Thyroid Stimulating Hormone in Patients with Macrocytic Anemia

Abstract

Background Aims: The study aimed to examine the frequency of hypothyroidism among patients
with macrocytic anemia and to compare this with the frequency of megaloblastic anemia.
Materials and Methods: Routinely transferred specimens for a complete blood count test were sent
to the hematology lab in our institution and prospectively screened for high mean cell volume (MCV).
A total of 100 cases with macrocytosis were examined for the levels of thyroid stimulating hormone
(TSH), vitamin B12 and folate levels. Statistical analysis was performed to investigate a potential
association between hypothyroidism and other variables.
Results: There were 52 women and 48 men. The range of age was 21–83, with a mean of 59 years.
The mean MCV was 104.18 fL, while the mean hematocrit was 35.96%. Fifty-three (53%) patients
had anemia. Eighteen (18%) patients had TSH level above the normal range qualifying for
hypothyroidism. Among these, eight (44%) had low hematocrit and six (33%) a concomitant
megaloblastic anemia. The presence of high TSH level did not show a statistically significant
correlation with gender, age, vitamin B12, folate or hematocrit levels.
Conclusions: Hypothyroidism is commonly present in patients with macrocytosis. Its frequency is
comparable with megaloblastic anemia, and both can occur simultaneously. Routine TSH level testing
is recommended in patients with macrocytosis even if hematocrit level is normal or if the patient has
megaloblastic anemia.