Baseline characteristics of participants. The characteristics of the participants are shown in Table 1. Compared with the high sALB group (≥ 4g/dL), the low sALB group (< 4g/dL) had lower levels of BMI, Hb, T-chol, TG, LDL, EGFR, ALT, and higher CRP level. Given that the low sALB group were older, the lower levels of BMI, sALB, lipoprotein, EGFR and liver enzyme might be associated with age.
Relationship between the sALB and MACE. The unadjusted and adjusted models are shown in Table 2. Cox model was used to evaluate the association between sALB and the risk of MACE. In the crude model, the HR of MACE was 0.18 (95%CI: 0.10 ~ 0.34, P < 0.0001). In model I adjusted for demographic variables (Age, Sex, BMI), the HR of MACE was 0.24 (95%CI: 0.12 ~ 0.46, P < 0.0001). In model II fully adjusted for confounders, the risk of MACE decreased by 63% (95%CI: 0.14 ~ 0.98, P = 0.0462) for each 1g/dL sALB increased. Cox models were established by dividing the sALB of participants into the low sALB group (< 4g/dL) and the high sALB group (≥ 4g/dL) according to the median level. The results showed that, compared with the low sALB group, the HR of MACE in the high sALB group were 0.20 (95% CI: 0.08 ~ 0.49, P = 0.0004) and 0.30 (95% CI: 0.12 ~ 0.78, P = 0.0137) in the crude model and model I respectively. In model II, the HR of MACE in the high sALB group was 0.58 without statistical significant (95% CI: 0.19 ~ 1.78, P = 0.3378). Figure 1 showed a trend in the association between sALB and the risk of MACE (logHR), indicating that the risk of MACE decreased as the baseline sALB increased. When sALB level was in the range of 4.0g/dL to 4.5g/dL, it remained a protective factor although the risk of MACE increased. However, when sALB level was more than 4.5g/dL, the risk of MACE would increased with the increase of sALB. It is consistent with the clinical reference range of sALB.
Statistical interaction between sALB and total cholesterol on MACE. Figure 2 presents the association between sALB level and the risk of MACE (logHR), stratified by total cholesterol level. The solid line, which represents those whose total cholesterol level less than 200 mg/dL, shows a decline in MACE risk with increasing sALB level after adjusting for confounders. Contrarily, there is no such association in those whose total cholesterol level more than 200 mg/dL. This association was further demonstrated by Cox models as presented in Table 3. Correspondingly, we found that the risk of varied by sALB level and total cholesterol level. Specifically, there was an negative association between sALB level and the risk of MACE in participants whose total cholesterol level less than 200 mg/dL in the fully adjusted model (HR, 0.19;95%CI, 0.06 ~ 0.64; P = 0.0072). However, no such association was found in those whose total cholesterol level more than 200 mg/dL (HR, 3.16; 95% CI, 0.30 ~ 33.51; P = 0.3392). A test for interaction between sALB level and total cholesterol level on the risk of MACE was statistically significant (P = 0.0176). And the similar association and statistically significant interaction test were observed in other model (Table 3).
Table 1
Baseline Characteristics of the Study Participants*
Variable | sALBumin (g/dL) | P-value |
< 4 (n = 89) | ≥ 4 (n = 115) |
Age (years) | 75.96 ± 10.87 | 69.98 ± 9.15 | < 0.001 |
Male sex, n (%) | 59 (66.29%) | 83 (72.17%) | 0.365 |
BMI (kg/m2) | 22.49 ± 4.17 | 24.51 ± 3.49 | < 0.001 |
Systolic blood pressure (mmHg) | 134.20 ± 23.40 | 137.90 ± 17.76 | 0.201 |
Diastolic blood pressure (mmHg) | 76.07 ± 15.21 | 78.48 ± 11.38 | 0.197 |
Hypertension, n (%) | 58 (65.17%) | 93 (80.87%) | 0.011 |
Dyslipidemia, n (%) | 32 (35.96%) | 72 (62.61%) | < 0.001 |
Diabetes mellitus, n (%) | 33 (37.08%) | 40 (34.78%) | 0.734 |
Atrial fibrillation, n (%) | 14 (15.73%) | 12 (10.43%) | 0.261 |
Old cerebral infarction, n (%) | 19 (21.35%) | 16 (13.91%) | 0.162 |
PAD, n (%) | 27 (30.34%) | 26 (22.61%) | 0.212 |
Past smoker, n (%) | 34 (38.20%) | 67 (58.26%) | 0.004 |
Hb (g/dL) | 12.41 ± 2.02 | 14.48 ± 1.46 | < 0.001 |
T-chol (mg/dL) | 174.62 ± 34.60 | 197.24 ± 34.54 | < 0.001 |
TG (mg/dL) | 111.57 ± 87.82 | 150.66 ± 105.01 | 0.005 |
HDL-C (mg/dL) | 49.09 ± 14.03 | 52.60 ± 13.81 | 0.075 |
LDL-C (mg/dL) | 99.44 ± 27.76 | 117.56 ± 27.07 | < 0.001 |
eGFR(mL/min/1.73m2) | 51.99 ± 28.46 | 68.54 ± 18.25 | < 0.001 |
AST(U/L) | 24.48 ± 12.59 | 24.83 ± 9.54 | 0.195 |
ALT(U/L) | 18.51 ± 12.58 | 22.82 ± 11.62 | < 0.001 |
HbA1C (%) | 8.79 ± 21.33 | 6.31 ± 0.85 | 0.501 |
CRP (mg/dL) | 0.82 ± 1.50 | 0.16 ± 0.27 | < 0.001 |
LVEF (%) | 61.06 ± 10.62 | 64.94 ± 8.72 | 0.005 |
Aspirin, n (%) | 87 (97.75%) | 115 (100.00%) | 0.189 |
Thienopiridines, n (%) | 87 (97.75%) | 113 (98.26%) | 1.000 |
Warfarin, n (%) | 2 (2.25%) | 3 (2.61%) | 1.000 |
DOAC, n (%) | 11 (12.36%) | 10 (8.70%) | 0.393 |
Ezetimibe, n (%) | 1 (1.12%) | 2 (1.74%) | 1.000 |
PPI, n (%) | 57 (64.04%) | 77 (66.96%) | 0.664 |
ACE-I, n (%) | 9 (10.11%) | 10 (8.70%) | 0.730 |
ARB, n (%) | 40 (44.94%) | 48 (41.74%) | 0.647 |
β-blocker, n (%) | 25 (28.09%) | 30 (26.09%) | 0.749 |
MRA, n (%) | 6 (6.74%) | 5 (4.35%) | 0.453 |
MACE: major adverse cardiac events (Defined as all-cause death, non-fatal myocardial infarction, non-fatal stroke); BM: body mass index; PAD: Peripheral artery disease; Hb: hemoglobin; T-chol: total cholesterol; TG: Triglycerides; HDL-C: high-density lipoprotein cholesterol; LDL Chol: low density lipoprotein cholesterol; eGFR = estimated glomerular filtration rate; HbA1c: hemoglobin A1c; CRP: C-reactive protein; LVEF: left ventricular ejection fraction; DOAC: direct oral anticoagulants; PPI: proton pump inhibitor; ACE-I: angiotensin converting enzyme inhibitor; ARB: angiotensin-receptor blocker; MRA: mineralocorticoid receptor antagonist; . |
*For continuous variables, values are presented as mean ± SD; For Categorical variable, values are presented as N(%). |
Table 2
Relationship between sALB and major adverse cardiac events in different models*
sALB, g/dL | Crude Model (n = 204) | Model I (n = 204) | Model II (n = 196) |
As linear trend | 0.18 (0.10, 0.34) < 0.0001 | 0.24 (0.12, 0.46) < 0.0001 | 0.37 (0.14, 0.98) 0.0462 |
As median cutoff point | | | |
Lower(< 4) | Reference | Reference | Reference |
Higher(≥ 4) | 0.20 (0.08, 0.49) 0.0004 | 0.30 (0.12, 0.78) 0.0137 | 0.58 (0.19, 1.78) 0.3378 |
Model I adjusted for: Age, MALE (sex), BMI |
Model II adjusted for: Age; MALE (sex) ; BMI; Hb; T-chol; eGFR; CRP; PAD; Warfarin |
*Models are presented as HR (95% CI) P-value. |
The graph displays the adjusted association between sALB and the risk of MACE. The model adjusted for Age; MALE (sex) ; BMI; Hb; T-chol; eGFR; CRP; PAD; Warfarin.
The graph displays the adjusted association between sALB and the risk of MACE stratified by total cholesterol. The model adjusted for Age, MALE (sex), BMI, Hb, eGFR, CRP, PAD, Warfarin.
Table 3
The prognostic significance of sALB on major adverse cardiac events stratified by total cholesterol in different models*
Model | T-chol < 200 mg/dL (n = 132) | T-chol ≥ 200 mg/dL (n = 72) | P interaction |
Crude Model | 0.07 (0.03, 0.17) < 0.0001 | 1.15 (0.27, 4.99) 0.8475 | 0.0003 |
Model I | 0.09 (0.03, 0.22) < 0.0001 | 1.32 (0.30, 5.85) 0.7116 | 0.0005 |
Model II | 0.15 (0.05, 0.47) 0.0012 | 2.95 (0.43, 20.08) 0.2679 | 0.0010 |
Model II# | 0.19 (0.06, 0.64) 0.0072 | 3.16 (0.30, 33.51) 0.3392 | 0.0176 |
Model I adjusted for: Age, MALE (sex), BMI |
Model II adjusted for: Age, MALE (sex), BMI, Hb, eGFR, CRP, PAD, Warfarin |
Model II# adjusted for: Age, MALE (sex), BMI, Hb, eGFR, CRP, PAD, Warfarin and the interaction terms for following variables: Age, BMI, Hb, eGFR |
*Models are presented as HR (95% CI) P-value. |