Table 2.
Association Between Hemoglobin (g/dL) and Estimated Glomerular Filtration Rate [mL/(min·1.73 m2] According to Altitude Above the Sea Level
| Overall | Low | Intermediate | High | |
|---|---|---|---|---|
| β (95% CI) | β (95% CI) | β (95% CI) | β (95% CI) | |
| Crude | ||||
| N = 4125 | N = 1806 | N = 1599 | N = 720 | |
| Hemoglobin | −0.55 (−0.91 to −0.20) | −0.40 (−1.34 to 0.54) | 0.75 (0.16 to 1.34) | −1.20 (−2.02 to −0.38) |
| Adjusted | ||||
| N = 4046 | N = 1794 | N = 1563 | N = 689 | |
| Hemoglobin | −0.12 (−0.62 to 0.39) | −0.19 (−1.29 to 0.91) | 0.30 (−0.33 to 0.94) | −1.09 (−2.22 to 0.04) |
Adjusted models include sex, age (numeric variable), education, hypertension, diabetes, BMI (numeric variable), and height (numeric variable); the adjusted model for overall also include altitude above the sea level. Estimates in bold are statistically significant (p < 0.050). Interpretation: within each altitude category, for one additional hemoglobin unit, the eGFR changes (increases or decreases) in a magnitude equal to the β value.