Sunday, April 3, 2011

Ironclad Liver Hampers Insulin Sensitivity: Association Between Hepatic Iron Load and Insulin Resistance Discovered

"Insulin resistance", "insulin sensitivity", etc. Type in these key words and find 4.000.000 +1 results on Google. I want to focus on the +1 here and briefly report the results of a study (Haap. 2011) coming from the University of Thübingen, Germany.

Via magnetic resonance gradient echo imaging technique Michael Haap and his colleges assessed the iron load in the livers of of 113 healthy nondiabetic subjects [69 females, 44 males; age 47 ± 1 yr; body mass index (BMI) = 28.9 ± 0.5 kg/m2], who were "at increased risk for type 2 diabetes". Various statistical analysis of their data revealed that:
[Hepatic iron levels] adjusted for age negatively associated with serum ferritin levels (P < 0.0001) and positively associated with IS [insulin resistance] (P = 0.009). In addition, T2* values [indicator of hepatic iron load] associated with LF [liver fat] (P = 0.008) but not with BMI (P = 0.6). In a multivariate model, IS adjusted for gender, age, and BMI was associated with T2* values (P = 0.015). IS adjusted for gender and age was independently associated with LF (P = 0.033) and T2* values (P = 0.004). In a stepwise regression analysis, LF explained 13.5% (P < 0.01) of the variation in IS, and HIL [hepatic iron load] explained an additional 4.1% (P = 0.03).
With 4.1% the contribution of iron to the development of type II diabetes is certainly only one out of a multitude of factors. I would yet still be interested in further information on the interplay of iron, insulin and blood glucose, also because low ferritin levels, which, according to the study, go hand in hand with high hepatic iron loads, have also been implicated in other metabolic disorders such as hypothyroidism, which in and out of itself would further aggravate existing blood sugar and weight issues within the pre-diabetic study population.