Diabetes - Special topics

How does the estimated mean glucose level compare to A1c values?

Glucose levels are usually slightly higher than what the A1c % is

What happens to PPG as patients get closer to their A1c target?

PPG becomes a larger percentage of contributions to the A1c

(so need to manage PPG more)

What does a clinical frailty score of 1-3 indicate?

Functionally independent

What does a clinical frailty score of 4-5 indicate?

Functionally dependent

What does a clinical frailty score of 6-8 indicate?

Frail and/or with dementia

How do FPG and PPG targets change with clinical frailty?

What is the evidence for targeting a low A1c?

Trials show decreased risk of microvascular complications (12% RRR)

(mostly driven by the nephropathy results)

What do the DCCT trials say about targeting a low A1c?

• reduction in retinopathy

• reduction in nephropathy

• reduction in neuropathy

• reduction of MACE

• reduction in mortality

What risk is involved with targeting a low A1c?

Severe hypoglycemia risk is doubled with intensive targets vs conventional

What does fructosamine testing reflect?

Average glycemic level over the preceding 2-3 wks

When would it be helpful to use fructosamine instead of A1c?

• patients when A1c is unreliable

• monitoring shorter term control of glucose

Why do we use the fingertip for CBG?

Changes in BG appear most rapidly at this site vs alternate sites

When can additional test strips get covered by ODB in exceptional circumastances?

• acute illness

• drug interactions

• GDM

• occupation requiring strict avoidance of hypo

• not meeting glycemic target for 3 months or greater

Max amount of test strips covered in 365 days for different scenarios

• on insulin - 3000/yr

• meds with high risk of hypos - 400/yr

• meds with low risk of hypos - 200/yr

• managing with non-pharms only - 200/yr

How often should patients verify the accuracy of their glucometer?

Once per year (check right after getting lab FPG and compare results)

Accuracy required for glucometers as per ISO

• 95% of meter readings must be within ± 0.83 mmol/L of lab results at concentrations lower than 5.6 mmol/L

• 95% of meter readings must be within ± 15% of lab results at concentrations of 5.5 mmol/L or higher

Target glycemic variability for CGM

36% or less

Target time in range for CGM

>70%

(if older/high risk: >50%)

Examples of benefits of exercise in T2DM

• decrease insulin resistance

• improve lipids

• improve BP

• improve glycemic control

What is included in the pre-exercise assessment?

• neuropathy

• retinopathy

• coronary artery disease

• peripheral arterial disease

• risk of hypo

  • if BG <5 mmol/L, have 10-20 g CHO before activity

• risk of hyper

  • if BG >16.7 mmol/L, ensure adequate hydration and monitor for signs/sx of dehydration

  • if BG >16.7 mmol/L AND feels ill, test for ketones - if elevated avoid or delay physical activity

Preconception checklist for women with pre-existing diabetes

• use reliable BC until adequate glycemic control

• attain preconception A1c of 7% or less

  • 6.5% or lower is safe

• can continue metformin and glyburide, otherwise switch to insulin

• Assess for and manage any complications of diabetes

• folic acid 1mg/d: 3 months pre-conception to 12 wks post-conception

• discontinue potential embryopathic meds

  • ACEi/ARB

  • Statins

Target BG values for pregnant patient with pre-existing diabetes

• Fasting and pre-prandial <5.3

• 1h postprandial <7.8

• 2h postprandial <6.7

• A1c 6.5% or less (6.1% or less if possible)

Why do we target a lower A1c in pregnancy?

Lower late stillbirth and infant death

Risk factors for GDM

• 35 yrs or older

• high-risk group (African, Arab, Asian, Hispanic, Indigenous, South Asian)

• Using corticosteroids

• BMI 30 or higher

• Prediabetes

• previous GDM

• given birth to macrosomal infant

• 1st degree relative with T2DM

• PCOS or acenthosis nigricans (darkened patches of skin)

How does pregnancy normally affect glucose?

Insulin resistance occurs and insulin sensitivity decreases

What is the mechanism in GDM

Insufficient insulin secretion to maintain normoglycemia

True or false. Hyperglycemia in pregnancy is often symptomatic.

False - often asymptomatic

GDM implications for mom

Increased risk of:

• pre-eclampsia

• preterm delivery

• c-section

• shoulder dystocia

• postpartum hemorrhage

GDM implications for baby

Increased risk of:

• congenital malformations

• macrosomia

• neonatal hyperglycemia

• NICU admission

• jaundice

When does GDM screening occur?

24-28 weeks of gestational age

(first trimester if diabetes risk factors)

GDM glucose targets

• fasting and preprandial <5.3

• 1h postprandial <7.8

• 2h postprandial <6.7

When is pharmacologic therapy initiated in GDM?

If glycemic targets are not achieved within 1-2 wks

What is considered “in range” for CGM in a T1DM pregnancy?

3.5-7.8

CGM targets for GDM or T2DM pregnancy

Unknown

First line therapy in GDM

Insulin (all rapid-acting have similar outcomes)

What can be used as an alternative to insuilin in GDM?

Metformin

(good safety data in pregnancy)

What has metformin showed evidence of in pregnancy?

• less maternal weight gain

• less large-for-gestational-age

• less neonatal hypoglycemia

What should pregnant patients be made aware of before starting metformin?

Should be informed that it crosses the placenta

What can be added to metformin in GDM?

Glyburide

Post-partum, should patients who had GDM be screened for diabetes?

Yes - lifelong diabetes screening q 1-3 yrs

What is MODY?

Monogenic diabetes

(rare genetic disorder that presents in young people, <25 yrs old)

Are people with MODY insulin-dependent?

No

How is MODY inherited?

Autosomal dominant

Which atypical antipsychotics have the highest incidence of hyperglycemia?

• olanzapine

• clozapine

Mechanism by which atypical antipsychotics cause hyperglycemia

• decreased peripheral insulin sensitivity

• decreased insulin secretion

  • inhibition of beta-cell responsiveness

• weight gain

At what doses of thiazide diuretics should you start to worry about hyperglycemia?

>25 mg HCTZ equivalent

Mechanism by which glucocorticoids cause hyperglycemia

• increased gluconeogenesis

• increased insulin resistance

• decreased pancreatic insulin secretion

Mechanism by which statins can cause hyperglycemia

• increased insulin resistance

• decreased insulin secretion

Why can hyperglycemia occur if someone is sick?

• stress

• increased hormones (cortisol, catecholamines, glucagon)

(leads to gluconeogenesis and glycogenolysis)

Do insulin requirements usually increase or decrease during acute illness?

Usually increase

SADMANS

• Sulfonylureas

• ACEi

• Diuretics, direct renin inhibitors

• Metformin

• ARBs

• NSAIDs

• SGLT2i

Reason for holding metformin and sulfonylureas during acute illness

Have reduced clearance and increase risk for AEs

When should patients monitor ketones?

• BG 14 mmol/L or higher

• during acute illnesss, infections, injuries

Meaning of various blood ketone levels

• <0.6 mmol/L is acceptable

• 0.6-1.5 mmol/L - recheck BG and ketones in 2-4 hrs

• 1.5-3 mmol/L - may be at risk of DKA

• >3 mmol/L - requires immediate medical attention

What should diabetic patients consider when booking surgeries?

Try to book for mornings so that fasting overnight

What should diabetic patients do if they are on a liquid diet when preparing for a procedure?

Replace CHO portion of meals with clear fluids with similar CHO content

(apple juice, white grape juice, regular

Jell-O, regular gingerale, regular sprite)

What should patients on insulin know if getting a procedure done?

• bring fast-acting sugar to prepare for treating a hypo

• basal insulin may stay the same or need to be reduced by 20-50%

• bolus insulin:

  • dose based on CHO content during clear fluids

  • hold on day of procedure

  • resume after procedure once eating meals

Guidelines for SGLT2is prior to a procedure

Stop 2-3 days before procedure (to decrease risk of DKA)

Guidelines for SUs and meglitinides prior to a procedure

Stop when starting clear fluid diet (since it increases risk of hypos)

Guidelines for metformin prior to a procedure

Stop when starting clear fluid diet

Guidelines for GLP-1 RAs prior to a procedure

Stop when starting clear fluid diet or dose prior

Guidelines for DPP-IVs prior to a procedure

No changes necessary

Which antihyperglycemic agents should be held on the day of a procedure?

All

Significance of IV contrast dye usage for medications

If used, metformin must be held for additional 2 days after procedure, and renal function may need to be checked prior to restarting the metformin

At what BG level does driving performance start to deteriorate?

<3.8 mmol/L

After taking fast-acting sugar for a low BG before driving, how long should a person wait before checking their BG again?

At least 40 minutes

After a low BG level, what BG level does someone need to have before driving?

At least 5 mmol/L