Effects of trans fatty acids on glucose homeostasis: a meta-analysis of randomized, placebo-controlled clinical trials.
BACKGROUND
Although evidence from cohort studies has suggested that trans fatty acid (TFA) consumption may be associated with insulin resistance and diabetes, randomized placebo-controlled trials (RCTs) have yielded conflicting results.


OBJECTIVE
In a meta-analysis, we combined all available RCTs that examined the role of TFA intake on glucose homeostasis.


METHODS
A systematic review of PubMed was performed, and a total of 7 RCTs were included in the meta-analysis. Primary outcomes were glucose and insulin concentrations. Secondary outcomes were total, LDL-, and HDL-cholesterol and triglyceride concentrations. The pooled effect size (ES) was calculated through fixed- and random-effects meta-analyses. The potential existence of publication bias was evaluated by using funnel-plot analysis. Metaregression analysis was performed to evaluate for potential dose-response relations between the ES of outcomes and TFA intake.


RESULTS
Increased TFA intake did not result in significant changes in glucose or insulin concentrations. Increased TFA intake led to a significant increase in total and LDL-cholesterol [ES (95% CI): 0.28 (0.04, 0.51) and 0.36 (0.13, 0.60), respectively] and a significant decrease in HDL-cholesterol concentrations [ES (95% CI): -0.25 (-0.48, -0.01)]. Our analysis also showed the absence of publication bias and any dose-response relations between the ES and TFA intake.


CONCLUSIONS
Increased TFA intake does not result in changes in glucose, insulin, or triglyceride concentrations but leads to an increase in total and LDL-cholesterol and a decrease in HDL-cholesterol concentrations. There is no evidence to support a potential benefit of the reduction of dietary TFA intake on glucose homeostasis.
Section of Endocrinology, Department of Internal Medicine, VA Boston Healthcare System, Boston, MA, USA.
Konstantinos N
KN
Aronis
Sami M
SM
Khan
Christos S
CS
Mantzoros
D002784:Cholesterol / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006706:Homeostasis / Q000187:drug effects; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D016032:Randomized Controlled Trials as Topic; D044242:Trans Fatty Acids / Q000008:administration & dosage*; D014280:Triglycerides / Q000378:metabolism
D007328:Insulin; D044242:Trans Fatty Acids; D014280:Triglycerides; D002784:Cholesterol; D005947:Glucose