Comparisons of the iron deficient metabolic response in rats fed either an AIN-76 or AIN-93 based diet

Abstract

BackgroundPrevious studies examining the metabolic consequences of dietary iron deficiency have reported elevated serum glucose concentrations in iron-deficient animals. Importantly, the majority of these findings were observed using an earlier version of a laboratory animal diet (AIN-76A) in which the primary carbohydrate source was sucrose – a disaccharide known to negatively impact both glucose and lipid homeostasis. The AIN-76A diet formula was improved in 1993 (AIN-93) to optimize animal nutrition with a major change being the substitution of cornstarch for sucrose. Therefore, we sought to examine the effects of iron deficiency on steady-state glucose homeostasis and the hepatic expression of glucose- and lipid-related genes in rats fed an iron-deficient diet based on either an AIN-76A or AIN-93 diet.MethodsThe study design consisted of 6 treatment groups: control (C; 40 mg Fe/kg diet), iron deficient (ID; ≤ 3 mg Fe/kg diet), or pair-fed (PF; 40 mg Fe/kg) fed either an AIN-76A or AIN-93 diet for 21 d. Hemoglobin and hematocrit were measured in whole blood. Serum insulin and cortisol were measure by ELISA. Serum glucose and triacylglycerols were measured by standard colorimetric enzyme assays. Alterations in hepatic gene expression were determined by real-time qPCR.ResultsHemoglobin and hematocrit were significantly reduced in both ID groups compared to the C and PF groups. Similarly, animals in the both ID groups exhibited elevated steady-state levels of blood glucose and insulin, and significantly decreased levels of circulating cortisol compared to their respective PF controls. Serum triacyglycerols were only increased in ID animals consuming the AIN-76A diet. Hepatic gene expression analyses revealed a ~4- and 3-fold increase in the expression of glucokinase and pyruvate dehydrogenase kinase-4 mRNA, respectively, in the ID group on either diet compared to their respective PF counterparts. In contrast, the expression of lipogenic genes was significantly elevated in the AIN-76 ID group, while expression of these genes was unaffected by iron status in the AIN-93 ID group.ConclusionsThese results indicate that an impaired iron status is sufficient to alter glucose homeostasis, though alterations in lipid metabolism associated with ID are only observed in animals receiving the AIN-76A diet.

Association of Serum Ferritin with Risk of Anemia in Non-Diabetic Adolescents with Family History of Type 2 Diabetes Mellitus

“…19 however a study found that altered status of iron is enough to impair homeostasis of glucose. 20 Diet and physical activity are not only aimed for weight reduction but also have a role in boosting immunity including (immune activation and immune-senescence) and metabolism (obesity, diabetes, and metabolic syndrome). 21 Consumption of fresh foods, eggs and consuming meals 3 times / day were also related to lower risk of anemia.…”

Iron Homeostasis and Diabetes Risk

“…However, other studies, in the moderate in¬duction of iron deficiency in ro¬dents are sufficient to disrupt normal metabolic homeostasis, to cause glucose and insulin elevations in both steady-state levels with the basal diet for-mulation in the IDanimals. High cortisol secretion, the secondary of the stress of anemia status, is not responsible for the hyperglycemia, while hyperglycemia was associated with de¬crease cortisol levels in the ID-animals [104][105][106][107][108][109].…”

“…However, in the non-severe hemoglobin reductions are not correlated with hyperglycemia and hyperlipidemia. These findings may suggest that these may have a certain threshold exists in order to develop these potentially negative meta¬bolic consequences [103][104][105][106]. However, other studies, in the moderate in¬duction of iron deficiency in ro¬dents are sufficient to disrupt normal metabolic homeostasis, to cause glucose and insulin elevations in both steady-state levels with the basal diet for-mulation in the IDanimals.…”

Iron-Enriched Nutritional Supplements for the 2030 Pharmacy Shelves

“…Ulva polysaccharides conjugated with iron ions can effectively rescue mice from artificially induced anemia [165]. Moreover, Ulva polysaccharides-iron molecules raised B and T cell levels to a number comparable to control animals [166].…”