Serum T3 Level Can Predict Cardiovascular Events and All-Cause Mortality Rates in CKD Patients with Proteinuria

Figures & data

Table 1. Comparison of basal characteristics and study results between survival and death groups.

Variable	Survival group (N = 135)	Death group (N = 47)	p-Value
Age (years)	53.40 ± 15.32^a	67.04 ± 11.78	0.000
Sex (male)	76 (56.2%)	22 (46.8%)	NS
Diabetes mellitus	72 (53.3%)	32 (68.0%)	NS
Hypertension	118 (87.4%)	43 (91.4%)	NS
Nephrotic syndrome	52 (38.5%)	15 (31.9%)	NS
WBC (L^−1)	7897.78 ± 3154.15	9917.33 ± 3851.17	0.028
Hemoglobin (g/dL)	10.18 ± 2.16	9.23 ± 1.88	0.008
Hematocrit (%)	29.73 ± 6.13	27.21 ± 5.64	0.015
Platelet (×1000 L^−1)	253.64 ± 85.46	238.42 ± 108.76	NS
Sodium (mmol/L)	138.81 ± 4.67	136.38 ± 4.69	0.003
Potassium (mmol/L)	4.68 ± 3.86	4.38 ± 0.92	NS
Glucose (mg/dL)	134.92 ± 59.52	127.86 ± 58.07	NS
BUN (mg/dL)	51.12 ± 26.89	57.86 ± 25.03	NS
Creatinine (mg/dL)	5.07 ± 3.72	4.83 ± 2.71	NS
GFR_MDRD (mL/min)	25.06 ± 27.59	19.46 ± 21.01	NS
Protein (g/dL)	6.29 ± 1.00	6.10 ± 0.91	NS
Albumin (g/dL)	3.31 ± 0.75	3.18 ± 0.67	NS
Cholesterol (mg/dL)	195.90 ± 102.18	165.04 ± 47.44	0.007
Triglyceride (mg/dL)	177.93 ± 102.01	129.60 ± 62.37	0.000
CRP (mg/dL)	1.87 ± 3.17	3.49 ± 6.54	NS
Uric acid (mg/dL)	7.49 ± 2.17	7.47 ± 3.67	NS
T3 (ng/mL)	0.96 ± 0.29	0.83 ± 0.34	0.011
fT4 (ng/dL)	1.13 ± 0.29	1.09 ± 0.27	NS
TSH (μIU/mL)	2.91 ± 3.78	3.06 ± 4.72	NS
24 h urine protein (mg/day)	3304.22 ± 2893.47	2964.38 ± 2331.96	NS
24 h urine albumin (mg/day)	2185.63 ± 2066.90	1368.02 ± 1044.89	0.001
24 h urine albumin/creatinine	2.84 ± 2.58	3.11 ± 3.07	NS

Notes: WBC, white blood cell; BUN, blood urea nitrogen; GFR, glomerular filtration rate; MDRD, modification of diet in renal disease; CRP, C-reactive protein; TSH, thyroid-stimulating hormone; NS, nonsignificant; fT4, free T4. Bold values signifies p-value < 0.05.

^aMean ± SD.

Table 2. Comparison of basal characteristics and study results between normal and cardiovascular event groups.

Variable	No cardiovascular event (N = 126)	Cardiovascular event (N = 41)	p-Value
Age (years)	53.20 ± 15.36^a	62.49 ± 13.71	0.001
Sex (male)	75/134	12/24	NS
Diabetes mellitus	72/134	15/24	NS
Hypertension	117/133	23/24	NS
Nephrotic syndrome	52/134	8/24	NS
Hemoglobin (g/dL)	10.14 ± 2.13	9.89 ± 2.02	NS
Hematocrit (%)	29.63 ± 6.08	29.04 ± 5.95	NS
Platelet (×1000 L^−1)	253.72 ± 82.93	236.64 ± 107.18	NS
Sodium (mmol/L)	138.88 ± 4.78	136.64 ± 3.68	0.011
Potassium (mmol/L)	4.75 ± 3.99	4.21 ± 0.90	NS
BUN (mg/dL)	51.94 ± 27.69	52.16 ± 21.68	NS
Creatinine (mg/dL)	5.25 ± 3.82	4.60 ± 2.32	NS
GFR_MDRD (mL/min)	25.00 ± 28.42	16.69 ± 12.62	0.011
Protein (g/dL)	6.26 ± 1.00	6.38 ± 0.92	NS
Albumin (g/dL)	3.30 ± 0.75	3.40 ± 0.65	NS
Cholesterol (mg/dL)	194.55 ± 105.31	183.07 ± 48.25	NS
Triglyceride (mg/dL)	173.62 ± 100.92	158.28 ± 87.36	NS
CRP (mg/dL)	1.77 ± 3.05	2.79 ± 3.69	NS
T3 (ng/mL)	0.95 ± 0.30	0.92 ± 0.31	NS
fT4 (ng/dL)	1.14 ± 0.29	1.07 ± 0.28	NS
TSH (μIU/mL)	2.76 ± 3.81	3.31 ± 3.55	NS
24 h urine protein (mg/day)	3310.66 ± 2882.69	3117.34 ± 2436.73	NS
24 h urine albumin (mg/day)	2170.27 ± 2071.24	1741.20 ± 1486.46	NS
24 h urine albumin/creatinine	2.80 ± 2.52	3.47 ± 3.40	NS

Notes: WBC, white blood cell; BUN, blood urea nitrogen; GFR, glomerular filtration rate; MDRD, modification of diet in renal disease; CRP, C-reactive protein; TSH, thyroid-stimulating hormone; NS, nonsignificant; fT4, free T4. Bold values signifies p-value < 0.05.

^aMean ± SD.

Table 3. Comparison of basal characteristics and study results between normal and low T3 groups.

Variable	Normal T3 group (N = 178)	Low T3 group (N = 33)	p-Value
Age (years)	56.58 ± 15.10^a	62.21 ± 16.37	NS
Sex (male)	95 (53.3%)	19 (57.5%)	NS
Diabetes mellitus	104 (58.4%)	17 (51.5%)	NS
Hypertension	161 (90.4%)	27 (81.8%)	NS
Nephrotic syndrome	65 (36.5%)	10 (30.3%)	NS
WBC (L^−1)	7764.29 ± 3004.43	10,145.00 ± 3896.26	0.032
Hemoglobin (g/dL)	10.06 ± 2.07	9.29 ± 1.87	NS
Hematocrit (%)	29.45 ± 5.99	27.55 ± 5.74	NS
Platelet (×1000 L^−1)	249.62 ± 90.37	225.34 ± 85.73	NS
Sodium (mmol/L)	138.13 ± 4.77	138.06 ± 4.13	NS
Potassium (mmol/L)	4.71 ± 3.39	4.13 ± 0.84	NS
Glucose (mg/dL)	128.80 ± 56.82	139.56 ± 65.14	NS
BUN (mg/dL)	51.02 ± 26.76	60.51 ± 26.92	NS
Creatinine (mg/dL)	4.89 ± 3.56	5.56 ± 3.04	NS
GFR_MDRD (mL/min)	24.08 ± 25.91	16.44 ± 19.17	NS
Protein (g/dL)	6.26 ± 0.93	5.88 ± 1.03	0.041
Albumin (g/dL)	3.32 ± 0.71	2.95 ± 0.70	0.006
Cholesterol (mg/dL)	187.77 ± 76.44	185.50 ± 136.33	NS
Triglyceride (mg/dL)	163.84 ± 93.48	145.12 ± 87.40	NS
CRP (mg/dL)	2.20 ± 4.19	2.35 ± 4.14	NS
Uric acid (mg/dL)	7.47 ± 2.31	7.47 ± 3.24	NS
fT4 (ng/dL)	1.18 ± 0.45	0.90 ± 0.26	0.001
TSH (μIU/mL)	2.88 ± 3.99	4.07 ± 7.03	NS
24 h urine protein (mg/day)	3105.32 ± 2674.22	3117.31 ± 2798.10	NS
24 h urine albumin (mg/day)	1994.93 ± 1883.84	1595.26 ± 1650.32	NS
24 h urine albumin/creatinine	2.79 ± 2.49	3.58 ± 3.57	0.019

Notes: WBC, white blood cell; BUN, blood urea nitrogen; GFR, glomerular filtration rate; MDRD, modification of diet in renal disease; CRP, C-reactive protein; TSH, thyroid-stimulating hormone; NS, nonsignificant; fT4, free T4. Bold values signifies p-value < 0.05.

^aMean ± SD.

Figure 1. Linear regression analysis of age, renal function, and proteinuria affecting serum thyroid hormone level. (A) T3 and age. (B) T3 and serum albumin. (C) Free T4 (fT4) and 24 h urine protein. (D) fT4 and serum creatinine.

Figure 2. Cause of death of all patients during 36 months.

Note: GI, gastrointestinal.

Figure 3. Kaplan–Meier survival curve during 36 months. (A) Cumulative survival rate (p = 0.000). (B) Cardiovascular event (p = 0.013). (C) Cardiovascular mortality (p = 0.001).

Table 4. Cox regression analysis of factors affecting cardiovascular events and GFR_MDRD.

					95% CI
	β	SE	p-Value	Exp(B)	Lower limit	Upper limit
Sodium	−0.120	0.050	0.016	0.887	0.804	0.978
Total cholesterol	−0.002	0.004	0.551	0.998	0.990	1.006
Hematocrit	0.056	0.047	0.242	1.057	0.963	1.160
Age	0.098	0.027	0.000	1.103	1.046	1.163
Low T3	2.364	0.692	0.001	10.633	2.742	41.239
24 h urine albumin	0.000	0.000	0.837	1.000	1.000	1.000
GFR_MDRD	−0.005	0.018	0.797	0.995	0.961	1.031
Sex	−0.875	0.513	0.088	0.417	0.153	1.138
Diabetes	−0.247	0.544	0.650	0.781	0.269	2.270
Hypertension	1.509	1.199	0.208	4.524	0.432	47.410

Notes: GFR, glomerular filtration rate; MDRD, modification of diet in renal disease; SE, standard error; CI, confidence interval; Exp(B), relative hazards. Bold values signifies p-value < 0.05.

Table 5. Cox regression analysis of factors affecting cardiovascular mortality.

					95% CI
	β	SE	p-Value	Exp(B)	Lower limit	Upper limit
Sodium	−0.071	0.036	0.048	0.931	0.867	0.999
Total cholesterol	0.001	0.003	0.759	1.001	0.996	1.006
Hematocrit	0.033	0.033	0.311	1.034	0.970	1.102
Age	0.051	0.016	0.001	1.052	1.020	1.085
Low T3	1.916	0.543	0.000	6.794	2.342	19.712
24 h urine albumin	0.000	0.000	0.429	1.000	1.000	1.000
GFR_MDRD	−0.004	0.012	0.701	0.996	0.973	1.018
Sex	−0.119	0.369	0.748	0.888	0.431	1.829
Diabetes	0.125	0.395	0.752	1.133	0.522	2.458
Hypertension	1.720	1.114	0.123	5.585	0.629	49.603

Notes: GFR, glomerular filtration rate; MDRD, modification of diet in renal disease; SE, standard error; CI, confidence interval; Exp(B), relative hazards. Bold values signifies p-value < 0.05.

Table 6. Cox regression analysis of factors affecting all-cause mortality.

					95% CI
	β	SE	p-Value	Exp(B)	Lower limit	Upper limit
Sodium	−0.081	0.034	0.017	0.922	0.863	0.986
Total cholesterol	−0.005	0.004	0.209	0.995	0.988	1.003
Hematocrit	−0.009	0.035	0.800	0.991	0.925	1.062
Age	0.077	0.019	0.000	1.080	1.041	1.120
Low T3	1.952	0.465	0.000	7.042	2.832	17.514
24 h urine albumin	0.000	0.000	0.333	1.000	1.000	1.000
GFR_MDRD	0.012	0.008	0.143	1.012	0.996	1.028
Sex	−0.891	0.383	0.020	0.410	0.194	0.869
Diabetes	−0.111	0.408	0.786	0.895	0.402	1.992
Hypertension	0.780	0.690	0.258	2.182	0.564	8.434

Notes: GFR, glomerular filtration rate; MDRD, modification of diet in renal disease; SE, standard error; CI, confidence interval; Exp(B), relative hazards. Bold values signifies p-value < 0.05.

Figure 4. The receiver operating characteristic (ROC) curve of T3 and all-cause mortality (T3 = 0.855; sensitivity, 61.7%; specificity, 63.0%).