Regional Laboratory Alliance

Newsletters

 Medical Laboratory Services

Anatomic Pathology

Drug Testing 

 

Overview	Locations	Map	Speciality Testing	Links	Drug Testing	Home	Newsletters

Volume 2 Issue 9 October 1997

Management of Patients with Diabetes Mellitus

Diabetes mellitus is a chronic illness that requires continuing medical care and education to prevent acute complications and reduce the risk of chronic complications such as retinopathy, nephropathy, and neuropathy. The Diabetes Control and Complications Trial (DCCT) demonstrated that in patients with type 1 diabetes the risk of developing these complications was reduced 50 to 75% by intensive treatment regimens that decreased the average hemoglobin A1c level to 7.2%. The reduction in risk of these complications correlated continuously with the reduction in hemoglobin A1c levels, implying that complete normalization of glycemia levels may prevent complications.

In view of the DCCT’s findings, the American Diabetes Association has recommended the following goals for glycemic control in patients with type 1 diabetes. Similar goals have been recommended for patients with type 2 diabetes. These goals may not be appropriate for patients with a history of hypoglycemia.

Biochemical Index Nondiabetic Diabetic Goal Action suggested

Preprandial glucose <115 mg/dL 80 - 120 mg/dL <80 or >140

Bedtime glucose <120 mg/dL 100 - 140 mg/dL <100 or >160

Hemoglobin A1c <6% <7% >8%

Initial Patient Visit

During the initial visit, laboratory tests should be performed to establish the diagnosis of diabetes, determine the degree of glycemic control, and detect chronic complications and risk factors. Recommended tests include:

· Fasting plasma glucose ( random plasma glucose is acceptable in an undiagnosed symptomatic patient)

· Glycated hemoglobin

· Fasting lipid profile including total, HDL, and LDL cholesterol & triglycerides in adults and children >2 years

· Serum creatinine in adults and children with proteinuria

· Urinalysis including glucose, ketones, protein, and sediment

· Urine culture if the sediment is abnormal or patient is symptomatic

· Urine microalbumin for postpubertal patients with diabetes for at least 5 years and all patients with type 2 diabetes

· Thyroid function tests when clinically indicated

Patients should be instructed in self monitoring of blood glucose and urine ketones and in the use of a record system. The frequency of blood glucose monitoring should be individualized according to the severity of illness, treatment plan, and response to treatment.

Continuing Care

Periodic follow-up tests play an essential part in the continuing management of every patient with diabetes.

Glycated hemoglobin should be performed routinely in all patients with diabetes; first to document the degree of glycemic control at initial assessment and then as part of continuing care. Since glycated hemoglobin reflects the mean blood glucose level over the preceding two to three months, repeat measurements approximately every three months are required to determine whether a patient’s metabolic control has remained continuously within the target range. Patients with stable glycemic control may require less frequent testing. Glycated hemoglobin levels performed in different laboratories should not be compared or trended.

Laboratory Test	Patient Population	Frequency of Testing
Glycated hemoglobin	Stable glycemic control Poor control or changed therapy	At least 1 to 2 times per year Quarterly
Lipid profile	Initial profile abnormal Treatment for dyslipidemia Children with normal lipid values	Annually As needed to monitor therapy Every 5 years
Urinalysis	Adults & Children	Adults annually, children quarterly
Microalbumin	Type 1 diabetes beginning at puberty & after 5 years duration Type 2 diabetes at time of diagnosis	Annually   Annually
Creatinine clearance	Patients with albuminuria or proteinuria	As needed to monitor nephropathy
Serum potassium	Hypertensive patients treated with ACE inhibitors	As needed to monitor for hyperkalemia

Adults should be tested for lipid disorders annually with a fasting cholesterol, HDL cholesterol, calculated LDL cholesterol, and triglycerides. If all values are within normal limits, less frequent testing may be necessary. Acceptable, borderline, and high risk lipid levels for adults are listed in the following table.

Risk for Adult Diabetics	Cholesterol (mg/dL)	HDL(mg/dL)	LDL(mg/dL)	Triglycerides(mg/dL)
Acceptable	<200	.	<130	<200
Borderline	200 - 239	.	130-159	200 - 399
High	>239	<36	>159	>399

Borderline or abnormal values should be repeated for confirmation. Lipid values should be reevaluated in the presence of a macrovascular event. A lipid profile should be performed on children older than two years after glucose control has been established. Borderline or abnormal results should be repeated for confirmation. If values fall within accepted risk levels, assessment should be repeated every five years.

Routine urinalysis should be performed yearly in adults. If positive for protein, quantitation is helpful in monitoring treatment. If urinalysis is negative for protein, a test for microalbumin is necessary. Microalbumin testing of patients with type 1 diabetes should begin at puberty and after five years duration. Patients with type 2 diabetes should be tested at the time of diagnosis. First void or other morning urine collections are preferred because of the diurnal variation in albumin excretion. Three different microalbumin tests are available:

· Measurement of albumin/creatinine ratio on a random, spot collection

· 24 hour collection with creatinine

· Timed collection (e.g. 10 hour)

Random urine specimens are often most convenient for outpatients and are generally accurate. There is marked day to day variability in albumin excretion; therefore, at least two of three microalbumin levels should be elevated during a three to six month period before a patient is considered to have microalbuminuria. Renal function should be monitored with periodic measurements of creatinine clearance. Hypertensive diabetic patients who are treated with ACE inhibitors should be monitored for hyperkalemia.

Reference

1. American Diabetes Association. "Standards of Medical Care for Patients with Diabetes Mellitus." Diabetes Care 1997; 20 (supplement 1): S5-13.