Risk Factors for Major Amputation in Diabetic Foot Ulcer Patients

Figures & data

Table 1 Clinical Characteristics and Univariate Analysis of Risk Factors for Patients with Major Amputation and Minor Amputation

Characteristic/Variable	Major Amputation Group (n=139)	Minor Amputation Group (n= 224)	p value	OR	95% CI
Age, years	65.68±11.00	65.24±10.85	0.71
Age			0.38
<45	9(6.5)	11(4.9)	0.39
46–55	12(8.6)	35(15.6)	0.12
56–65	45(32.4)	67(22.9)	0.69
66–75	50(36.0)	69(30.8)	0.80
76–85	20(14.4)	39(17.4)	0.38
>85	3(2.2)	3(1.3)	0.83
Gender			0.10
Female	34(24.5)	73(32.6)
Male	105(75.5)	151(67.4)
Smoking (present or past)	94(67.6)	121(54)	0.01	1.78	1.14–2.77
Diabetes duration, years	15.22±6.64	15.53±8.43	0.71
Ulcer duration, months	4.35±6.00	2.82±3.52	0.01	1.08	1.02–1.14
MDR bacterial infection	79(61.2)	137(56.8)	0.44
Wagner classification			0.00
3	15(10.8)	57(25.4)
4	64(46.0)	114(50.9)	0.02	2.13	1.12–4.07
5	60(43.2)	53(23.7)	0.00	4.30	2.18–8.48
ABI			0.00
≥0.4	54(38.8)	188(83.9)
<0.4	85(61.2)	36(16.1)	0.00	8.22	5.02–13.46
Previous amputation history	58(41.7)	49(21.9)	0.00	2.56	1.61–4.06
WBC, ×10^9/L	15.21±8.22	9.79±4.52	0.00	1.17	1.12–1.22
ALB, g/L	28.91±4.56	33.63±5.83	0.00	0.82	0.78–0.86
Hb, g/L	96.03±19.16	111.30±20.95	0.00	0.96	0.95–0.97
HbA1c, %	8.80±1.85	8.10±1.82	0.00	1.23	1.09–1.38
D-Dimer	1.32±1.50	0.98±1.01	0.01	1.26	1.04–1.52
Fib, g/L	6.38±1.79	5.43±1.83	0.00	1.33	1.17–1.50
APTT, second	36.32±9.19	32.04±7.33	0.00	1.07	1.04–1.10
Comorbidities
hypertension	82(59.0)	149(66.5)	0.18
hyperlipidemia	17(12.2)	22(9.8)	0.49
CAD	95(68.3)	124(55.4)	0.02	1.74	1.11–2.71
PAD	111(79.9)	150(67.0)	0.01	1.96	1.19–3.22
Cerebral infarction	41(29.5)	74(33.0)	0.56
Renal insufficiency	20(14.4)	41(18.3)	0.33

Notes: Continuous variables are presented as mean and standard deviation (M±SD); categorical parameters are presented as counts, with percentages in parentheses, n (%).

Abbreviations: OR, odds ratio; CI, confidence interval; MDR, multi-drug resistant; ABI, ankle brachial index; WBC, white blood cell; ALB, plasma albumin; Hb, hemoglobin; HbA1c, glycosylated hemoglobin; Fib, fibrinogen; APTT, activated partial thromboplastin time; CAD, coronary artery disease; PAD, peripheral arterial disease; CRI, chronic renal insufficiency.

Figure 1 Selection flow diagram.

Table 2 Multivariate Analysis of Risk Factors for Patients with Major Amputation and Minor Amputation

Variable	p value	OR	95% CI
Smoking (present or past)	0.01	2.58	1.31–5.07
Ulcer duration, months	0.13
Wagner classification	0.01
3		1
4	0.06
5	<0.01	5.50	1.89–16.01
ABI	<0.01
≥0.4		1
<0.4	<0.01	15.77	7.51–33.13
Previous amputation history	0.02	2.31	1.17–4.53
WBC, ×10^9/L	<0.01	1.10	1.04–1.16
ALB, g/L	<0.01	0.88	0.81–0.95
Hb, g/L	0.01	0.98	0.96–1.00
HbA1c, %	0.03	1.23	1.03–1.48
D-Dimer	0.81
Fib, g/L	0.48
APTT, second	0.01	1.05	1.01–1.09
CAD	0.01	2.67	1.35–5.29
PAD	0.97

Abbreviations: OR, odds ratio; CI, confidence interval; ABI, ankle brachial index; WBC, white blood cell; ALB, plasma albumin; Hb, hemoglobin; HbA1c, glycosylated hemoglobin; Fib, fibrinogen; APTT, activated partial thromboplastin time; CAD, coronary artery disease; PAD, peripheral arterial disease.

Figure 2 Independent risk factors for major amputation. (A) categorical variable (amputation history, smoking, CAD, ABI<0.4, Wagner 5); (B) continuous variables (APTT, HbA1c, Hb, ALB, WBC).

Abbreviations: OR, odds ratio; CI, confidence interval; CAD, coronary artery disease; ABI, ankle brachial index; APTT, activated partial thromboplastin time; HbA1c, glycosylated hemoglobin; Hb, hemoglobin; ALB, plasma albumin; WBC, white blood cell.