ABSTRACT
BACKGROUND: The effects of intermittent, high dose vitamin D treatment in older adults have not been documented. We conducted a meta-analysis to provide a quantitative assessment of the efficiency of intermittent, high dose vitamin D treatment on falls, fractures, and mortality among older adults. METHODS: Electronic databases were searched for randomized controlled trials (RCTs) on high dose, intermittent vitamin D supplementation among older adults. Two researchers independently screened the literature according to specified inclusive and exclusive criteria to extract the data. Meta-analysis was performed by using Review Manager 5.1.0 software. RESULTS: Nine trials were included in this meta-analysis. High dose, intermittent vitamin D therapy did not decrease all-cause mortality among older adults. The risk ratio (95% CI) was 1.04 (0.91-1.17). No benefit was seen in fracture or fall prevention. The risk ratio for hip fractures (95% CI) was 1.17 (0.97-1.41) while for non-vertebral fractures (95% CI) it was 1.06 (0.91-1.22), and the risk ratio for falls (95% CI) was 1.02 (0.96-1.08). Results remained robust after sensitivity analysis. CONCLUSION: Supplementation of intermittent, high dose vitamin D may not be effective in preventing overall mortality, fractures, or falls among older adults. The route of administration of vitamin D supplements may well change the physiological effects.
Subject(s)
Dietary Supplements , Fractures, Bone/epidemiology , Vitamin D/administration & dosage , Accidental Falls/prevention & control , Aged , Aged, 80 and over , Female , Fractures, Bone/drug therapy , Fractures, Bone/etiology , Humans , Male , Mortality , Odds Ratio , Publication Bias , Qualitative ResearchABSTRACT
AIM: To study the effect of ginkgolide B from Ginkgo leave on action potential (AP), L-type calcium current (I(Ca) - L) and delayed rectifier potassium current (I(K)) in normal and ischemic guinea pig ventricular myocytes. METHODS: With the standard microelectrode technique to record action potential and whole-cell variant patch-clamp technique to record calcium and potassium current. RESULTS: (1) Under normal condition, ginkgolide B shortened APD and had no effect on RP, AP and V(max). Ginkgolide B also increased I(K) in a concentration dependent manner and had no significant effect on I(Ca) - L (2) Under ischemia condition, it was observed that shortening of APD, APA, decrease V(max) and depolarization of RP was induced by ischemia, but ginkgolide B could attenuate above--mentioned changes. (3) Under ischemia condition, I(Ca) - L and I(K) were inhibited, perfusion with ischemia solution containing ginkgolide B could reverse the decrease of I(Ca) - L and I(K). CONCLUSION: Ginkgolide B had protective effect on ischemic myocardium to prevent ischemic arrhythmia.
