The Durk Pearson & Sandy Shaw®
Life Extension NewsTM
Volume 12 No.
5 • October 2009
Co-Association Between Insulin Sensitivity and Measures of Liver Function
This interesting recent study reports on the relationship in apparently healthy men (472 men free of coronary heart disease and diabetes and taking no blood pressure-, lipid-, or uric acid-lowering medication) of various measures of liver function and insulin sensitivity. This could be a useful way to help evaluate one’s insulin sensitivity with simple blood tests.
Insulin sensitivity S1 was determined using “the minimal model of glucose disappearance.” The insulin sensitivity was found to correlate independently with serum gamma-glutamyl transferase (GGT), aspartate transaminase, and alkaline phosphatase activities; blood pressure; leukocyte count; and erythrocyte sedimentation rate.
The authors explain that there is a difference between correlation and clustering of risk factors. “For example, dyslipidemia and hypertension may both be associated with insulin resistance, but processes underlying their associations could be shared or separate. Evaluation of simple correlation will not discriminate which alternative predominates, whereas this can be achieved by an assessment of co-association. Co-association will be present when high or low levels of a particular combination of risk factors show a strong tendency to be present together [clustering] in individuals.” “In apparently healthy men, blood pressure and indices of subclinical inflammation do not cluster with other insulin resistance-related risk factors, despite correlating with insulin sensitivity. In contrast, both GGT activity and uric acid concentrations correlated with insulin sensitivity and co-associated with insulin resistance-related risk factors and are therefore components of a true risk factor cluster.”
“Among inflammation-related variables, S1 was a significant independent negative determinant of serum globulin concentration, ESR, and WBC.” “Among liver function-related variables, S1 was a significant independent negative determinant of GGT, AST, and ALP activities and of uric acid concentrations and was an independent positive determinant of serum bilirubin concentration.”
- Godsland and Johnston. Co-association between insulin sensitivity and measures of liver function, subclinical inflammation, and hematology. Metab Clin Exp 57:1190-7 (2008).