Diabetes Viewpoints

Dehydration, Diabetes, and Summer Heat

By Melissa Conrad Stöppler, M.D.

Where my family lives, summer temperatures routinely hover in the high 90s, and the humidity can be unbearable. Although our summer isn’t the optimal time for any kind of strenuous outdoor exercise, no one wants to remain indoors until October, when it begins to cool off. So we adjust our schedules a bit, scheduling walks or runs in the early morning hours, decreasing the time and intensity of our outdoor sports activities, and taking along plenty of fluids to prevent dehydration.

Dehydration can occur any time when our body loses more water (for example, from extreme sweating) than we take in. Thirst is the first and most obvious sign of dehydration. As the condition progresses, dehydration can lead to dry mouth, reduced sweating, and a decrease in urine output. Severe dehydration can result in damage to the brain and other organs and can even lead to coma and death. Dehydration resulting from profuse sweating can also cause a loss of sodium and other electrolytes from the bloodstream that accompanies the loss of water. If the water and electrolyte losses progress, blood pressure can fall to perilously low levels.

People with diabetes can face further challenges in maintaining an adequate level of hydration in hot weather, since diabetes can lead to an increase in the body’s excretion of urine when blood glucose levels are elevated. But exercise is an essential part of the prevention and management of type 2 diabetes as well as a component of a healthy overall lifestyle, and most people will want to continue some type of outdoor activities even when it’s hot outside.

Prevention of dehydration is essential for everyone during the hot summer months, especially when spending time outdoors. Staying well-hydrated can help prevent fluctuations in blood glucose levels as well as heat-related complications such as heat exhaustion or heat stroke. Drinking plenty of water may be all that is needed to offset the mild dehydration that occurs when you’re outside in the summer heat, but if sodium and other electrolytes are lost through prolonged or heavy exercise, they must be replaced. (Drinking large amounts of water, without accompanying replacement of sodium and other electrolytes, has been associated with dangerously low sodium levels in marathon runners and those who participate in extremely strenuous sports activities.)

While flavored sports drinks like Gatorade and PowerAde have been designed to replace electrolytes lost during exercise, these aren’t necessarily the best choice for hydration maintenance for people with diabetes (or for people watching their weight), since they are often loaded with sugar and calories. Unless you’re trying to combat hypoglycemia, those extra carbohydrates aren’t necessary and can even sabotage your weight control plan. Consuming a small amount of salt (for example, by taking salt tablets or eating a small amount of food) along with water during or after exercise is another option for electrolyte replacement and is probably the better choice for most people. It’s also possible to find zero-calorie sports drinks or to make your own sports drinks by adding a small amount of salt to low-calorie flavored fruit beverages and flavored waters.

Finally, if you’re out in the summer heat, remember to avoid drinks containing caffeine and alcohol. Both alcohol and caffeine have diuretic effects, meaning that they promote the excretion of urine and can increase your risk of becoming dehydrated.

Read more of Melissa's columns here.

Disclaimer
dLife's Daily Living columnists are not all medical experts, but everyday people living with diabetes and sharing their personal experiences. While their method of diabetes management may work for them, everyone is different. Please consult with your diabetes care team to find out what will work best for you.