What should you add to prevent a loss of limb?

Amputations can be a major potential complication of diabetes. Only a small percentage of people diagnosed with diabetes require amputations, diabetic patients still account for approximately 60% of non-traumatic lower-limb amputations performed in people over the age of 20. Since diabetes is a major risk factor for peripheral arterial disease (PAD), it is important to properly manage PAD in order to reduce complications down the rode in diabetes patients. Although statins are recommended for PAD patients, there is little research as to whether statins are an effective option to aid the prevention of amputations in type 2 diabetes patients.

Researchers used data from Taiwan’s National Health Insurance Research Database (NHIRD) to “investigate whether the use of statins is associated with a lower extremity amputation rate in a high risk population with known PAD as compared to two propensity score-matched cohorts without statin use while taking into consideration the competing risk of death.” The study population included patients who were age 20 or older with a diagnosis of both diabetes mellitus and peripheral arterial disease during the search period and had 5 years of data before inclusion in the study.  Patients were then divided into three groups based on current PAD treatment: statin-user, non-statin lipid-lowering agent, or non-user. Patients who were excluded from the study were those who were on a combination of statins and other lipid-lowering agents. A propensity score was calculated for patients to determine the probability of a patient receiving a lipid-lowering agent and control patients were matched to both statin and non-statin users with a similar propensity. The primary outcome of the study was new lower extremity amputation and secondary outcomes were in-hospital cardiovascular death and all-cause mortality.

The study included a total of 69,332 diabetes patients with a mean age of 62.6 years who were diagnosed with PAD during the study period.  The majority of the patients, approximately 77%, were non-users of lipid-lowering agents, 17% of the patients were statin users, and 6% used non-statin lipid-lowering agents. Over approximately 5.7 years of follow up, patients in the statin user group had less incidence of any lower extremity amputation, less total lower extremity amputation, and less in-hospital cardiovascular death and all-cause mortality compared to non-users. After adjusting for relevant factors, statin users had significantly lower risk of lower extremity amputation events (adjusted HR [aHR] 0.75, 95% CI 0.62-0.90) and significantly lower risk of total lower extremity amputations (aHR 0.58, 95% CU 0.36-0.93) when compared to non-users. In comparison, non-statin lipid-lowering agents were not associated with any significant decrease in lower extremity amputation events (aHR 0.95, 95% CI 0.73-1.23) and both the statin user group and non-statin lipid-lowering agent group. For the propensity score-matched analysis, 11,373 patients from both the statin user group and non-user group were matched and 4,428 patients from both the non-statin lipid-lowering agent group and the non-user group were matched. In the propensity score-match analysis, the statin user group had a 25% lower risk of any lower extremity amputation (HR 0.75, 95% CI 0.60-0.94), 52% lower total extremity amputation (HR 0.48, 95% CI 0.28-0.83), lower in-hospital cardiovascular death (HR 0.75, 95% CI 0.66-0.87), and lower all-cause mortality (HR 0.72, 95% CI 0.67-0.77) when compared to matched non-users, while non-statin lipid-lowering agents had a neutral effect on all outcomes compared to matched non-users. Other factors, such as gender, age> 65, hypertension, heart failure, CAD, use of antiplatelet drugs, and use of a high potency statin showed no significant effects on the outcome of the study.

Statins have known pleiotropic effects that aid in its protective effects for lowering risk of amputations in diabetes mellitus patients. While this study had a very large sample size, further studies may be needed in varying populations to determine relative effect and real world practice application.

Practice Pearls:

• Statins can decrease the risk of lower limb amputation in diabetes mellitus patients with peripheral arterial disease.
• Non-statin lipid lowering agents are not as beneficial as statins in decreasing the risk for lower limb amputations.
• Statins should be combined with diet, exercise, and regular foot checks for the best outcome.

References:

“Statistics About Diabetes.” American Diabetes Association. Web.

Hsu, Chien-Yi, Yung-Tai Chen, Yu-Wen Su, Chun-Chin Chang, Po-Hsun Huang, and Shing-Jong Lin. “Statin therapy reduces future risk of lower limb amputation in patient with diabetes and peripheral artery disease.” The Journal of Clinical Endocrinology & Metabolism (2017). Web.

Priscilla Rettman, BS, PharmD Candidate 2017, Philadelphia College of Osteopathic Medicine – GA Campus

Does an ounce of prevention beat a pound of cure?

According to the ADA, treatment of diabetic foot ulcers (DFUs) along with associated infections, below the knee amputations, and surgeries to revascularize the lower limbs account for a significant portion of the costs incurred in the treatment of diabetes. Yet with the frequency of occurrence of these complications, there are very few studies that drive the paradigm toward either primary prevention (avoiding DFUs entirely) or secondary/tertiary measures (efficient treatment of DFUs in those who are not aware [secondary]/are aware [tertiary] of diabetic ulcers), which are combined into a single term (secondary prevention) for purposes of the article. Sadly, utilization of primary prevention of these complications is spotty in most health care systems, and implementation of secondary prevention is often delayed in patients with DFUs. It is speculated that one reason little attention is paid to these secondary measures may be the concern over a “small return on the investment” in trying to prevent amputations, an attitude that certainly appears to be both counter-intuitive and counterproductive. An attempt to show otherwise was made by N.R. Barshes et al. who utilized a Markov model demonstrating the probability of significant cost savings attributable to otherwise less costly preventive measures.

The idea of the Markov model allows prediction of transition from one condition to another, with the understanding that the probability of any transition is only dependent on the current condition, but not any past condition, and that these conditions exist over a continuum. A simple example would be the states of untreated, treated, and final outcomes (cure, amputation, or death, the latter two of which would be considered “inescapable” outcomes, where return to the state immediately prior is not possible). Barshes looked at 1,000 repeated simulations of 100,000 hypothetical diabetes patients with no current or historical DFU, over a period of five years in 1-month intervals. Each month, each “patient” would exist in one of six clinical states: no DFU, uninfected DFU, infected DFU, limb loss, healed DFU, and all-cause death. Based on available clinical data, the patients were stratified into low, moderate, and high risk, and transition probabilities for moving from state to state each month were assigned (for example, the chance of transitioning from no DFU to initial DFU event in moderate risk patients was 0.3%, while the chance of limb loss in undertreated DFU in high risk was 3.1%). Each of the simulations was run with transitions occurring over five years (60 months/transitions), and the outcome probabilities were pooled. Each outcome was assigned a monthly cost estimate (for example, the median monthly cost of a healed DFU was $45, infected DFU $12,955, and major limb amputation such as BKA $38,934). Remember, each of these costs were per case, not the total population.

By applying costs of both primary and secondary preventive measures to all levels of risk-presenting patients (low to high), cost thresholds, at which at least 90% of simulations demonstrated savings, were established. An example was a measure that decreased the occurrence of DFU by 10% (0.90 RR), costing $50 per person and would have greater than a 90% probability of reducing amputations (at almost $39K) in diabetes patients at a cost that is equal or even lower than the standard of care, compared to no preventive care. The same 10% reduction in moderate- to high-risk patients from preventive care costs $125 per patient, with increases in cost as risk reduction also increases, yet said costs are considerably less than the outcome of amputation. For the purpose of this discussion, these results have been simplified.

The lack of programs designed to prevent/eliminate DFUs is troubling, this in spite of the known impact these DFUs have on amputation requirements, increasing healthcare costs, and overall quality of life. The paucity of such programs, even in larger academic healthcare centers, may be related to the perception of a clear lack of economic benefit.  Studies have been few and far between, and prior Markov models have not demonstrated a potential for overall savings, where cost effectiveness has been shown. The difference in this study from past offerings is this one looked at differing degrees of effectiveness (risk reductions ranging from 5% to 25%), assigning costs to each and determining a likely cost threshold for determining the need for preventive measures. One important limitation stated by the authors was separating low-risk from moderate- to high-risk patients, which may cause those higher risk populations to lose favor due to increased costs of prevention. An examination of the overall population as a whole would have been warranted to help support better utilization of prevention of diabetic foot ulcers and subsequent complications. If little else, there is certainly a need to encourage preventive programs as a means to reduce these high costs of care.

Practice Pearls:

• Resistance to diabetic foot ulcer prevention programs seems driven by the lack of perceived “return on investment” of such measures.
• Markov models can be used to demonstrate reduction in risk of developing costly complications from DFUs
• A clear cost benefit can also be demonstrated, where utilizing relatively low cost prevention can result in avoidance of significantly costlier events.

Reference:

Barshes NR, Saedi S, Wrobel J, Kougias P, Kundakcioglu OE, Armstrong DG. A model to estimate cost-savings in diabetic foot ulcer prevention efforts. J Diabetes Complications. 2017;31(4):700-7. Epub 2017/01/21. doi: 10.1016/j.jdiacomp.2016.12.017. PubMed PMID: 28153676.

Mark T. Lawrence, RPh, PharmD Candidate, University of Colorado-Denver, School of Pharmacy NTPD

I am a diabetes educator and certified foot care nurse. Through the years, I’ve learned that most topics we teach people who have diabetes are really topics every person should know about.

I teach patients how to care for their feet, how to prevent foot problems, and how to treat them if they should have problems.

I have had so many patients return from vacation with foot wounds due to the particular shoes they were wearing. Some didn’t bring enough shoes or bought and wore brand new shoes, while some wore the type of shoes we don’t recommend and some didn’t wear shoes at all.

As I write this, I am on vacation. Before leaving, I thought about the above. I needed new shoes for the trip, so I bought 2 pair of the same shoes, one normal width and one wide. I didn’t have much time before leaving, but I did practice wearing them before leaving. “Something” told me to also bring a pair of old faithfuls…shoes I have worn a lot and had no problem with.

I’m so glad I heeded my own teaching. The first day, in one of the new pair of shoes, it went pretty well, no pain or redness. After wearing them all daytime, I changed to old faithful that evening. The next morning I noted a little redness and soreness on an area of my foot. I took no chances. I wore the pair with the wide width that day. No problems.

I thought about the wisdom we teach our patients. Glad to have feeling and sight to prevent a problem I’m sure would have occurred…more personal ammunition to teach my patients.

Lessons Learned:

• When helping your patients prepare for travel, always teach to take more than one pair of shoes. If they are taking new shoes, this is especially important. And…always take a pair of “old faithfuls.”
• Whether traveling or not, teach your patients to “listen” to any sign of redness, soreness, or pain that is telling them to wear different shoes.
• Always teach the importance of looking at feet at least daily for changes and treat them early.
• Remember, what’s good for people who have diabetes is most likely good for everyone.
• Heed your own knowledge and practice what you teach.

Joy Pape, FNP-C, CDE, CFCN, FAADE
Associate Editor, DiabetesInControl

Anonymous

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People who have diabetes are usually taught to purchase protective soft leather shoes with a wide toe box. That doesn’t mean everybody who has diabetes follows those recommendations.

A woman, type 2 diabetes, who is knowledgeable about diabetes and foot complications was wearing cloth shoes with a “corded” bottom and manmade rubber sole. She was caught in the rain. Her shoes were soaked. When she got home she let them dry out. Later when she put them back on they were tight. At first she thought she may have some lower extremity edema, but then realized her shoes must have shrunk from being wet and drying out. She started to wear them, thinking they would stretch out. She then felt pressure on the sole of her left foot. She remembered all the stories she had heard about people with diabetes who have peripheral neuropathy, can’t feel when shoes don’t fit right, and ultimately develop a sore which can get infected and for too many end up needing an amputation. She realized how lucky she was to have sensation and even pain to protect her from this happening…that is, if she listened to those signs. Although it would make her late, she immediately went home and changed her shoes. Disaster Averted.

Lessons Learned:

• Teach diabetes foot care, which includes prevention, to all patients who have diabetes.
• Teach that just because shoes once fit well does not mean they always will.
• Teach that if you feel something, you should listen to what that feeling is telling you. It could be saying, “Change your shoes.”
• Teach that if you can’t feel…see podiatrist!

The Society for Vascular Surgery, the American Podiatric Medical Association and the Society for Vascular Medicine collaboratively publish first-ever set of clinical practice guidelines for treating the diabetic foot.

New guidelines, “The Management of the Diabetic Foot,” were developed after three years of studies and later were published online and in print in the Journal for Vascular Surgery.

Diabetes mellitus continues to grow in global prevalence and to consume an increasing amount of healthcare resources. One of the key areas of morbidity associated with diabetes is the diabetic foot. To improve the care of patients with diabetic foot and to provide an evidence-based multidisciplinary management approach, the Society for Vascular Surgery (SVS) in collaboration with the American Podiatric Medical Association and the Society for Vascular Medicine developed this clinical practice guideline.

The committee made specific practice recommendations using the Grades of Recommendation Assessment, Development, and Evaluation system. This was based on five systematic reviews of the literature. Specific areas of focus included (1) prevention of diabetic foot ulceration, (2) off-loading, (3) diagnosis of osteomyelitis, (4) wound care, and (5) peripheral arterial disease.

Although they identified only limited high-quality evidence for many of the critical questions, they used the best available evidence and considered the patients’ values and preferences and the clinical context to develop these guidelines. They include preventive recommendations such as those for adequate glycemic control, periodic foot inspection, and patient and family education. They recommend using custom therapeutic footwear in high-risk diabetic patients, including those with significant neuropathy, foot deformities, or previous amputation. In patients with plantar diabetic foot ulcer (DFU), they recommend off-loading with a total contact cast or irremovable fixed ankle walking boot. In patients with a new DFU, they recommend probe to bone test and plain films to be followed by magnetic resonance imaging if a soft tissue abscess or osteomyelitis is suspected. They provide recommendations on comprehensive wound care and various débridement methods. For DFUs that fail to improve (>50% wound area reduction) after a minimum of 4 weeks of standard wound therapy, we recommend adjunctive wound therapy options. In patients with DFU who have peripheral arterial disease, they recommend revascularization by either surgical bypass or endovascular therapy.

Whereas these guidelines have addressed five key areas in the care of DFUs, they do not cover all the aspects of this complex condition. Going forward as future evidence accumulates, they plan to update recommendations accordingly.

Diabetes is one of the leading causes of chronic disease and limb loss worldwide, currently affecting 382 million people. It is predicted that by 2035, the number of reported diabetes cases will soar to 592 million. This disease affects the developing countries disproportionately as >80% of diabetes deaths occur in low- and middle-income countries.

As the number of people with diabetes is increasing globally, its consequences are worsening. The World Health Organization projects that diabetes will be the seventh leading cause of death in 2030. A further effect of the explosive growth in diabetes worldwide is that it has become one of the leading causes of limb loss. Every year, >1 million people with diabetes suffer limb loss as a result of diabetes. This means that every 20 seconds an amputation occurs in the world as an outcome of this debilitating disease. Diabetic foot disease is common, and its incidence will only increase as the population ages and the obesity epidemic continues.

Approximately 80% of diabetes-related lower extremity amputations are preceded by a foot ulcer. The patient demographics related to diabetic foot ulceration are typical for patients with long-standing diabetes. Risk factors for ulceration include neuropathy, PAD, foot deformity, limited ankle range of motion, high plantar foot pressures, minor trauma, previous ulceration or amputation, and visual impairment. Once an ulcer has developed, infection and PAD are the major factors contributing to subsequent amputation.

Available U.S. data suggest that the incidence of amputation in persons with diabetes has recently decreased; toe, foot, and below-knee amputation declined from 3.2, 1.1, and 2.1 per 1,000 diabetics, respectively, in 1993 to 1.8, 0.5, and 0.9 per 1,000 in 2009. However, including the costs of outpatient ulcer care, the annual cost of diabetic foot disease in the United States has been estimated to be at least $6 billion. A Markov modeling approach suggests that a combination of intensive glycemic control and optimal foot care is cost-effective and may even be cost-saving.

DFUs and their consequences represent a major personal tragedy for the person experiencing the ulcer and his or her family as well as a considerable financial burden on the healthcare system and society. At least one-quarter of these ulcers will not heal, and up to 28% may result in some form of amputation. Therefore, establishing diabetic foot care guidelines is crucial to ensure the most cost-effective healthcare expenditure. These guidelines need to be goal focused and properly implemented.

This progression from foot ulcer to amputation leads to several possible steps where intervention based on evidence-based guidelines may prevent major amputation. Considering the disease burden and the existing variations in care that make decision-making very challenging for patients and clinicians, the SVS, American Podiatric Medical Association, and Society for Vascular Medicine deemed the management of DFU a priority topic for clinical practice guideline development. These recommendations are meant to pertain to all people with diabetes regardless of etiology.

Practice Pearls:

• “The Management of the Diabetic Foot,” was developed after three years of studies and later published online and in print in the Journal for Vascular Surgery.
• This progression from foot ulcer to amputation lends to several possible steps where intervention based on evidence-based guidelines may prevent major amputation.
• Every year, >1 million people with diabetes suffer limb loss as a result of diabetes.

Researched and prepared by Steve Freed, BPharm, Diabetes Educator, Publisher and reviewed by Dave Joffe, BSPharm, CDE

Anil Hingorani, MD Glenn M. LaMuraglia, MD, Journal of Vascular Surgery Feb 2016 , Volume 63, Issue 2, Supplement, Pages 3S–21S