Haematinic Deficiency and Macrocytosis in Middle-Aged and Older Adults

Therese Mcnamee,Sharon Cadogan,Janas Harrington,Ivan J Perry,Bahman Honari,Anthony P Fitzgerald,Trish Hyland,Mary R Cahill,Kanthi Perera,James F Collins

doi:10.1371/journal.pone.0077743

Abstract

ObjectiveTo assess the prevalence and determinants of haematinic deficiency (lack of B12 folate or iron) and macrocytosis in blood from a national population-based study of middle-aged and older adults.MethodsA cross-sectional study involving 1,207 adults aged ≥45 years, recruited from a sub-study of the Irish National Survey of Lifestyle Attitudes and Nutrition (SLÁN 2007). Participants completed a health and lifestyle questionnaire and a standard food frequency questionnaire. Non-fasting blood samples were obtained for measurement of full blood count and expert morphological assessment, serum ferritin, soluble transferrin receptor assay (sTfR), B12, folate and coeliac antibodies. Blood samples were also assayed for thyroid function (T4, TSH), liver function, aminotransferase (AST) and gamma-glutamyl transferase (GGT).ResultsThe overall prevalence (95% C.I.) of anaemia (Hb <13.5g/dl men and 11.3 g/dl women) was 4.6% (2.9%–6.4%) in men and 1.0% (0.2%–1.9%) in women. Iron deficiency (ferritin <17ng/ml men and <11ng/ml in women) was detected in 6.3% of participants (3.7% in males and 8.7% in females, p<0.001). Based on both low ferritin and raised sTfR (>21nmol/ml) only 2.3% were iron-deficient. 3.0% and 2.7% were found to have low levels of serum folate (<2.3ng/ml) and serum B12 (<120ng/l) respectively. Clinically significant macrocytosis (MCV>99fl) was detected in 8.4% of subjects. Strong, significant and independent associations with macrocytosis were observed for lower social status, current smoking status, moderate to heavy alcohol intake, elevated GGT levels, deficiency of folate and vitamin B12, hypothyroidism and coeliac disease. The population attributable fraction (PAF) for macrocytosis associated with elevated GGT (25.0%) and smoking (24.6%) was higher than for excess alcohol intake (6.3%), folate deficiency (10.5%) or vitamin B12 (3.4%).ConclusionsHaematinic deficiency and macrocytosis are common in middle-aged/older adults in Ireland. Macrocytosis is more likely to be attributable to an elevated GGT and smoking than vitamin B12 or folate deficiency.

Highlights

Deficiency of a number of vitamins and minerals required for normal erythropoiesis is associated with anaemia
The data showed that 31.3% of men and 13.2% of women had evidence of abnormal liver function based on elevated gamma glutamyl transferase (GGT) concentrations (GGT> 48 u/L)
Iron intakes were higher in men than in women and a substantial proportion of the population sample had estimated iron intakes below the Recommended Daily Allowance (RDA) ranging from 31% in men aged 45-64 years to 70% in women in the 45-64 age group

Summary

Introduction

Deficiency of a number of vitamins and minerals required for normal erythropoiesis (haematinics) is associated with anaemia. Deficiency of iron, B12 and folate (the most common haematinics) are the most prevalent forms of vitamin deficiency worldwide [1], [2], [3]. And collectively, deficiency of iron, B12 and folate are significant causes of morbidity in the population. The estimated prevalence of haematinic deficiency varies widely with studies from Europe ranging from 5% to 46%. In a recent Canadian population study the estimated prevalence of folate deficiency was close to zero (following flour supplementation) while B12 deficiency was estimated at approximately 5% of the population [7]. In the NHANES 2005–2006 study in the US the prevalence of folate deficiency was estimated at 4.5% using a more sensitive measure of red cell folate [8]

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Conclusion