The global diabetes epidemic part 1: foot disease
In the first in his series on the global diabetes epidemic, Joshua Schulman-Marcus discusses the hugely important, but often neglected topic of diabetic foot disease
On 14 November 2007, the United Nations observed its first World Diabetes Day. Such prominent recognition is a sign that the international community is increasingly aware of the global burden of diabetes. It is estimated that 4.5% of the developing world population had diabetes in 2003, with a 31% increase in prevalence projected by 2025 (1). This conservative projection is almost entirely accounted for by an increase in Type 2 diabetes (”non-insulin dependent”). Early mortality from diabetes is already an immense problem; in 2000 it was estimated that about one in ten people aged 35-64 in the developing world died as a result of diabetes (2). A worrisome hypothesis is that lifestyle shifts, demographic aging, and urbanization will exacerbate these trends by increasing risk factors (3).
One of the most significant complications of diabetes is foot disease, which most often presents with ulcers or infection. Developed world studies have estimated that 15% of people with diabetes will ultimately have diabetic foot ulcers, with an annual incidence in at least 2.2% of people with diabetes (4,5).
In the absence of comparable studies, it is estimated that people with diabetes in developing countries have similar rates of disease. Major risk factors for the development of ulcers include peripheral neuropathy, peripheral vascular disease, prior foot ulcer, and poor foot care. While diabetic foot ulcers may have either a neuropathic or vascular etiology (6), several studies suggest that in developing countries the great majority are neuropathic (7, 8). This is likely attributable to the trend of people with diabetes in developing countries being younger and therefore less likely to have peripheral vascular disease (7).
The long-term sequelae of diabetic ulcers in developing countries can be devastating. Small ulcers can become easily infected, leading to potential gangrene, osteomyelitis or limb sepsis (8). Such infections are difficult to treat even in well-resourced developed countries (5,6); in many developing countries, access to broad-spectrum antibiotics and imaging may be nonexistent (8). In Africa diabetic patients, especially in poor rural areas with little access to care, will frequently present with untreated complicated ulcers (8). The ultimate catastrophic consequence for these patients is limb amputation.
Thus, the economic consequences of diabetic foot disease are substantial. Untreated peripheral neuropathy, ulcers, or small infections can result in serious work-limiting disability. Such situations potentially have major impacts for dependents in a household, and may compel children to leave school in order to work (9). Furthermore, the estimated costs of diagnosis and treatment in developing countries are substantially higher than for people with diabetes without foot disease (6). These costs are most burdensome for the poor, who may forego adequate preventive or therapeutic care due to lack of funds (8,10). Anecdotal reports from India show that poor patients who have severe infections and amputations often lose their livelihoods and have little access to limb prostheses (11).
Progress and Obstacles
Guidelines on diabetic foot disease consistently stress that disease prevention and early treatment are paramount. The International Diabetes Federation Guidelines (12) state that as a minimum all people with diabetes should have an annual foot care review. Patients should have a physical examination looking for ulcers or abrasions, a neuropathy screen with a monofilament or tuning fork, and palpation of peripheral pulses. Foot-ware should be examined and improvements recommended. Higher risk patients, such as those with existing neuropathy, should be screened more often. Patients with existing ulcers should be promptly treated as indicated with debridement, wound dressings, and antibiotics. Most importantly, patients need to be adequately educated on the importance of proper foot care and frequent self-inspection (5,6,8).
While a multidisciplinary approach with podiatric specialists is ideal, even small measures can lead to significant reductions in complications and amputations (5,13). The second report of the Disease Control Priorities Project found that foot care for diabetic patients is one of the most well-validated and cost-saving diabetes interventions in all regions of the world. It requires little capital and is easy to implement (even by non-physicians), with large potential direct and indirect savings. The evidence is even stronger in high-risk patients or those with a previous ulcer (1).
Any sustainable intervention must also consider local cultural and economic factors that affect foot disease prevalence and progression. It is normative in many developing countries, especially in rural areas, for people to walk barefoot. Those who do wear shoes often wear only slippers owing to low income (7,14); such shoes can actually encourage skin degradation and ulceration (15). It is even more common for one to not wear shoes in one’s home, and it has been observed that most people take the majority of their footsteps inside (16). People in rural areas or slums may have their feet bitten by rodents or fleas, but not recognize subsequent infection owing to peripheral neuropathy (6,8). In Tanzania, it has been observed that some patients refuse to be treated for ulcers owing to shame (8), while others are reluctant to undergo minor amputations due to cultural and religious norms against such procedures (17). The profound influence of these cultural issues has largely been overlooked in the scientific literature (17); a search on PubMed results in only a handful of articles.
As the number of people with diabetes in developing countries rapidly ascends, more lives will be affected by subsequent foot disease. The urban and rural poor are likely to be severely affected, with consequent disability and worsening destitution. Fortunately, this epidemic can be blunted with cost-effective primary prevention, early treatment, and self-education. The development and efficacy of such interventions is contingent on a greater understanding of cultural influences and improved access to care. Most of all, it is vital that the public and international health community begin to recognize that diabetes is not confined to wealthy countries, but rather is a global health concern of the highest priority.
Joshua Schulman-Marcus
4th year medical student
Mount Sinai School of Medicine
New York
USA
and
2007-08 Sarnoff Cardiovascular Foundation Fellow
Brigham and Women’s Hospital/Harvard School of Public Health
Boston
USA
jschumar@gmail.com
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(3) Preventing chronic diseases: a vital investment. Geneva: WHO, 2005
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(6) Boulton AJM, Vileikyte L, Ragnarson-Tennvall G et al. The global burden of diabetic foot disease. Lancet 2005; 366:1719-24.
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(10) Viswanathan V, Madhavan S, Rajasekar S et al. Urban-rural differences in the prevalence of foot complications in South-Indian diabetic patients. Diabetes Care 2006; 29:701-03.
(11) Kleinfeld, NR. Modern ways open India’s doors to diabetes. New York Times, 13 September 2006, page 1A.
(12) IDF Clinical guidelines task force. Global guidelines for type 2 diabetes: recommendations for standard, comprehensive, and minimal care. Diabet Med 2006; 23:579-593.
(13) Viswanathan V, Madhavan S, Rajasekar S et al. Amputation prevention initiative in south India: positive impact of foot care education. Diabetes Care 2005; 28:1019-21.
(14) Jayasinghe SA, Atukorala I, Gunethilleke B et al. Is walking barefoot a risk factor for diabetic foot disease in developing countries? Rural Remote Health 2007; 7:692 Epub 15 Jun 2007.
(15) Macfarlane RM, Jeffcoate WJ. Factors contributing to the presentation of diabetic foot ulcers. Diabet Med 1997; 14:867-70.
(16) Armstrong DG, Lavery LA, Kimbriel HR et al. Activity patterns of patients with diabetic foot ulceration: patients with active ulceration may not adhere to a standard pressure off-loading regimen. Diabetes Care 2003; 26:2595-7
(17) Ramachandran A. Specific problems of the diabetic foot in developing countries. Diabet Metag Res Rev 2004; 20 (suppl 1): S19-S22.
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