 0.81–0.87 P < 0.001), physical inactivity (OR = 1.62, 95% CI 1.07–2.44 P 0.021), previous fracture (OR = 1.49, 95% CI 1.12–1.97 P = 0.006) and bisphosphonate use (OR = 2.26, 95% CI 1.63–3.13 P < 0.001) were significant risk factors for osteoporosis. In participants with compared to without atrophic gastritis, after adjustment for BMI and 25- hydroxyvitamin D concentrations, BMD [mean (95% CI) g/cm2] was lower at the total hip [0.944 (0.920, 0.968) vs 0.974 (0.967, 0.982); P = 0.038] and lumbar spine [1.096 (1.063, 1.129) vs 1.134 (1.124, 1.145); P = 0.025], but not significantly so at the femoral neck [P = 0.089]; and the prevalence of osteopenia/osteoporosis was higher (69% vs 61%; P = 0.054). In addition, mean (95% CI) concentrations of the bone resorption marker, tartrate-resistant acid phosphatase [TRAP; 3.3 (3.1, 3.5)μg/ml vs 3.0 (3.0, 3.1)μg/ml; P = 0.002], was significantly higher in those with atrophic gastritis.
In conclusion, atrophic gastritis lowers vitamin B12 status and is associated with lower BMD and a greater risk of osteoporosis in older adults. Further research is warranted to investigate the relationship of atrophic gastritis and related vitamin B12 status with bone health in ageing.
