Dietary changes for pre-activity meals and a decrease in the amount of insulin normally given for the variability smoothed out glucose levels.

Published: May 25, 2022 | Updated: February 6, 2025

The patient

A teenage male with Type 1 diabetes mellitus, who is very active in sports and physical activity: He was having extreme difficulty with blood glucose control.

The challenge

Patient’s blood glucose levels often were high before activity. Lows would occur during activity or after. Treatment of lows often would cause a rebound high blood glucose, and patient was becoming frustrated with yo-yoing glucose values. Variability in blood glucose such as our patient reported is common with activity.

Activity started at 1 p.m. Following activity, patient experienced both hypoglycemia and hyperglycemia.

The providers

Bradly J. Thrasher, D.O., MBA, pediatric endocrinologist with Norton Children’s Endocrinology, affiliated with the UofL School of Medicine; director of the Christensen Family Sports & Activity Program; assistant professor of pediatrics at the University of Louisville School of Medicine

Kupper A. Wintergerst, M.D., chief, pediatric endocrinology; director, Wendy Novak Diabetes Institute; pediatric endocrinologist with Norton Children’s Endocrinology

Eric Davenport, R.D., CDCES, clinical nutritionist with Norton Children’s Endocrinology

Tim McKay, M.S, CEP, exercise physiologist with Norton Children’s Research Institute, affiliated with the UofL School of Medicine

The solution

Our team did a deep dive into our patient’s nutrition, activity and insulin regimen. We recommended dietary changes for pre-activity meals, reducing carbohydrate intake while increasing protein. We changed the patient’s insulin-to-carbohydrate ratio to deliver less insulin with meals before activity and used a temporary basal rate, starting one hour before activity, and continuing for one hour post-activity.

The result

After implementing activity strategies, our patient’s blood glucose variability improved. The second image shows our patient’s Dexcom continuous glucose monitor (CGM) data following implementation of recommendations. His blood glucose declined, but did not go below the 70 mg/dL threshold. This recommendation not only prevented a low blood glucose level after activity, but also the subsequent high blood glucose, keeping him in the goal range of 70 mg/dL to 180 mg/dL for a longer period of time. Recommendations and strategies such as these improve blood glucose variability following activity and keep it within target range for a longer period of time.

Activity started at 1 p.m., but with new strategies, patient did not experience hypoglycemia.