Hematologic Aspects of Iron Deficiency and Less Common Nutritional Anemias1



Hematologic Aspects of Iron Deficiency and Less Common Nutritional Anemias1


Christopher R. Chitambar

AŚok C. Antony





Iron deficiency is the most common and widespread nutritional disorder in the world. As well as affecting a large number of children and women in developing countries, it is the only nutrient deficiency which is also significantly prevalent in industrialized countries. The numbers are staggering: 2 billion people—over 30% of the world’s population—are anaemic, many due to iron deficiency, and in resource-poor areas, this is frequently exacerbated by infectious diseases. Malaria, HIV/AIDS, hookworm infestation, schistosomiasis, and other infections such as tuberculosis are particularly important factors contributing to the high prevalence of anaemia in some areas.

Iron deficiency affects more people than any other condition, constituting a public health condition of epidemic proportions. More subtle in its manifestations than, for example, protein-energy malnutrition, iron deficiency exacts its heaviest overall toll in terms of ill-health, premature death and lost earnings.

Iron deficiency and anaemia reduce the work capacity of individuals and entire populations, bringing serious economic consequences and obstacles to national development. Overall, it is the most vulnerable, the poorest and the least educated who are disproportionately affected by iron deficiency, and it is they who stand to gain the most by its reduction.

—World Health Organization (WHO) Report on Iron-deficiency Anemia (1)


GENERAL CONCEPTS

Iron deficiency looms largest among the factors that contribute to the global burden of anemia, which affects one third of the world’s population and has serious consequences for maternal and perinatal health and child development (2). In many developing countries, more than half of specific groups of individuals are affected. Even in developed countries, the problem of iron deficiency is significant (Table 98.1). The WHO quotation cited above encapsulates the fundamental problem that this chapter aims to highlight. Coincident with the diagnosis of iron deficiency is the imperative for identification of all underlying root causes, which must be addressed to prevent a recurrence of iron deficiency after iron replacement.

From the public health point of view, the main hematopoietic nutrients are iron, folate, and vitamin B12. These nutrients are discussed in separate chapters. Whereas other trace metals and vitamins contribute to normal hematopoiesis, their clinical role independent of the three major nutrients is of lesser public health importance. Nevertheless, when patients continue to have anemia despite repletion with iron, folate, and vitamin B12, and other causes for anemia have been ruled out, the additional
role of other trace metals and vitamins should be sought. Anemia is defined as a low concentration of hemoglobin in the blood. Optimum hemoglobin values at different ages are presented in Table 98.2.








TABLE 98.1 PREVALENCE OF IRON DEFICIENCY FROM THE UNITED STATES NATIONAL HEALTH AND NUTRITION EXAMINATION SURVEYS, 1988 TO 1994 AND 1999 TO 2000a







































































































































SEX AND AGE


1988-1994


1999-2000


GROUPS (y)


%


(95% CI)a


%


(95% CI)


Both sexes







1-2


9


(6, 7, 8, 9, 10, 11)


7


(3, 4, 5, 6, 7, 8, 9, 10, 11)



3-5


3


(2, 3, 4)


5


(2, 3, 4, 5, 6, 7)



6-11


2


(1, 2, 3)


4


(1, 2, 3, 4, 5, 6, 7)


Males







12-15


1


(0.1-2.0)


5


(2, 3, 4, 5, 6, 7, 8)



16-69


1


(0.6-1.0)


2


(1, 2, 3)



≥70


4


(2, 3)


3


(2, 3, 4, 5, 6, 7)


Females (nonpregnant)







12-15


9


(6, 7, 8, 9, 10, 11, 12)


9


(5, 6, 7, 8, 9, 10, 11, 12)



16-19


11


(7, 8, 9, 10, 11, 12, 13, 14)


16


(10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)



20-49


11


(10, 11, 12, 13)


12


(10, 11, 12, 13, 14, 15, 16)



White, non-Hispanic


8


(7, 8, 9)


10


(7, 8, 9, 10, 11, 12, 13)



African-American, non-Hispanic


15


(13, 14, 15, 16, 17)


19


(14 -24)



Mexican-American


19


(17, 18, 19, 20, 21)


22


(17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)



50-69


5


(4, 5, 6, 7)


9


(5, 6, 7, 8, 9, 10, 11, 12)



≥70


7


(5, 6, 7, 8)


6


(4, 5, 6, 7, 8, 9)


CI, confidence interval.


aAll racial and ethnic groups, except where noted.


Adapted with permission from Centers for Disease Control and Prevention. Iron deficiency: United States, 1999-2000. MMWR Morb Mortal Wkly Rep 2002;51:897-9.

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Jul 27, 2016 | Posted by in PUBLIC HEALTH AND EPIDEMIOLOGY | Comments Off on Hematologic Aspects of Iron Deficiency and Less Common Nutritional Anemias1

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