Study supports personalized exercise plans
“It is important to evaluate effects of exercise in people with type 1 diabetes and evaluate whether there is a difference those effects in men and women,” said Helena W. Rodbard, MD, an endocrinologist in private practice in Rockville, Md., in an interview. “There is also a need to evaluate to what extent the changes in blood glucose patterns in women in response to exercise differ depending on the phase of the ovarian cycle,” said Dr. Rodbard, who was not involved in the study.
Dr. Helena W. Rodbard
In the current study, “the researchers observed a decline in glucose during a 45-minute period of moderate aerobic exercise, cycling at 50% VO2peak followed by an increase during a 60-minute recovery period. There was a suggestive finding, in the nine subjects, that more carbohydrate supplementation was needed during the late luteal phase of the menstrual cycle than during the follicular phase,” Dr. Rodbard noted. “In contrast, the authors reported a significantly increased degree of hyperglycemia during the recovery phase for subjects during the follicular phase. These findings are consistent with and extend several recent studies from Dr. Yardley and coworkers, who have been focused on this area of research,” she said.
“This study provides provocative evidence that glucose responses to aerobic exercise in women may depend on the timing in relationship to their ovarian cycle,” said Dr. Rodbard. “These findings are based on a small group of subjects and were present in some but not all subjects. Clinicians should encourage women to evaluate and record their experiences during and after exercise in terms of need for carbohydrate supplementation for documented or symptomatic hypoglycemia and in terms of glucose changes as recorded using continuous glucose monitoring (CGM), both in relation to type of exercise and in relation to time in the menstrual cycle,” she said.
The findings also highlight the importance of individualized therapy that is “based on subjective inputs combined with analysis of CGM data during and following exercise,” said Dr. Rodbard. “It is likely that use of Automated Insulin Delivery (AID) will be helpful in achieving this level of individualization in view of the wide range of types, intensity, and duration of physical activity and exercise in which people with T1D engage and the myriad factors that can influence the glycemic response,” she said.
Looking ahead, “the authors and others should expand the present series of subjects using aerobic exercise and examine other types of exercise as well,” Dr. Rodbard noted. “It will be important to evaluate the consistency of these changes in glucose patterns within individuals on multiple occasions, and it would be helpful to repeat the studies in women using oral contraceptives.”
Dr. Yardley disclosed research support from Abbott, Dexcom, and LifeScan and disclosed serving on the speaker’s bureau for Abbott Diabetes. Dr. Rodbard had no financial conflicts to disclose. She serves on the Editorial Advisory Board of Clinical Endocrinology News.