What are the expected hemoglobin (hgb) and hematocrit (hct) levels for a 68-year-old female living at high altitude?

Expected Hemoglobin and Hematocrit Values for a 68-Year-Old Female at 5700 Feet

For a 68-year-old female living at 5700 feet (approximately 1737 meters), the expected hemoglobin level is approximately 13.7-16.5 g/dL and hematocrit is approximately 41-49%. 1

Altitude Effects on Hemoglobin and Hematocrit

• At 5700 feet (1737 meters), there is an expected increase of approximately +0.65 g/dL in hemoglobin levels compared to sea level values due to physiological adaptation to lower oxygen partial pressure 1
• This adaptation occurs through increased erythropoietin production in response to hypobaric hypoxia, stimulating erythropoiesis and subsequent hematological adaptation 2, 1
• Hematocrit values typically follow hemoglobin values at a ratio of approximately 3:1, resulting in an expected increase of about 2% in hematocrit at this altitude 1

Age and Sex Considerations

• Older women typically have lower baseline hemoglobin and hematocrit values compared to younger women or men of similar age 3
• Studies show that hemoglobin levels in women tend to decline less significantly with age compared to men, with an annual decline of approximately 0.05-0.06 g/L in women from age 70-88 3
• The altitude-related increase in hemoglobin is generally smaller in women (+6.6%) than in men (+12%) at similar altitudes 2

Factors Affecting Hemoglobin Values at Altitude

• Individual erythropoietic response to altitude is highly variable and may be influenced by several factors 2:
  • Iron status and potential deficiency 2
  • Hormonal status, including estrogen levels which can inhibit EPO production 2
  • Presence of inflammation or illness 2
  • Duration of residence at altitude (adaptation occurs over time) 1

Clinical Implications

• When evaluating anemia in older women living at altitude, the threshold hemoglobin level should be adjusted upward by approximately 0.65 g/dL at 5700 feet 1
• Failure to account for altitude-related increases in hemoglobin may lead to underdiagnosis of anemia 1, 4
• Studies suggest that even "low-normal" hemoglobin values might have adverse effects on mobility function in older women, with optimal functional performance observed at hemoglobin levels of 13.0-14.0 g/dL 5
• For older women with chronic conditions such as chronic kidney disease, maintaining hemoglobin in the range of 11.8-12.1 g/dL has been associated with better functional outcomes 6

Altitude-Specific Considerations

• Current altitude adjustment formulas may underadjust hemoglobin for those residing at lower altitudes (like 5700 feet) and overadjust for those at higher altitudes 4
• At significantly higher altitudes (4000m/13,123 feet), normal hemoglobin ranges for women are considerably higher (12-19 g/dL) with hematocrit ranges of 41-56% 7
• The physiological adaptation to altitude is a normal response and should not be confused with polycythemia vera or other pathological conditions 1, 8