5 research outputs found
The role of homocysteine in bone
__Abstract__
Osteoporosis is characterized by low bone mass and deterioration of microarchitectural
structure. It is a very common disease; in 2007 it was estimated
that 1.9 in 1,000 men and 16.1 in 1,000 women had diagnosed osteoporosis in
the Netherlands. However, the true number is expected to be 2-3 times higher,
since osteoporosis often goes undetected because it causes no symptoms until
a fracture occurs. Whether one develops osteoporosis is determined by multiple
factors; for instance, high age, female sex, low body weight, smoking, limited
physical activity and use of medication such as glucocorticoids are all risk factors. In addition, osteoporosis is high
Low vitamin D status is associated with more depressive symptoms in Dutch older adults
Purpose: The existence of vitamin D receptors in the brain points to a possible role of vitamin D in brain function. We examined the association of vitamin D status and vitamin D-related genetic make-up with depressive symptoms amongst 2839 Dutch older adults aged ≥65 years. Methods: 25-Hydroxyvitamin D (25(OH)D) was measured, and five ‘vitamin D-related genes’ were selected. Depressive symptoms were measured with the 15-point Geriatric Depression Scale. Results were expressed as the relative risk of the score of depressive symptoms by quartiles of 25(OH)D concentration or number of affected alleles, using the lowest quartile or minor allele group as reference. Results: A clear cross-sectional and pr
A Randomized Controlled Trial to Examine the Effect of 2-Year Vitamin B12 and Folic Acid Supplementation on Physical Performance, Strength, and Falling: Additional Findings from the B-PROOF Study
Elevated homocysteine concentrations are associated with a decline in physical function in elderly persons. Homocysteine-lowering therapy may slow down this decline. This study aimed to examine the effect of a 2-year intervention of vitamin B12 and folic acid supplementation on physical performance, handgrip strength, and risk of falling in elderly subjects in a double-blind, randomized placebo-controlled trial. Participants aged ≥65 years with elevated plasma homocysteine concentrations [12–50 µmol/L (n = 2919)] were randomly assigned to daily supplementation of 500 µg vitamin B12, 400 µg folic acid, and 600 I
Effect of Vitamin B<inf>12</inf> and Folic Acid Supplementation on Bone Mineral Density and Quantitative Ultrasound Parameters in Older People with an Elevated Plasma Homocysteine Level: B-PROOF, a Randomized Controlled Trial
High plasma homocysteine (Hcy) levels are associated with increased osteoporotic fracture incidence. However, the mechanism remains unclear. We investigated the effect of Hcy-lowering vitamin B12 and folic acid treatment on bone mineral density (BMD) and calcaneal quantitative ultrasound (QUS) parameters. This randomized, double-blind, placebo-controlled trial included participants aged ≥65 years with plasma Hcy levels between 12 and 50 µmol/L. The intervention comprised 2-year supplementation with either a combination of 500 µg B12, 400 µg folic acid, and 600 IU vitamin D or placebo with 600 IU vitamin D only. In total, 1111 participants underwent repeated dual-energy X-ray assessment and 1165 participants underwent QUS. Femoral neck (FN) BMD, lumbar spine (LS) BMD, calcaneal broadband ultrasound attenuation (BUA), and calcaneal speed of sound (SOS) were assessed. After 2 years, FN-BMD and BUA had significantly decreased, while LS-BMD significantly increased (all p 80 years (estimated marginal mean 64.4 dB/MHz for the intervention group and 61.0 dB/MHz for the placebo group, p = 0.04 for difference). In conclusion, this study showed no overall effect of treatment with vitamin B12 and folic acid on BMD or QUS parameters in elderly, mildly hyperhomocysteinemic persons, but suggests a small beneficial effect on BUA in persons >80 years who were compliant in taking the supplement
Beta-blocker use and fall risk in older individuals: Original results from two studies with meta-analysis
Aims: To investigate the association between use of β-blockers and β-blocker characteristics – selectivity, lipid solubility, intrinsic sympathetic activity (ISA) and CYP2D6 enzyme metabolism – and fall risk. Methods: Data from two prospective studies were used, including community-dwelling individuals, n = 7662 (the Rotterdam Study) and 2407 (B-PROOF), all aged ≥55 years. Fall incidents were recorded prospectively. Time-varying β-blocker use was determined using pharmacy dispensing records. Cox proportional hazard models adjusted for age and sex were applied to determine the association between β-blocker use, their characteristics – selectivity, lipid solubility, ISA and CYP2D6 enzyme metabolism – and fall risk. The results of the studies were combined using meta-analyses. Results: In total 2917 participants encountered a fall during a total follow-up time of 89 529 years. Meta-analysis indicated no association between use of any β-blocker, compared to nonuse, and fall risk, hazard ratio (HR) = 0.97 [95% confidence interval (CI) 0.88–1.06]. Use of a selective β-blocker was also not associated with fall risk, HR = 0.92 (95%CI 0.83–1.01). Use of a nonselective β-blocker was associated with an increased fall risk, HR = 1.22 (95%CI 1.01–1.48). Other β-blocker characteristics including lipid solubility and CYP2D6 enzyme metabolism were not associated with fall risk. Conclusion: Our study suggests that use of a nonselective β-blocker, contrary to selective β-blockers, is associated with an increased fall risk in an older population. In clinical practice, β-blockers hav