E associations of genetic variants, intermediate phenotypes, and disease status has been increasingly utilized to inform causal inference in observational studies [59]. However, we are not aware of such studies investigating associations of both adipokine levels and genetic variants relevant to adipokine levels with GDM risk using Mendelian randomization analysis approach. The strengths of this systematic review include comprehensive literature search and meticulous protocol for study selection and data analysis. There are several limitations. First, prospective studies of adipokines and GDM risk among non-Caucasian populations are sparse. This limited the capacity of exploring the adipokines-GDM association by race/ ethnicity groups. Compared with Caucasian women, Asian, Hispanic, and Native American women have an increased risk of GDM [3]. In addition, the associations between adipokines and insulin sensitivity varied by race/ethnicity [60]. Future studies among non-Caucasian populations are warranted. Second, the number of included studies for most adipokines was small. Even for adiponectin and leptin, the pooled sample size was limited. Thus it may compromise the statistical power of the meta-analysis. Although the statistical test showed no indication of publication bias for the two adipokines included in the meta-analysis, we cannot rule out the possibility of publication bias due to the small number of studies.Author Manuscript Author Manuscript Author Manuscript Author Manuscript5. ConclusionsIn summary, in this systematic review, we observed that adiponectin levels in the first or second trimester of pregnancy are lower among pregnant women who later develop GDM than non-GDM women, whereas leptin levels are Pyrvinium pamoate web higher. Future studies are warranted to clarify the association of other adipokines and GDM. Moreover, well-designed prospective studies with longitudinal assessment of adipokines during pregnancy are needed to understand the trajectories and dynamic associations of adipokines with GDM risk.Metabolism. Author manuscript; available in PMC 2016 June 01.Bao et al.PageSupplementary MaterialRefer to Web version on PubMed Central for supplementary material.Author Manuscript Author Manuscript Author Manuscript Author ManuscriptAcknowledgmentsFunding: This work was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (to C.Z., W.B., and M.K.), research grants R01-DK-062290 (to S. L.), R01-DK-58845 and R01-DK-088078 (to Y.S.) from the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health.AbbreviationsADA AFABP BMI EIA GDM IADPSG IL-6 RBP4 RIA SD SMD T2DM TNF- WHO WMD American Diabetes Association adipocyte fatty acid-binding protein body mass index enzyme immunoassays Gestational diabetes mellitus International Association of the Diabetes and Pregnancy Study Groups interleukin-6 retinol binding protein 4 radioimmunoassay standard deviation standardized mean LY317615 web difference type 2 diabetes mellitus tumor necrosis factor- World Health Organization weighted mean difference
HHS Public AccessAuthor manuscriptJ R Anthropol Inst. Author manuscript; available in PMC 2015 April 08.Published in final edited form as: J R Anthropol Inst. 2014 December 1; 20(4): 711?27. doi:10.1111/1467-9655.12131.Author Manuscript Author Manuscript Author Manuscript Author ManuscriptFlexible kinship: caring for AIDS orphans in rural LesothoEllen Blo.E associations of genetic variants, intermediate phenotypes, and disease status has been increasingly utilized to inform causal inference in observational studies [59]. However, we are not aware of such studies investigating associations of both adipokine levels and genetic variants relevant to adipokine levels with GDM risk using Mendelian randomization analysis approach. The strengths of this systematic review include comprehensive literature search and meticulous protocol for study selection and data analysis. There are several limitations. First, prospective studies of adipokines and GDM risk among non-Caucasian populations are sparse. This limited the capacity of exploring the adipokines-GDM association by race/ ethnicity groups. Compared with Caucasian women, Asian, Hispanic, and Native American women have an increased risk of GDM [3]. In addition, the associations between adipokines and insulin sensitivity varied by race/ethnicity [60]. Future studies among non-Caucasian populations are warranted. Second, the number of included studies for most adipokines was small. Even for adiponectin and leptin, the pooled sample size was limited. Thus it may compromise the statistical power of the meta-analysis. Although the statistical test showed no indication of publication bias for the two adipokines included in the meta-analysis, we cannot rule out the possibility of publication bias due to the small number of studies.Author Manuscript Author Manuscript Author Manuscript Author Manuscript5. ConclusionsIn summary, in this systematic review, we observed that adiponectin levels in the first or second trimester of pregnancy are lower among pregnant women who later develop GDM than non-GDM women, whereas leptin levels are higher. Future studies are warranted to clarify the association of other adipokines and GDM. Moreover, well-designed prospective studies with longitudinal assessment of adipokines during pregnancy are needed to understand the trajectories and dynamic associations of adipokines with GDM risk.Metabolism. Author manuscript; available in PMC 2016 June 01.Bao et al.PageSupplementary MaterialRefer to Web version on PubMed Central for supplementary material.Author Manuscript Author Manuscript Author Manuscript Author ManuscriptAcknowledgmentsFunding: This work was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (to C.Z., W.B., and M.K.), research grants R01-DK-062290 (to S. L.), R01-DK-58845 and R01-DK-088078 (to Y.S.) from the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health.AbbreviationsADA AFABP BMI EIA GDM IADPSG IL-6 RBP4 RIA SD SMD T2DM TNF- WHO WMD American Diabetes Association adipocyte fatty acid-binding protein body mass index enzyme immunoassays Gestational diabetes mellitus International Association of the Diabetes and Pregnancy Study Groups interleukin-6 retinol binding protein 4 radioimmunoassay standard deviation standardized mean difference type 2 diabetes mellitus tumor necrosis factor- World Health Organization weighted mean difference
HHS Public AccessAuthor manuscriptJ R Anthropol Inst. Author manuscript; available in PMC 2015 April 08.Published in final edited form as: J R Anthropol Inst. 2014 December 1; 20(4): 711?27. doi:10.1111/1467-9655.12131.Author Manuscript Author Manuscript Author Manuscript Author ManuscriptFlexible kinship: caring for AIDS orphans in rural LesothoEllen Blo.