Nine Amino Acids are Associated with Decreased Insulin Secretion and Elevated Glucose Levels in a 4.6-Year Follow-Up Study of 5,181 Finnish Men
Several amino acids have been shown to be associated with insulin resistance and increased risk of type 2 diabetes, but none of previous studies has investigated the association of amino acids with insulin secretion in a longitudinal setting. Our study included 5181 participants of the cross-sectional METabolic Syndrome In Men study having metabolomics data on twenty amino acids. A total of 4851 of them had a 4.6-year follow-up visit. Nine amino acids (phenylalanine, tryptophan, tyrosine, alanine, isoleucine, leucine, valine, aspartate and glutamate) were significantly ( P -5 ) associated with decreases in insulin secretion (Disposition index) and the elevation of fasting or 2 hour glucose levels. Five of these amino acids (tyrosine, alanine, isoleucine, aspartate and glutamate) were also found to be significantly associated with an increased risk of incident type 2 diabetes after adjustment for confounding factors. Our study is the first population-based large cohort to report that amino acids are not only associated with insulin resistance but also with decreased insulin secretion.