September 12, 2000
Gestational Diabetes
Question from Seattle, Washington, USA:
Can you provide some information as to how a hot environment affects blood sugar levels? I am 32 weeks pregnant and have gestational diabetes. I have been following a diet with great success for about two weeks (no blood sugar levels over 115mg/dl [6.4 mmol/L] two hours after a meal). Yesterday, I ate a small meal (3 carbs, 2 proteins, similar to other meals that had produced levels of 85 mg/dl [4.7 mmol/L] or so after two hours at lunch, but it was extremely hot outside. I did not exercise following this meal, but stayed inside a hot house. My blood sugar was 133 mg/dl [7.4 mmol/L] at two hours. After subsequently going for a swim in a cold lake, my level (one-half hour later) was 83 mg/dl [4.6 mmol/L]. Is this because of the cooling effect of swimming? Is it important for people with gestational diabetes to avoid heat, or should we eat less during hot weather to make up for higher blood sugar levels?
Answer:
The only idea I had on this is that, when you are hot, you tend to vasodilate, and, when you are cool, your blood vessels constrict. This may affect your blood sugar readings based on fingerstick samples. Your body regulates its internal temperature very well (as long as you are otherwise healthy), so the weather should not dictate what you eat.
OWJ