TIBC Saturation Research Articles

Effect of ferrous fumarate on the iron status and physical work capacity of women

The effect of iron supplementation (ferrous fumarate) on the iron status and physical work capacity was studied in anaemic middle class Maharastrian women. It was observed that 60% of the subjects were suffering from mild to moderate iron deficiency anaemia. The serum iron, ferritin, TIBC and transferrin saturation levels in the anaemic subjects were not only significantly lower than the levels observed in the non anaemics, but also lower than the normal values. Although the calorie and nutrient intake of the two groups was observed to be similar, it was significantly lower than the RDA suggesting no association between the diet intake and blood parameters observed. The non-anaemics had significantly better scores on the Harvard step test (used to assess the physical work capacity) in comparison to the anaemic subjects. After iron supplementation not only was a significant increase in the haematological and biochemical parameters noted (Hb + 5g/dl, serum ferritin + 35.6 ng/ml, transferrin saturation + 16%, serum iron + 45.4 mcg/dl), but also the anaemics physical work performance showed significant improvement. The above values (after supplementation) were also found to be significantly higher than the non anaemic values.

Serum ferritin and iron status in a population of ‘healthy’ 85-year-old individuals

Iron status, including S-ferritin, S-iron, S-total iron binding capacity (TIBC), TIBC saturation, haemoglobin (Hb) and dietary iron intake, was assessed in a population study comprising 92 healthy 85-year-old subjects (32 males, 60 females). S-iron, S-TIBC, TIBC saturation and S-ferritin values were not significantly different in the two sexes. Males had a geometric mean S-ferritin of 130 micrograms/l, females of 98 micrograms/l. Ferritin levels less than 15 micrograms/l (i.e. depleted iron stores) were found in one female (1.6%); and in one male (3.1%), who in addition had iron deficiency anaemia. None of the females displayed latent iron deficiency (i.e. S-ferritin less than 15 micrograms/l and S-TIBC saturation less than 15%) or iron deficiency anaemia. Arithmetic mean Hb was 145 +/- 13 (SD) g/l (9.0 +/- 0.8 mmol/l) in males and 139 +/- 11 g/l (8.6 +/- 0.7 mmol/l) in females (p less than 0.02). Median nutritional iron intake was 10 mg/day (range 3-17), higher in males (median 12) than in females (median 9) (p less than 0.0001). Iron intake showed significant correlations to S-iron, S-TIBC and TIBC saturation, but not to S-ferritin.

Serum ferritin and iron status in a population of ‘healthy’ 85-year-old individuals

Iron status, including S-ferritin, S-iron, S-total iron binding capacity (TIBC), TIBC saturation, haemoglobin (Hb) and dietary iron intake, was assessed in a population study comprising 92 healthy 85-year-old subjects (32 males, 60 females). S-iron, S-TIBC, TIBC saturation and S-ferritin values were not significantly different in the two sexes. Males had a geometric mean S-ferritin of 130 (ig/1, females of 98 (ig/1. Ferritin levels <15 (j.g/1 (i.e. depleted iron stores) were found in one female (1.6%); and in one male (3.1%), who in addition had iron deficiency anaemia. None of the females displayed latent iron deficiency (i.e. S-ferritin <15 (ig/1 and S-TIBC saturation <15%) or iron deficiency anaemia. Arithmetic mean Hb was 145 ± 13 (SD) g/1 (9.0±0.8 mmol/l) in males and 139 ± 11 g/1 (8.6±0.7 mmol/l) in females (p<0.02). Median nutritional iron intake was 10 mg/day (range 3-17), higher in males (median 12) than in females (median 9) (p<0.0001). Iron intake showed significant correlations to S-iron, S-TIBC and TIBC saturation, but not to S-ferritin.

6 Diagnosis and clinical evaluation of iron overload

Diagnostic evaluation of the various forms of iron overload requires information about the total amount and distribution of iron stores. Direct information on the quantity of storage iron can be obtained only by its mobilization in response to repeated phlebotomy or after dilution of a labelled iron test dose in the total body iron pool. Both approaches are cumbersome and time-consuming and are suitable only for research purposes. Detailed information on the amount and distribution of tissue iron in iron overload can be obtained from biopsy specimens of the major iron storage organs such as the liver and bone marrow. However, the invasive nature of these procedures limits their clinical usefulness. Indirect measures, such as serum iron concentration, TIBC saturation, serum ferritin, chelate-induced urinary iron excretion or intestinal iron absorption, and ferrokinetic measurements may provide useful information on the amount of total body iron reserve. However, they all have important limitations in their diagnostic use for evaluating iron overload. The most suitable indirect storage iron index among these methods is the ferritin assay, which has a well established place in the diagnosis of iron overload and monitoring of the effect of therapy. Recent developments in physical methods such as CT, SQUID and NMR have significantly improved the applicability of these techniques for non-invasive measurement of liver iron. It is expected that quantitative measurement of hepatic iron stores will soon be integrated into the diagnostic procedures available by imaging techniques such as CT and NMR. In combination with screening parameters such as serum ferritin and TIBC saturation these new but expensive diagnostic tools may simplify and shorten the diagnostic process and may also be useful for monitoring the treatment of iron overload by phlebotomy or chelating drugs.

Screening for iron overload using transferrin saturation.

People with parenchymal iron overload exhibit an elevated serum iron concentration and a raised transferrin (TIBC) saturation early in the course of the disease. They can therefore be detected by simple laboratory tests before organ damage has occurred. In this study running for 2 months, 10512 samples from approximately 8750 patients and blood donors were examined in a county hospital in Central Sweden. Abnormal TIBC saturation (greater than 70%) was found in 1.7% of the samples. This abnormality was caused by physiological fluctuations in serum iron in 44%, liver disease in 22%, blood disorder in 10%, iron therapy in 10.5% and parenchymal iron overload in 11.5%. The diagnosis of iron overload was confirmed by measuring the serum ferritin concentration and by performing the desferrioxamine test, liver biopsy, quantitative phlebotomy and family studies including HLA typing. We found a prevalence of iron overload of 0.24%. This figure is almost certainly too low because some affected patients were probably lost because of TIBC desaturation induced by inflammatory conditions.

Prevalence of iron overload in central Sweden.

An increase in the iron content of food may be harmful to people with genetic hemochromatosis. We studied the prevalence of this disorder in Sweden, which is the country with the world's highest iron fortification of food. Serum ferritin and transferrin (TIBC) saturation levels were used as initial screening methods. Three (0.5%) of 623 males aged 30-39 years were found to have genetic hemochromatosis. Family studies revealed 10 additional homozygotic family members. A prevalence of 0.5% of homozygotes (q2) implies a gene frequency (q) of 6.9% or a heterozygote frequency (2 x Q) of 13.8%. The high gene frequency may be explained by a possible genetic advantage of heterozygotes in the past. We conclude that idiopathic hemochromatosis is not as rare as previously thought. Affected persons should be detected and treated before irreversible organ damage occurs. This study demonstrates that serum ferritin levels together with TIBC saturation levels are adequate methods for screening populations.