
- With Mayo Clinic endocrinologist
Maria Collazo-Clavell, M.D.
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Maria Collazo-Clavell, M.D.
Maria Collazo-Clavell, M.D.
Dr. Maria Collazo-Clavell is board certified in internal medicine, endocrinology, diabetes and metabolism. She's a consultant in the Division of Endocrinology, Diabetes, Metabolism & Nutrition at Mayo Clinic and an associate professor at College of Medicine, Mayo Clinic.
The Aibonito, Puerto Rico, native has been with Mayo Clinic since 1994.
She's a member of the American Association of Clinical Endocrinologists, the American College of Endocrinology, the American Diabetes Association and The Endocrine Society.
Dr. Collazo-Clavell is medical editor of diabetes content on Mayo's health information website and for "Mayo Clinic The Essential Diabetes Book." Her clinical interests include management of type 1 and type 2 diabetes, obesity and nutritional disorders.
Risk factors (1)
- Diabetes: Does alcohol and tobacco use increase my risk?
Symptoms (1)
- The dawn phenomenon: What can you do?
Complications (1)
- Diabetes: How do I help protect my liver?
Treatments and drugs (5)
- Avandia safety concerns: What should I do?
- Diabetes management: Does aspirin therapy prevent heart problems?
- Blood glucose monitors: What factors affect accuracy?
- see all in Treatments and drugs
Lifestyle and home remedies (11)
- Diabetes: Are electric blankets off-limits?
- Vegetarian diet: Can it help me control my diabetes?
- Air pollution and exercise: Is outdoor exercise risky?
- see all in Lifestyle and home remedies
Alternative medicine (1)
- Diabetes treatment: Can cinnamon lower blood sugar?
Question
The dawn phenomenon: What can you do?
What is the dawn phenomenon that some people with diabetes experience? Can anything be done about it?
Answer
from Maria Collazo-Clavell, M.D.
The dawn phenomenon, also called the dawn effect, is the term used to describe an abnormal early-morning increase in blood sugar (glucose) — usually between 2 a.m. and 8 a.m. — in people with diabetes.
Some researchers believe the natural overnight release of hormones — including growth hormones, cortisol, glucagon and epinephrine — increases insulin resistance, causing blood sugar to rise. High morning blood sugar may also be caused by insufficient insulin the night before, incorrect medication dosages or carbohydrate snack consumption at bedtime.
If you have persistently elevated blood sugar in the morning, checking your blood sugar once during the night — around 2 a.m. or 3 a.m. — for several nights in a row will help you and your doctor to determine if you have the dawn phenomenon or if there's another reason for an elevated morning blood sugar reading.
Your doctor may recommend a number of options to help you prevent or correct high blood sugar levels in the morning:
- Avoid carbohydrates at bedtime
- Adjust your dose of medication or insulin
- Switch to a different medication
- Adjust the time of your medication or insulin from dinnertime to bedtime
- Use an insulin pump to administer extra insulin during early-morning hours
Diabetes and depression: Coping with the two conditions
- Umesh M, et al. Treatment of diabetes mellitus. In: Gardner DG, et al., eds. Greenspan's Basic and Clinical Endocrinology. 9th ed. New York, N.Y.: Mc-Graw Hill Companies, Inc.; 2011. http://www.accessmedicine.com/content.aspx?aID=8407903. Accessed Sept. 22, 2011.
- Collazo-Clavell M (expert opinion). Mayo Clinic, Rochester, Minn. Sept. 28, 2011.
- Eisenbarth GS, et al. Type 1 diabetes mellitus. In: Kronenberg HM, et al. Williams Textbook of Endocrinology. 12th ed. Philadelphia, Pa.: Saunders Elsevier; 2011. http://www.mdconsult.com/das/book/body/191205553-3/0/1555/0.html#. Accessed Oct. 2, 2011.

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