Table 2.

Observational and intervention studies testing the relationship between IGF-1 and hemoglobin and anemia.

Author reference	Year	Type of survey	Population	Dose/follow-up	Results
Observational
De Vita et al. [80]	2015	Cross-sectional	402 m 536 w >65 y	—	Negative association between IGF-1 and anemia in men and positive between IGF-1 and Hb in both sexes
Nilsson-Ehle et al. [81]	2005	Cross-sectional	302 m 317 w 70 y	—	IGF-1 positive predictor of Hb levels regardless of EPO, health status, and sex
Landi et al. [82]	2007	Cross-sectional	85 m 168 w  mean age 85 y	—	Higher IGFBP-3 level is associated with higher Hb concentration among older people
Succurro et al. [83]	2011	Cross-sectional	491 m 548 w mean age 48 y	—	IGF-1 is an independent determinant of Hb; lower IGF-1 is associated with anemia
Ureña et al. [84]	1992	Cross-sectional	17 m and w  mean age 46 y HD	—	Positive correlation between IGF-1 and hematocrit, but not with EPO
Kim et al. [85]	2007	Cross-sectional	41 m 36 w 29–86 y	—	IGF-1 is independently associated with Hb level in DM-CKD patients
Intervention
Sohmiya et al. [86]	1998	No RCT	3 m 5 w 46–83 y CRF	Infusion rhGH 2 µg/kg/day 7 days	GH treatment increases EPO levels and reticulocyte counts in CRF patients
Chu et al. [87]	2001	Double-blind RCT	19 m and w >70 y	Infusion rhGH 0.09 µg/kg/week 4 weeks	Low-dose rhGH improves nutritional status and physical function in elderly with protein-energy malnutrition
Iglesias et al. [88]	1998	Pilot RCT	8 m 9 w 30–78 y HD	rhGH 0.2 IU/kg/day sc 4 weeks	Short-term rhGH administration increases Hb and hematocrit values
Johannsson et al. [89]	1999	Double-blind RCT	14 m 6 w 53–92 y HD	rhGH 0.6 IU/kg/week sc 6 months	rhGH supplementation produces anabolic effects but does not significantly affect Hb levels

CRF: chronic renal failure

DMn: diabetic nephropathy

HD: hemodialysis

SC: subcutaneously

DM-CKD: chronic kidney disease (CKD) from DM.