Bmc Med
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Considerable controversy exists regarding the association between dietary calcium intake and risk of mortality from cardiovascular disease and all causes. Therefore, we performed a meta-analysis of prospective cohort studies to examine the controversy. ⋯ This meta-analysis of prospective cohort studies suggests that dietary calcium intake is associated with cardiovascular mortality in a U-shaped manner and that high dietary calcium intake (>900 mg/day) is not associated with a decreased risk of all-cause mortality.
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Comparative Study
An international comparison of deceased and living organ donation/transplant rates in opt-in and opt-out systems: a panel study.
Policy decisions about opt-in and opt-out consent for organ donation are based on limited evidence. To fill this gap we investigated the difference between deceased and living organ donation rates in opt-in and opt-out consent systems across a 13 year period. We controlled for extensive covariates and estimated the causal effect of consent with instrumental variables analysis. ⋯ While the number of deceased donors is higher than the number of living donors, opt-out consent leads to a relative increase in the total number of livers and kidneys transplanted.
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Review Meta Analysis
The association between dietary factors and gestational hypertension and pre-eclampsia: a systematic review and meta-analysis of observational studies.
Dietary factors have been suggested to play a role in the prevention of hypertensive disorders of pregnancy (HDP), including gestational hypertension and pre-eclampsia, but inconsistent findings have been reported. A systematic review and meta-analyses were performed to synthesize evidence from observational studies of reproductive-aged women on the association between dietary factors and HDP. ⋯ Based on a limited number of studies, higher total energy and lower magnesium and calcium intake measured during pregnancy were identified as related to HDP. Further prospective studies are required to provide an evidence base for development of preventive health strategies, particularly focusing on dietary factors during pre-pregnancy and early pregnancy.
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Pre-eclampsia is a common pregnancy related condition, which contributes significantly both to maternal and perinatal morbidity and mortality. The precise pathophysiology of pre-eclampsia is uncertain, and the development of effective preventive strategies remains elusive. Schoenaker and colleagues conducted a systematic review and meta-analysis of observational studies reporting dietary intake and dietary patterns. ⋯ This is in contrast to the findings of systematic reviews and meta-analyses of randomised trials in pregnancy evaluating calcium supplementation and anti-oxidant vitamin C and E supplementation. The validity of any systematic review is reliant on both the underlying methodology and the quality of each of the included studies; the review by Schoenaker and colleagues is limited by the observational nature of the included studies. Please see related article: http://www.biomedcentral.com/1741-7015/12/157/abstract.
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Considerable controversy exists regarding the relation between maternal caffeine intake during pregnancy and risk of low birth weight (birth weight <2,500 g). We aim to assess this association using a systematic review and dose-response meta-analysis of prospective studies. ⋯ Higher maternal caffeine intake during pregnancy was associated with a higher risk of delivering low birth weight infants. These findings support recommendations to restrict caffeine intake during pregnancy to low levels.