LAB TESTING IN DIABETES
Hemoglobin A1C Every 3- 6 months
Hemoglobin A1c is a measure of their overall blood glucose control for the past 3 months. Blood glucose levels fluctuate from hour to hour, day to day; but the A1C level reflects the overall average and is the best test to monitor blood glucose control in the past 3 months.
How it works: Hemoglobin is a protein found inside of red blood cells. Its job is to carry oxygen from the lungs to all the cells of the body. Glucose enters your red blood cells and links up (or glycates) with molecules of hemoglobin. The more glucose in your blood, the more hemoglobin gets glycated. By measuring the percentage of glycated hemoglobin (A1C) in the blood, you get an overview of your average blood glucose control for the past few months.
The A1C test is an important tool for diagnosing and monitoring diabetes. After diagnosis, most patients should take the A1C test every 3 months, though the test might be spaced to every 6 months for patients with consistently good levels.
Optimal A1C levels to reduce the risk of developing complications in most non-pregnant people with diabetes are less than 7%, though older persons with multiple medications and other complex medical problems may have a less stringent goal (less than 8%).
Creatinine, eGFR, and microalbumin to creatinine ratio- At least annually
Chronic kidney disease (CKD) is common in diabetes, occurring in about 20–40% of people with diabetes. It is important to detect it early in order to prevent it from worsening. CKD is diagnosed by the persistent presence of high levels of albumin in the urine or if there is a decreased estimated glomerular filtration rate (eGFR). eGFR is a calculated value based off the creatinine.
- An eGFR persistently less than 60 mL/min/1.73 m2 is considered abnormal (though optimal thresholds for clinical diagnosis are debated in older adults)
- A urine albumin to creatinine ratio of greater than 30mg/g Cr is considered abnormal.
Liver enzymes (AST and ALT)- At least annually
Liver enzymes should be monitored in all people with diabetes. These enzymes can be elevated due to fatty liver disease, which is closely associated with obesity and insulin resistance. Other common causes of elevated liver enzymes include viral infections and alcohol.
Lipids- At least annually
Atherosclerotic cardiovascular disease (ASCVD) is the still the most common cause of death in the United States, and people with diabetes have risk of cardiac events that is far higher than the general population. Having a family history of heart disease, high blood pressure, and smoking increase this risk even further. The American College of Cardiology has an ASCVD risk estimator, and I encourage you to go through the exercise of estimating your risk.
Extensive research has shown that most patients with diabetes can reduce their risk of heart attack and stroke by taking cholesterol-reducing medications called “statins”. The benefit is so clear that the American Diabetes Association has for years recommended statin use for adults over the age of 40.
Cholesterol goals for most people with diabetes
- LDL cholesterol: Less than 70mg/dL
- HDL cholesterol: greater than 40 mg/dL in men, greater than 50 mg/dL in women
- Triglycerides: Less than 150 mg/dL
Vitamin B12- Annually, if on metformin
Metformin is associated with Vitamin B12 depletion. This typically takes several years to happen, but it is good practice to screen for B12 deficiency yearly to catch the issue before it happens.
Testosterone- Every few years, in men
Men with diabetes have been shown to have an increased risk of low testosterone. This can be due to poorly controlled diabetes, obesity, or disrupted sleep.