ABSTRACT
Background
Although hyperinsulinemia is assumed to be involved in brain carcinogenesis, data on the link between dietary insulin index (DII) and dietary insulin load (DIL) and risk of glioma are lacking.
Objective
The current study aimed to investigate the relation between DII and DIL and risk of glioma in a case–control study among Iranian adults.
Methods
In this hospital-based case–control study, 128 pathologically confirmed cases of glioma and 256 age and sex-matched controls were enrolled. Dietary intakes of study participants were assessed using a validated Block-format 123-item semi-quantitative FFQ. DII and DIL were computed using a published food insulin index (FII) data.
Results
A significant positive association was found between DIL and glioma (OR: 3.56; 95% CI: 1.85–6.58, P < 0.001); such that after controlling for potential confounders, participants in the highest quartile of DIL had 2.95 times greater odds of glioma than those in the lowest quartile (OR: 2.95; 95% CI: 1.40–6.24, Ptrend = 0.006). Furthermore, we observed a significant positive association between DII and glioma (OR: 2.65; 95% CI: 1.43–4.93, Ptrend = 0.001). This association remained significant even after considering energy intake (OR: 2.66; 95% CI: 1.43–4.95, Ptrend = 0.001). However, when further potential confounders were taken into account, this relationship became non-significant (OR: 1.87; 95% CI: 0.92–3.80, Ptrend = 0.03), despite a significant trend of increased odds ratios (P = 0.03).
Conclusions
In conclusion, we found a significant positive association between DIL and odds of glioma. DII was not significantly associated with odds of glioma after controlling for confounders.
Acknowledgments
The authors would like to thank authorities in Tehran University of Medical Sciences for financial support of the study.
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Funding
Notes on contributors
Javad Anjom-Shoae
Javad Anjom-Shoae has obtained his Bachelor of Science (Nutrition Science and Dietetics) from Isfahan University of Medical Sciences, Isfahan, in 2016 and is currently a M.Sc. candidate at the Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran. His research interest lies in investigating diet-disease associations, specifically with the aim of maintenance of physical and mental well-being as well as the prevention of chronic diseases such as cardiovascular disease.
Mehdi Shayanfar
Mehdi Shayanfar is a research associate at the Department of Clinical Nutrition and Dietetics, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Minoo Mohammad-Shirazi
Minoo Mohammad-Shirazi is a research associate at the Department of Clinical Nutrition and Dietetics, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Omid Sadeghi
Omid Sadeghi is a Ph.D. candidate at the Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
Giuve Sharifi
Giuve Sharifi is a research associate at the Department of Neurosurgery, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Fereydoun Siassi
Fereydoun Siassi is a professor (full) at the Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
Ahmad Esmaillzadeh
Ahmad Esmaillzadeh is a professor (full) at the Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran. His research goal is to develop and validate dietary strategies that effectively protect against obesity-associated chronic conditions, including metabolic syndrome, cardiovascular disease, gastrointestinal disease, psychological disorders, and different cancers.