Effect of TCF7L2 on the relationship between lifestyle factors and glycemic parameters: a systematic review.
Study Goal
The researchers aimed to determine whether Artichoke Extract (ALE) supplementation could improve insulin resistance and glycemic parameters in individuals with the TT genotype of the rs7903146 variant of TCF7L2.
Results Summary
Two RCTs found that ALE supplementation significantly decreased insulin concentration and improved insulin resistance in the TT genotype of the rs7903146 variant of TCF7L2. However, the broader study context showed mixed results regarding TCF7L2's modification effects on glycemic parameters in response to lifestyle factors.
Population
Individuals with the TT genotype of the rs7903146 variant of TCF7L2 (specific to insulin resistance and glycemic parameters).
Effective Dosage
Not specified
Duration
Not specified
Interactions
None mentioned
| Intervention | Direction | Endpoint | Population | Dosage | Impact | Claim # |
|---|---|---|---|---|---|---|
diet (fatty acids and fiber) | neutral | insulin resistance | participants with non-diabetes | - | modified the association | #1 |
consumption of meals with different percentages of total dietary fat | increase | glucose concentrations | healthy risk-allele carriers | - | increased | #2 |
consumption of meals with different percentages of total dietary fat | decrease | insulin sensitivity | healthy risk-allele carriers | - | impaired | #3 |
dietary intervention involving different macronutrients | no change | glycemic parameters | - | - | did not modify | #4 |
weight loss dietary | decrease | serum glucose levels | non-risk allele subjects with overweight/obesity | - | decreased | #5 |
weight loss dietary | decrease | insulin levels | non-risk allele subjects with overweight/obesity | - | decreased | #6 |
weight loss dietary | decrease | insulin resistance | non-risk allele subjects with overweight/obesity | - | improved | #7 |
artichoke extract supplementation (ALE) | decrease | insulin concentration | the TT genotype of the rs7903146 variant of TCF7L2 | - | significantly decreased | #8 |
artichoke extract supplementation (ALE) | decrease | insulin resistance | the TT genotype of the rs7903146 variant of TCF7L2 | - | improved | #9 |
physical activity levels | neutral | glycemic parameters | - | - | modified the association | #10 |
smoking status | neutral | glycemic parameters | - | - | modified the association | #11 |
physical activity | no change | glycemic parameters | participants with different levels of physical activity | - | observed no effect | #12 |
smoking status | no change | glycemic parameters | participants with different levels of smoking status | - | observed no effect | #13 |
BACKGROUND: Among candidate genes related to type 2 diabetes (T2DM), one of the strongest genes is Transcription factor 7 like 2 (TCF7L2), regarding the Genome-Wide Association Studies. We aimed to conduct a systematic review of the literature on the modification effect of TCF7L2 on the relation between glycemic parameters and lifestyle factors. METHODS: A systematic literature search was done for relevant publications using electronic databases, including PubMed, EMBASE, Scopus, and Web of Science, from January 1, 2000, to November 2, 2021. RESULTS: Thirty-eight studies (16 observational studies, six meal test trials, and 16 randomized controlled trials (RCTs)) were included. Most observational studies had been conducted on participants with non-diabetes showing that TCF7L2 modified the association between diet (fatty acids and fiber) and insulin resistance. In addition, findings from meal test trials showed that, compared to non-risk-allele carriers, consumption of meals with different percentages of total dietary fat in healthy risk-allele carriers increased glucose concentrations and impaired insulin sensitivity. However, ten RCTs, with intervention periods of less than ten weeks and more than one year, showed that TCF7L2 did not modify glycemic parameters in response to a dietary intervention involving different macronutrients. However, two weight loss dietary RCTs with more than 1-year duration showed that serum glucose and insulin levels decreased and insulin resistance improved in non-risk allele subjects with overweight/obesity. Regarding artichoke extract supplementation (ALE), two RCTs observed that ALE supplementation significantly decreased insulin concentration and improved insulin resistance in the TT genotype of the rs7903146 variant of TCF7L2. In addition, four studies suggested that physical activity levels and smoking status modified the association between TCF7L2 and glycemic parameters. However, three studies observed no effect of TCF7L2 on glycemic parameters in participants with different levels of physical activity and smoking status. CONCLUSION: The modification effects of TCF7L2 on the relation between the lifestyle factors (diet, physical activity, and smoking status) and glycemic parameters were contradictory. PROSPERO REGISTRATION NUMBER: CRD42020196327.