B Vitamins and Hip Fracture: Secondary Analyses and Extended Follow-Up of Two Large Randomized Controlled Trials.

Elevated plasma homocysteine levels are associated with increased risk of fractures in observational studies. However, it is unsettled whether homocysteine-lowering treatment affects fracture risk. The aim of this study was to investigate the effect of an intervention with B vitamins on the risk of hip fracture in a secondary analysis of combined data from two large randomized controlled trials originally designed to study cardiovascular diseases. Both trials had identical design, intervention, and primary objective. Based on a two-by-two factorial design, the intervention consisted of a daily capsule with either (1) folic acid (0.8 mg) plus vitamin B12 (0.4 mg) and vitamin B6 (40 mg); (2) folic acid (0.8 mg) plus vitamin B12 (0.4 mg); (3) vitamin B6 alone (40 mg); or (4) placebo. The participants were followed with respect to hip fracture during the trial or during an extended follow-up (from the trial start for each patient until the end of 2012). No statistically significant association was found between folic acid plus vitamin B12 treatment and the risk of hip fracture, neither during the trial (median 3.3 years; hazard ratio [HR] 0.87; 95% confidence interval [CI], 0.48 to 1.59) nor during the extended follow-up (median 11.1 years; HR 1.08; 95% CI, 0.84 to 1.40). Nor were there significant differences in the risk of hip fracture between groups receiving versus not receiving vitamin B6 during the trial (HR 1.42; 95% CI, 0.78 to 2.61). However, during the extended follow-up, those receiving vitamin B6 showed a significant 42% higher risk of hip fracture (HR 1.42; 95% CI, 1.09 to 1.83) compared to those not receiving vitamin B6 . In conclusion, treatment with folic acid plus vitamin B12 was not associated with the risk of hip fracture. Treatment with a high dose of vitamin B6 was associated with a slightly increased risk of hip fracture during the extended follow-up (in-trial plus post-trial follow-up). © 2017 American Society for Bone and Mineral Research.

Bone mineral density is close to normal for age in long-term lymphoma survivors treated with high-dose therapy with autologous stem cell transplantation.

BACKGROUND: Few studies have assessed bone health in lymphoma survivors treated with high-dose therapy with autologous stem cell transplantation (HDT-ASCT). Therefore, we aimed to assess bone mineral density (BMD) at six different skeletal sites and to investigate associations between clinical factors and BMD in these survivors. MATERIAL AND METHODS: Eligible lymphoma survivors were aged ≥18 years at diagnosis and at HDT-ASCT given between 1987 and 2008. Participants responded to questionnaires, blood samples were drawn, and a dual energy X-ray absorptiometry (DXA) was performed. Mean Z-score was applied for assessment of BMD in relation to age. Prevalence of Z-scores ≥-1, between -1 and -2, and ≤-2 is reported for each measurement site and for the lumbar spine, femoral neck, and hip in combination. Likewise, T-scores were applied to assess the prevalence of normal BMD (≥-1), osteopenia (between -1 and -2.5), and osteoporosis (≤-2.5). RESULTS: We included 228 lymphoma survivors, of whom 62% were males. The median age at survey was 56 years, and median observation time from HDT-ASCT was eight years. Among males, Z-scores were lower at the left femoral neck and higher at the ultra-distal (UD) radius and whole body compared to the Lunar reference database. In females, Z-scores were lower at UD radius and one-third (33%) radius and higher at the whole body. Using a classification based on Z-scores at the lumbar spine, femoral neck, and hip in combination, 25% of males and 16% of females had Z-scores <-1 and >-2, while 8% and 6% had Z-scores ≤-2. According to T-scores, 35% of males and 41% of females had osteopenia, while 8% and 13% had osteoporosis, respectively. CONCLUSION: BMD was close to normal for age in this population of long-term lymphoma survivors treated with HDT-ASCT.

No increase in risk of hip fracture at high serum retinol concentrations in community-dwelling older Norwegians: the Norwegian Epidemiologic Osteoporosis Studies.

BACKGROUND: Norway has the highest hip fracture rates worldwide and a relatively high vitamin A intake. Increased fracture risk at high intakes and serum concentrations of retinol (s-retinol) have been observed in epidemiologic studies. OBJECTIVE: We aimed to study the association between s-retinol and hip fracture and whether high s-retinol may counteract a preventive effect of vitamin D. DESIGN: We conducted the largest prospective analysis of serum retinol and hip fracture to date in 21,774 men and women aged 65-79 y (mean age: 72 y) who attended 4 community-based health studies during 1994-2001. Incident hip fractures occurring up to 10.7 y after baseline were retrieved from electronic hospital discharge registers. Retinol determined by high-pressure liquid chromatography with ultraviolet detection in stored serum was available in 1154 incident hip fracture cases with valid body mass index (BMI) data and in a subcohort defined as a sex-stratified random sample (n = 1418). Cox proportional hazards regression weighted according to the stratified case-cohort design was performed. RESULTS: There was a modest increased risk of hip fracture in the lowest compared with the middle quintile of s-retinol (HR: 1.41; 95% CI: 1.09, 1.82) adjusted for sex and study center. The association was attenuated after adjustment for BMI and serum concentrations of α-tocopherol (HR: 1.16; 95% CI: 0.88, 1.51). We found no increased risk in the upper compared with the middle quintile. No significant interaction between serum concentrations of 25-hydroxyvitamin D and s-retinol on hip fracture was observed (P = 0.68). CONCLUSIONS: We found no evidence of an adverse effect of high serum retinol on hip fracture or any interaction between retinol and 25-hydroxyvitamin D. If anything, there tended to be an increased risk at low retinol concentrations, which was attenuated after control for confounders. We propose that cod liver oil, a commonly used food supplement in Norway, should not be discouraged as a natural source of vitamin D for fracture prevention.