Background: People with T1D commonly struggle with co-managing weight and glycemia, which increases cardiovascular disease risk. We evaluated the effect of an adaptive Sequential, Multiple Assignment, Randomized Trial (SMART) pilot on weight and glycemia in people with T1D.

Methods: The SMART pilot tested the hypocaloric Look AHEAD (Low Fat) or Low Carbohydrate (Low Carb) ; or Mediterranean (Med, not calorie restricted) diets among young adults with T1D ages 19-30 (BMI 27-39.9 kg/m²) . We report data from the first 3-month diet period pre-pandemic before a shift to a virtual protocol for primary (weight, HbA1c, and % time below range [TBR, 54-69 mg/dl]) and secondary outcomes (body fat % and % time in range [70-180 mg/dl]) . We computed descriptive within-group changes in outcomes. Adjusted models tested diet differences.

Results: Overall weight change was -2.0 kg (95% CI -3.0, -1.1, p<0.0001, n=38) and did not vary by diet. Body fat % decreased overall. Per adjusted models, HbA1c decreased on Low Fat vs. Low Carb (-0.60% [95% CI -1.5, -0.3], p=0.049) and TBR trended towards a decrease on Med vs. Low Carb (-3.1% [95% CI -6.4, 0.083], p=0.056) .

Conclusions: Our intervention decreased adiposity and maintained glycemia in young adults with T1D. We will use these results to power an efficacy trial to co-optimize weight and glycemia among individuals with T1D.


D.Igudesman: None. R.E.Pratley: Other Relationship; Bayer AG, Corcept Therapeutics, Dexcom, Inc., Hanmi Pharm. Co., Ltd., Merck & Co., Inc., Metavention, Novo Nordisk, Pfizer Inc., Poxel SA, Sanofi, Scohia Pharma Inc., Sun Pharmaceutical Industries Ltd. M.R.Kosorok: n/a. D.M.Maahs: Advisory Panel; Abbott Diabetes, Eli Lilly and Company, Medtronic, Novo Nordisk, Sanofi, Consultant; Aditx Therapeutics, Inc., Biospex. E.J.Mayer-davis: None. J.Crandell: n/a. T.Pokaprakarn: None. K.Corbin: None. D.P.Zaharieva: Research Support; Insulet Corporation, International Society for Pediatric and Adolescent Diabetes, Leona M. and Harry B. Helmsley Charitable Trust. A.Addala: None. J.Thomas: None. A.Casu: None. M.Riddell: Advisory Panel; Zealand Pharma A/S, Zucara Therapeutics, Consultant; Eli Lilly and Company, Jaeb Center for Health Research, Speaker's Bureau; Dexcom, Inc., Eli Lilly and Company, Novo Nordisk.


National Institutes of Health 1DP3DK113358

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