Similar hematological profile in CMS patients and non-CMS residents at 5100 m
| . | Sea level (Lima) . | 3800 m (Puno) . | 5100 m (La Rinconada) . | P . | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| . | All CMS− . | All . | CMS− . | CMS+ . | All . | CMS− . | CMS+ . | Altitude (All) . | Altitude (only CMS−) . | Altitude (only CMS+) . | CMS 3800 m . | CMS 5100 m . |
| Participant characteristics | ||||||||||||
| N | 17 | 25 | 17 | 8 | 36 | 12 | 24 | |||||
| Age, y | 28 (23 to 35) | 32 (23 to 50) | 24 (22 to 32) | 51 (49 to 52) | 42 (35 to 47)* | 39 (36 to 47)*‡ | 43 (35 to 47) | .005 | .017 | .002 | <.001 | .591 |
| Body weight, kg | 69 (64 to 75) | 69 (63 to 74) | 65 (63 to 73) | 72 (63 to 83) | 71 (65 to 76) | 70 (66 to 73) | 72 (65 to 77) | .658 | .732 | .896 | .307 | .481 |
| Height, m | 1.69 (1.66 to 1.71) | 1.67 (1.63 to 1.69) | 1.68 (1.63 to 1.69) | 1.66 (1.62 to 1.67) | 1.64 (1.61 to 1.69) | 1.64 (1.61 to 1.72) | 1.64 (1.61 to 1.67) | .051 | .481 | .896 | .143 | .534 |
| BMI, kg·m−2 | 24.1 (23.2 to 25.0) | 24.6 (22.3 to 26.9) | 24.6 (22.2 to 26.2) | 25.7 (24.0 to 30.5) | 25.8 (24.4 to 27.5) | 24.8 (24.1 to 26.1) | 26.7 (24.4 to 28.0) | .118 | .485 | .983 | .162 | .159 |
| Duration of stay, y | — | 32 (23 to 50) | 25 (23 to 32) | 50 (50 to 51) | 13 (8 to 20)† | 10 (10 to 20)‡ | 14 (6 to 18) | <.00001 | <.001 | <.0001 | <.001 | .942 |
| [Hb], g·dL−1 | 13.6 (13.4 to 14.4) | 18.8 (18.2 to 20.8)* | 18.5 (18.0 to 19.0)* | 21.4 (20.2 to 23.3) | 23.0 (21.7 to 24.4)*† | 22.3 (20.0 to 23.9)*‡ | 23.4 (22.3 to 24.4) | <.00001 | <.00001 | .043 | .047 | .180 |
| SpO2, % | 98 (98 to 98) | 92 (88 to 94)* | 93 (92 to 94)* | 86 (82 to 90) | 80 (77 to 85)*† | 83 (80 to 86)*‡ | 79 (77 to 83) | <.00001 | <.00001 | .006 | .002 | .117 |
| CMS score with [Hb] | 0 (0 to 2) | 2 (1 to 7) | 1 (0 to 2) | 8 (8 to 10) | 9 (5 to 12)*† | 5 (4 to 5)*‡ | 11 (9 to 13) | <.00001 | <.001 | .175 | <.0001 | <.00001 |
| CMS score without [Hb] | 0 (0 to 2) | 1 (0 to 5) | 1 (0 to 2) | 8 (5 to 9) | 6 (2 to 9)*† | 2 (2 to 2)‡ | 8 (6 to 10) | <.00001 | .019 | .381 | <.0001 | <.00001 |
| Hematological characteristics | ||||||||||||
| Hematocrit, % | 43.8 (43.0 to 46.3) | 56.0 (55.0 to 65.0)* | 55.3 (54.5 to 56.3)* | 65.5 (63.8 to 68.4) | 73.4 (68.7 to 78.0)*† | 69.5 (64.0 to 76.2)*‡ | 74.0 (71.3 to 78.0) | <.00001 | <.00001 | .003 | .007 | .240 |
| EPO, mIU·mL−1 | 8.9 (7.2 to 11.0) (n = 11) | 13.5 (8.5 to 16.3) (n = 12) | 13.1 (8.2 to 14.2) (n = 9) | 15.8 (14.3 to 20.0) (n = 3) | 24.0 (19.6 to 48.6)*† (n = 35) | 21.7 (16.0 to 36.6)*‡ (n = 12) | 25.3 (20.6 to 52.4) (n = 23) | <.0001 | .004 | .118 | .229 | .224 |
| RBCV, mL·kg−1 | 34.0 (29.5 to 36.6) | 42.2 (36.1 to 56.1)* | 39.9 (34.6 to 42.2)* | 58.8 (50.8 to 66.2) | 69.8 (57.2 to 92.7)*† | 72.3 (58.7 to 95.6)*‡ | 69.7 (55.4 to 92.1) | <.00001 | <.00001 | .098 | .001 | .712 |
| PV, mL·kg−1 | 40.7 (35.8 to 49.6) | 29.3 (28.2 to 33.7)* | 29.3 (27.6 to 33.7)* | 29.6 (28.3 to 32.2) | 26.7 (23.0 to 32.6)* | 28.9 (25.5 to 34.7)* | 24.8 (21.5 to 31.9) | <.00001 | <.0001 | .074 | .954 | .081 |
| BV, mL·kg−1 | 77.2 (68.5 to 80.1) | 75.5 (63.7 to 86.5) | 70.2 (62.9 to 75.5) | 88.5 (80.3 to 93.5) | 97.6 (81.2 to 124.3)*† | 100.2 (90.2 to 120.4)*‡ | 94.8 (75.6 to 124.3) | <.0001 | <.0001 | .602 | .004 | .365 |
| Hbmass, g·kg−1 | 10.8 (9.4 to 11.3) | 13.3 (12.2 to 18.1)* | 12.7 (11.8 to 14.0)* | 18.8 (16.1 to 22.7) | 22.7 (18.1 to 29.5)*,† | 22.5 (18.8 to 30.6)*,‡ | 22.7 (17.2 to 29.3) | <.00001 | <.00001 | .164 | .003 | .814 |
| . | Sea level (Lima) . | 3800 m (Puno) . | 5100 m (La Rinconada) . | P . | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| . | All CMS− . | All . | CMS− . | CMS+ . | All . | CMS− . | CMS+ . | Altitude (All) . | Altitude (only CMS−) . | Altitude (only CMS+) . | CMS 3800 m . | CMS 5100 m . |
| Participant characteristics | ||||||||||||
| N | 17 | 25 | 17 | 8 | 36 | 12 | 24 | |||||
| Age, y | 28 (23 to 35) | 32 (23 to 50) | 24 (22 to 32) | 51 (49 to 52) | 42 (35 to 47)* | 39 (36 to 47)*‡ | 43 (35 to 47) | .005 | .017 | .002 | <.001 | .591 |
| Body weight, kg | 69 (64 to 75) | 69 (63 to 74) | 65 (63 to 73) | 72 (63 to 83) | 71 (65 to 76) | 70 (66 to 73) | 72 (65 to 77) | .658 | .732 | .896 | .307 | .481 |
| Height, m | 1.69 (1.66 to 1.71) | 1.67 (1.63 to 1.69) | 1.68 (1.63 to 1.69) | 1.66 (1.62 to 1.67) | 1.64 (1.61 to 1.69) | 1.64 (1.61 to 1.72) | 1.64 (1.61 to 1.67) | .051 | .481 | .896 | .143 | .534 |
| BMI, kg·m−2 | 24.1 (23.2 to 25.0) | 24.6 (22.3 to 26.9) | 24.6 (22.2 to 26.2) | 25.7 (24.0 to 30.5) | 25.8 (24.4 to 27.5) | 24.8 (24.1 to 26.1) | 26.7 (24.4 to 28.0) | .118 | .485 | .983 | .162 | .159 |
| Duration of stay, y | — | 32 (23 to 50) | 25 (23 to 32) | 50 (50 to 51) | 13 (8 to 20)† | 10 (10 to 20)‡ | 14 (6 to 18) | <.00001 | <.001 | <.0001 | <.001 | .942 |
| [Hb], g·dL−1 | 13.6 (13.4 to 14.4) | 18.8 (18.2 to 20.8)* | 18.5 (18.0 to 19.0)* | 21.4 (20.2 to 23.3) | 23.0 (21.7 to 24.4)*† | 22.3 (20.0 to 23.9)*‡ | 23.4 (22.3 to 24.4) | <.00001 | <.00001 | .043 | .047 | .180 |
| SpO2, % | 98 (98 to 98) | 92 (88 to 94)* | 93 (92 to 94)* | 86 (82 to 90) | 80 (77 to 85)*† | 83 (80 to 86)*‡ | 79 (77 to 83) | <.00001 | <.00001 | .006 | .002 | .117 |
| CMS score with [Hb] | 0 (0 to 2) | 2 (1 to 7) | 1 (0 to 2) | 8 (8 to 10) | 9 (5 to 12)*† | 5 (4 to 5)*‡ | 11 (9 to 13) | <.00001 | <.001 | .175 | <.0001 | <.00001 |
| CMS score without [Hb] | 0 (0 to 2) | 1 (0 to 5) | 1 (0 to 2) | 8 (5 to 9) | 6 (2 to 9)*† | 2 (2 to 2)‡ | 8 (6 to 10) | <.00001 | .019 | .381 | <.0001 | <.00001 |
| Hematological characteristics | ||||||||||||
| Hematocrit, % | 43.8 (43.0 to 46.3) | 56.0 (55.0 to 65.0)* | 55.3 (54.5 to 56.3)* | 65.5 (63.8 to 68.4) | 73.4 (68.7 to 78.0)*† | 69.5 (64.0 to 76.2)*‡ | 74.0 (71.3 to 78.0) | <.00001 | <.00001 | .003 | .007 | .240 |
| EPO, mIU·mL−1 | 8.9 (7.2 to 11.0) (n = 11) | 13.5 (8.5 to 16.3) (n = 12) | 13.1 (8.2 to 14.2) (n = 9) | 15.8 (14.3 to 20.0) (n = 3) | 24.0 (19.6 to 48.6)*† (n = 35) | 21.7 (16.0 to 36.6)*‡ (n = 12) | 25.3 (20.6 to 52.4) (n = 23) | <.0001 | .004 | .118 | .229 | .224 |
| RBCV, mL·kg−1 | 34.0 (29.5 to 36.6) | 42.2 (36.1 to 56.1)* | 39.9 (34.6 to 42.2)* | 58.8 (50.8 to 66.2) | 69.8 (57.2 to 92.7)*† | 72.3 (58.7 to 95.6)*‡ | 69.7 (55.4 to 92.1) | <.00001 | <.00001 | .098 | .001 | .712 |
| PV, mL·kg−1 | 40.7 (35.8 to 49.6) | 29.3 (28.2 to 33.7)* | 29.3 (27.6 to 33.7)* | 29.6 (28.3 to 32.2) | 26.7 (23.0 to 32.6)* | 28.9 (25.5 to 34.7)* | 24.8 (21.5 to 31.9) | <.00001 | <.0001 | .074 | .954 | .081 |
| BV, mL·kg−1 | 77.2 (68.5 to 80.1) | 75.5 (63.7 to 86.5) | 70.2 (62.9 to 75.5) | 88.5 (80.3 to 93.5) | 97.6 (81.2 to 124.3)*† | 100.2 (90.2 to 120.4)*‡ | 94.8 (75.6 to 124.3) | <.0001 | <.0001 | .602 | .004 | .365 |
| Hbmass, g·kg−1 | 10.8 (9.4 to 11.3) | 13.3 (12.2 to 18.1)* | 12.7 (11.8 to 14.0)* | 18.8 (16.1 to 22.7) | 22.7 (18.1 to 29.5)*,† | 22.5 (18.8 to 30.6)*,‡ | 22.7 (17.2 to 29.3) | <.00001 | <.00001 | .164 | .003 | .814 |
Participant characteristics of male residents at sea level, 3800 m, and 5100 m. Individuals were categorized with the CMS Qinghai score including the [Hb] criterion. The effect of altitude was assessed with a Kruskal-Wallis test including all participants and also with CMS− only or with CMS+ only. Pairwise comparisons using a Mann-Whitney U test with Bonferroni correction were performed with *P < .05 vs sea level; †P < .05 vs 3800 m all; ‡P < .05 vs 3800 m CMS−. The observed tendency toward an effect of altitude on height (P = .051) may be explained by the fact that growth is delayed in Andean highlanders due to a combination of undernutrition, poor health, and chronic hypoxia.23 However, the absence of a difference in BMI suggests comparable development between populations. The effect of CMS at 3800 m or 5100 m on participant and hematological characteristics was assessed with a Mann-Whitney U test. Values are presented as median and interquartile range.
BMI, body mass index; EPO, serum erythropoietin concentration; Hbmass, total hemoglobin mass; SpO2, arterial oxygen saturation by pulse oximetry.