Table 3.
Relative Hazard of All-Cause Mortality by Anion Gap Quartile in 11,957 participants of NHANES 1999–2004
| Relative Hazard (95% CI) | ||||
|---|---|---|---|---|
| Anion Gap | Model 1 | Model 2 | Model 3 | Model 4 |
| Traditional | ||||
| Continuous* | 1.15 (1.02–1.29) | 1.15 (1.03–1.29) | 1.14 (1.02–1.27) | 1.08 (0.94–1.24) |
| Quartile 1 | Ref | Ref | Ref | Ref |
| Quartile 2 | 0.86 (0.66–1.12) | 0.86 (0.67–1.10) | 0.86 (0.67–1.10) | 0.83 (0.64–1.07) |
| Quartile 3 | 1.01 (0.76–1.35) | 0.99 (0.75–1.32) | 0.98 (0.74–1.30) | 0.90 (0.66–1.23) |
| Quartile 4 | 1.30 (0.96–1.74) | 1.32 (1.01–1.72) | 1.29 (1.00–1.67) | 1.20 (0.89–1.61) |
| P for trend | 0.04 | 0.02 | 0.03 | 0.15 |
| Albumin adjusted | ||||
| Continuous* | 1.40 (1.25–1.58) | 1.28 (1.14–1.44) | 1.27 (1.13–1.42) | 1.19 (1.03–1.38) |
| Quartile 1 | Ref | Ref | Ref | Ref |
| Quartile 2 | 1.36 (1.05–1.76) | 1.29 (0.99–1.67) | 1.27 (0.99–1.64) | 1.24 (0.97–1.59) |
| Quartile 3 | 1.30 (1.00–1.70) | 1.19 (0.91–1.56) | 1.18 (0.91–1.53) | 1.07 (0.82–1.38) |
| Quartile 4 | 2.17 (1.62–2.91) | 1.82 (1.37–2.41) | 1.76 (1.34–2.32) | 1.62 (1.19–2.21) |
| P for trend | <0.001 | <0.001 | <0.001 | 0.007 |
| Full | ||||
| Continuous* | 1.50 (1.33–1.68) | 1.29 (1.15–1.45) | 1.28 (1.14–1.43) | 1.20 (1.03–1.41) |
| Quartile 1 | Ref | Ref | Ref | Ref |
| Quartile 2 | 1.67 (1.22–2.29) | 1.40 (1.01–1.94) | 1.36 (0.98–1.89) | 1.31 (0.97–1.79) |
| Quartile 3 | 1.59 (1.19–2.13) | 1.28 (0.95–1.72) | 1.26 (0.94–1.68) | 1.19 (0.90–1.57) |
| Quartile 4 | 2.68 (1.87–3.83) | 1.88 (1.31–2.70) | 1.82 (1.28–2.59) | 1.64 (1.17–2.31) |
| P for trend | <0.001 | 0.001 | 0.001 | 0.01 |
Abbreviations: CI, Confidence Interval.
Bold values indicate p<0.05.
Quartile cutoff levels for each anion gap definition: Traditional: Q1 ≤10; Q2 10.1–12; Q3 12.1–14; Q4 ≥14.1mEq/L; Albumin adjusted: Q1 ≤ −0.50; Q2 −0.45–1.05; Q3 1.10–2.95; Q4 ≥3 mEq/L; Full: Q1 ≤3.61; Q2 3.62–5.34; Q3 5.35–7.23; Q4 >7.23 mEq/L.
Per standard deviation higher anion gap (traditional SD = 2.55 mEq/L; Albumin adjusted SD = 2.47 mEq/L; Full SD = 2.49 mEq/L).
Model 1: unadjusted
Model 2: adjusted for age, sex, race/ethnicity
Model 3: adjusted for age, sex, race/ethnicity, and eGFR categories
Model 4: adjusted for age, sex, race/ethnicity, eGFR categories, BMI, education, activity level, smoking status, diagnosis of diabetes mellitus, hypertension, cardiovascular disease, log-transformed urine albumin-creatinine ratio, serum bicarbonate, and hemoglobin