INTRODUCTION

In 2017, the prevalence of Diabetes Mellitus (DM) was estimated at 8.8% of the world population aged 20 to 79 years, totaling approximately 425 million people, with a tendency of 9.9% for the year 2045 and may reach 628.6 million citizens worldwide. It has stood out among the most growing and important public health problems, being among the top ten causes of death worldwide¹ .

Persistent hyperglycemia results in tissue damage and complications in the kidneys, eyes, nerves and peripheral vascular system are common. The main complications of DM are diabetic retinopathy, diabetic neuropathy, nephropathy, peripheral arterial disease, coronary heart disease, cerebrovascular disease, and diabetic foot syndrome² .

Within the group of complications of DM involving the cardiovascular system, hypertension is highlighted, which occurs as a result of changes in autonomic function and the damage that DM causes in the organs, leading diabetic patients to present greater variability of blood pressure and a difficulty in reducing nocturnal blood pressure values³ .

Among the changes, diabetic foot ulcers and associated amputations are the most common complications, producing disability and increasing care costs^{4 , 5} .

The term diabetic foot (DF) refers to any foot injury in people with DM, such as infection, ulcer, tissue destruction, which appears as a result of disease complications⁶ . It is the leading cause of non-traumatic amputations in Western countries, which can cause death or physical and mental disability, negatively affecting quality of life and representing a high cost to society^{7 , 8} .

The development of DF is directly related to the duration of DM and consequently with age, therefore, delayed diagnosis and initiation of appropriate treatment increases the occurrence of complications and eventually amputations⁹ .

It is estimated that approximately 15% of DM patients will have lifelong lower extremity ulcers and between 17 and 20% of them will have some type of amputation¹⁰ .

The prevalence of foot ulcers affects 4% to 10% of people with DM. About 40% to 60% of non-traumatic lower limb amputations occur in these patients and 85% of them are preceded by foot ulcers^{9 , 11} .

From this perspective, it becomes evident the need for commitment by government leaders and health managers to create mechanisms that minimize the onset, as well as the aggravation of DM² .

These efforts should be directed to both the reorganization of care for people with DM and the provision of necessary inputs for disease management, in order to reduce the costs arising from early non-detection and complications related to lack of metabolic control¹² .

In Brazil, Primary Health Care follows the principles of universality, accessibility, bond, continuity of care, comprehensive care, accountability, humanization, equity and social participation. We highlight the care model of the Family Health Strategy (FHS), which is based on the work of multiprofessional teams. The service is focused on local reality and the needs of the population, with the main objective of bringing families closer to the health service, facilitating access and strengthening bond¹³ .

Gathering data on DM complications can attract the attention of public authorities, enabling effective and rapid action, focused at the local level, with expanded potential, to focus efforts on the worst conditions identified. This favors the rationalization of resources for high, medium and low complexity in health care. With this knowledge, measures can be rationally chosen to face the problems in professional practice, increasing the chances of their resolution.

Based on previous statements , the present study aimed to analyze the prevalence of DF and related risk factors in the diabetic population residing in Espírito Santo State, Brazil.

METHODS

RESULTS

DISCUSSION

Our findings showed that, in the State of Espírito Santo, Brazil, the prevalence of DF were higher in type 2 DM n = 228 (3.3%), and even higher in DM coexistence and hypertension n = 2,480 (4.5%). These numbers converge with results of a recent systematic meta-analysis review on prevalence of DF, in which DF lesions were also more prevalent in type 2 DM patients (6.4%) than in patients with type 1 DM (5; 5%) and high prevalence of hypertension (63.4%) in the population studied¹⁷ .

German researchers also observed a higher prevalence of DF in the type 2 DM population (13.7%) compared with type 1 DM (5.1%) and correlation with hypertension in both samples, in a retrospective cohort study with a total of 899 patients with DM type 1 and 4,007 with type 2 DM¹⁸ . A study carried out in Brazil, a much higher prevalence was estimated in the population of Recife city with 9% among individuals with type 2 DM (n = 1,374 - 95% CI)¹⁹ .

In Romania, when approaching 126 patients with type 1 DM and 142 with type 2 DM, a prevalence of peripheral neuropathy was found in 28.7% of patients with type 1 DM and 50.7% of those with type 2 DM, demonstrating a higher risk of PD syndrome in patients with type 2 DM²⁰ .Peripheral neuropathy is an important triggering factor for foot injuries in people with DM¹ .

In type 1 diabetics, the lower prevalence of DF may be justified by good glycemic control related to intensive insulin use, slowing the chain of pathophysiological events of microvascular complications, being associated with an improvement in skin microcirculation and a lower incidence of ischemic foot ulcers²¹ . The higher prevalence among people with DM associated with hypertension may be justified by the fact that hypertension contributes significantly to microvascular disease in DM, responsible for the pathophysiological changes that determine DF²² .

When analyzing the literature, it is observed that the prevalence of DF in the state of Espirito Santo is below the national average, which may be correlated with low notification of cases, since the detection of this condition is directly related to the foot examination, however, this analysis was not the object of this research. In 2013, the National Health Survey showed that in the state of Espírito Santo the proportion of diabetics who never had their feet clinicallyexamined was higher (58.64%) than those who had²³ .

A study conducted in Spain with 443 type 2 diabetic patients followed by primary care services showed that only 37% had their feet examined²⁴ .In another study, South African researchers demonstrated that only 22.2% of 200 type 2 diabetics reported having their feet examined before developing foot problems²⁵ .

Regarding the variable gender, the highest prevalence of DF was observed in males in both types of DM. In DM type 1 n = 44 (3.9%) RP = 1.77 p = 0.0180 (CI = 95%), DM type 2 n = 110 (3.8%) RP = 1.34p = 0.0307 (CI = 95 %) and DM with hypertension n = 901 (5.2%) RP = 1.22 p = <0.0001 (CI = 95%). The results converge with the EURODIALE study, which shows that males are at higher risk of developing DF as well as have a higher frequency of foot injuries²⁶ .

A cross-sectional study of 1,515 people with type 2 DM, aged over 40 years, in southern Brazil also showed that risk of DF was more frequent among men n = 97 (17.3%) than in women n = 108 (11.3%)²⁷ . In Pernambuco, Brazil, a survey conducted with 1,374 people with type II DM also evidenced a higher prevalence of DF in males n = 410 (9.8%) than females n = 963 (8.6%) with PR. = 1.1319.However, a slightly higher prevalence in females (51.46%) was observed in the Brazilian population, as revealed by the National Health Survey²³ .

The higher prevalence of DF in men has been associated with the fact that men tend to be more careless about their own health care, and more reluctant to seek medical attention and follow preventive recommendations^{28 , 29} .

Higher DF prevalence by age group was observed among individuals aged 60 years and older in type 1 DM n = 23 (4.4%) PR = 3.41, 2.09 and 1.26 p = 0.0174 and in type 2 DM n = 96 (4.5%) PR = 2.24, 1.57 and 1.11 p <0.001 and up to 19 years in patients with DM and hypertension n = 13 (6.3%) RP = 1.42, 1, 37 and 1,35 p <0.001. Complications and self-care deficit are known to appear with aging people living with DM. Predominantly after 40 years of age, macrovascular and microvascular complications are more frequent, and may affect the retina, renal glomerulus, and peripheral nerves, further compromising the practice of foot self-care³⁰ .

The data are also compatible with the worldwide prevalence of mean age from 56.1 to 61.7 years¹⁷ . Data from the National Health Survey are alike with our findings indicating in Brazil a higher prevalence of wounds or PD ulcers in the age group above 60 years²³ .

Our researched population showed a higher prevalence of DF in hypertensive diabetics under the age of 19 years. This fact suggests that hypertension may be associated with the higher rate of progression of microvascular and macrovascular complications of DM in the young population with associated DM and hypertension, however this analysis was not the focus of our study. Other studies have shown an association between DF and hypertension in individuals older than 40 years^{20 , 31 , 32 , 33} .Association of hypertension with increased risk of microvascular and macrovascular complications, and increased cardiovascular risk in DM has also been demonstrated^{34 , 22 , 35} .

Higher DF prevalence was observed when associated with smoking, physical inactivity, AMI, stroke and CKD in type 1 DM, type 2 DM and hypertensive DM. In overweight individuals, the prevalence of DF was higher only in type 1 DM.

Analysis of the correlation between PD and associated risk factors and comorbidities showed a statistically significant association in all variables except overweight, sedentary lifestyle and stroke in type 1 DM, and overweight in type 2 DM and in DM with hypertension.

Diabetes Care in General Practice study demonstrated an association of smoking, physical inactivity, AMI and stroke with a higher occurrence of DF both at the time of diagnosis as well as six years after³⁶ . In Germany, a higher prevalence of DF was associated with smoking, CKD and hypertension in both type 1 and type 2 diabetics18.

In southern Brazil, a higher risk for DF was observed in patients with a history of AMI n = 17 (18.1%) and stroke n = 12 (12.8%). They also presented higher risk of hypertension n = 62 (66%) and smoking n = 12 (12.8%), however without significant statistical correlation³⁷ .

In Canada, an analysis of 2,040 adults with type 2 DM showed a prevalence of DF in 5.58% of the sample, and predictors of DF injuries were smoking, heart disease, and stroke (<0.001) in both neuropathy and in vasculopathy³⁸ .

Tobacco is related to the development of type 2 DM as a triggering or aggravating factor due to its effects on cortisol concentrations, inflammatory markers, oxidative stress, insulin resistance and an increase in fasting glucose, thus favoring vascular and neuropathic complications^{39 , 40} .

Sedentary lifestyle and smoking were associated with higher cardiovascular risk⁴¹ . Several studies relate sedentary lifestyle to increased insulin resistance, favoring increased glycemic rates with pathophysiological repercussions on diabetic neuropathy and on micro and macrovascular changes⁴² .

Patients with mild to moderate CKD are at higher risk for DF and amputations⁴³ . Higher morbidity and mortality related to coronary and cerebrovascular diseases were also associated, which justifies the findings of this research⁴⁴ .

The pathophysiological mechanism of peripheral neuropathy is directly related to hyperglycemia caused by poor control of DM, which leads to a disturbance in the peripheral nervous system through the activation of metabolic, biochemical and inflammatory pathways, mediated by the immune system, damaging the nerve fibers^{45 , 46} .

This same process is also related to neuropathic dysfunctions that directly affect the autonomic nerves. It is important to recognize the presence of diabetic autonomic neuropathy in patients because of its impact not only on morbidity but also on mortality. Specifically, the presence of cardiac autonomic neuropathy is associated with an increased risk of mortality. These may be related to cardiac arrhythmias, silent ischemia, and increased risk of AMI⁴⁷ .

Given the factors that directly affect the development of DF, we realize the need that individuals with diabetes should have to maintain self-care and also the importance of the multidisciplinary team to ensure quality of life of these patients, advising on the disease and its risks⁴⁸ .

Another research demonstrated the importance of a new look at the work processes, aiming at the individual’s health instead of just looking at the disease⁴⁹ . In addition, it is essential to carry out educational methods with patients to improve health promotion and education practices, these practices are fundamental for the delivery of services and assistance to individuals with chronic diseases, ensuring the change in the care model^{50 , 51} .

The results show a significant prevalence of DF in the state of Espírito Santo, requiring constant monitoring and periodic review of strategies for the implementation of public policies for coping with the disease.

It is noticed that the diabetic population is in permanent threat to have complications associated to the disease and that the adoption of effective public policies are essential to control the risk factors related to the pathophysiological development of DF and eventual amputation.

Ensuring comprehensive care, self-care education, androutine feet examination of diabetic people, especially at the primary level of health care, by family health teams can promote the reduction of DF prevalence and consequently improve the quality of life of people with DM.

As a limitation of this study, we highlight the low notification of DF in the researched database, however, this can be a warning to the public power on the need to implement health policies capable of encouraging the routine assessment of diabetic feet by health professionals.

CONCLUSION

Important prevalence rates of DF in Espitiro Santo State was observed, especially, in men of 60 years and older.

Higher prevalences were observed in individuals with smoking, physical inactivity, AMI, stroke and CKD in type 1 DM, type 2 DM and DM with hypertension. In overweight individuals, the prevalence of DF was higher only in type 1 DM.

Analysis of the correlation between DF and associated risk factors and comorbidities showed a statistically significant association in all studied variables, except overweight in type 1 DM, type 2 DM and DM with hypertension, and sedentary lifestyle and stroke in type 1 DM.