Psychological predictors of glucose control in patients with IDDM

Testing the Glucose Hypothesis among Capuchin Monkeys: Does Glucose Boost Self-Control?

The ego-depletion hypothesis states that self-control diminishes over time and with exertion. Accordingly, the glucose hypothesis attributes this depletion of self-control resources to decreases in blood glucose levels. Research has led to mixed findings among humans and nonhuman animals, with limited evidence for such a link between glucose and self-control among closely-related nonhuman primate species, but some evidence from more distantly related species (e.g., honeybees and dogs). We tested this hypothesis in capuchin monkeys by manipulating the sugar content of a calorie-matched breakfast meal following a nocturnal fast, and then presenting each monkey with the accumulation self-control task. Monkeys were presented with food items one-by-one until the subject retrieved and ate the accumulating items, which required continual inhibition of food retrieval in the face of an increasingly desirable reward. Results indicated no relationship between self-control performance on the accumulation task and glucose ingestion levels following a fast. These results do not provide support for the glucose hypothesis of self-control among capuchin monkeys within the presented paradigm. Further research assessing self-control and its physiological correlates among closely- and distantly-related species is warranted to shed light on the mechanisms underlying self-control behavior.

Glycemic control and blood glucose monitoring over time in a sample of young Australians with type 1 diabetes: the role of personality

OBJECTIVE

To determine whether personality traits (conscientiousness, agreeableness, emotional regulation, extraversion, and openness to experience) are associated with glycemic control and blood glucose monitoring behavior, and change or stability of these outcomes over time, in young people with type 1 diabetes.

RESEARCH DESIGN AND METHODS

A 3-year longitudinal study was conducted using data from 142 individuals with type 1 diabetes, 8-19 years of age. Personality was assessed at baseline using the Five-Factor Personality Inventory for Children. Data relating to glycemic control (HbA1c) and frequency of blood glucose monitoring (based on meter memory) were collected annually. Relationships between personality traits and HbA1c and monitoring frequency were examined using regression models and mixed-design ANOVA.

RESULTS

Three of the Five-Factor domains were independently associated with glycemic control. Individuals high in conscientiousness and agreeableness had a lower and more stable HbA1c across the 3-year study period. In contrast, the HbA1c of individuals scoring low on these traits was either consistently worse or deteriorated over time. Low or high emotional regulation scores were also associated with worse glycemic control. By the third year, these domains, together with initial HbA1c, accounted for 39% of HbA1c variance. Conscientiousness was the only personality factor associated with blood glucose monitoring behavior.

CONCLUSIONS

Results of this study underline the importance of personality in contributing to diabetes outcomes. Attention to a young person's personality, and appropriate tailoring of diabetes management to ensure an individualized approach, may help to optimize diabetes outcomes.

Unlocking the Energy Dynamics of Executive Functioning: Linking Executive Functioning to Brain Glycogen

Past work suggests that executive functioning relies on glucose as a depletable energy, such that executive functioning uses a relatively large amount of glucose and is impaired when glucose is low. Glucose from the bloodstream is one energy source for the brain, and glucose stored in the brain as glycogen is another. A review of the literature on glycogen suggests that executive functioning uses it in much the same way as glucose, such that executive functioning uses glycogen and is impaired when glycogen is low. Findings on stress, physical persistence, glucose tolerance, diabetes, sleep, heat, and other topics provide general support for this view.

The physiology of willpower: linking blood glucose to self-control

Past research indicates that self-control relies on some sort of limited energy source. This review suggests that blood glucose is one important part of the energy source of self-control. Acts of self-control deplete relatively large amounts of glucose. Self-control failures are more likely when glucose is low or cannot be mobilized effectively to the brain (i.e., when insulin is low or insensitive). Restoring glucose to a sufficient level typically improves self-control. Numerous self-control behaviors fit this pattern, including controlling attention, regulating emotions, quitting smoking, coping with stress, resisting impulsivity, and refraining from criminal and aggressive behavior. Alcohol reduces glucose throughout the brain and body and likewise impairs many forms of self-control. Furthermore, self-control failure is most likely during times of the day when glucose is used least effectively. Self-control thus appears highly susceptible to glucose. Self-control benefits numerous social and interpersonal processes. Glucose might therefore be related to a broad range of social behavior.

Child and parental personality are associated with glycaemic control in Type 1 diabetes

AIM

Little is known about the influence of the personality of the child and the personalities of the child's parents on glycaemic control in Type 1 diabetes. Our objective was to examine the extent to which glycaemic control is associated with the child's and the parents' stable personality traits, using the Big Five personality model as the basic framework.

METHODS

Participants were 64 children (aged 6-16 years) with recent-onset Type 1 diabetes and their parents. Glycaemic control (HbA(1c)) was assessed at 6 months, 1 year and 2 years after diagnosis; personality was assessed at 4-6 weeks, 6 months and 1 year after diagnosis. Associations of personality with mean HbA(1c) over 2 years were examined.

RESULTS

Children with better glycaemic control had a personality pattern of high Agreeableness, high Conscientiousness and low Neuroticism. Mothers of children with better glycaemic control showed a similar personality pattern, whereas the personality of the father was only marginally related to glycaemic control. Children's Conscientiousness and mothers' Agreeableness together predicted 18% of the variability in mean HbA(1c). All associations were unchanged when we controlled for child's age.

CONCLUSIONS

Glycaemic control in the child was associated with the same child and maternal personality characteristics that influence treatment adherence, health-promoting behaviours and general adjustment in adult populations. In future, studies are needed to examine attitudinal and behavioural mediators of this relationship. It is suggested that attention to the personalities of the child and the mother can help to tailor diabetes education to the individual child.

Utilizing content analysis of counseling sessions to identify psychosocial stressors among patients with type II diabetes

This qualitative, descriptive study identified specific individual and family psychosocial stressors that impact on the ability of patients with type II, non-insulin-dependent diabetes mellitus to manage the self-care regimens recommended by healthcare professionals. A series of 2 to 12 counseling sessions was incorporated into a nationally recognized outpatient diabetes education program. Data collection consisted of in-depth interviews in which six patients with type II diabetes and their families discussed current problems associated with their diabetes. Content analysis identified the following themes and problem areas: patients' inner experience with diabetes, family stressors that affect patients with diabetes, coping strategies of type II diabetes patients, and psychopathology. Based on these findings, specific interventions that emphasize family involvement and support were developed for the healthcare team to use with patients with type II diabetes.

Psychological and demographic correlates of glycaemic control in adult patients with type 1 diabetes

The relationship between an objective measure of glycaemic control (glycated haemoglobin (HbA1)) and personality variables was examined in two separate groups of adult Type 1 (insulin-dependent) diabetic patients. Study 1 included 121 patients, all of whom also had subjective self-reporting of treatment compliance assessed, while the first 57 patients had individual differences in intelligence, major dimensions of personality and forgetfulness documented. Study 2 examined 303 patients, all of whom had their major dimensions of personality assessed using a shortened and updated version of the original personality questionnaire. Demographic indices (age, onset-age, duration of diabetes) were assessed in both groups. No significant correlation was found between HbA1 and self-report compliance suggesting that self-reporting may be invalid as a measure of glycaemic control. In study 1 personality and intelligence variables did not correlate significantly with HbA1 values. Older patients with shorter duration of diabetes had significantly better glycaemic control (p < 0.05). A significant correlation was observed between HbA1 concentration and onset-age of diabetes (p < 0.001); the patients who had developed diabetes later in life were achieving better control of their blood glucose. In the larger number of subjects in study 2 no significant correlations were evident between HbA1 and personality variables. It is concluded that the predictors of glycaemic control indexed by HbA1 may be distinct from predictors of self-report compliance and that the latter have limited or no value in providing an assessment of quality of glycaemic control. There is no evidence of an effect of personality on glycaemic control as measured by HbA1.

Predictors of glycaemic control in type 1 diabetic patients after participation in an intensified treatment and teaching programme

The aim of the study was to identify predictors of long-term glycaemic control in Type 1 diabetic patients after participation in an intensified insulin treatment and teaching programme. The study population consisted of 697 Type 1 diabetic patients (mean age 26 +/- 7 (SD) years, duration of diabetes 8 +/- 7 years) who participated in the same structured intensified insulin treatment and teaching programme in 10 hospitals and who were re-examined after 1, 2, and 3 years. Multiple and logistic regression analyses were performed including a set of demographic, disease-related, social, and psychosocial variables as potential predictors. As dependent variables the average HbA1 values during the 3-year follow-up period and a composite variable (average HbA1 values/frequency of severe hypoglycaemia)--dividing patients into three groups with good, moderate or poor metabolic control--were considered. Regression analysis of average HbA1 values revealed significance (p < 0.05) for seven independent predictors in descending order: smoking, age at onset of diabetes, frequency of home blood glucose monitoring, socioeconomic status, diabetes-related knowledge, perceived coping abilities, and sex (R2 (percentage of variation explained by the model) = 17%). In a second regression model, HbA1 values before the intervention programme were added to the model and achieved the highest standardized regression coefficient (0.38), increasing R2 to 29%. In the logistic regression models considering both HbA1 and severe hypoglycaemia as a composite dependent variable, diabetes-related knowledge, HbA1 values before the intervention, smoking, perceived coping abilities, age at onset of diabetes, and C-peptide levels were the strongest predictors of glycaemic control. In conclusion, the relationship between demographic, disease-related, psychosocial, and social variables and metabolic control is complex. Therefore, simplistic concepts of linear causality should be abandoned. In addition to HbA1 values before the intervention, smoking, diabetes-related knowledge, home blood glucose monitoring, age at onset of diabetes, perceived coping abilities and C-peptide levels were the most significant and consistent predictors of glycaemic control.

Psychological moderator variables and metabolic control in recent onset type 1 diabetic patients--a two year longitudinal study

The relationships between psychosocial adjustment and subsequent glycaemic control were prospectively examined in forty-three adult patients during the first 2 yr after onset of type 1 diabetes mellitus. Decreasing depression was the single psychosocial parameter that changed over time. No correlations were found between the decrease in HbA1c levels and psychological variables at 8- and 16-month follow-ups. Global and specific coping features such as high control attitude, low coping anxiety and low emotional attribution correlated significantly with the decrease in HbA1c levels at the 2-yr follow-up, whereas stressful life events, depression, state-trait anxiety did not correlate. In a regression analysis coping explained 22% variance of the 2 yr decrease in HbA1c levels. We conclude that coping is a better predictor for metabolic control than emotional adaptation and life events. Metabolic control might deteriorate with prolonged stage of the disease being a first sign for psychophysiological coping exhaustion.

Addressing attitudes during diabetes education: suggestions from adult education

Suggestions from adult education can improve the effectiveness of diabetes education programs. While information and knowledge are noted as important factors in diabetes education, the literature indicates that they are insufficient to insure improved treatment outcomes. Research suggests that addressing psychosocial variables can improve diabetes education effectiveness. Although there are a multitude of psychosocial variables, attitude is consistently identified as an important contributor to positive diabetes management. Practical suggestions from adult education are offered to improve the learner's attitude about diabetes, the learning process, and the instructor.

Metabolic control, residual insulin secretion and self-care behaviours in a defined group of patients with type 1 diabetes

A population of 185 type 1 diabetes patients (insulin-dependent, IDDM), 25-45 years old, was studied retro- and prospectively over a 9-year period with the aim of analysing background factors of importance for the ability to perform adequate self-care. Expressed as mean HbA1c, the metabolic control was slightly improved at the end of the study, when the insulin schedule had been changed in 60% of the patients to multidose treatment. The degree of metabolic control remained constant over the years. The impact of residual insulin secretion, measured as 24-hour urinary C peptide, was low. Patients with less good metabolic control often had a poor educational background and made less use of self-monitoring of blood glucose (SMBG); they also experienced difficulties with SMBG. The applied knowledge of diabetes also differed between groups with good and poor control. Subjectively, most patients considered their metabolic control to be good, irrespective of the HbA1c values. When asked about their own diabetes complications, their answers were often discrepant from the medical records. Patients with particularly "good" or "poor" metabolic control were on the whole less satisfied with the education and information received than those with intermediate blood glucose regulation. Development of strategies for individually adjusted education seems important.