Increased Serum Cystatin C Levels Were Associated with Depressive Symptoms in Patients with Type 2 Diabetes

Figures & data

Table 1 Clinical Characteristics in 254 Patients with DM at Baseline

Variables	All Patients with DM (n=254)
Age (years)	63.2±7.9
Gender (male), n (%)	120 (47.2)
BMI (kg/m2)	25.6±5.3
Current smoker, n (%)	72 (28.3)
Current drinker, n (%)	87 (34.3)
Admission systolic BP (mmHg)	138.1 (132.6–147.8)
Admission diastolic BP (mmHg)	85.6 (80.3–95.3)
Antidepressant therapy, n (%)	31 (9.6)
CESD score	10.7 ± 9.2
Depressive symptoms, n (%)	53 (20.9)
CVD history
Hypertension, n (%)	135 (53.1)
Coronary heart disease, n (%)	31 (12.2)
Stroke, n (%)	24 (9.4)
CKD history	11 (43.3)
Laboratory measurements
eGFR (mL/min/1.73 m^2)	62.5 (57.6–65.3)
Hs-CRP (pg/mL)	8.3 (5.1–15.3)
Hb (g/L)	108.4±4.6
ALB (g/L)	34.5 ±3.9
FBG (mmol/L)	12.8±2.9
HbA1c (%)	10.1 (8.1–12.4)
HDL (mmol/L)	1.3±0.2
LDL (mmol/L)	2.7±1.1
Serum cystatin C (mg/L)	1.39 (1.03–1.52)

Note: Data are presented as mean ± SD for normally distributed data, as median (interquartile range) for nonnormally distributed data, and as n (%) for categoric variables.

Abbreviations: DM, diabetes mellitus; BMI, body mass index; BP, blood pressure; CESD, Centre for Epidemiological Studies Depression; CVD, cardiovascular disease; CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; Hb, hemoglobin; hs-CRP, hs-C-reactive protein; ALB, albumin; FBG, fasting blood glucose on admission; HbA1c, glycosylated hemoglobin; HDL, high-density lipoprotein; LDL, low-density lipoprotein.

Table 2 Multivariate Linear Regression Analysis for the Association Between the Serum Cystatin C Levels and CESD Score in 254 Patients with DM at Baseline

Variables	R^2	Sβ	95% CI	P value
Serum cystatin C (mg/L) (per 1-SD increase)
Model 1	0.124	0.153	0.104–0.224	<0.001
Model 2	0.153	0.143	0.095–0.200	<0.001
Model 3	0.196	0.127	0.083–0.185–	0.002

Notes: Model 1: No adjustment Model 2: Adjusted for age, gender, BMI, current smoker, current drinker, admission systolic and diastolic BP and CVD history. Model 3: Adjusted for age, gender, BMI, current smoker, current drinker, admission systolic and diastolic BP, CVD history and laboratory measurements.

Abbreviations: DM, diabetes mellitus; CESD, Centre for Epidemiological Studies Depression; BMI, body mass index; BP, blood pressure; CVD, cardiovascular disease.

Table 3 Cox Proportional Hazard Analysis for the Association of Serum Cystatin C Levels and Depressive Symptoms

Variables	Model 1	Model 2	Model 3
Serum cystatin C (mg/L) (per 1-SD increase)
Quartile 1	1.000 (ref.)	1.000 (ref.)	1.000 (ref.)
Quartile 2	1.650 (1.241–3.319)	1.540 (1.217–3.115)	1.462 (1.200–2.813)
Quartile 3	2.329 (1.562–3.993)	2.148 (1.456–3.495)	1.832 (1.320–3.391)
Quartile 4	2.738 (1.773–4.405)	2.684 (1.598–4.123)	2.360 (1.500–3.891)
P-trend	<0.001	<0.001	<0.001

Notes: Model 1: No adjustment. Model 2: Adjusted for age, gender, BMI, current smoker, current drinker, admission systolic and diastolic BP and CVD history. Model 3: Adjusted for age, gender, BMI, current smoker, current drinker, admission systolic and diastolic BP, CVD history and laboratory measurements.

Abbreviations: DM, diabetes mellitus; CESD, Centre for Epidemiological Studies Depression; BMI, body mass index; BP, blood pressure; CVD, cardiovascular disease.

Figure 1 Kaplan–Meier analysis of depression events free stratified into 2 groups by the median levels of serum cystatin C.

Table 4 Sensitivity Analysis for the Association of Serum Cystatin C Levels and Depressive Symptoms

Variables	Model 1	Model 2	Model 3
Serum cystatin C (mg/L) (per 1-SD increase)
Quartile 1	1.000 (ref.)	1.000 (ref.)	1.000 (ref.)
Quartile 2	1.631 (1.320–3.211)	1.565 (1.281–3.001)	1.501 (1.201–2.991)
Quartile 3	2.161 (1.439–3.518)	2.120 (1.328–3.204)	2.004 (1.298–3.092)
Quartile 4	2.337 (1.640–4.343)	2.201 (1.600–4.112)	2.102 (1.473–3.685)
P-trend	<0.001	0.002	0.009

Notes: Model 1: Antidepressant therapy. Model 2: Adjusted for age, gender, BMI, current smoker, current drinker, admission systolic and diastolic BP, CVD history and antidepressant therapy Model 3: Adjusted for age, gender, BMI, current smoker, current drinker, admission systolic and diastolic BP, CVD history, laboratory measurements and antidepressant therapy.

Abbreviations: DM, diabetes mellitus; CESD, Centre for Epidemiological Studies Depression; BMI, body mass index; BP, blood pressure; CVD, cardiovascular disease.

Table 5 Stratified Analysis for the Association of Serum Cystatin C Levels and Depressive Symptoms

Variables	Model 1	Model 2	Model 3
CKD history (yes)
Serum cystatin C (mg/L) (per 1-SD increase)	2.214 (1.628–3.662)	2.109 (1.546–3.301)	1.988 (1.458–3.074)
P value	<0.001	<0.001	<0.001
CKD history (no)
Serum cystatin C (mg/L) (per 1-SD increase)	1.621 (1.202–2.335)	1.4092 (0.993–1.944)	1.273 (0.917–1.592)
P value	0.031	0.076	0.112

Notes: Model 1: No adjustment Model 2: Adjusted for age, gender, BMI, current smoker, current drinker, admission systolic and diastolic BP and CVD history. Model 3: Adjusted for age, gender, BMI, current smoker, current drinker, admission systolic and diastolic BP, CVD history and laboratory measurements.

Abbreviations: DM, diabetes mellitus; CESD, Centre for Epidemiological Studies Depression; BMI, body mass index; BP, blood pressure; CVD, cardiovascular disease.