Diabetes Mellitus Monitoring

Diabetes Mellitus Monitoring

 

Diabetes mellitus (DM) is a chronic illness that leads to significant morbidity and death in the U.S.

Criteria for the Diagnosis of Diabetes
One of the following criteria:
  • Fasting plasma glucose ≥126 mg/dl (7.0 mmol/l)
    • Fasting is defined as no caloric intake for at least 8 hours
  • Symptoms of diabetes and a casual plasma glucose ≥200 mg/dl (11.1 mmol/l)
    • Casual is defined as any time of day without regard to time since last meal
    • The classic symptoms of diabetes include polyuria, polydipsia, and unexplained weight loss
  • 2-h plasma glucose ≥200 mg/dl (11.1 mmol/l) during an OGTT
    • The test should be performed as described by the World Health Organization, using a glucose load containing the equivalent of 75-g anhydrous glucose dissolved in water
(Used with permission from Standards of Medical Care, 2007, S5)

Disease Complications

  • Acute
    • Diabetic ketoacidosis – Type 1 DM
    • Hyperosmolar nonketotic coma – Type 2 DM
  • Long-term (Types 1 and 2 DM)
    • Cardiac – coronary artery disease
    • Immunologic – recurrent infections
    • Neurologic – neuropathy
    • Ophthalmic – retinopathy
    • Renal – proteinuria with renal failure
    • Vascular – small vessel disease with extremity loss
  • A large body of evidence supports that structured care with appropriate clinical interventions may prevent acute complications and improve long-term outcomes in DM patients

Disease Monitoring

Recommendations for Physical Examination
  • Blood pressure determination every visit, including orthostatic measurements when indicated (goal <130/80 mmHg)
  • Fundoscopic examination and dilated eye exam by expert (if first exam is normal, then every 2-3 years)
  • Thyroid palpation
  • Skin examination (for acanthosis nigricans and insulin injection sites)
  • Neurological/foot examination
  • Inspection
  • Palpation of DP and PT pulses
  • Presence/absence of patellar and Achilles reflexes
  • Determination of proprioception, vibration and monofilament sensation
(Adapted with permission from Standards of Medical Care, 2007, S8)

Laboratory Testing

  • Glycemic control
    • Hemoglobin A1c
      • Premise of testing
        • Glycation of hemoglobin is non-linear over time and occurs over the whole lifespan of the red blood cell
        • Correlates with risk of long term complications and with diabetes control over previous 2-3 months
      • Target goal: <7% of glycated hemoglobin
      • Laboratory testing recommendations 
        • 2 measurements per year for patients meeting goal of <7%
          • If patient is not hypoglycemic, goal should be <6%
        • More frequent monitoring in patients with HbA1c ≥7%; however not more often than every 3 months
        • Do not use for diagnosis for diabetes
    • Fructosamine
      • Premise of testing
        • Intermediate marker of glycemia
        • Measures glycation of serum proteins (principally albumin)
        • Provides glycemia index over 20-day period
      • Laboratory testing recommendations
        • May be useful in monitoring gestational DM; not recommended as a standard to use for other types of DM
        • May be used in patients with shortened red cell survival (eg, sickle cell disease)
    • Albumin, glycated
      • Premise of testing
        • Intermediate marker of glycemia
        • Measures glycation of serum albumin
        • Provides glycemia index over 20-day period
      • Laboratory testing recommendations
        • May be useful in monitoring gestational DM; not recommended as a standard to use for other types of DM
        • May be used in patients with shortened red cell survival (eg, sickle cell disease)
    • 1-5-Anhydroglucitol
      • Premise of testing
        • Measures levels of a compound that competes with glucose for reabsorption at the renal tubule
        • Less sensitive to small changes in glycemic control at high HbA1c levels
      • Laboratory testing recommendations
        • Not recommended as a standard test for monitoring DM
        • May be useful for identifying post-prandial hyperglycemia
    • Insulin levels
      • Premise of testing
        • Circulating levels of insulin may be prognostic for likelihood of progression to insulin dependence in diabetes
      • Testing recommendations
        • Not recommended as a standard test for monitoring DM
    • C-peptide
      • Premise of testing
        • C-peptide connects the A& B chains of proinsulin
        • Released in equimolar concentrations with insulin
        • Reflects endogenous insulin production
      • Laboratory testing recommendations
        • Not recommended as a standard test for monitoring DM
        • May be useful for assessing endogenous insulin production to confirm need for insulin therapy
  • Dyslipidemia
    • Lipid panel
      • Premise of testing
        • Patients with diabetes have an increased incidence of lipid abnormalities
        • Lipid lowering therapies have been demonstrated to reduce macrovascular disease
    • Target goal: LDL <70 mg/dL (particularly if there is evidence or risk of CVD); HDL >40 mg/dL, triglycerides <150 mg/dL
      • Recommended laboratory testing
        • Initial evaluation and every year if goals are met
          • More often if goals are not met
        • Treat aggressively with statins if goals not met
  • Hepatic function
    • Liver function tests (SGOT, SGPT, alkaline phosphatase, bilirubin)
      • Premise of testing
        • Patients with DM are at-risk for steatohepatitis
        • Recommend testing – initial and annually thereafter if values are normal on initial testing
  • Renal function
    • Creatinine 
      • Premise of testing
        • Many drugs will require adjusted dosing based on creatinine, creatinine clearance or estimated glomerular filtration rates (eGFR)
        • Absolute creatinine values do not reflect glomerular filtration rates in many patients
          • Diabetic nephropathy diminishes creatinine
          • Renal function thereby diminishes clearance and glomerular filtration rate
        • Creatinine and eGFR are broad measures of renal function
      • Target goal
        • Normal ranges
          • Males – 97-113 mL/min
          • Females – 88-128 mL/min
        • Recommended laboratory testing
          • Serum creatinine and eGFR (calculated) annually
    • Microalbumin (urine)
      • Premise of testing
        • Diabetic nephropathy occurs in 20-40% of patients with diabetes and is the single leading cause of end stage renal disease
        • Microalbuminuria (persistent albuminuria) (range 30-299 mg/g creatinine, 30-299 mg/24 hours) signifies the earliest stage of diabetic nephropathy
        • Target goal
          • <30 mg/g creatinine, <30 mg/24 hour urine
          • Recommended laboratory testing
            • Spot urine or 24-hour urine for microalbumin annually
        • Addition of angiotensin converting enzyme inhibitors to diabetes regimen is renoprotective if microalbuminuria is present
    • Thyroid function
      • TSH
        • Premise of testing
          • Autoimmune thyroid disease occurs more frequently in patients with DM
          • Recommend testing initially and, if normal, every 3 years thereafter

See Also