Review Article

The Role of the Multiple Hormonal Dysregulation in the Onset of “Anemia of Aging”: Focus on Testosterone, IGF-1, and Thyroid Hormones

Table 3

Observational and intervention studies testing the relationship between thyroid hormones and hemoglobin and anemia.

Author referenceYearType of surveyPopulationFollow-upResults

Observational
Bremner et al. [90]2012Cohort504 m 507 w mean age 58 yFT4 levels are positively associated with Hb, hematocrit, and erythrocytes
Schindhelm et al. [91]2013Cohort708 m and w mean age 68 yFT4, but not TSH, is associated with Hb, hematocrit, and erythrocytes
Lippi et al. [92]2014Retrospective221 m 829 w
58–73 y
TSH and FT4 are associated with RDW
Shimizu et al. [93]2013Cross-sectional843 m
30–89 y
FT4 is inversely associated with anemia in nondrinkers
Bashir et al. [94]2012Cross-sectional216 m 384 w
25–60 y
Alterations in hematological parameters in untreated subclinical and overt hypothyroid patients
Lippi et al. [95]2008Retrospective331 m 615 w
21–87 y
No difference in the prevalence of folic acid and B12 deficiency between hypo- or hyperthyroid subjects
Stella et al. [96]2007Cross-sectional119 m 160 w
60–85 y
Thyroid hormones are associated with vitamin B12 levels, but not with homocysteine

Intervention
Kazemi-Jahromi et al. [97]2010No RCT14 m 56 w
18–75 y
LT4 101.7 ± 38.3 µg/day
3 months
LT4 supplementation improves hypothyroidism and anemia
Christ-Crain et al. [98]2003Double-blind RCT63 w
18–75 y
LT4 85.5 ± 4.3 µg/day
48 weeks
LT4 replacement significantly increases serum erythropoietin levels but did not affect Hb or hematocrit
Ravanbod et al. [99]2013Double-blind RCT30 m 30 w
mean age 32-33 y
Iron 65 mg/day, T4 50 µg/day or iron + T4 65 mg + 50 µg/day
3 months
Higher efficacy of a LT4 plus iron salts in hematological parameters
Cinemre et al. [100]2009Double-blind RCT44 m 6 w
27–55 y
Iron 240 mg/day or
Iron + LT4 240 mg + 75 µg/day 3 months
Higher efficacy of LT4 plus iron salts in iron status and blood count indices

RDW: red blood cell distribution width.