J Hematol

Journal of Hematology, ISSN 1927-1212 print, 1927-1220 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Hematol and Elmer Press Inc

Journal website https://jh.elmerpub.com

Original Article

Volume 14, Number 1, February 2025, pages 20-25

Increased Transferrin Concentrations Are Not Associated With Thrombosis in People Living at High Altitude

**Table 1.** Demographics, Laboratory Studies, and Iron Status in 286 High Altitude Patients, 137 With Anemia and 149 With Erythrocytosis, According to the History of Thrombosis
Baseline variable	No thrombosis history	History of thrombosis present	P value
Median (IQR) or n (%) of covariates are presented according to thrombosis history. P values were estimated using linear regression for continuous variables and Fisher’s exact test for binary variables. WBC, neutrophils, lymphocytes, and iron were square root transformed; platelets and ferritin were logarithm transformed. WBC: white blood cell; MCV: mean corpuscular volume; IQR: interquartile range.
Demographics
High altitude anemia	126 (49.2%)	256	11 (36.7%)	30	0.25
Age (years)	49 (41 - 58)	256	65 (56 - 74)	30	< 0.001
Female gender	149 (58.2%)	256	13 (43.3%)	30	0.13
Blood count
MCV (fL)	85.5 (70.5 - 91.6)	256	75.5 (69.3 - 86.2)	30	0.20
WBC (/µL)	5,685 (4,770 - 6,908)	256	5,600 (4,595 - 7,200)	30	0.60
Neutrophils (/µL)	3,365 (2,700 - 4,132)	256	3,850 (2,950 - 4,712)	30	0.055
Lymphocytes (/µL)	1,895 (1,400 - 2,275)	256	1,315 (1,100 - 1,722)	30	< 0.001
Platelets (× 10³/µL)	235 (167 - 325)	255	204.5 (171 - 249)	30	0.32
Iron metabolism
Iron (µg/dL)	68.5 (31.75 - 106)	240	45 (17.5 - 88.4)	29	0.11
Ferritin (ng/mL)	34 (11 - 99)	256	14 (7 - 45)	30	0.030
Iron deficiency	94 (36.7%)	256	18 (60%)	30	0.017
Transferrin (mg/dL)	334 (262 - 387)	256	304 (242 - 358)	30	0.25

Table 1. Demographics, Laboratory Studies, and Iron Status in 286 High Altitude Patients, 137 With Anemia and 149 With Erythrocytosis, According to the History of Thrombosis

Baseline variable

No thrombosis history

History of thrombosis present

P value

Median (IQR) or n (%)

Median (IQR) or n (%) of covariates are presented according to thrombosis history. P values were estimated using linear regression for continuous variables and Fisher’s exact test for binary variables. WBC, neutrophils, lymphocytes, and iron were square root transformed; platelets and ferritin were logarithm transformed. WBC: white blood cell; MCV: mean corpuscular volume; IQR: interquartile range.

Demographics

High altitude anemia

126 (49.2%)

256

11 (36.7%)

0.25

Age (years)

49 (41 - 58)

256

65 (56 - 74)

< 0.001

Female gender

149 (58.2%)

256

13 (43.3%)

0.13

Blood count

MCV (fL)

85.5 (70.5 - 91.6)

256

75.5 (69.3 - 86.2)

0.20

WBC (/µL)

5,685 (4,770 - 6,908)

256

5,600 (4,595 - 7,200)

0.60

Neutrophils (/µL)

3,365 (2,700 - 4,132)

256

3,850 (2,950 - 4,712)

0.055

Lymphocytes (/µL)

1,895 (1,400 - 2,275)

256

1,315 (1,100 - 1,722)

< 0.001

Platelets (× 10³/µL)

235 (167 - 325)

255

204.5 (171 - 249)

0.32

Iron metabolism

Iron (µg/dL)

68.5 (31.75 - 106)

240

45 (17.5 - 88.4)

0.11

Ferritin (ng/mL)

34 (11 - 99)

256

14 (7 - 45)

0.030

Iron deficiency

94 (36.7%)

256

18 (60%)

0.017

Transferrin (mg/dL)

334 (262 - 387)

256

304 (242 - 358)

0.25

**Table 2.** Independent Correlations With Serum Transferrin Concentration in 286 High Altitude Patients, 137 With Anemia and 149 With Erythrocytosis
Baseline variable	β (95% CI)	P value	N
Serum transferrin was regressed on baseline variables using univariate linear models. WBC, neutrophils, lymphocytes, and iron were square root transformed; platelets and ferritin were logarithm transformed. WBC: white blood cell; MCV: mean corpuscular volume; CI: confidence interval.
Demographics
High altitude anemia	-26 (-51 - -1.7)	0.037	288
Age (years)	0.13 (-0.67 - 0.94)	0.75	288
Female gender	-9.3 (-34 - 16)	0.47	288
Blood count
MCV (fL)	-1.38 (-2.26 - -0.496)	0.0024	288
WBC (/µL)	-0.404 (-1.48 - 0.667)	0.46	287
Neutrophils (/µL)	-0.580 (-1.66 - 0.501)	0.29	288
Lymphocytes (/µL)	0.476 (-1.03 - 1.98)	0.54	288
Platelets (× 10³/µL)	-4.80 (-31.2 - 21.6)	0.72	287
Iron metabolism
Iron (µg/dL)	-1.94 (-5.77 - 1.88)	0.32	271
Ferritin (ng/mL)	-14.2 (-22.1 - -6.23)	< 0.001	288
Iron deficiency	49 (24 - 73)	< 0.001	288

Table 2. Independent Correlations With Serum Transferrin Concentration in 286 High Altitude Patients, 137 With Anemia and 149 With Erythrocytosis

Baseline variable

β (95% CI)

P value

Serum transferrin was regressed on baseline variables using univariate linear models. WBC, neutrophils, lymphocytes, and iron were square root transformed; platelets and ferritin were logarithm transformed. WBC: white blood cell; MCV: mean corpuscular volume; CI: confidence interval.

Demographics

High altitude anemia

-26 (-51 - -1.7)

0.037

288

Age (years)

0.13 (-0.67 - 0.94)

0.75

288

Female gender

-9.3 (-34 - 16)

0.47

288

Blood count

MCV (fL)

-1.38 (-2.26 - -0.496)

0.0024

288

WBC (/µL)

-0.404 (-1.48 - 0.667)

0.46

287

Neutrophils (/µL)

-0.580 (-1.66 - 0.501)

0.29

288

Lymphocytes (/µL)

0.476 (-1.03 - 1.98)

0.54

288

Platelets (× 10³/µL)

-4.80 (-31.2 - 21.6)

0.72

287

Iron metabolism

Iron (µg/dL)

-1.94 (-5.77 - 1.88)

0.32

271

Ferritin (ng/mL)

-14.2 (-22.1 - -6.23)

< 0.001

288

Iron deficiency

49 (24 - 73)

< 0.001

288

**Table 3.** Transferrin Concentrations (mg/dL; Median and IQR) According to the History of Thrombosis at High Altitude (Adjusted for Erythrocytosis Versus Anemia and Iron Deficiency)
	Transferrin in subjects with no thrombosis history, adjusted mean (95% CI)	Transferrin in subjects with a history of thrombosis, adjusted mean (95% CI)	β (95% CI)	P value
^aThere was one patient with both venous and arterial thrombosis. CI: confidence interval; IQR: interquartile range.
Total thrombosis	324 (306 - 341) (n = 256)	277 (237 - 316) (n = 30)	-47.2 (-86.0 - -8.32)	0.018
Venous thrombosis^a	321 (303 - 339) (n = 266)	292 (245 - 339) (n = 20)	-29 (-75.5 - 17.5)	0.22
Arterial thrombosis^a	321 (304 - 338) (n = 275)	258 (196 - 320) (n = 11)	-63.2 (-124 - -1.96)	0.044

Table 3. Transferrin Concentrations (mg/dL; Median and IQR) According to the History of Thrombosis at High Altitude (Adjusted for Erythrocytosis Versus Anemia and Iron Deficiency)

Transferrin in subjects with no thrombosis history, adjusted mean (95% CI)

Transferrin in subjects with a history of thrombosis, adjusted mean (95% CI)

β (95% CI)

P value

^aThere was one patient with both venous and arterial thrombosis. CI: confidence interval; IQR: interquartile range.

Total thrombosis

324 (306 - 341) (n = 256)

277 (237 - 316) (n = 30)

-47.2 (-86.0 - -8.32)

0.018

Venous thrombosis^a

321 (303 - 339) (n = 266)

292 (245 - 339) (n = 20)

-29 (-75.5 - 17.5)

0.22

Arterial thrombosis^a

321 (304 - 338) (n = 275)

258 (196 - 320) (n = 11)

-63.2 (-124 - -1.96)

0.044