Blood cell and iron status analytes of preterm and full-term infants from 20 weeks onwards during the first year of life.

BACKGROUND: The goal of this study was to evaluate the dynamics of blood cell and iron status laboratory analytes in preterm and full-term infants during the first year of life. METHODS: This was a prospective study of 100 preterm and 50 full-term infants. Preterm infants received iron supplementation beginning at 3 weeks of age. Laboratory tests were serially analyzed up to 12 months of corrected age. RESULTS: Estimated means and the 95% reference intervals (RIs) from 20 weeks of age and onwards are presented separately for preterm and full-term infants. At the age of 20 weeks, mean hemoglobin (Hb) in preterm infants was lower than mean Hb in full-term infants, but this difference changed during follow-up. Ferritin concentrations were initially lower in preterm infants, but decreased to similar levels in both groups. Estimated mean values for transferrin receptor and reticulocyte Hb content were quite stable between the ages of 20 and 55 weeks in both groups. CONCLUSIONS: Our study suggests that the same RIs for preterm and full-term infants can be used from the age of 20 or 30 weeks onwards, depending on the analyte. The RIs will help physicians detect iron deficiency or other problems of erythropoiesis in infants.

Hematological parameters in preterm infants from birth to 16 weeks of age with reference to iron balance.

BACKGROUND: The objective of this study was to describe the natural kinetics of serum soluble transferrin receptor (S-TfR), ferritin and reticulocyte indices in preterm neonates, and to find out whether these analytes relate to hematocrit (Hct) level in determining the need for red cell (RBC) transfusions. METHODS: During a 2-year period, 100 preterm neonates were recruited in a tertiary level neonatal intensive care unit. Inclusion criteria were gestational age < or =34 weeks or birth weight <2000 g. Biochemical markers of iron deficiency and hematological indices were serially analyzed from birth. This report focuses on the first 16 weeks after birth. RESULTS: The trends of the studied analytes were presented with reference ranges. RBC transfusions did not have a significant effect on reticulocyte hemoglobin content (CHr) or reticulocyte count. Reticulocytes were lowest after the first week and S-TfR at 9 weeks of age. CHr and fraction of immature reticulocytes were highest at birth and decreased thereafter. CHr and reticulocyte count were significantly different in two groups determined by Hct level (Hct < or > or =0.30). This difference was not observed in S-TfR or ferritin concentrations. CONCLUSIONS: In addition to reflecting the activity of erythropoiesis, S-TfR seems to reflect iron balance in preterm neonates. By using CHr and reticulocyte, it is possible to obtain more information about iron balance in relation to erythropoiesis, and it might be useful to combine this information with Hct before making a decision about a transfusion.

Undiagnosed diseases in patients with dementia--a potential target group for intervention.

OBJECTIVE: To study undiagnosed diseases in older people with and without dementia. DESIGN: Cross-sectional population-based study in Lieto, southwestern Finland. PARTICIPANTS: All the inhabitants aged 64 and more in Lieto. Participation rate was 82% (n = 1,260). MEASUREMENTS: Dementia and its subtypes were diagnosed according to prevailing criteria. Medical conditions were assessed in clinical examinations and from medical records. RESULTS: 112 patients with dementia were found; 66% of them had at least 1 undiagnosed disease compared to 48% of the non-demented group (p = 0.041). The demented subjects had more undiagnosed hypercholesterolaemia (p = 0.039) and undiagnosed hypothyroidism (p = 0.032) than the controls. CONCLUSION: Undiagnosing is more common among patients with dementia. Screening strategies should be developed further to find these patients.

Increased serum soluble transferrin receptor concentration detects subclinical iron deficiency in healthy adolescent girls.

The objective of this study was to investigate whether the measurement of serum soluble transferrin receptor could detect subclinical iron deficiency in adolescent girls, and to assess the possible specificity-compromising effects of growth, menarche, and intensive physical activity. The study population consisted of 191 physically active (control) girls aged 9-15 years. Dietary iron intake was estimated at baseline, and after 6 and 12 months. Iron status of the subjects was assessed by haematological laboratory tests at 6 and 12 months. A 3-month iron and multivitamin supplementation was started after the visit at 6 months. The supplementation consistently decreased soluble transferrin receptor concentrations in subjects with initial values greater than 2.4 mg/l, which was determined by regression analysis to be the cut-off value for iron-deficient erythropoiesis. The 95% reference interval in the iron-replete subjects (0.9-2.4 mg/l) was consistent with this finding. In our population, the incidence of subclinical iron deficiency was 10%. Growth or physical activity had no effect on the iron status. This study shows that, similarly to adults, soluble transferrin receptor measurement can be used to detect subclinical iron deficiency in adolescents (competitive athletes or normal controls). We suggest that soluble transferrin receptor concentrations above 2.4 mg/l indicate clinically relevant iron deficiency in adolescents.