Semba RD, et al. - In older community-dwelling adults, researchers identified plasma metabolites associated with altered glucose metabolism and insulin resistance. They found that targeted metabolomics identified four plasma amino acids and 16 plasma lipid species, primarily containing polyunsaturated fatty acids, that were related to abnormal glucose metabolism and insulin resistance in older adults.

Methods

• Using a targeted metabolomics approach, researchers identified plasma metabolites related to impaired fasting plasma glucose, 2-hour plasma glucose on oral glucose tolerance testing, and homeostatic model assessment insulin resistance (HOMA-IR) in 472 participants who partook in the Baltimore Longitudinal Study of Aging, with a mean (standard deviation) age of 70.7 (9.9) years.

Results

• A total of 143 plasma metabolites were measured.
• In ordinal logistic regression analyses, using a false discovery rate of 5% and adjusting for potential confounders, results showed that alanine, glutamic acid, and proline were significantly related to increased odds of abnormal fasting plasma glucose.
• It was noted that phosphatidylcholine (diacyl C34:4, alkyl-acyl C32:1, C32:2, C34:2, C34:3, and C36:3) was correlated with decreased odds of abnormal fasting plasma glucose.
• Data reported that glutamic and acid phosphatidylcholine alkyl-acyl C34:2 were related to increased and decreased odds of 2-hour plasma glucose, respectively.
• Findings suggested an association of glutamic acid with increased odds of higher tertiles of HOMA-IR.
• The outcomes highlighted that glycine; phosphatidylcholine (diacyl C32:0, alkyl-acyl C32:1, C32:2, C34:1, C34:2, C34:3, C36:2, C36:3, C40:5, C40:6, C42:3, C42:4, and C42:5); sphingomyelin C16:0, C24:1, and C26:1; and lysophosphatidylcholine C18:1 were related to diminished odds of abnormal HOMA-IR.