We enrolled 1347 participants in this study, and 649 (63.3%) were male. The average age was 74 ± 7 years old. 252 (18.7%) participants were robust, 835 (63.3%) participants were pre-frail, and 242 (18%) participants were frail (Table 1). Frail participants were older and had a lower BMI. Frail participants were more likely to have DM, HTN, and CHF. In the laboratory data, frail participants had lower ALT, eGFR, serum albumin, cholesterol, higher ACR, and hCRP.
Table 1
Characteristics of all participants
Characteristics | Robust | Pre-frail | Frail | p |
| N = 252 | N = 853 | N = 242 | |
Age (year) | 73 ± 6 | 74 ± 6 | 78 ± 7 | < 0.001 |
Male | 240 (95.2) | 314 (36.8) | 95 (39.3) | < 0.001 |
BMI (kg/m2) | 24.5 ± 3.1 | 24.6 ± 3.6 | 23.9 ± 4.0 | 0.031 |
HTN | 114 (45.2) | 448 (52.5) | 139 (57.4) | 0.023 |
DM | 28 (11.1) | 132 (15.5) | 56 (23.1) | 0.001 |
CHF | 68 (27.0) | 261 (30.6) | 97 (40.1) | 0.004 |
SBP (mmHg) | 140 ± 16 | 137 ± 17 | 137 ± 17 | 0.039 |
DBP (mmHg) | 81 ± 11 | 78 ± 11 | 74 ± 11 | < 0.001 |
Hb (g/dl) | 14.5 ± 1.2 | 13.5 ± 1.4 | 13.1 ± 1.6 | < 0.001 |
ALT (IU/L) | 25 ± 13 | 24 ± 14 | 21 ± 11 | < 0.001 |
BUN (mg/dl) | 15 ± 5 | 15 ± 5 | 17 ± 10 | < 0.001 |
Creatinine (mg/dl) | 1.0 [0.9, 1.1] | 0.8 [0.7, 1.0] | 0.8 [0.7, 1.1] | < 0.001 |
eGFR (ml/min/1.73m2) | 74 [64, 83] | 77 [66, 88] | 73 [60, 90] | 0.005 |
Uric acid (mg/dl) | 6.2 ± 1.2 | 5.8 ± 1.5 | 5.8 ± 1.7 | < 0.001 |
Albumin (g/dl) | 4.3 ± 0.3 | 4.3 ± 0.3 | 4.1 ± 0.4 | < 0.001 |
HCRP (mg/dl) | 0.1 [0, 0.2] | 0.1 [0, 0.2] | 0.2 [0.1, 0.3] | < 0.001 |
hCRP(log-transfomred) | -2.4 ± 1.1 | -2.2 ± 1.2 | -1.8 ± 1.1 | < 0.001 |
Cholesterol (mg/dl) | 189 ± 33 | 194 ± 36 | 187 ± 34 | 0.021 |
Triglyceride (mg/dl) | 108 ± 59 | 120 ± 80 | 114 ± 66 | 0.054 |
HDL (mg/dl) | 45 ± 14 | 47 ± 14 | 47 ± 13 | 0.095 |
LDL (mg/dl) | 115 ± 28 | 115 ± 32 | 111 ± 28 | 0.222 |
ACR (mg/g) | 7 [4, 17] | 9 [5, 22] | 13 [7, 40] | < 0.001 |
ACR (log-transformed) | 2.2 ± 1.3 | 2.5 ± 1.4 | 2.9 ± 1.5 | < 0.001 |
BMI: body mass index, HTN: hypertension, DM: diabetes mellitus, CHF: congestive heart failure, CVA: cerebral vascular accident, SBP: systolic blood pressure, DBP: diastolic blood pressure, PR: pulse rate, Hb: hemoglobin, ALT: alanine transaminase, BUN blood urea nitrogen, eGFR: estimated glomerular filtration rate, hCRP: high-sensitivity c-reactive protein, HDL: high-density lipoprotein, LDL: low-density lipoprotein, ACR: urine albumin-creatinine ratio |
ACR (log-transformed) was associated with frail (Table 2) in univariate (p < 0.001) and multivariable logistic regression (p = 0.006). The likelihood of being frail was increased with advancing age (p < 0.001 and < 0.001) and diabetes (p = 0.001 and 0.003) in univariable and multivariable regression. Males (p = 0.002 and < 0.001) and higher BMI (p = 0.010 and 0.038) were associated with a lower likelihood of being frail. An increased ALT (p < 0.001 and p = 0.029), and cholesterol (p = 0.033 and p = 0.001) were associated with less likelihood of frail in univariable and multivariable regression. An increased hCRP was associated increased chance of being frail. Factors related to frail in both univariable and multiple variable regression were selected in the model (Table 3). ACR (OR 1.12, 95% CI 1.05–1.25), hCRP (OR 1.36, 95% CI 1.19–1.54), age (OR 1.10, 95% CI 1.08–1.12), male (OR 0.53, 95% CI 0.38–0.72), BMI (OR 0.95, 95% CI 0.90–0.99), diabetes (OR 1.81, 95% CI 1.22–2.65), and ALT (OR 0.98, 95% CI 0.97-1.00) were independently associated with frail.
Table 2
The odds ratio of pre-frailty or frailty in univariable and multivariable logistic regression
Factors | Uunivariable | Multivariable |
| OR | 95% CI | p | OR | 95% CI | p |
ACR (log-transformed, mg/g) | 1.22 | 1.11–1.34 | < 0.001 | 1.19 | 1.04–1.37 | 0.006 |
Age (years) | 1.10 | 1.08–1.13 | < 0.001 | 1.10 | 1.08–1.13 | < 0.001 |
Male | 0.64 | 0.48–0.85 | 0.002 | 0.51 | 0.36–0.70 | < 0.001 |
BMI (kg/m2) | 0.95 | 0.91–0.99 | 0.010 | 0.96 | 0.92-1.00 | 0.038 |
DM | 1.78 | 1.26–2.49 | 0.001 | 1.69 | 1.12–2.51 | 0.003 |
HTN | 1.30 | 0.99–1.73 | 0.064 | 0.98 | 0.71–1.36 | 0.918 |
CHF | 1.58 | 1.18–2.10 | 0.002 | 1.27 | 0.92–1.74 | 0.113 |
ALT (IU/L) | 0.97 | 0.96–0.98 | < 0.001 | 0.98 | 0.97-1.00 | 0.029 |
hCRP (log-transformed, mg/dl) | 1.32 | 1.22–1.55 | < 0.001 | 1.66 | 1.38–2.02 | < 0.001 |
Cr (mg/dl) | 1.18 | 0.94–1.45 | 0.079 | 1.14 | 0.84–1.53 | 0.070 |
eGFR (ml/min/1.73m2) | 1.00 | 0.99-1.00 | 0.122 | 1.00 | 0.99–1.01 | 0.392 |
Cholesterol (mg/dl) | 1.00 | 0.99-1.00 | 0.033 | 0.96 | 0.94–0.99 | 0.001 |
Triglyceride (mg/dl) | 1.00 | 1.00–1.00 | 0.489 | 1.01 | 1.00-1.01 | 0.017 |
HDL (mb/dl) | 1.00 | 0.99–1.01 | 0.722 | 1.03 | 1.01–1.06 | 0.010 |
LDL (mg/dl) | 1.00 | 0.99-1.00 | 0.084 | 1.04 | 1.01–1.06 | 0.002 |
ACR: urine albumin-creatinine ratio, BMI: body mass index, HTN: hypertension, DM: diabetes mellitus, CHF: congestive heart failure, ALT: alanine transaminase, Cr: creatinine, eGFR: estimated glomerular filtration rate, hCRP: high-sensitivity c-reactive protein, HDL: high density lipoprotein, LDL: low density lipoprotein |
Table 3
Odd ratio (OR) of frail in multivariable logistic regression
Factors | OR | 95% CI | p |
ACR (log-transformed, mg/g) | 1.12 | 1.05–1.25 | 0.001 |
hCRP (log-transformed, mg/dl) | 1.36 | 1.19–1.54 | < 0.001 |
Age (years) | 1.10 | 1.08–1.12 | < 0.001 |
Male | 0.53 | 0.38–0.72 | < 0.001 |
BMI (kg/m2) | 0.95 | 0.90–0.99 | 0.011 |
DM | 1.81 | 1.22–2.65 | 0.003 |
ALT (IU/L) | 0.98 | 0.97-1.00 | 0.027 |
Cholesterol (mg/dl) | 1.00 | 0.99-1.00 | 0.125 |
BMI: body mass index, DM: diabetes mellitus, ALT: alanine transaminase, hCRP: high-sensitivity c-reactive protein |
We showed the OR of frail according to ACR in Fig. 1. The OR and 95% CI of the OR were increased with the increased urinary ACR in multivariable logistic regression with adjustments for age, gender, BMI, diabetes, eGFR, hCRP and ALT. A histogram of urinary ACR (black bars) showed this distribution of ACR after log transformation.
We presented the OR and 95% CI of frail in subgroups (Fig. 2) as a forest plot. The likelihood of frail was not different in participants with an ACR < 30 mg/g, 30–300 mg/g, and > = 300mg/g. Participants older than 90 had the highest likelihood of being frail, followed by participants aged between 80–89 and between 70–79 years. The possibility of being frail was higher in underweight participants (BMI < 18). Diabetic participants were likelier to be frail, and the OR of frail was 1.81 (95% CI 1.23–2.65, p = 0.002). Participants with CKD stage 1 were more likely to be frail than participants with no CKD (OR 2.74, 95% CI 1.05–7.07). The participants with an hCRP 1–3 mg/dl were more at risk of frail, and the OR of frail was 3.00 (95% CI 1.42–6.10, p = 0.003).