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    Practice Pearls: Diabetes

    Evidence syntheses and practical tips on diabetes management.
    Welcome to Practice Pearls: quick, current, and easy-to-digest insights on diabetes to help inform patient care, from diagnosis to follow-up. Let us know what you think!
    Statin-induced diabetes
    Does my low cardiovascular risk patient really need statins?
    theNNT

    theNNT.com recently published a review of the evidence behind statins for people with low cardiovascular risk:

    NNTNNH
    • 0 statistically significant mortality benefit
    • 1 in 217 avoided a nonfatal heart attack (myocardial infarction)
    • 1 in 313 avoided a nonfatal stroke
    • 1 in 21 experienced pain from muscle damage
    • 1 in 204 developed diabetes mellitus

    “The USPSTF review found no increase in the risk of new-onset diabetes associated with statin therapy for primary prevention. However, the best predictor of developing statin-induced diabetes is diabetes risk, not cardiovascular risk. Therefore, analyzing exclusively primary prevention data may have underpowered the analysis. A 2010 meta-analysis of 13 trials with more than 90,000 patients, which is broadly cited as the most complete assessment of statin-induced diabetes, shows a 9% relative increase (not far from the USPSTF’s result of 5%) in diabetes risk. The absolute increase was 0.098% per year of statin exposure. This becomes 0.49% at five years, although the number will vary with diabetes risk, just as statin benefits vary with cardiovascular risk.”

    Read the full review for the full summary as well as caveats. 

    The physician’s role: a look at the evidence
    Should docs stick to managing complications and leave the rest to others?
    Kate Rowland, MD

    Evidence shows that the best outcomes with diabetes education come after 10 contact hours, but what primary care doctor has that time to devote to every patient with diabetes?

    Motivational interviewing, a different style of counseling focused on helping patients identify potential areas of change, may offer better outcomes: a 2013 meta-analysis of 48 RCTs of motivational interviewing found improvement in weight loss, quality of life, and activity level. Still, there was no clear improvement in blood glucose levels or medication adherence.

    Read Dr. Kate Rowland’s review of the evidence, plus her personal perspective of a family physician caring for patients living with diabetes, on Paging MDCalc.

    Do insulin pumps prevent complications?
    DKA and type I diabetics may not always benefit
    MDCalc Editorial Team

    Karges et al, JAMA, Oct 2017

    A: Yes, but more so for hypoglycemia than for DKA: there were 9.55 severe hypoglycemic episodes per 100 patient-years for patients on the pump versus 13.97 for those on injections, and 3.64 DKA episodes versus 4.26 per 100 patient-years for pump vs injection, respectively. Glycemic control was also better in the insulin pump group.

    Why this matters: This further supports the use of insulin pumps over multiple daily injections for younger patients with type 1 diabetes.

    Diabetic foot: tips for callus debridement
    Podiatrist Dr. Haywan Chiu shares insights (with GIFs!)
    Haywan Chiu, DPM

    Callus Debridement Can Be Diagnostic

    Calluses form when shear forces and pressure induce the epidermis to reinforce itself. In patients with diminished pain sensation such as in diabetic neuropathy, continued friction from shear forces and pressure evolves the callus into a blister, then a blood blister (figure 1). When I see a bloody foot callus, I know that at some point, there was a break in the dermis. I don’t know if it has healed on its own or if it has expanded into a full blown ulcer because I can’t see past the callus. In fact, some calluses can be so thick I can’t even see the blood underneath! The only way to find out what’s hiding is to debride the callus.

    Technique, Tips, and Tricks

    Figure 5. Take multiple slices and “chase the bump” until you get down to the level of normal adjacent epithelium.

    I got started by debriding an orange at home in my early training. Consider asking a foot specialist for supervision. Think of the callus as a small bump, and take slices or scrapes parallel to the skin until you get down to the level of normal skin. At first, you want to take as thin a slice as possible. After every 2-3 slices, feel the callus with your thumb to get an idea of how much callus tissue remains. It is easier build a mental image of the callus by feel rather than by look, because hyperkeratotic epidermis can vary in transparency.

    As a safety precaution, understand that dull blades are much more dangerous than sharp blades. As the blade dulls, it becomes harder to control and you need to use more force to get through the tissue, thus increasing your chances of slipping and cutting yourself. Use as many fresh blades as you need to get the job done safely.

     width=  width=
    Figure 6. Take thin slices of tissue using the blade. Figure 7. Use a dermal curette to scrape away at the tissue.

    Check out the full article for more on calluses and osteomyelitis, tools of the trade, and iatrogenic injury. 

    National Diabetes Statistics Report
    2017 insights from the CDC on US diabetes trends
    Centers for Disease Control and Prevention (CDC)

    The National Diabetes Statistics Report, last updated in 2017, provides statistics on diabetes in the United States, including prevalence, risk factors, complications, deaths, and costs. 

    Highlights: 

    Prevalence of Both Diagnosed and Undiagnosed Diabetes
    • Estimated 30.3 million people (9.4% of US population).
    • 23.8% had undiagnosed diabetes.
    • Among those ≥65 years, 25.2% had diabetes. 
    Prevalence of Diagnosed Diabetes
    • Estimated 23.1 million people (7.2% of US population).
    • Type 1 diabetes accounts for ~5%.
    • Highest prevalence among American/Alaskan Natives, non-Hispanic blacks, and Hispanic ethnicity. 
    Incidence of Diagnosed Diabetes
    • Two times higher in those without a high school education.
    • >50% of new cases were in adults 45-64 years. 
    Prevalence of Prediabetes
    • 33.9% of adults have prediabetes.
    • 48.3% of adults ≥65 years have prediabetes.
    Risk Factors for Complications
    • Current smokers: 15.9%
    • BMI (adults):
      • 25 to <30 kg/m2: 26.1%
      • 30 to <40 kg/m2: 43.5%
      • ≥40 kg/m2: 17.8%
    • Physically inactive: 40.8%
    • Blood pressure ≥140 mmHg: 73.6%
    • Blood glucose >9%: 15.6%
    Coexisting Conditions and Complications 
    • Most common reasons for hospitalization included major cardiovascular disease (ischemic heart disease, stroke), lower-extremity amputation, diabetic ketoacidosis.
    • For those ≥20 years old with diabetes, 36.5% had chronic kidney disease (CKD) (stages 1-4). 
    Deaths
    • Seventh leading cause of death. 
    Cost
    • 2012 estimated direct and indirect costs: $245 billion.
    • Avg. medical costs for a patient with diabetes: $13,700 per year. 

    Does bariatric surgery cure diabetes?
    Surgery and long-term remission outcomes
    MDCalc Editorial Team

    Adams et al, NEJM, Sept 2017

    A: Moderately, with decreasing efficacy over time—75% remission at 2 years, 62% at 6 years, 51% at 12 years (odds ratio of T2DM incidence at 12 years = 0.08). Of note, patients undergoing surgery had a higher suicide rate than those who sought surgery but did not have it (5/418 surgical patients versus 2/417 who did not have surgery).

    Why this matters: This is a prospective, controlled study showing moderate long-term efficacy of bariatric surgery in curing diabetes. The relatively higher suicide rate in patients undergoing surgery should be further explored, and physicians should be particularly vigilant to ensure adequate access to mental health services for these patients.

    Lose the weight, lose the diabetes
    ADA Standards of Care 2017 on obesity and diabetes
    American Diabetes Association (ADA)

    Studies show weight loss can induce remission of diabetes, either through bariatric surgery or oral medications, with differing bodies of literature for each. The ADA Standards of Care 2017 address obesity as it pertains to diabetes risk and management of T2DM and provides recommendations in the following sections, which are summarized below:

    2. Classification and Diagnosis of Diabetes

    7. Obesity Management for the Treatment of Type 2 Diabetes

    BMIADA Recommendation
    Non-AsianAsianPrediabetes testing (if undiagnosed)*Weight loss meds (diagnosed T2DM)**Metabolic surgery (diagnosed T2DM)***
    2523X
    2727XX
    3027.5XXIf inadequate glycemic control on optimal medical therapy (including insulin)
    3532.5XXIf inadequate glycemic control on optimal lifestyle and medical therapy
    4037.5XXX
    *If undiagnosed and ≥1 additional diabetes risk factor(s) present. Screen with fasting plasma glucose, oral glucose tolerance test, or A1c.
    **Consider as an adjunct to diet, exercise, counseling. See below for comparison of FDA-approved weight-loss drugs.
    ***Consider for referral, assuming is otherwise an adequate surgical candidate.

    Drugs approved by the FDA for weight loss

    Does continuous glucose monitoring improve outcomes?
    Or are fingersticks good enough?
    MDCalc Editorial Team

    Beck et al, Ann Intern Med, Sept 2017

    A: Maybe. Use of the CGM lowered HgbA1c from a mean of 8.5% to 7.7% in the CGM group and 8.0% in the FGM group. Note that reduction in A1c is a surrogate outcome. There was no significant difference in hypoglycemic episodes or quality-of-life outcomes, and follow-up was only 6 months. Also note that the study was funded by Dexcom, a CGM device manufacturer.

    Why this matters: The FDA just approved the first CGM (FreeStyle Libre Flash, Abbott). The limitations of this study should be noted.

    Motivational interviewing
    How and why it works for people with diabetes
    Centers for Disease Control and Prevention (CDC)
    Steroid-induced diabetes
    Professor Simon Griffin, creator of the Cambridge Diabetes Score, on steroids and diabetes.
    Simon J. Griffin, DM

    "We did not distinguish between the different potential underlying causes of diabetes. In our original analysis, the prescription of steroids was significantly associated with the presence of diabetes. Presumably, this is because the underlying indication for the prescription or the steroids themselves increase the risk of diabetes. We included any variable that increased the predictive utility of the model, irrespective of whether we understood the underlying mechanism. Unsurprisingly, the obvious known risk factors such as age and body mass index were the variables that most strongly predicted the presence of diabetes."

    Statin-induced diabetes
    Does my low cardiovascular risk patient really need statins?

    theNNT.com recently published a review of the evidence behind statins for people with low cardiovascular risk:

    NNTNNH
    • 0 statistically significant mortality benefit
    • 1 in 217 avoided a nonfatal heart attack (myocardial infarction)
    • 1 in 313 avoided a nonfatal stroke
    • 1 in 21 experienced pain from muscle damage
    • 1 in 204 developed diabetes mellitus

    “The USPSTF review found no increase in the risk of new-onset diabetes associated with statin therapy for primary prevention. However, the best predictor of developing statin-induced diabetes is diabetes risk, not cardiovascular risk. Therefore, analyzing exclusively primary prevention data may have underpowered the analysis. A 2010 meta-analysis of 13 trials with more than 90,000 patients, which is broadly cited as the most complete assessment of statin-induced diabetes, shows a 9% relative increase (not far from the USPSTF’s result of 5%) in diabetes risk. The absolute increase was 0.098% per year of statin exposure. This becomes 0.49% at five years, although the number will vary with diabetes risk, just as statin benefits vary with cardiovascular risk.”

    Read the full review for the full summary as well as caveats. 

    The physician’s role: a look at the evidence
    Should docs stick to managing complications and leave the rest to others?

    Evidence shows that the best outcomes with diabetes education come after 10 contact hours, but what primary care doctor has that time to devote to every patient with diabetes?

    Motivational interviewing, a different style of counseling focused on helping patients identify potential areas of change, may offer better outcomes: a 2013 meta-analysis of 48 RCTs of motivational interviewing found improvement in weight loss, quality of life, and activity level. Still, there was no clear improvement in blood glucose levels or medication adherence.

    Read Dr. Kate Rowland’s review of the evidence, plus her personal perspective of a family physician caring for patients living with diabetes, on Paging MDCalc.

    Do insulin pumps prevent complications?
    DKA and type I diabetics may not always benefit

    Karges et al, JAMA, Oct 2017

    A: Yes, but more so for hypoglycemia than for DKA: there were 9.55 severe hypoglycemic episodes per 100 patient-years for patients on the pump versus 13.97 for those on injections, and 3.64 DKA episodes versus 4.26 per 100 patient-years for pump vs injection, respectively. Glycemic control was also better in the insulin pump group.

    Why this matters: This further supports the use of insulin pumps over multiple daily injections for younger patients with type 1 diabetes.

    Diabetic foot: tips for callus debridement
    Podiatrist Dr. Haywan Chiu shares insights (with GIFs!)

    Callus Debridement Can Be Diagnostic

    Calluses form when shear forces and pressure induce the epidermis to reinforce itself. In patients with diminished pain sensation such as in diabetic neuropathy, continued friction from shear forces and pressure evolves the callus into a blister, then a blood blister (figure 1). When I see a bloody foot callus, I know that at some point, there was a break in the dermis. I don’t know if it has healed on its own or if it has expanded into a full blown ulcer because I can’t see past the callus. In fact, some calluses can be so thick I can’t even see the blood underneath! The only way to find out what’s hiding is to debride the callus.

    Technique, Tips, and Tricks

    Figure 5. Take multiple slices and “chase the bump” until you get down to the level of normal adjacent epithelium.

    I got started by debriding an orange at home in my early training. Consider asking a foot specialist for supervision. Think of the callus as a small bump, and take slices or scrapes parallel to the skin until you get down to the level of normal skin. At first, you want to take as thin a slice as possible. After every 2-3 slices, feel the callus with your thumb to get an idea of how much callus tissue remains. It is easier build a mental image of the callus by feel rather than by look, because hyperkeratotic epidermis can vary in transparency.

    As a safety precaution, understand that dull blades are much more dangerous than sharp blades. As the blade dulls, it becomes harder to control and you need to use more force to get through the tissue, thus increasing your chances of slipping and cutting yourself. Use as many fresh blades as you need to get the job done safely.

     width=  width=
    Figure 6. Take thin slices of tissue using the blade. Figure 7. Use a dermal curette to scrape away at the tissue.

    Check out the full article for more on calluses and osteomyelitis, tools of the trade, and iatrogenic injury. 

    National Diabetes Statistics Report
    2017 insights from the CDC on US diabetes trends

    The National Diabetes Statistics Report, last updated in 2017, provides statistics on diabetes in the United States, including prevalence, risk factors, complications, deaths, and costs. 

    Highlights: 

    Prevalence of Both Diagnosed and Undiagnosed Diabetes
    • Estimated 30.3 million people (9.4% of US population).
    • 23.8% had undiagnosed diabetes.
    • Among those ≥65 years, 25.2% had diabetes. 
    Prevalence of Diagnosed Diabetes
    • Estimated 23.1 million people (7.2% of US population).
    • Type 1 diabetes accounts for ~5%.
    • Highest prevalence among American/Alaskan Natives, non-Hispanic blacks, and Hispanic ethnicity. 
    Incidence of Diagnosed Diabetes
    • Two times higher in those without a high school education.
    • >50% of new cases were in adults 45-64 years. 
    Prevalence of Prediabetes
    • 33.9% of adults have prediabetes.
    • 48.3% of adults ≥65 years have prediabetes.
    Risk Factors for Complications
    • Current smokers: 15.9%
    • BMI (adults):
      • 25 to <30 kg/m2: 26.1%
      • 30 to <40 kg/m2: 43.5%
      • ≥40 kg/m2: 17.8%
    • Physically inactive: 40.8%
    • Blood pressure ≥140 mmHg: 73.6%
    • Blood glucose >9%: 15.6%
    Coexisting Conditions and Complications 
    • Most common reasons for hospitalization included major cardiovascular disease (ischemic heart disease, stroke), lower-extremity amputation, diabetic ketoacidosis.
    • For those ≥20 years old with diabetes, 36.5% had chronic kidney disease (CKD) (stages 1-4). 
    Deaths
    • Seventh leading cause of death. 
    Cost
    • 2012 estimated direct and indirect costs: $245 billion.
    • Avg. medical costs for a patient with diabetes: $13,700 per year. 

    Does bariatric surgery cure diabetes?
    Surgery and long-term remission outcomes

    Adams et al, NEJM, Sept 2017

    A: Moderately, with decreasing efficacy over time—75% remission at 2 years, 62% at 6 years, 51% at 12 years (odds ratio of T2DM incidence at 12 years = 0.08). Of note, patients undergoing surgery had a higher suicide rate than those who sought surgery but did not have it (5/418 surgical patients versus 2/417 who did not have surgery).

    Why this matters: This is a prospective, controlled study showing moderate long-term efficacy of bariatric surgery in curing diabetes. The relatively higher suicide rate in patients undergoing surgery should be further explored, and physicians should be particularly vigilant to ensure adequate access to mental health services for these patients.

    Lose the weight, lose the diabetes
    ADA Standards of Care 2017 on obesity and diabetes

    Studies show weight loss can induce remission of diabetes, either through bariatric surgery or oral medications, with differing bodies of literature for each. The ADA Standards of Care 2017 address obesity as it pertains to diabetes risk and management of T2DM and provides recommendations in the following sections, which are summarized below:

    2. Classification and Diagnosis of Diabetes

    7. Obesity Management for the Treatment of Type 2 Diabetes

    BMIADA Recommendation
    Non-AsianAsianPrediabetes testing (if undiagnosed)*Weight loss meds (diagnosed T2DM)**Metabolic surgery (diagnosed T2DM)***
    2523X
    2727XX
    3027.5XXIf inadequate glycemic control on optimal medical therapy (including insulin)
    3532.5XXIf inadequate glycemic control on optimal lifestyle and medical therapy
    4037.5XXX
    *If undiagnosed and ≥1 additional diabetes risk factor(s) present. Screen with fasting plasma glucose, oral glucose tolerance test, or A1c.
    **Consider as an adjunct to diet, exercise, counseling. See below for comparison of FDA-approved weight-loss drugs.
    ***Consider for referral, assuming is otherwise an adequate surgical candidate.

    Drugs approved by the FDA for weight loss

    Does continuous glucose monitoring improve outcomes?
    Or are fingersticks good enough?

    Beck et al, Ann Intern Med, Sept 2017

    A: Maybe. Use of the CGM lowered HgbA1c from a mean of 8.5% to 7.7% in the CGM group and 8.0% in the FGM group. Note that reduction in A1c is a surrogate outcome. There was no significant difference in hypoglycemic episodes or quality-of-life outcomes, and follow-up was only 6 months. Also note that the study was funded by Dexcom, a CGM device manufacturer.

    Why this matters: The FDA just approved the first CGM (FreeStyle Libre Flash, Abbott). The limitations of this study should be noted.

    6
    Motivational interviewing
    How and why it works for people with diabetes
    ...
    Steroid-induced diabetes
    Professor Simon Griffin, creator of the Cambridge Diabetes Score, on steroids and diabetes.

    "We did not distinguish between the different potential underlying causes of diabetes. In our original analysis, the prescription of steroids was significantly associated with the presence of diabetes. Presumably, this is because the underlying indication for the prescription or the steroids themselves increase the risk of diabetes. We included any variable that increased the predictive utility of the model, irrespective of whether we understood the underlying mechanism. Unsurprisingly, the obvious known risk factors such as age and body mass index were the variables that most strongly predicted the presence of diabetes."