Table 4.
Sensitivity Analyses of Associations of Anion Gap with All-Cause Mortality in 11,957 participants of NHANES 1999–2004
| Relative Hazard among Participants with eGFR ≥60 mL/min/1.73m2 (n=10,828; 467 deaths) | |||
|---|---|---|---|
| Relative Hazard (95% CI) | |||
| Anion Gap | Traditional | Albumin adjusted | Full |
| Continuous* | 1.17 (1.00–1.37) | 1.31 (1.13–1.52) | 1.30 (1.12–1.51) |
| Quartile 1 | Ref | Ref | Ref |
| Quartile 2 | 0.76 (0.51–1.13) | 1.38 (0.92–2.05) | 1.34 (0.88–2.04) |
| Quartile 3 | 0.92 (0.62–1.37) | 1.02 (0.71–1.48) | 1.07 (0.72–1.60) |
| Quartile 4 | 1.34 (0.91–1.96) | 1.86 (1.24–2.78) | 1.79 (1.17–2.75) |
| P for trend | 0.06 | 0.007 | 0.01 |
| Relative Hazard among Participants with eGFR ≥60 mL/min/1.73m2 and UACR <300 mg/g (n=10,697; 446 deaths) | |||
|---|---|---|---|
| Relative Hazard (95% CI) | |||
| Anion Gap | Traditional | Albumin adjusted | Full |
| Continuous* | 1.14 (0.97–1.34) | 1.28 (1.10–1.50) | 1.27 (1.09–1.48) |
| Quartile 1 | Ref | Ref | Ref |
| Quartile 2 | 0.76 (0.51–1.14) | 1.37 (0.92–2.03) | 1.32 (0.86–2.00) |
| Quartile 3 | 0.93 (0.64–1.37) | 1.03 (0.70–1.50) | 1.06 (0.71–1.60) |
| Quartile 4 | 1.28 (0.87–1.88) | 1.84 (1.24–2.73) | 1.76 (1.16–2.68) |
| P for trend | 0.10 | 0.008 | 0.01 |
| Relative Hazard among Participants with eGFR ≥60 mL/min/1.73m2 and UACR <30 mg/g (n=9,700; 324 deaths) | |||
|---|---|---|---|
| Relative Hazard (95% CI) | |||
| Anion Gap | Traditional | Albumin adjusted | Full |
| Continuous* | 1.07 (0.86–1.33) | 1.21 (0.98–1.48) | 1.20 (0.99–1.46) |
| Quartile 1 | Ref | Ref | Ref |
| Quartile 2 | 0.70 (0.43–1.14) | 1.45 (0.89–2.36) | 1.24 (0.78–1.99) |
| Quartile 3 | 0.75 (0.50–1.12) | 0.99 (0.63–1.57) | 1.05 (0.66–1.67) |
| Quartile 4 | 1.10 (0.63–1.91) | 1.55 (0.91–2.63) | 1.45 (0.85–2.48) |
| P for trend | 0.63 | 0.21 | 0.24 |
Abbreviations: CI, Confidence Interval; eGFR, estimated glomerular filtration rate; UACR, urinary albumin-creatinine ratio.
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).
Models 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.