Comparison of risk factors for major and minor amputation in diabetic patients included in a Family Health Program

Abstracts

CONTEXTO: Dentre as maiores causas de internamento hospitalar em pacientes com diabetes melito tipos 1 e 2 estão as complicações do pé diabético, principalmente pelas sequelas, muitas vezes incapacitantes, destacando-se as amputações de membros inferiores. A insuficiência vascular periférica ocorre mais precocemente nesses pacientes. A coexistência de neuropatia, isquemia e imunodeficiência favorece o desenvolvimento de infecções nos membros inferiores, que, se não tratadas adequadamente, podem levar a amputações e até à morte. OBJETIVOS: Comparar os fatores de risco para amputações maiores e menores em pacientes diabéticos de um Programa de Saúde da Família do CAIC Virgem dos Pobres III, em Maceió, AL. MÉTODOS: Foram examinados 93 pacientes com o diagnóstico de diabetes melito, sendo avaliada a realização ou não de amputações de membros inferiores. As variáveis analisadas foram: sexo, idade, tipo do diabetes, pressão arterial, amputação prévia (se maior ou menor), alterações dermatológicas, alterações de pulsos arteriais pedioso e tibial posterior, deformidades e neuropatia, e foram classificadas de acordo com a classificação de Wagner e de Texas. RESULTADOS: Todos os pacientes eram diabéticos tipo 2. Verificou-se que 4,30% dos pacientes evoluíram para amputação de membros inferiores. Não se observou variação significativa da hipertensão, deformidades e neuropatia em relação ao grupo de pacientes que foram amputados. Entretanto, a ausência de detecção dos pulsos distais dos membros inferiores revelou-se bastante significativa com relação ao desfecho de amputação. CONCLUSÃO: Deve-se proporcionar aos diabéticos um atendimento ambulatorial adequado para que seja possível prevenir ou minimizar tais complicações.

Amputação; pé diabético; diabetes melito

ORIGINAL ARTICLE

Comparison of risk factors for major and minor amputation in diabetic patients included in a Family Health Program

Elvira Cancio Assumpção^I; Guilherme Benjamin Pitta^II; Ana Carolina Lisboa de Macedo^I; Gustavo Borges de Mendonça^I; Larissa Christyne Araújo de Albuquerque^I; Lívia Cavalcanti Braga de Lyra^I; Raquel Menezes Timbó^I; Ticiana Leal Leite Buarque^III

^IAcadêmicos de Medicina, Universidade de Ciências da Saúde de Alagoas (UNCISAL), Maceió, AL, Brazil

^IIDoutor. Professor adjunto, Departamento de Cirurgia, UNCISAL, Maceió, AL, Brazil

^IIIFisioterapeuta, UNCISAL, Maceió, AL, Brazil. Mestranda, Reabilitação Pulmonar, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil. Especialização, Fisioterapia Cardiopulmonar, UNCISAL, Maceió, AL, Brazil

Correspondence

ABSTRACT

Background: The main causes of hospital admission in patients with type 1 and 2 diabetes mellitus include diabetic foot complications, which may result in particularly disabling sequelae, such as lower limb amputation. Peripheral vascular insufficiency is a common early occurrence in these patients. The coexistence of neuropathy, ischemia, and immunodeficiency favors the development of infections in the lower limbs, which if not treated properly can lead to amputation and even death.

Objective: Compare risk factors for major and minor amputations in diabetic patients in the Family Health Program of the health care facility CAIC Virgem dos Pobres III, in Maceió, state of Alagoas, Brazil.

Methods: We examined 93 patients diagnosed with diabetes, assessing whether or not lower limb amputation was performed. The variables analyzed were: sex, age, type of diabetes, blood pressure, previous amputation (whether major or minor), skin changes, changes in arterial pedal and posterior tibial pulses, deformities, and neuropathy. Variables were classified according to the Wagner and Texas wound classification.

Results: All patients were diagnosed with type 2 diabetes. We found that 4.30% of the patients progressed to lower limb amputation. There was no significant variation in hypertension, deformities and neuropathy in relation to the amputee group. However, absence of distal pulses in the lower limb proved to be quite significant in relation to amputation outcome.

Conclusion: Diabetic patients should receive appropriate outpatient medical care in order to prevent or minimize diabetes-related complications.

Keywords: Amputation, diabetic foot, diabetes mellitus.

Introduction

Diabetic patients have a 15-fold risk of lower limb amputation, which is reportedly more frequent among low socioeconomic status diabetic patients with precarious hygiene conditions and poor access to health care.^1-3 In general, patients seek medical attention with advanced-stage lesions, requiring surgical intervention that often results in impaired capacity for activities of daily living.^4,5 Diabetic foot causes considerable suffering and changes in the patient's lifestyle and quality of life, thereby hindering normal functional performance and, in some cases, eventually leading to amputation with extreme consequences, such as the financial burden on the social security system due to early retirement, impaired work capacity during an individual's most productive years, and acute hospital costs for treatment and rehabilitation.^1,6,7 Peripheral vascular insufficiency occurs earlier in diabetic patients than in nondiabetic patients, affecting infrapatellar arteries in most cases. Ischemia may contribute to or be considered a cause for the progression of lesion in the lower extremities, favoring the development of infections. The coexistence of neuropathy, ischemia, and immunodeficiency favors the development of extensive and severe infections in the lower limbs, which if not treated properly can lead to amputation and even death.¹ Studies indicate that diabetic foot ulcers precede approximately 85% of lower extremity amputations. The long-term course of the disease, prolonged hyperglycemia, dyslipidemia, smoking and alcohol consumption habits, and presence of neuropathy, peripheral vascular disease and previous ulcerative lesions are some risk factors for amputations in individuals with diabetes mellitus.^8-11 "Major" amputations are defined as those involving the proximal part of the foot, leg (below the knee), thigh (above the knee), and hip disarticulation; whereas "minor" amputations are limited to toes or the anterior part of the foot, thus being, in a way, better accepted by patients since there is no need for the use of prosthesis and walking is not affected.^1,10 In order to improve diabetic patient care, it is essential to combine prophylaxis for diabetes mellitus and lesion control and treatment, in association with surgical, antimicrobial and peripheral vascular disease treatment, aiming to reduce diabetes-related morbidity and mortality.^1,11

Methods

The sample was composed of 130 patients with an established diagnosis of type 1 and 2 diabetes mellitus, registered with the Family Health Program (FHP) of the health care facility CAIC Virgem dos Pobres III, in Maceió, state of Alagoas, Brazil. Exclusion criteria were: patients who died, pregnancy, indigenous ancestry, and patients with some degree of impaired autonomy, such as psychiatric disorders. The study was analyzed and approved by the Research Ethics Committee of Universidade de Ciências da Saúde de Alagoas (protocol no. 895) and conducted in accordance with resolution no. 196/96 of the Brazilian Health Council and the Declaration of Helsinki. Consecutive diabetic patients registered with FHP, of the health care facility Virgem dos Pobres III, were included in this study, according to the sample distribution performed by health agents. Based on the preestablished protocol, 93 diabetic patients were evaluated in June-July 2008 and, after signed informed consent was obtained from all patients, they underwent clinical examination, including medical history and physical examination. The primary variable was whether or not lower limb amputation was performed. The variables analyzed in relation to the primary variable were: sex, age, type of diabetes, blood pressure ≥ 140 x 90 mmHg,¹² occurrence of previous amputation, presence of skin changes - such as dryness, fissures, paleness, hyperemia, active ulcer, onychomicosis -, changes in arterial pedal and posterior tibial pulses, presence of deformities, and neuropathy (Semmes-Weinstein 10-g monofilament was used to asses cutaneous pressure perception in both feet, in 10 different places). The patients were also assessed regarding amputation level (whether major or minor). There was no distinction among neuropathic, infectious, ischemic or mixed diabetic feet. Among patients with type 1 and 2 diabetes, lesions were classified according to the Wagner wound classification:

- Grade 0: foot is at risk, presence of interdigital or heel fissure, without apparent infection;

- Grade 1: mild mycotic and/or bacterial superficial infection;

- Grade 2: deep infection, extending to subcutaneous cell tissue, tendon and ligament, without osteomyelitis;

- Grade 3: deep infection, with abscess in the midfoot region, with septic tendinitis or synovitis and osteomyelitis;

- Grade 4: infection and gangrene localized to forefoot and heel;

- Grade 5: infection and gangrene involving the whole foot.

Diabetic foot was also assessed according to the University of Texas wound classification:

- 0: no pathology (history of ulceration absent and protective sensory function intact);

- 1: neuropathy without deformities (both foot deformity and protective sensory function absent);

- 2: neuropathy with deformities (foot deformity present and protective sensory function absent);

- 3: history of pathology (history of Charcot joint and/or neuropathic ulceration, foot deformity present);

- 4A: foot with neuropathic ulceration (non-infected neuropathic ulceration present);

- 4B: foot with acute Charcot neuroarthropathy (Charcot joint present);

- 5: diabetic foot with infection (infected wound present);

- 6: vascular diabetic foot (impairment of blood perfusion).

The Fisher's test was used to analyze interdependence among the above-mentioned variables. Statistical decision was based on descriptive test value (p value). Multivariate analysis used odds ratio (OR) as a measure of association.

Results

Among 130 diabetic patients registered with FHP at CAIC Virgem dos Pobres III, 37 failed to undergo examination, five no longer lived in the neighborhood, eight had died, and 24 were not found at home on the three visits conducted during the study period. Of the 93 patients analyzed, 32.3% were men and 67.7% were women. Patient age ranged from 30 to 82 years, with a mean age of 58.5 years and standard deviation of 11.49. All participants were type 2 diabetic patients. Of the patients analyzed, 4.30% (4/93) progressed to some type of lower limb amputation; of these, 75% (3/4) were women, 25% (1/4) were men, and 3.2% (3/93) had a history of previous ulcer. The mean age of patients who underwent amputation was 61.75 years. Report of previous amputation was verified in 50% (2/4). Of total previous amputations, 50% were major and 50% were minor amputations. Among all 93 patients, 62.4% (58/93) were normotensive, whereas 37.6% (35/93) showed elevated blood pressure at examination. During skin examination of the foot, only 15 patients, i.e., 16.1% (15/93), did not show any skin changes, whereas 83.9% (78/93) had some type of skin change, such as dryness (68.8%), fissures (37.63%), and paleness (18.27%). Some of the patients showed association of more than one skin change. Neurological examination using Semmes-Weistein 10-g monofilament revealed that 49.5% (46/93) of patients did not show any sensory deficit and that 50.5% (47/93) had sensory alterations, suggesting diabetic neuropathy. Physical examination revealed that 94.6% did not have foot deformities and 5.4% had some type of deformity. According to the Fisher's test, the following variables were not significant: amputation vs. hypertension (p = 0.630), presence of deformities (p = 0.201), neurological examination (p = 0.117), Wagner classification (p = 0.064), and previous amputation (p = 0.125). Therefore, the hypothesis of independence between each one of these variables and lower limb amputation outcome was accepted (Table 1).

Table 1
- Hypertension, deformities, neurological examination, Wagner classification, and previous ulcer among patients with and without amputation

Variable	Amputation		Total	p
	No	Yes
Hypertension
No	56	2	58
Yes	33	2	35
Total	89	4	93	0.630
Deformities
No	85	3	88
Yes	4	1	5
Total	89	4	93	0.201
Neurological examination
Altered	43	4	47
Normal	46	0	46
Total	89	4	93	0.117
Wagner classification
0	88	2	90
1	1	1	2
Total	89	3	92	0.064
Previous ulcer
No	87	3	90
Yes	2	1	3
Total	89	4	93	0.125

In relation to amputation vs. arterial pulses, the Fisher's test revealed a significant difference between such variables. The occurrence of amputation was significantly higher when related to absence of pulses (p < 0.05);however, this relation was not so evident regarding left posterior tibial pulse (Table 2). The analysis of lesion severity using the Wagner wound classification revealed that 96.8% (90/93) of patients had grade 0 lesion, whereas 2.2% (2/93) were classified as grade 1 and 1.1% (1/93) as grade 2.

Table 2
- Relation between pedal and posterior tibial pulses

Amputation	Pulses
	RP present	RP absent	LP present	LP absent	RPT present	RPT absent	LPT present	LPT absent
No	69	5	64	8	45	6	49	9
Yes	1	2	1	2	0	3	1	2
p		0.021		0.045		0.003		0.081

None of the statistical tests could be applied to the Texas wound classification, but it was possible to verifiy the prevalence of patients in each lesion type according to such classification (Table 3).

Table 3
- Texas wound classification

Score	Frequency	Percentage	Valid percentage
0	48	51.6	51.6
1	32	34.4	34.4
2	7	7.5	7.5
3	2	2.2	2.2
4A	1	1.1	1.1
4B	0	0	0
5	1	1.1	1.1
6	2	2.2	2.2
Total	93	100	100

Discussion

It is well known that diabetic foot complications are frequent and responsible for about 20% of hospital admissions among diabetic patients.⁷ It is also known that these patients have a 15-fold risk of undergoing amputation, which is reportedly more frequent among low socioeconomic status diabetic patients with precarious hygiene conditions and poor access to health care.^4,5,13 The aim of this study is to detect risk factors involved in major and minor amputations, as well as their occurrence in a low socioeconomic status community included in a FHP. Aware of the importance of actions concerning prevention and treatment of diabetic foot complications, a cross-sectional descriptive study was developed to analyze the association between amputations in diabetic patients and risk factors for their occurrence. Such study aims to reduce amputation rates through a better orientation to improve the planning of therapeutic and prophylactic actions, in an attempt to minimize the number of these interventions that could, at least in part, be avoided.^5,14 The population sample is composed of diabetic outpatients, which might have caused selection bias. This sample selection was chosen due to the lack of studies analyzing the occurence of amputations in diabetic patients, correlating them to possible risk factors in a low-income community attending a FHP. During the months of June and July, 93 patients were evaluated, and we observed that all of them were type 2 diabetic patients, thus preventing an analysis of the variables proposed for type 1 diabetic patients. Most patients were women (67.7%). According to studies by Moss et al.,^1,15 male gender is a risk factor for amputations in type 2 diabetic patients, but of the total sample analyzed in the present study, 4.3% progressed to some type of lower limb amputation; of these, 75% (3/4) were women and 25% (1/4) were men, therefore, not exhibiting a higher prevalence among men. The mean age of patients who progressed to amputation was 61.75 years, revealing that these patients are more susceptible from the sixth decade of life.⁵ Chronic complications, such as neuropathy, seem not to be dependent on sex, being more related to glycemic control, although a higher mortality rate, resulting from infections, has been demonstrated among men.¹⁶ According to Gamba et al.,⁹ hypertension contributed to the development and progression of diabetes-related chronic complications, although no statistically significant differences were observed between amputations and hypertension (p = 0.630) and amputations and deformities (p = 0.201), according to the Fisher's test in this study. The analysis using odds ratio also failed to reveal such relation. A possible explanation may lie in the fact that, in the presence of other variables, the association betwen amputations and hypertension loses its intensity. However, according to the Brazilian Diabetes Association (Sociedade Brasileira de Diabetes),¹⁷ hypertension behaves as a risk factor, when compared to the general population without diabetes. There was evidence of a relation between amputation and neuropathy variables. This corroborates the study by Santos et al.,¹ with respect to chronic complications of diabetes mellitus, such as atherosclerotic disease, immune alterations and presence of peripheral neuropathy, which increase the incidence and severity of disease complications, but these authors did not mention major and minor amputation rates. The presence of peripheral arterial disease has been described by some authors as a risk factor for amputations in diabetic patients.^1,18 Of the total patients analyzed, 44.1% showed distal pulse alterations. When related to amputations and presence, decrease and absence of pedal and posterior tibial pulses, it was confirmed that when there is a change in these events, the patient can progress to amputation if not submitted to revascularization. Therefore, arterial disease may be considered one of the main risk factors for ulceration and, consequently, amputation.¹⁹ Distal pulse palpation is considered a very useful screening tool for arterial occlusive disease.⁵ The occurrence of previous ulcer, when related to amputation, was considered a risk factor, since odds ratio was 14.5, which means that patients with previous ulceration are 14.5 times more likely to progress to amputation. In the present study, the Wagner classification, which is simple and easy to use, was used to distribute the lesions presented by the patients (96.8% were classified as grade 0, 2.2% as grade 1, and 1.1% as grade 2). Therefore, all patients could be classified as foot at risk. This classification was associated with the occurrence of amputations, and odds ratio was 44, highlighting the importance of such classification and its relation to lower limb amputations. According to Nunes et al.⁵ and Santos et al.,¹ grades 4 and 5, in the Wagner classification, are more often associated with amputation outcome. With respect to the Texas classification, none of the statistical tests could be applied, but according to patient classification, 95.6% showed risk of ulceration (types 0 and 3) and 4.4% showed risk of amputation (types 4A, 4B, 5, and 6). In view of the data analyzed, we suggest that the important role FHP plays in primary health care be reinforced, since, based on amputation rates, we could observe that when there is appropriate health care delivery, it is possible to minimize morbidity and mortality of diseases such as diabetes mellitus. We observed that most associated risk factors can be prevented by providing proper primary health care attention.^4,5,8,20,21 We highlight the role played by FHP at Virgem dos Pobres III, which effectively contributed to the improvement of health care delivery and quality of life of individuals, especially those with a diagnosis of diabetes mellitus. We conclude that prevention remains the easiest and most effective approach. We should aim at providing diabetic patients with specialized outpatient medical care, with a multidisciplinary team, in order to provide proper orientation and to reinforce the importance of glycemic control, foot care, and of seeking medical attention as soon as any lower limb lesions occur.^4,5,9,21 In order to reduce the number of amputations, it is necessary to assess in detail all the patient's needs and the care so far provided, thus defining the best approach to improve the patient's condition.

Conclusion

In view of the data obtained, we highlight the prevalence of skin lesions (83.9%) and neuropathies (50.5%), as well as the absence (in 44%) of at least one of the pulses in the study population, which could receive special medical attention in order to avoid the occurrence of amputations. Conducting similar studies is of utmost importance for an assessment of the occurrence and risk factors of amputations, in order to set goals in the control of diabetes mellitus. Thus, its main complications (such as lower extremity amputation) could be reduced, as well as the predicted impact of the disease, through the promotion of good health practices, preventive medical care, and better medical attention, which would consequently lead to a better quality of life for these patients.

References

• 1. Santos VP, Silveira DR, Caffaro RA. Fatores de risco para amputações maiores primárias em pacientes diabéticos. Sao Paulo Med J. 2006;124:66-70.
• 2. Gamba, MA. Amputações por diabetes mellitus: uma prática prevenível? Acta Paul Enf. 1998;11:92-100.
• 3. Aguiar, ET. Doença vascular periférica. . 1999;8:971-80.
• 4. Jorge BH, Borges MF, Brito VN, Santos TG, Thirone AC. Análise clínica e evolução de 70 casos de lesões podais infectadas em pacientes diabéticos. Arq Bras Endocrinol Metab. 1999;43:366-72.
• 5. Nunes MA, Resende KF, Castro AA, Pitta GB, Figueiredo LF, Miranda Jr F. Fatores predisponentes para amputação de membro inferior em pacientes diabéticos internados com pés ulcerados no estado de Sergipe. J Vasc Bras. 2006;5:123-30.
• 6. Miyajima S, Shirai A,Yamamoto S, Okada N, Matsushita T. Risk factors for major limb amputations in diabetic foot gangrene patients. Diabetes Res Clin Pract. 2006;71:272-9.
• 7. Pitta GB, Castro AA, Soares AM, et al. Perfil dos pacientes portadores de pé diabético atendidos no Hospital Escola José Carneiro e na Unidade de Emergência Armando Lages. J Vasc Bras. 2005;4:5-10.
• 8. de Luccia, N. Doença vascular e diabetes. J Vasc Bras. 2003;2:49-60.
• 9. Gamba MA, Gotlieb SLD, Bergamaschi DP, Vianna LAC. Amputações de extremidades inferiores por diabetes mellitus: estudo caso-controle. Rev Saude Publica. 2004;38:399-404.
• 10. Spichler D, Miranda Jr F, Spichler ES, Franco LJ. Amputações maiores de membros inferiores por doença arterial periférica e diabetes melito no município do Rio de Janeiro. J Vasc Bras. 2004;3:111-22.
• 11. Consenso Brasileiro sobre Detecção e Tratamento das Complicações Crônicas de Diabetes Melito. Arq Bras Endocrinol Metab. 1999;43:7-20.
• ¹²
  Sociedade Brasileira de Cardiologia, Sociedade Brasileira de Hipertensão, Sociedade Brasileira de Nefrologia. V Diretrizes Brasileiras de Hipertensão Arterial. http://www.sbn.org.br/Diretrizes/V_Diretrizes_Brasileiras_de_Hipertensao_Arterial.pdf Acesso: 03/04/2008.
• 13. Brasileiro JL, Oliveira WT, Monteiro LB, et al. Pé diabético: aspectos clínicos. J Vasc Bras. 2005;4:11-21.
• 14. Apelqvist J, Larsson J. What is the most effective way to reduce incidence of amputation in the diabetic foot? Diabetes Metab Res Rev. 2000;16 Suppl 1:S75-83.
• 15. Moss SE, Klein R, Klein BE. The prevalence and incidence of lower extremity amputation in diabetic population. Arch Intern Med. 1992;152:610-6.
• 16. Malerbi DA, Franco LJ. Multicenter study of the prevalence of diabetes mellitus and impaired glucose tolerance in the urban Brazilian population aged 30-69 yr. The Brazilian Cooperative Group on the Study of Diabetes Prevalence. Diabetes Care. 1992;15:1509-16.
• ¹⁷
  Ministério da Saúde. Consenso brasileiro sobre diabetes - diagnóstico e classificação do diabetes mellitus e tratamento do diabetes mellitus tipo 2: recomendações da Sociedade Brasileira de Diabetes. Brasília: Ministério da Saúde; 2000.
• 18. Carvalho FS, Kunz VC, Depieri TZ, Cervelini R. Prevalência de amputação em membros inferiores de causa vascular: análise de prontuários. Arq Cienc Saude Unipar. 2005;9:23-30.
• 19. Margolis DJ, Allen-Taylor L, Hoffstad O, Berlin JA. Diabetic neuropathic foot ulcers and amputation. Wound Repair Regen. 2005;13:230-6.
• 20. Jeffcoate WJ. The incidence of amputation in diabetes. Acta Chir Belg. 2005;105:140-4.
• 21. Coelho JC. Prevenção de amputação de membros inferiores no paciente diabético. J Bras Med. 2004;87:11-6.

Publication Dates

• Publication in this collection
  02 Oct 2009
• Date of issue
  June 2009

History

• Accepted
  05 May 2009
• Received
  16 Sept 2008