Executive Cognitive Functions and Behavioral Control Differentially Predict HbA1c in Type 1 Diabetes across Emerging Adulthood

A daily examination of executive functioning and chronotype in bedtime procrastination

STUDY OBJECTIVES

Bedtime procrastination, or delays in bedtime not attributable to external obligations, is a behavioral tendency that undermines sleep and is conceptualized as a consequence of poor self-regulation. Prior studies investigating the mechanistic role of self-regulation in bedtime procrastination relied on cross-sectional methods and self-reported self-regulation. The present study examined the association between bedtime procrastination and both objective and self-reported executive functioning (EF) as indices of self-regulation, as well as the moderating role of chronotype, using methods that examined these associations at the daily level.

METHODS

A total of 273 young adult participants (78% female; Mage = 24.4) completed daily measures of objective EF (i.e., Stroop task), self-reported EF (i.e., self-reported cognitive, behavioral, and emotional regulation difficulties), and bedtime procrastination over 14 days, in addition to measures of chronotype. Multilevel models were constructed to examine the associations between bedtime procrastination and EF, as well as EF-chronotype interactions.

RESULTS

Poorer daily objective EF and self-reported behavioral regulation were associated with greater same-night bedtime procrastination. Additionally, poorer subjective cognitive and emotional regulation were associated with greater average bedtime procrastination across 14 days. Later chronotypes reported greater bedtime procrastination than early chronotypes.

CONCLUSIONS

The present study provides support for the association between EF and bedtime procrastination, but finds no evidence for the moderating role of chronotype in this association. Results suggest that some EF processes may be more relevant to bedtime procrastination than others. Current findings have implications for assessment and intervention for this consequential sleep-relevant behavioral tendency.

A critical review of the relationship between type 1 diabetes mellitus, inhibition, and behavioral management

Type 1 diabetes mellitus (T1DM) is a chronic and lifelong condition that requires adequate behavior management in order to meet desired health outcomes. The effects of T1DM on the neurocognitive functioning of affected individuals raise concerns about how the disease may influence executive functioning. Inhibition is a core component of executive functioning, and plays a vital role in self-regulation and the restriction of impulsive behaviors. Inhibition may thus play a vital role in the behavior management of people with T1DM. The aim of this study was to identify current gaps in existing knowledge regarding the relationship between T1DM, inhibition, and behavior management. This study employed a critical review design to analyze and synthesize the current scientific literature. Twelve studies were identified through an appraisal process, and the data extracted were thematically analyzed and integrated. The findings of this study indicate that a possible cycle arises between these three constructs, in which T1DM affects inhibition, inhibition affects behavior management, and poor behavior management affects inhibition. It is recommended that future research should focus more specifically on this relationship.

Intra-individual variability identifies individuals vulnerable to contextually induced executive lapses

Contextual stressors, such as engagement in burdensome emotion regulation known as expressive suppression (ES), can result in transient but clinically meaningful decrement in performance on measures of executive functioning (EF). The goal of the present investigation was to examine whether intra-individual variability (IIV-I), which has been identified as an indicator of cognitive weakness, could serve as a marker of vulnerability to EF decrements due to both naturally-occurring and experimentally-manipulated ES.

In Study 1, 180 cognitively healthy older adults completed the Push-Turn-Taptap (PTT) task to assess IIV-I, four Delis-Kaplan Executive Function System (D-KEFS) subtests to assess EF, and the Burden of State Emotion Regulation Questionnaire (B-SERQ) to assess naturally-occurring ES. In Study 2, a subset (n = 81) of participants underwent experimental manipulation to induce ES, followed by second administration of the D-KEFS to examine ES-induced decrements in EF.

In Study 1, hierarchical linear regression yielded a significant interaction between ES and IIV-I as predictors of EF performance, demonstrating that high ES was associated with low EF only among individuals with high IIV-I. In Study 2, repeated measures ANOVA demonstrated an interaction between time (pre- vs. post- manipulation), group (ES vs. control), and IIV-I (high vs. low), such that only individuals who exhibited high IIV-I were negatively impacted by the ES manipulation.

IIV-I moderates the association between ES and EF, such that only individuals with high IIV-I exhibit vulnerability to the impact of ES. Thus, IIV-I may act as a marker of vulnerability to temporary EF depletion.

Associations of Executive Function With Diabetes Management and Glycemic Control in Adolescents With Type 1 Diabetes

AIMS

The aims of this study were to assess domains of executive function in relation to diabetes management and glycemic control in adolescents with type 1 diabetes and to compare adolescent self-report and parent proxy-report of adolescent executive function.

METHODS

Adolescents with type 1 diabetes (N = 169, 46% female, age 15.9 ± 1.3 years) and their parents completed self-report and parent proxy-report versions of the Behavior Rating Inventory of Executive Function (BRIEF).

RESULTS

Self-report and parent proxy-report BRIEF T scores were moderately to strongly correlated; parent proxy scores were significantly higher than self-report scores. Executive function problems (Global Executive Composite T score ≥60) occurred in 9% of adolescents by self-report and 26% by parent proxy-report. For almost all Metacognition Index scales, elevated (T score ≥60) parent proxy scores were associated with lower adherence, lower adolescent diabetes self-efficacy, and more parent involvement in diabetes management. Elevated scores on several Metacognition Index scales were associated with less pump use (Plan/Organize by self-report, Initiate by parent proxy-report, and Monitor by parent proxy-report) and higher A1C (Plan/Organize by self-report and parent proxy-report and Organization of Materials by parent proxy-report). The only significant associations for the Behavioral Regulation Index scales occurred for adherence (by parent proxy-report) and diabetes self-efficacy (by self-report and parent-report).

CONCLUSION

Adolescents with type 1 diabetes who have problems with metacognition may need additional support for diabetes self-management.

Evaluation of the effects of glycated hemoglobin on cardiac function in patients with short-duration type 2 diabetes mellitus: A cardiovascular magnetic resonance study

AIMS

To investigate the association between glycated hemoglobin (HbA1c) and myocardial dysfunction and to determine whether its association is independent of myocardial perfusion.

METHODS

Sixty-four patients with type 2 diabetes mellitus (T2DM) were recruited. They were divided into groups according to their HbA1c level: the controlled T2DM group (HbA1c < 7%) and uncontrolled T2DM groups (HbA1c ≥ 7%). Meanwhile, 30 age-matched healthy volunteers were included. All patients with T2DM and healthy controls underwent cardiovascular magnetic resonance imaging to evaluate the myocardial mechanics and perfusion parameters.

RESULTS

The circumferential and longitudinal peak strain (PS) (p = 0.009 and 0.002 respectively) and global radial, circumferential, and longitudinal peak strain diastolic strain rates (PDSRs) (p = 0.002, 0.001, and 0.001 respectively) were lower in the uncontrolled T2DM group than in the controls without diabetes. In multivariable linear regression analysis, HbA1c was independently related to all directions of the PS and PDSR. The myocardial perfusion parameters were not independently associated with the PS or PDSR.

CONCLUSIONS

Cardiac function is impaired in Chinese T2DM patients with poor glucose control (HbA1c ≥ 7%), with preserved left ventricular (LV) ejection fraction, and disease duration <10 years. Poor blood glucose control is an independent predictor of LV myocardial dysfunction for patients with short-term T2DM.