Homocysteine-Lowering Treatment and the Risk of Fracture: Secondary Analysis of a Randomized Controlled Trial and an Updated Meta-Analysis

High plasma homocysteine is a risk factor for osteoporotic fractures. Several studies have assessed the possible preventive effect of homocysteine-lowering B-vitamin treatment on the risk of fracture with inconclusive results. In the current study, we include new results from the Aspirin Folate Polyp Prevention Study (AFPPS) together with an updated meta-analysis of randomized controlled trials (RCTs). Our objective was to determine whether there is an association between homocysteine-lowering B-vitamin treatment and the risk of fracture. The AFPPS trial was performed between 1994 and 2004 in nine clinical centers in the United States, and 1021 participants were randomized to a daily folic acid dose of 1 mg (n = 516) or placebo (n = 505). The main outcome was fracture of any type. In addition, we analyzed the risk of hip fracture. In the meta-analysis, studies were identified following a search strategy in electronic database and by hand searching. Risk ratio with 95% confidence interval (CI) was chosen for pooled analyses. In the AFPPS, no statistically significant association was found between folic acid treatment and fractures of any type (risk ratio [RR] = 0.95; 95% CI 0.61-1.48) or hip fracture (RR = 0.98; 95% CI 0.25-3.89). In the meta-analysis, six RCTs were included with a total of 36,527 participants. For interventions including folic acid and/or vitamin B12, the pooled RR for treatment was 0.97 (95% CI 0.87-1.09) for fractures of any type (n = 1199) and 1.00 (95% CI 0.81-1.23) for hip fractures (n = 335). In conclusion, no association was found between homocysteine-lowering treatment with B vitamins (folic acid and vitamin B12) and the risk of fracture. © 2018 The Authors. JBMR Plus is published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

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.

Individually modifiable risk factors to ameliorate cognitive aging: a systematic review and meta-analysis

A number of health and lifestyle factors are thought to contribute to cognitive decline associated with age but cannot be easily modified by the individual patient. We identified 12 individually modifiable interventions that can be implemented during midlife or later with the potential to ameliorate cognitive aging. For ten of these, we used PubMed databases for a systematic review of long-duration (at least 6 months), randomized, controlled trials in midlife and older adults without dementia or mild cognitive impairment with objective measures of neuropsychological performance. Using network meta-analysis, we performed a quantitative synthesis for global cognition (primary outcome) and episodic memory (secondary outcome). Of 1038 publications identified by our search strategy, 24 eligible trials were included in the network meta-analysis. Results suggested that the Mediterranean diet supplemented by olive oil and tai chi exercise may improve global cognition, and the Mediterranean diet plus olive oil and soy isoflavone supplements may improve memory. Effect sizes were no more than small (standardized mean differences 0.11-0.22). Cognitive training may have cognitive benefit as well. Most individually modifiable risk factors have not yet been adequately studied. We conclude that some interventions that can be self-initiated by healthy midlife and older adults may ameliorate cognitive aging.

Long-term proton pump inhibitor therapy and falls and fractures in elderly women: a prospective cohort study

Proton pump inhibitors (PPIs) are widely used in the elderly. Recent studies have suggested that long-term PPI therapy is associated with fractures in the elderly, however the mechanism remains unknown. We investigated the association between long-term PPI therapy ≥1 year and fracture risk factors including bone structure, falls, and balance-related function in a post hoc analysis of a longitudinal population-based prospective cohort of elderly postmenopausal women and replicated the findings in a second prospective study of falling in elderly postmenopausal women. Long-term PPI therapy was associated with increased risk of falls and fracture-related hospitalizations; adjusted odds ratio (AOR) 2.17; 95% CI, 1.25-3.77; p = 0.006 and 1.95; 95% CI, 1.20-3.16; p = 0.007, respectively. In the replication study, long-term PPI use was associated with an increased risk of self-reported falling; AOR, 1.51; 95% CI, 1.00-2.27; p = 0.049. No association of long-term PPI therapy with bone structure was observed; however, questionnaire-assessed falls-associated metrics such as limiting outdoor activity (p = 0.002) and indoor activity (p = 0.001) due to fear of falling, dizziness (p < 0.001) and numbness of feet (p = 0.017) and objective clinical measurement such as Timed Up and Go (p = 0.002) and Romberg eyes closed (p = 0.025) tests were all significantly impaired in long-term PPI users. Long-term PPI users were also more likely to have low vitamin B12 levels than non-users (50% versus 21%, p = 0.003). In conclusion, similar to previous studies, we identified an increased fracture risk in subjects on long-term PPI therapy. This increase in fracture risk in elderly women, already at high risk of fracture, appears to be mediated via increased falls risk and falling rather than impaired bone structure and should be carefully considered when prescribing long-term PPI therapy.

The chemistry of anti-pernicious anaemia factors; 5:6-disubstituted benziminazoles as products of acid hydrolysis of vitamin B12

Evidence is presented for the presence of three chemically related substances, components α, β, and γ, in acid hydrolysates of vitamin B12. Spectroscopic examination of these components has led to their classification as benziminazole derivatives. Spectroscopic comparison with 22 methylated benziminazoles synthesised to serve as model compounds, has resulted in the identification of components α and β as 1:5:6-trisubstituted benziminazoles, and of component γ as a 5:6-disubstituted benziminazole. Preliminary paper chromatographic studies point to the identity of component γ with 5:6-dimethylbenziminazole; from which it is concluded that components α and β are both 1-substituted 5:6-dimethyl-benziminazoles. Spectroscopic and chemical evidence leads to the conclusion that only one 5:6-dimethylbenziminazole residue is released from vitamin B12 on acid hydrolysis and that the benziminazole nucleus exists preformed in the vitamin. It is, therefore, concluded that components α, β, and γ represent successive stages of degradation of a common precursor. The bearing of these results on the biogenesis and structure of vitamin B12 is briefly discussed. It is a pleasure to acknowledge the encouragement of the Directors of The British Drug Houses, Ltd., in this work. Footnote. While preparing this paper for publication we became aware at the meeting of the First International Congress of Biochemistry held at Cambridge in August, 1949, of the findings of Dr. K. Folkers and his colleagues, and at the same session we announced the conclusions we had reached in the work now reported (Holiday and Petrow, J. Pharm. Pharmacol, 1949, 1, 734).

Selective toxicity of 1,2-dichloro-4,5-diaminobenzene: its relation to requirements for riboflavin and vitamin B12

In a series of 26 species selected from widely differing classes, 1,2-dichloro-4,5-diaminobenzene was toxic to those which did not exhibit a nutritional need for riboflavin plus vitamin B₁₂. It failed to retard the growth of those which needed both of these vitamins. The compound was conceived as an antimetabolite of 1,2-dimethyl-4,5-diaminobenzene. This latter, which is contained within the structures of the two vitamins, was pictured as a metabolic precursor of them. It was found to have very slight activity as either riboflavin or as vitamin B₁₂ for lactic acid bacteria and algae. The growth-inhibiting action of the dichlorodiaminobenzene was overcome competitively by the dimethyidiaminobenzene, and also, to a lesser extent, by o-phenylenediamine. The toxicity was not influenced by additions of riboflavin plus vitamin B₁₂, except in the cases of two species, where the influence was slight. These facts were considered to support the idea that properly constructed analogs of a precursor of two or more essential participants in cell division may be able to circumvent the counteraction which the vitamin has been found to exert on an antimetabolite of its precursor. Alternate explanations of the observed data were likewise considered.