Background: Subtle but significant cognitive differences between youth with and without type 1 diabetes (T1D) have been observed and found to be related to chronic hyperglycemia. We report continued follow-up of prospectively acquired cognitive data obtained over 4.5 years in a large cohort of young children with and without T1D.

Methods: 181 children with T1D and 90 age-matched nondiabetic controls underwent age-appropriate neuropsychological testing at three time points: baseline, 18 months, and approximately 2.9 years after the second visit (T1D group: 11.2 ± 1.9 y, HbA1c: 8.1 ± 1.0%, diabetes duration 6.4 y at the time of latest evaluation; control group: mean age 11.6 ± 1.7 years). Effects of T1D on cognition were estimated based on longitudinal mixed effects modeling after controlling for parental full-scale IQ.

Results: The T1D group continued to show significantly lower scores on Full Scale IQ (Cohen’s d=-0.31, p=0.024), Verbal IQ (d=-0.33, p=0.009), and Vocabulary (d=-0.42, p=0.002) compared to nondiabetic controls at last follow-up. Processing speed, memory and learning were similar between the T1D and the control groups. Within the T1D group, there was a significant inverse relationship between HbA1c at last follow-up and Vocabulary (r=-0.307, p=0.001) as well as between HbA1c and VIQ (r=-0.200, p=0.037), controlling for parental IQ.

Conclusion: In this large cohort of children with relatively well-controlled T1D followed for 4.5 years, differences in full-scale and verbal IQ persist over time compared to nondiabetic controls, and effects on vocabulary and verbal IQ are related to glycemic control. These findings further support the importance of optimizing glycemic control during this critical period of brain maturation.


S.A. Weinzimer: Consultant; Self; Eli Lilly and Company, Sanofi. Consultant; Spouse/Partner; Tandem Diabetes Care. Consultant; Self; Zealand Pharma A/S. Speaker's Bureau; Self; Insulet Corporation, Medtronic MiniMed, Inc., Tandem Diabetes Care. Stock/Shareholder; Self; InsuLine Medical Ltd. J.M. Ambrosino: Consultant; Spouse/Partner; Eli Lilly and Company, Sanofi. Consultant; Self; Tandem Diabetes Care. Consultant; Spouse/Partner; Zealand Pharma A/S. Speaker's Bureau; Spouse/Partner; Insulet Corporation, Medtronic, Tandem Diabetes Care. Stock/Shareholder; Spouse/Partner; InsuLine Medical Ltd. A. Cato: None. B. Jo: None. K.A. Englert: Consultant; Self; PicoLife Technologies, LLC. N.H. White: None. A. Arbelaez: None. T. Hershey: Research Support; Spouse/Partner; Sage Pharmaceuticals. L.A. Fox: None. E. Tsalikian: None. M. Tansey: Advisory Panel; Self; Daiichi Sankyo Company, Limited. B.A. Buckingham: Advisory Panel; Self; ConvaTec Inc., Novo Nordisk Inc., Profusa, Inc. Consultant; Self; Medtronic MiniMed, Inc. Research Support; Self; Beta Bionics, ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Medtronic MiniMed, Inc., Tandem Diabetes Care. Other Relationship; Self; Insulet Corporation, Tandem Diabetes Care. T. Aye: None. D.M. Wilson: Advisory Panel; Self; Tolerion, Inc. Research Support; Self; Beta Bionics, Dexcom, Inc., Medtronic. W.V. Tamborlane: Consultant; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Medtronic MiniMed, Inc., Novo Nordisk Inc., Sanofi, Takeda Pharmaceutical Company Limited. A.L. Reiss: None. N. Mauras: Consultant; Self; Novo Nordisk Inc., PicoLife. Research Support; Self; Medtronic MiniMed, Inc.


Eunice Kennedy Shriver National Institute of Child Health and Human Development (DIRECNET: U01HD-41906, HD-41908, HD-41915, HD-41918, HD-56526, R01HD-078463, U54HD087011); National Center for Advancing Translational Sciences (UL1TR000448)

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