Abstract
Salivary amylase initiates the digestion of starch and it has been hypothesized that salivary amylase may play a role in the development of insulin resistance and type 2 diabetes. The aim was to examine the interaction between copy number variation in the salivary amylase gene AMY1 and starch intake. We studied 3,624 adults without diabetes or elevated blood glucose in the Malmö Diet Cancer cohort. We assessed the associations and interactions between starch intake, AMY1 copies and glucose homeostasis traits (i.e., fasting plasma glucose, insulin and HOMA-IR) and risk of type 2 diabetes over an average of 18 follow-up years. AMY1 copy number was not associated with glucose, insulin or HOMA-IR. We observed a significant interaction between starch intake and AMY1 copies on insulin and HOMA-IR after adjusting for potential confounders (p < 0.05). The inverse association between starch intake and insulin and HOMA-IR was stronger in the group with 10 or more copies (Ptrend < 0.001). In addition, we observed an inverse association between starch intake and type 2 diabetes in the group with 10 or more copies (ptrend = 0.003), but not in the other groups. This cross-sectional observational study suggests that AMY1 copy numbers might interact with starch intake on glucose homeostasis traits. Interventional studies are required to determine whether individuals with high AMY1 copy numbers may benefit from a high starch intake.
Highlights
Salivary α-amylases cleaves starch molecules into smaller saccharides that are further digested by pancreatic α-amylases in the gut
It has been hypothesized that salivary amylase may play a role in the development of insulin resistance and type 2 diabetes [7]; observational studies in large cohorts investigating the association between AMY1 copy number variation (CNV) and glucose homeostasis traits are limited
Because of the suggested importance of salivary amylase levels for glucose homeostasis, we aimed to explore the association between AMY1 CNV and levels of fasting plasma glucose, plasma insulin and estimated insulin resistance based on the homeostasis model assessment (HOMA-IR) and risk of type 2 diabetes and whether there is an interaction between AMY1 CNV and starch intake on these traits
Summary
Salivary α-amylases cleaves starch molecules into smaller saccharides that are further digested by pancreatic α-amylases in the gut. Individuals with low copy numbers of AMY1 have lower salivary amylase levels and might have a decreased capacity to metabolize starch into glucose. It has been hypothesized that salivary amylase may play a role in the development of insulin resistance and type 2 diabetes [7]; observational studies in large cohorts investigating the association between AMY1 CNV and glucose homeostasis traits are limited. Low AMY1 copy numbers have been associated with an increased obesity risk in European and Asian populations [11,12,13,14,15]. Because of the suggested importance of salivary amylase levels for glucose homeostasis, we aimed to explore the association between AMY1 CNV and levels of fasting plasma glucose, plasma insulin and estimated insulin resistance based on the homeostasis model assessment (HOMA-IR) and risk of type 2 diabetes and whether there is an interaction between AMY1 CNV and starch intake on these traits
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
