Chapter 1: Understanding Diabetes and Diabetic Foot Ulcers
Diabetes mellitus is one of the most common chronic diseases affecting people worldwide. Over the past few decades, its prevalence has increased rapidly because of aging populations, urbanization, sedentary lifestyles, obesity, and unhealthy dietary habits. As the number of people living with diabetes continues to rise, so does the burden of its long-term complications. Among these complications, diabetic foot ulcers represent one of the most serious and costly conditions, often leading to prolonged hospitalization, disability, lower-limb amputation, and even death.
The systematic review on electrophysical therapy for diabetic foot ulcers reported that more than 220 million people worldwide were living with diabetes, and the World Health Organization projected that diabetes-related deaths would double between 2005 and 2030. The review also indicated that the lifetime risk of developing a diabetic foot ulcer may be as high as 25% among people with diabetes, emphasizing the enormous healthcare challenge posed by this condition.
A diabetic foot ulcer is much more than a simple wound. It is the result of multiple physiological abnormalities associated with diabetes that impair the body’s ability to repair damaged tissue. High blood glucose levels gradually damage nerves, blood vessels, and the immune system, making even a small injury capable of progressing into a chronic, non-healing ulcer. These ulcers often become infected and may eventually require amputation if appropriate treatment is not initiated promptly.
Diabetes mellitus is a metabolic disorder characterized by persistently elevated blood glucose levels due to inadequate insulin production, impaired insulin action, or both. Insulin is a hormone produced by the pancreas that allows glucose to enter body cells, where it serves as the primary source of energy. When insulin is deficient or ineffective, glucose accumulates in the bloodstream instead of entering cells. Over time, prolonged hyperglycemia damages nearly every organ system, including the eyes, kidneys, nerves, heart, and blood vessels.
There are several major forms of diabetes. Type 1 diabetes results from autoimmune destruction of the insulin-producing beta cells of the pancreas and requires lifelong insulin therapy. Type 2 diabetes, the most common form, develops because of insulin resistance combined with a gradual decline in insulin production. It is strongly associated with obesity, physical inactivity, advancing age, and family history. Gestational diabetes develops during pregnancy and increases the future risk of Type 2 diabetes in both mother and child.
The growing prevalence of diabetes has transformed it into one of the leading public health concerns worldwide. Millions of people require lifelong treatment and regular medical monitoring. Healthcare systems spend billions of dollars annually on diabetes care, much of which is devoted to managing preventable complications such as diabetic foot ulcers.
Long-term diabetes causes both microvascular and macrovascular complications. Microvascular complications include diabetic retinopathy, nephropathy, and peripheral neuropathy, while macrovascular complications include coronary artery disease, stroke, and peripheral arterial disease. Among these complications, peripheral neuropathy and peripheral arterial disease are particularly important because they are directly responsible for the development of diabetic foot ulcers.
A diabetic foot ulcer is defined as an open wound occurring on the foot of a person with diabetes. The ulcer may involve only the skin initially but can gradually extend into the underlying fat, muscles, tendons, joints, and even bone. These ulcers most commonly occur over pressure-bearing areas such as the heel, the ball of the foot, the great toe, and the metatarsal heads. Because many individuals with diabetes have reduced sensation in their feet, they often remain unaware of the injury until it has progressed significantly.
Peripheral neuropathy is considered one of the principal causes of diabetic foot ulceration. According to the systematic review, neuropathy causes loss of protective sensation and impairs the microvascular circulation of the foot. Patients may fail to recognize minor trauma, burns, cuts, or excessive pressure from poorly fitting footwear. Since pain is diminished or absent, repeated mechanical stress continues, causing progressive tissue destruction without the patient’s awareness.
Peripheral arterial disease further complicates the problem by reducing blood flow to the lower extremities. Adequate circulation is essential for delivering oxygen, nutrients, immune cells, and growth factors necessary for tissue repair. When blood flow is compromised, wounds heal slowly and become increasingly susceptible to infection and tissue necrosis. Reduced circulation also limits the effectiveness of antibiotics and other therapeutic interventions.
Infection is another critical factor contributing to poor outcomes in diabetic foot ulcers. Elevated blood glucose levels impair multiple aspects of immune function, reducing the body’s ability to eliminate invading microorganisms. Once bacteria enter an ulcer, infection may spread rapidly into deeper tissues, leading to cellulitis, abscess formation, osteomyelitis, or systemic sepsis. Severe infections often necessitate emergency surgical intervention or limb amputation.
Mechanical stress also plays a major role in ulcer formation. Individuals with diabetic neuropathy frequently develop abnormal walking patterns because of muscle weakness and joint deformities. These abnormalities concentrate pressure on specific regions of the foot. Continuous walking on these pressure points gradually damages the skin and underlying tissues, eventually resulting in ulcer formation. Foot deformities such as claw toes, Charcot foot, bunions, and prominent metatarsal heads further increase localized pressure and significantly elevate the risk of ulcer development.
The burden of diabetic foot ulcers extends beyond individual patients to healthcare systems and society as a whole. The systematic review reports that over 70 percent of all non-traumatic lower-limb amputations occur in people with diabetes. The authors also highlight the substantial financial burden associated with diabetic foot care, citing annual treatment costs of approximately £252 million in the United Kingdom alone.
Patients living with diabetic foot ulcers often experience prolonged hospitalization, repeated surgical procedures, extended antibiotic therapy, reduced mobility, chronic pain, social isolation, anxiety, depression, and diminished quality of life. Many are unable to continue employment, creating additional financial hardship for both families and healthcare systems.
Conventional treatment remains the cornerstone of diabetic foot ulcer management. Standard care typically includes strict blood glucose control, regular wound cleaning, surgical debridement of necrotic tissue, appropriate wound dressings, infection management with antimicrobial therapy when necessary, pressure offloading using specialized footwear or total contact casts, vascular assessment, and revascularization procedures for patients with severe peripheral arterial disease. Although these interventions have significantly improved patient outcomes, many ulcers remain resistant to treatment and fail to heal completely.
The systematic review emphasizes that despite the use of dressings, debridement, offloading, and vascular surgery, a considerable proportion of diabetic foot ulcers continue to demonstrate delayed healing. This therapeutic challenge has stimulated growing interest in adjunctive treatment modalities designed to enhance the body’s natural healing mechanisms.
Electrophysical therapy has emerged as one such promising adjunctive approach. These therapies include electrical stimulation, therapeutic ultrasound, low-level laser therapy, and electromagnetic field therapy. Rather than replacing conventional wound care, these modalities are intended to complement existing treatments by promoting cellular repair, improving blood flow, stimulating fibroblast activity, enhancing collagen synthesis, and encouraging angiogenesis. Experimental and early clinical studies have suggested that these therapies may accelerate wound healing, although the strength of clinical evidence varies among different modalities.
According to the systematic review, electrophysical therapy has become a fundamental component of physiotherapy practice in many countries. Common modalities include electrical stimulation, ultrasound, laser therapy, and electromagnetic energy. Laboratory studies have demonstrated their ability to promote tissue repair by enhancing fibroblast activity and angiogenesis. However, the authors note that much of the earlier evidence originated from laboratory experiments, animal studies, or studies involving wounds of non-diabetic origin. Consequently, there was a need to evaluate whether sufficient evidence existed specifically for diabetic foot ulcers in humans.
The review was therefore undertaken to critically evaluate randomized controlled trials investigating electrophysical therapy in diabetic foot ulcers. By systematically examining available clinical evidence, the authors sought to determine whether these therapies could improve healing outcomes compared with conventional care or sham treatment. Their findings provide the scientific foundation for the chapters that follow in this book.
Understanding the mechanisms responsible for diabetic foot ulcer development is essential before exploring advanced therapeutic interventions. Successful management depends not only on treating the wound itself but also on addressing the underlying metabolic, neurological, vascular, and mechanical factors responsible for impaired healing. A multidisciplinary approach involving endocrinologists, vascular surgeons, podiatrists, wound care specialists, physiotherapists, nurses, and diabetes educators remains essential for achieving the best possible patient outcomes.
The next chapter will examine the normal process of wound healing, including the anatomy of the skin and the biological events that occur during tissue repair. Understanding these physiological mechanisms provides the foundation for appreciating how diabetes disrupts healing and why electrophysical therapies may offer valuable support in restoring normal wound repair.
