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
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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

Tables

↓  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 (%) N Median (IQR) or n (%) 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%) 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 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 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 thrombosisa 321 (303 - 339) (n = 266) 292 (245 - 339) (n = 20) -29 (-75.5 - 17.5) 0.22
Arterial thrombosisa 321 (304 - 338) (n = 275) 258 (196 - 320) (n = 11) -63.2 (-124 - -1.96) 0.044