Diabetes Mellitus: Control and Complications

Robert S. Zimmerman

POINTS TO REMEMBER:

Screening

Fasting blood glucose (FBG) remains the screening test of choice for diabetes mellitus (DM)
FBG ≥ 126 mg/dL is consistent with a diagnosis of DM
Additional screening tests accepted by the American Diabetes Association (ADA) include:
- Two-hour postprandial blood glucose (≥200 mg/dL)
- Oral glucose tolerance test
- Glycosylated hemoglobin A_1c (HbA_1c) ≥ 6.5% (the newest accepted criterion)

Risk Factors and General Principles

Risk factors for DM type 2 include family history, obesity, hypertension, certain ethnicities, history of cardiovascular disease (CVD), history of gestational diabetes, and the presence of hypokalemia (regardless of diuretic use)
Having a first-degree family member with DM type 1 increases the risk of developing DM type 1 by 10-fold
DM type 1 results from autoimmune destruction of the pancreas, and patients with DM type 1 are at increased risk for developing other autoimmune diseases

Treatment

Treatment targets for ambulatory diabetic patients include the following:
- HbA_1c <7.0%
- Fasting and/or preprandial FBG between 70 and 130 mg/dL
Based on data from the NICE-SUGAR trial, intensive insulin therapy (maintaining glucose between 80 and 110 mg/dL) in hospitalized patients in the ICU setting is no longer advised. Glycemic target range for hospitalized ICU patients is 140 to 180 mg/dL
Type 1 DM results from absolute insulin deficiency and patients must be treated with insulin
The main role of long-acting insulin administered as part of a multi-dosing insulin regimen is to serve as basal insulin
For patients with hypoglycemic unawareness, intensive ambulatory insulin therapy is contraindicated
Because of possible lactic acidosis, metformin should be avoided in patients with cirrhosis, alcoholism, heart failure, or renal failure (serum creatinine >1.5 mg/dL)
The sulfonylurea medications work best if prescribed to DM type 2 patients who are age >40, with diabetes of <5 years duration who have a fasting blood glucose of <180 mg/dL, are overweight, and are prescribed little or no insulin therapy

Complications

Diabetic complications can be classified as microvascular (nephropathy, retinopathy, and neuropathy) or macrovascular (CVD and stroke)
DM is the leading cause of blindness in adults 25 to 74 years old in Europe and North America and one of the leading causes of kidney dialysis
If a diabetic patient presents with neuropathy, it is crucial to always consider causes other than DM
In type 2 DM, intensive ambulatory diabetes control has been shown to decrease microvascular complications. Data are inconclusive on macrovascular complication prevention
Reducing blood pressure with either a β-blocker or an angiotensin-converting enzyme (ACE) inhibitor reduces the risk of both microvascular and macrovascular complications and overall mortality