• Two separate measurements of any combination of the following:
  
  
  
  • Random plasma glucose ≥200 mg/dL with polydipsia, polyuria, polyphagia, and/or weight loss
    
  • Fasting plasma glucose ≥126 mg/dL
    
  • Two-hour oral glucose tolerance test ≥200 mg/dL after a 75-g glucose load
    
  • A1C ≥6.5%. (by lab using a method that is NGSPcertified and standardized to the DCCT assay.

The increasing acquisition of processed food combined with decreasing physical activity has led to an explosion in worldwide obesity and type 2 diabetes mellitus, with the greatest rate of increase in the young. Diabetes is now the sixth (www.cdc.gov/diabetes) leading cause of death in the United States, and its treatment consumes one in every seven health care dollars, with 63% spent on inpatient care. It is a major cause of blindness, renal failure, lower extremity amputations, cardiovascular disease, and congenital malformations. With 90% of patients receiving their care from primary care physicians, diabetes is the epitome of a chronic disease requiring a multidisciplinary management approach.

Diabetes develops from a complex interaction of genetic and environmental factors. In type 1 diabetes this leads to destruction of the pancreatic β cells and loss of the body’s ability to produce insulin. Type 2 diabetes is the result of increasing cellular resistance to insulin, a process accelerated by obesity and inactivity. A very small percentage of diabetic patients may have latent autoimmune diabetes with an onset similar to type 2, but with destruction of the β cells, and a more rapid progression to insulin dependence.

Diet and exercise have been shown to reduce the risk of developing type 2 diabetes by 58%. Several medications including metformin may also delay its onset by a more modest percentage. Tight control of hyperglycemia and blood pressure significantly reduce the complications of diabetes, and a sustained reduction in hemoglobin A1c (HbA1c) is associated with significant cost savings within 1-2 years.

Motivating individuals to make lifestyle changes is difficult but cost-effective and safe, and can result in reduced obesity and hypertension and improvement of lipid profiles. A low-fat, high-fiber diet, modest exercise, and smoking cessation are modalities vastly superior to the complexities of the care of patients with diabetes and its complications.

Fasting glucose is the screening method of choice, although a random glucose is acceptable. The US Preventive Services Task Force (USPSTF) recommends screening for diabetes in adults with hypertension. The American Diabetes Association (ADA) recommends screening every 3 years beginning at age 45 especially if BMI ≥25 kg/m2 . Testing should occur earlier and more frequently in patients with risk factors listed in Table 35-1.

A consensus panel has recommended screening of overweight children (weight >120% of ideal or a body mass index (BMI) >85th percentile) every 2 years beginning at age 10 or onset of puberty with two of the following risk factors:

1. 
   

   Family history of diabetes in first- or second-degree relative

   
   
2. 
   

   High-risk racial or ethnic group (Native Americans, African, Americans, Hispanics, or Pacific Islanders)

   
   
3. 
   

   Signs of, or conditions associated with insulin resistance (eg. acanthosis nigricans, hypertension, dyslipidemia, and polycystic ovarian syndrome)

Universal screening in pregnancy is controversial. Table 35-2 lists the risk factors for which screening is recommended by the ADA and the diagnostic criteria in pregnancy.

Signs and Symptoms

The classic signs of diabetes are polyuria, polydypsia, and polyphagia, but first signs may be subtle and nonspecific. Patients with type 1 diabetes exhibit fatigue, malaise, nausea and vomiting, irritability and weight loss. Abdominal pain is a common complaint in children. They present early in the disease process, but usually are quite ill at presentation, often already ketoacidotic. Signs and symptoms of ketoacidosis include those associated with dehydration (dry skin and mucous membranes, decreased skin turgor, tachycardia, and hypotension), tachypnea, and labored respirations with the classic “fruity” breath, abdominal pain, and confusion.

In type 2 diabetes symptoms are seen well after onset of the disease and may be due to complications. The classic signs are still prominent, but patients may also complain of fatigue, irritability, drowsiness, blurred vision, numbness or tingling in the extremities, slow wound healing, and frequent infections of the skin, gums, or urinary tract including candidal infections.

History and Physical Examination

The initial assessment for newly diagnosed diabetics is extensive (Table 35-3). The use of written checklists or questionnaires, electronic health records, or the assistance of a trained nurse or assistant can decrease physician time. Standing orders are an excellent way to make the visits more efficient and utilize nursing expertise (Table 35-4). It is important to update routine screening examinations (Papanicolaou [Pap], mammogram, colonoscopy) and ensure all immunizations are current (tetanus, pneumococcal, and yearly influenza vaccines). Interim visits focus attention on compliance and patients’ special issues with management (Table 35-5). Visit frequency is based on control of diabetes and the patient’s understanding and comfort. Patients initiating insulin therapy may require daily contact, by phone or e-mail. Those with poor control or making frequent changes may require weekly to monthly visits. When diabetes is well-controlled, visits are usually scheduled quarterly. Novel approaches to patient visits, such as group visits where several patients are seen simultaneously, maximize physician teaching time and allow sharing of ideas and information among the patients.

Laboratory Findings

Initial and yearly labs include fasting glucose, fasting lipid profile, serum electrolytes and blood urea nitrogen (BUN), creatinine, urinalysis, and microalbumin. Evaluation of thyroid-stimulating hormone may be indicated as concurrent hypothyroidism is common especially in women. Depending on age and duration of disease an electrocardiogram (ECG) may be performed, but as microalbuminuria is a marker for cardiovascular disease, an ECG should be performed once microalbuminuria is detected. HgbA1c is measured every 3 months. Random microalbumin levels or microalbumin/ creatinine ratios may be used for screening and/or monitoring, but patients may require a 24-hour urine for protein and creatinine clearance when there are significant changes. Common findings are elevations in glucose, HgbA1c, triglycerides, BUN and creatinine, and microalbumin with decreased HDL (high-density lipoprotein) cholesterol.

Preventing and delaying progression of all complications in patients with diabetes is dependent on lifestyle modification, tight control of blood glucose and blood pressure, and smoking cessation. The ACCORD trial, however, found that intensive glycemic control (HgbA1c ≤6%) did not lower the incidence of adverse microvascular outcomes.

Ketoacidosis

Ketoacidosis occurs when there is insufficient insulin to meet the body’s needs, resulting in increased gluconeogenesis, fatty acid oxidation, and ketogenesis. This leads to metabolic acidosis, osmotic diuresis, and dehydration. Ketoacidosis is one of the leading causes of death in children with diabetes with an incidence in children of about 8 per 100 person-years. It increases with age in girls, and is highest for children with poor control, inadequate insurance, or psychiatric disorders.