Carnitine deficiency is associated with late-onset hypogonadism and depression in uremic men with hemodialysis

Figures & data

Table 1. Clinical characteristics of the patients.

	Control subjects	HD patients	p Value
No. of patients	15	26
Age (years old)	57.6 ± 7.1	63.4 ± 10.0	0.056
HD duration (months)  (range)^a		51.3 (10–185)
Body mass index (kg/m^2)	22.3 ± 2.4	21.3 ± 1.9	0.156
Systolic BP (mmHg)	131 ± 21	151 ± 15	0.001
Diastolic BP (mmHg)	81 ± 10	84 ± 11	0.450
Hemoglobin (g/dl)	15.6 ± 0.8	11.5 ± 0.9	<0.001
Total protein (g/dl)	7.37 ± 0.36	6.85 ± 0.49	0.001
LDL-cholesterol (mg/dl)	132.6 ± 38.3	83.2 ± 21.3	<0.001
Triglycerides^a (mg/dl)  (range)	106.9 (38–200)	93.4 (31–442)	0.953
BUN (mg/dl)	14.6 ± 3.5	66.1 ± 15.8	<0.001
Serum Cr (mg/dl)	0.8 ± 0.1	11.9 ± 2.3	<0.001
Uric acid (mg/dl)	5.38 ± 1.40	8.39 ± 1.47	<0.001
Corrected Ca (mg/dl)	8.65 ± 0.24	9.32 ± 0.50	<0.001
Phosphate (mg/dl)	3.22 ± 0.42	4.60 ± 1.14	<0.001
Intact-PTH (pg/ml) (range)^a	50.0 (31–94)	93.5 (25–250)	<0.001
β2-MG (mg/l)	1.6 ± 0.4	28.1 ± 6.2	<0.001
Total carntine (µmol/l)	59.0 ± 6.0	43.1 ± 10.4	<0.001
Free carnitine (µmol/l)	48.1 ± 5.7	25.2 ± 5.7	<0.001
Acyl carnitine (µmol/l)	11.0 ± 2.2	17.9 ± 5.7	<0.001
Acyl/free carnitine ratio	0.23 ± 0.05	0.72 ± 0.18	<0.001
Free testosterone (pg/ml)	10.13 ± 3.54	6.06 ± 2.48	<0.001
Kt/V		1.57 ± 0.10
AMS scale		36.8 ± 11.8
SDS		43.9 ± 10.2
DM (No.) (±)	15/0	16/10
Medication
RAS inhibitors (No.) (±)	15/0	3/23
Statins (No.) (±)	15/0	21/5

Values are shown as mean ± SD or range. No., number; HD, hemodialysis; BP, blood pressure; LDL, low-density lipoprotein; BUN, blood urea nitrogen; Cr, creatinine; Ca, calcium; PTH, parathyroid hormone; β₂-MG, β₂-microglobulin; AMS, aging male symptom; SDS, self-rating depression scale; DM, diabetes mellitus; and RAS, renin–angiotensin system.

^aThese variables are shown in the original scale after using log-transformed values.

Figure 1. Correlation between AMS scale and SDS in male HD patients (n = 19). AMS, aging male symptom; SDS, self-rating depression scale; and HD, hemodialysis.

Figure 2. (A) Correlation between AMS scale and free carnitine levels in male HD patients (n = 26). (B) Correlation between SDS and free carnitine levels in male HD patients (n = 19). AMS, aging male symptom; SDS, self-rating depression scale; and HD, hemodialysis.

Table 2. Univariate and multiple stepwise regression analysis for the correlates of AMS scale.

	Univariate			Multiple stepwise regression
Variables	β	SE	p Value	β	SE	p Value
Age	0.023	0.240	0.910
HD duration^a	0.391	2.899	0.048
Body mass index	−0.083	1.245	0.685
Systolic BP	0.067	0.161	0.743
Diastolic BP	0.049	0.219	0.810
Hemoglobin	−0.026	2.754	0.899
Total protein	0.087	4.929	0.672
LDL-cholesterol	0.251	0.110	0.217
Triglyceride^a	−0.060	3.652	0.770
BUN	−0.160	0.151	0.435
Serum Cr	−0.089	1.069	0.667
Uric acid	0.234	1.597	0.249
Corrected Ca	0.139	4.783	0.499
Phosphate	0.067	2.120	0.746
Intact-PTH^a	0.046	4.940	0.825
β2-MG	0.114	0.388	0.579
Total carnitine	−0.483	0.204	0.013
Free carnitine	−0.559	0.350	0.003	−0.559	0.313	0.003
Acyl carnitine	−0.312	0.400	0.121
Acyl/free ratio	0.148	13.009	0.472
Free testosterone	−0.078	0.973	0.706
Kt/V	−0.062	23.385	0.765
DM	0.269	4.692	0.184
RAS inhibitors	−0.119	7.366	0.563
Statins	−0.061	6.003	0.768

β, standardized regression coefficients; SE, standard error; AMS, aging male symptom; HD, hemodialysis; BP, blood pressure; LDL, low-density lipoprotein; BUN, blood urea nitrogen; Cr, creatinine; Ca, calcium; PTH, parathyroid hormone; β₂-MG, β₂-microglobulin; DM, diabetes mellitus; RAS, renin–angiotensin system.

^aThese variables are shown in the original scale after using log-transformed values. R² = 0.313.

Table 3. Univariate and multiple stepwise regression analysis for the correlates of SDS.

	Univariate			Multiple stepwise regression
Variables	β	SE	p Value	β	SE	p Value
Age	−0.183	0.248	0.454
HD duration^a	0.110	3.024	0.653
Body mass index	0.081	1.278	0.742
Systolic BP	−0.011	0.198	0.964
Diastolic BP	0.178	0.229	0.466
Hemoglobin	−0.190	2.512	0.435
Total protein	0.058	4.901	0.812
LDL-cholesterol	0.306	0.124	0.202
Triglyceride^a	−0.315	3.341	0.188
BUN	0.063	0.149	0.797
Serum Cr	−0.105	1.064	0.699
Uric acid	0.360	1.534	0.130
Corrected Ca	−0.018	4.707	0.941
Phosphate	0.215	1.905	0.376
Intact-PTH^a	0.503	4.096	0.028
β2-MG	−0.110	0.368	0.655
Total carnitine	−0.343	0.215	0.150
Free carnitine	−0.520	0.340	0.022	−0.520	0.340	0.022
Acyl carnitine	−0.082	0.426	0.739
Acyl/free ratio	0.400	11.501	0.089
Free testosterone	−0.148	1.111	0.546
Kt/V	−0.248	20.130	0.305
DM	0.253	4.696	0.297
RAS inhibitors	−0.309	6.250	0.198
Statins	−0.033	5.439	0.893

β, standardized regression coefficients; SE, standard error; SDS, self-rating depression scale; HD, hemodialysis; BP, blood pressure; LDL, low-density lipoprotein; BUN, blood urea nitrogen; Cr, creatinine; Ca, calcium; PTH, parathyroid hormone; β₂-MG, β₂-microglobulin; DM, diabetes mellitus; RAS, renin–angiotensin system.

^aThese variables are shown in the original scale after using log-transformed values. R² = 0.270.