Table 1.

Summary of Environmental Factors Associated With Changes in Glucose and Insulin Metabolism

Author and Citation	Primary Finding	Study Type/Design	Covariates	Limitations
Pories and Dohm 2012 [27]	Fasting insulin rises from normal glucose tolerance lean subjects to normal glucose tolerance subjects with obesity to subjects with T2D Hyperinsulinemia corrects rapidly to normal levels after bariatric surgery	Review	NA	Mechanisms for metabolic improvements following bariatric surgery remain unclear
Corkey 2012 [28]	Large numbers of environmental chemicals are detectable in food and human serum, but evidence is lacking on their effects on metabolic health	Review	NA	Further research is necessary to validate and confirm mechanisms
Corkey 2012 [29]	In cultured INS-1 cells, monooleoylglycerol, saccharin, aspartame, sucralose, and iron stimulated insulin secretion	Review	NA	Translational work is needed to validate these in vitro findings
Chen et al. 2016 [30]	Air pollution exposure is associated with increases in fasting glucose and insulin	Cohort	Socioeconomic status, age, sex, percent body fat	Residual confounding
Kim et al. 2018 [31]	Early life near roadway air pollution exposure is associated with greater increases in BMI and higher attained BMI at age 10 y	Cohort	Age, sex, race/ethnicity, parental education, language	Unclear mechanism Residual confounding possible
Stahlhut et al. 2019 [32]	Acute bisphenol A exposure is associated with an increase in disposition index	Crossover trial with OGTT and hyperglycemic clamp	NA given crossover design	Acute exposure, small sample size
Meeks et al. 2017 [33]	Differences in BMI and waist circumference account for a significant proportion of the geographical variation among sub-Saharan African subjects	Cross-sectional	Age, sex, family history of diabetes, anthropometrics, health-related behaviors, geographical location	Residual confounding

Abbreviation: NA, not applicable.