Relationship Between Moderate-to-Vigorous Physical Activity and Glycemia Among Young Adults with Type 1 Diabetes and Overweight or Obesity: Results from the Advancing Care for Type 1 Diabetes and Obesity Network (ACT1ON) Study.

Aims: Using data from the ACT1ON study, we conducted secondary analyses to assess the relationship between minutes of moderate-to-vigorous physical activity (MVPA) and glycemia in adults with type 1 diabetes (T1D) and overweight or obesity. Materials and Methods: Participants (n = 66) with T1D provided measures of glycemia (hemoglobin A1c [HbA1c], percent of time below range <70 mg/dL, time-in-range [TIR 70-180 mg/dL], and time above range [TAR >180 mg/dL]) and self-reported physical activity (Global Physical Activity Questionnaire [GPAQ] and Previous Day Physical Activity Recalls [PDPAR]) at baseline, 3, 6, and 9 months postintervention. Wearable activity data were available for a subset of participants (n = 27). Associations were estimated using mixed effects regression models adjusted for design, demographic, clinical, and dietary covariates. Results: Among young adults 19-30 years of age with a baseline HbA1c of 7.9% ± 1.4% and body mass index of 30.3 (interquartile range 27.9, 33.8), greater habitual weekly MVPA minutes were associated with higher HbA1c through the GPAQ (P < 0.01) and wearable activity data (P = 0.01). We did not observe a significant association between habitual MVPA and any continuous glucose monitoring metrics. Using PDPAR data, however, we observed that greater daily MVPA minutes were associated with more TAR (P < 0.01) and reduced TIR (P < 0.01) on the day following reported physical activity. Conclusions: Among young adults with T1D and overweight or obesity, increased MVPA was associated with worsened glycemia. As physical activity is vital to cardiovascular health and weight management, additional research is needed to determine how to best support young adults with T1D and overweight or obesity in their efforts to increase physical activity. Clinical Trial Registration number: NCT03651622.

Physical Activity and Glycemia among Young Adults with Type 1 Diabetes and Overweight or Obesity-Results from Advancing Care for Type 1 Diabetes and Obesity Network (ACT1ON)

The ACT1ON pilot study evaluated the feasibility of three dietary strategies to optimize weight and glycemic management among young adults with T1D and overweight or obesity. As a secondary measure, self-reported physical activity (PA) was collected at baseline, 3-, 6-, and 9-months from 68 young adults with T1D (age 25.5 ± 3.1 years, 72.1% female, HbA1c 7.9 ± 1.8%, BMI 30.4 (27.9 - 33.9)) . Using the Global Physical Activity Questionnaire (GPAQ, n=195) and Previous Day Physical Activity Recalls (PDPAR, n=123) , we estimated weekly minutes of moderate-to-vigorous physical activity (MVPA) . Following the COVID-19 outbreak, a subset of participants wore Garmin Vivosmart4® PA trackers for two weeks at each visit (44 measurements from 27 participants) . Mixed effects regression models assessed the relationship between weekly minutes of MVPA and HbA1c using each PA measure. Median weekly minutes of MVPA were 33% lower following the COVID-19 outbreak compared to pre-pandemic PA levels (p=0.02) per the GPAQ, but not PDPAR (-7.7%, p=0.34) . After adjusting for design, demographic, clinical, and dietary variables, a 1 standard deviation increase in weekly minutes of MVPA (GPAQ) was associated with an absolute increase of 0.27% HbA1c (p>0.001) . A small, statistically non-significant association was observed for PDPAR (β=0.13, p=0.19) ;however, we observed a borderline statistically significant association using the PA tracker data (β=0.231, p=0.08) , despite a smaller sample size (n=44) . These results suggest that among young adults with T1D and overweight and obesity, higher levels of PA may lead to challenges in achieving optimal glycemia. Future work is needed to determine how to best support young adults with T1D and overweight and obesity in attaining both their PA and glycemic management goals.