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Objectives: The acute phase response (APR) influences indicators of iron status. A recent WHO/CDC consultation recommended concurrent measurement of [alpha]-1-acid-glycoprotein (AGP) in surveys to control for the APR, and aid in interpreting iron status. They proposed further exploratory analyses using AGP. We examined whether the APR (measured by AGP) influences the expected relationships between iron status indicators in an HIV-infected population. Subjects: We measured hemoglobin (Hb), serum ferritin (SF), transferrin receptor (TfR), erythropoietin (EPO) and AGP in a cross-sectional survey of 643 HIV-positive Zimbabwean women. Results: SF was significantly higher in APR-positive (AGP> 1 g/l) women (P Conclusions: AGP captured the influence of the APR on iron indicators and their relationships with each other. The APR influenced SF and its relationship with Hb as expected. TfR behaved unexpectedly. Although TfR has been promoted as an iron indicator that is uninfluenced by the APR, TfR concentrations were depressed among anemic APR-positive women. Because TfR reflects iron deficiency and erythropoietic activity, pro-inflammatory cytokines associated with the APR may be inhibiting erythropoeisis, which is reflected by lower TfR concentrations. We support the WHO/CDC recommendation that AGP is a useful indicator to assess the influence of the APR on iron status indicators. doi:10.1038/ejcn.2008.33; published online 28 May 2008 Keywords: acute phase response; AGP; iron status; SF; TfR; HIV, Introduction Despite considerable national, regional and global efforts targeted at the prevention of iron deficiency (ID), it remains among the most common nutritional problem in the world (WHO, 2001). In [...]

Background: Iron stores and haemoglobin iron deficits in menstruating women can be calculated from body iron losses and absorption of dietary iron using recently developed methods. Objective: To examine iron balance (iron status) expressed as body iron stores or haemoglobin iron deficites in menstruating women from amounts of iron lost (iron requirements) and amounts of dietary iron absorbed. Calculations are made both of stationary states and of the rate of changes in iron stores (iron status) when any of the two main factors determining iron balance are changed. Design: The study is based on (1) previous and new equations describing relationships between iron absorption, iron requirements (losses), iron stores and/or haemoglobin deficits and (2) published data on iron requirements and their variation in menstruating adult women. Results: Both iron stores and haemoglobin iron deficits are strongly related to iron requirements and absorption of dietary iron and follow the same equations during states of iron repletion and iron deficiency. When, for example, increasing or decreasing the bioavailability of the dietary iron, about 90% of the change in iron stores will occur within 1 y. Conclusions: There are strong relationships between iron requirements, bioavailability of dietary iron and amounts of stored iron. The observations that a reduction in iron stores and a calculated decrease of haemoglobin iron had the same increasing effect on iron absorption suggest that the control of iron absorption is mediated from a common cell, that may register both size of iron stores and hemoglobin iron deficit, eg the hepatocyte. Sponsorship: The Swedish Medical Research Council (project B96-19X-04721-21A), the Swedish Council for Forestry and Agriculture Research (50.0120/95 and 997/881, 113:3), the Swedish Dairy Association and The Danone International Prize for Nutrition 1999 (LH). Descriptors: iron absorption; diet; bioavailability; iron requirements; iron stores; iron deficiency; haemoglobin iron deficit; women; iron balance; serum ferritin; menstruation, Introduction Maintenance of iron balance, when absorption equals losses, is achieved by control of iron absorption since the body has no mechanisms to control iron losses. This was pointed out [...]