Glycemic Response after Starch Consumption in Relation to Salivary Amylase Activity and Copy-number Variation of AMY1 Gene

Gigliola Alberti¹, Javier Parada², L. Rodrigo Cataldo³, Javier Vega³, Concepción M. Aguilera⁴, Ana I. Alvarez-Mercado⁴, M. Isabel Hodgson^{1, 3}, Alberto López³, Isidora Angellotti³, Angel Gil⁴ and José L. Santos^3,

¹Department of Pediatric Gastroenterology and Nutrition, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile

²Instituto de Ciencia y Tecnología de los Alimentos (ICYTAL), Universidad Austral de Chile, Valdivia, Chile

³Department of Nutrition, Diabetes and Metabolism, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile

⁴Department of Biochemistry and Molecular Biology II, Institute of Nutrition and Food Technology, University of Granada, Spain

Cite this paper:
Gigliola Alberti, Javier Parada, L. Rodrigo Cataldo, Javier Vega, Concepción M. Aguilera, Ana I. Alvarez-Mercado, M. Isabel Hodgson, Alberto López, Isidora Angellotti, Angel Gil and José L. Santos. Glycemic Response after Starch Consumption in Relation to Salivary Amylase Activity and Copy-number Variation of AMY1 Gene. Journal of Food and Nutrition Research. 2015; 3(8):558-563. doi: 10.12691/jfnr-3-8-11

Abstract

Salivary amylase activity is partially determined by genetic factors and is possibly related with postprandial plasma glucose levels. The aim of this study is to evaluate the association of salivary amylase activity with plasma glucose and insulin levels after consumption of a gelatinized starchy model food (80% amylopectin; 70% gelatinization), as well as to assess the influence of the salivary amylase gene (AMY1) copy-number variation in amylase activity and concentration. Our results show a strong and significant relation between copy-number variation of AMY1 gene measured through qPCR with salivary amylase concentration, with an enhanced correlation with amylase activity when corrected by salivary flow (r = 0.83, P-value = 0.003). Subjects with high salivary amylase activity tend to have a higher early increase in plasma insulin concentration and a lower glycemic response after starch ingestion compared to subjects with low salivary amylase activity, although these observations did not achieve statistical significance (r = 0.41; P-value = 0.23). In conclusion, we found a strong association between copy-number of AMY1 gene with salivary amylase activity and concentration. However, we did not find evidences for a major role of salivary amylase activity on glycemic response after starch consumption.

Keywords:
amylase copy number variation starch glycemic response

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