Cigarette smoking and risk of gestational diabetes: a systematic review of observational studies

<p>Abstract</p> <p>Background</p> <p>Gestational diabetes is a prevalent disease associated with adverse outcomes of pregnancy. Smoking as been associated with glucose intolerance during pregnancy in some but not all studies. Therefore, we aimed to systematically review all epidemiological evidence to examine the association between cigarette smoking during pregnancy and risk of developing gestational diabetes mellitus.</p> <p>Methods</p> <p>We conducted a systematic review of articles published up to 2007, using PubMed, Embase, LILACS e CINAHL to identify the articles. Because this review focuses on studies of smoking during pregnancy, we excluded studies evaluating smoking outside pregnancy. Two investigators independently abstracted information on participant's characteristics, assessment of exposure and outcome, and estimates for the association under study. We evaluated the studies for publication bias and performed heterogeneity analyses. We also assessed the effect of each study individually through sensitivity analysis.</p> <p>Results</p> <p>We found and critically reviewed 32 studies, of which 12 met the criteria for inclusion in the review. Most of the studies provided only unadjusted measurements. Combining the results of the individual studies, we obtained a crude odds ratio of 1.03 (99% CI 0.85–1.25). Only 4 studies presented adjusted measurements of association, and no association was found when these alone were analyzed (OR 0.95; 99% CI 0.85–1.07). Subgroup analysis could not be done due to small sample size.</p> <p>Conclusion</p> <p>The number of studies is small, with major heterogeneity in research design and findings. Taken together, current data do not support an association between cigarette smoking during pregnancy and the risk of gestational diabetes.</p

Vitamin D-binding protein as it is understood in 2016: is it a critical key with which to help to solve the calcitriol conundrum?

Background The misnamed ‘vitamin’ D is actually the hormone calcitriol (1,25 dihydroxyhydroxyvitamin D). It has a central regulatory role in calcium metabolism, and more widely in the immune system. The prohormone calcifediol (25 hydroxyvitamin D) is more easily measured in the laboratory and is the analyte used in reference interval formulation. Being highly lipid soluble, both calcifediol and calcitriol travel in the bloodstream on carriage proteins, principally on vitamin D-binding protein. Summary This review reports our current understanding of vitamin D-binding protein. Its genetic determinants and their effect on it and secondarily on calcifediol concentrations and assays are described. Its complex interplay with parathyroid hormone is considered. The analytical state of the art is translated into the challenge it imposes clinically, in the formulation of reference intervals and in their use in advising and managing patients. Several recent challenges thrown up to laboratories by percipient clinicians highlight the dilemma vitamin D-binding protein poses. A way forward is suggested. </jats:sec