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Biomedical subjects

L Gonder-Frederick

Publications and source records attributed to L Gonder-Frederick.

At least 19 recordsLinked to original sources
PubMed2001

Blood glucose awareness training (BGAT-2): long-term benefits.

OBJECTIVE: Blood glucose awareness training (BGAT) has been shown to improve awareness of blood glucose (BG) fluctuations among adults with type 1 diabetes. This study investigates the long-term (12-month) benefits of BGAT-2. RESEARCH DESIGN AND METHODS: A total of 73 adults with type 1 diabetes participated in a 6-month repeated baseline design with a 12-month follow-up. At 6 months and 1 month before BGAT-2 and at 1,6, and 12 months after BGAT-2, subjects used a handheld computer for 50 trials and completed psychological tests. Throughout assessment, subjects completed diaries, recording occurrences of diabetic ketoacidosis, severe hypoglycemia, and motor vehicle violations During follow-up, 50% of the subjects received booster training. RESULTS: During the first and last halves of both the baseline period and the follow-up period, dependent variables were generally stable. However, from baseline to follow-up, BGAT-2 led to 1) improved detection of hypoglycemia and hyperglycemia; 2) improved judgment regarding when to lower high BG, raise low BG, and not drive while hypoglycemic; 3) reduction in occurrence of diabetic ketoacidosis, severe hypoglycemia, and motor vehicle violations; and 4) improvement in terms of worry about hypoglycemia, quality of life, and diabetes knowledge. Reduction in severe hypoglycemia was not associated with a worsening of metabolic control (HbA1). The presence or absence of booster training did not differentially affect these benefits. CONCLUSION: BGAT has sustained broad-ranging benefits, independent of booster intervention.

Anxiety↗
PubMed2001

Driving mishaps and hypoglycaemia: risk and prevention.

Driving is a complex, multi-task activity that can be affected by cognitive impairment resulting from episodes of severe hypoglycaemia. Intensive insulin therapy increases the likelihood of severe hypoglycaemia but there have been few studies examining effects on driving skills. A survey carried out recently indicated that patients with type 1 diabetes had twice the incidence of driving accidents than their non-diabetic spouses or patients with type 2 diabetes. The motor accidents were associated with more frequent low blood glucose while driving and less frequent self-monitoring. In driving simulation tests it was found that driving has an intrinsic metabolic demand that can contribute to hypoglycaemia. Driving performance began to deteriorate at around 3.6 mmol/l but drivers frequently did not recognise and failed to treat the hypoglycaemia. Those who did self-treat had more driving relevant symptoms and less neuroglycopenia quantified by EEG alpha-theta differences. Patients should be recommended not to begin driving if blood glucose is below 4.5 mmol/l and should not continue to drive if they suspect that blood glucose has fallen below 4 mmol/l while driving. If hypoglycaemia is suspected patients should immediately pull off the road, measure blood glucose if possible, treat themselves as necessary and not resume driving until glucose and cognitive-motor function return to normal. The problems of driving and hypoglycaemia should be discussed with patients with diabetes and behavioural interventions instigated. To this end, Blood Glucose Awareness Training (BGAT) and Hypoglycaemia Anticipation, Awareness and Treatment Training (HAATT) have been developed and shown to markedly reduce incidence of driving mishaps.

Accidents, Traffic↗
PubMed2000

Episodes of severe hypoglycemia in type 1 diabetes are preceded and followed within 48 hours by measurable disturbances in blood glucose.

This study quantifies blood glucose (BG) disturbances occurring before and after episodes of severe hypoglycemia (SH). For 6-8 months, 85 individuals with type 1 diabetes and a history of SH (age, 44+/-10 yr; 41 women and 44 men; duration of diabetes, 26+/-11 yr; hemoglobin A1c, 7.7+/-1.1%) used Lifescan One Touch BG meters for self-monitoring three to five times daily and recorded the date and time of SH episodes in diaries. For each subject, the timing of SH episodes was located in the temporal stream of SMBG readings recorded by the meter, and characteristics, including the Low BG index (LBGI), were computed in 24-h increments. In the 24-h period before the SH episode LBGI rose (P < 0.001), average BG was lower (P = 0.001), and BG variance increased (P = 0.001). In the 24 h after SH, LBGI and BGvariance remained elevated (P < 0.001), but average BG returned to baseline. These disturbances disappeared in 48 h. On the basis of LBGI we identified subjects at low, moderate, and high risk of SH, who reported, on the average, 1.7, 3.4, and 7.4 SH episodes (P < 0.005) during the study. In addition, we designed an algorithm that predicted 50% of all SH episodes that occurred in this subject group. We conclude that episodes of SH are preceded and followed by quantifiable BG disturbances, which could be used to devise warnings of imminent SH.

Activity Cycles↗
PubMed1999

Biopsychobehavioral model of risk of severe hypoglycemia. Self-management behaviors.

OBJECTIVE: To identify self-management antecedents of low blood glucose (BG) (< 3.9 mmol/l) that might be easily recognized, treated, or avoided altogether. RESEARCH DESIGN AND METHODS: Ninety-three adults with type 1 diabetes (age, 35.8 +/- 8 years [mean +/- SD]; duration of diabetes, 17.0 +/- 11 years; daily insulin dose, 0.58 +/- 0.18 U/kg; and HbAlc, 8.6 +/- 1.8%) were recruited to participate in the study. Of the 93 subjects, 42 had a history of severe hypoglycemia (SH), defined as two or more hypoglycemic episodes in the preceding 12 months, and 51 subjects had no history of SH (No-SH) in the same time period. Before each of 70 BG measurements obtained over a 3-week period, subjects used a handheld computer to record whether their most recent insulin, food, and exercise was more than, less than, or the same as usual. Associations among self-management behaviors preceding BG readings < 3.9 mmol/l versus those preceding BG readings of 5.6-7.8 mmol/l were determined using chi 2 tests, analyses of variance, and logistic regression analyses. RESULTS: Analysis of 6,425 self-management/self-monitoring of BG events revealed that the usual amounts of insulin, food, and exercise preceded the events 58.3% of the time. No significant differences were observed for changes in insulin before readings of BG < 3.9 mmol/l versus 7.8 < BG > 5.6 mmol/l, but significantly less food (P < 0.01) was eaten and more exercise (P < 0.001) was performed before the low BG measurement. No interactions between SH and No-SH groups and management behaviors were observed. However, each of the three management variables entered significantly in a logistic model that predicted 61% of all readings of BG < 3.9 mmol/l. CONCLUSIONS: Subjects with a history of SH did not report managing their diabetes differently from those with no such history. Specifically, when low BG occurred, the preceding management behaviors, although predictive of low BG, were not different in SH and No-SH subjects. Overall, self-management behaviors did not distinguish SH from No-SH subjects. Thus, even though it might be beneficial for all patients to review their food and exercise management decisions to reduce their frequency of low BG, an educational intervention whose content stresses insulin, food, and exercise would be unlikely by itself to be sufficient to reduce the frequency of SH.

Adult↗
PubMed1998

Stochastic model of self-regulation decision making exemplified by decisions concerning hypoglycemia.

The following sequence-internal condition --> symptom perception --> appraisal --> decision-models various symptom-based self-regulation processes. A formal mathematical model describes the first three steps by continuous variables and the decisions at the fourth step by binary variables. The stochastic transitions between the sequential steps are quantified by transition probabilities. The model is illustrated by blood glucose level estimation and detection and treatment of hypoglycemia in 78 patients with insulin-dependent diabetes mellitus. These patients made 50 to 70 data collection trials over 3 to 4 weeks recording perceived symptoms, cognitive-motor performance, subjective estimates of blood glucose, decisions about treatment of hypoglycemia, and driving. A statistical estimation of the model's parameters demonstrates the utility of this approach for understanding the awareness, detection, and treatment of hypoglycemia as a process of symptom-based decision making.

Adult↗
PubMed1997

The psychosocial impact of severe hypoglycemic episodes on spouses of patients with IDDM.

OBJECTIVE: No previous studies have examined the psychosocial impact of severe hypoglycemic episodes in IDDM patients on their spouses. This study compared spouses of IDDM patients with and without a history of recent severe hypoglycemia (SH) using traditional measures of psychosocial status and marital conflict, as well as diabetes-specific measures. RESEARCH DESIGN AND METHODS: A total of 61 nondiabetic spouses (23 wives and 38 husbands) of IDDM patients participated in the study. Spouses completed a battery of traditional psychometric measures (depression, anxiety, marital conflict) and diabetes-specific measures (fear of hypoglycemia, marital conflict over diabetes, sleep disturbance caused by hypoglycemia). Scores of spouses of IDDM patients with and without a recent history of SH were compared with t tests. RESULTS: Spouses of IDDM patients with and without a recent history of SH showed no differences on traditional psychometric measures of depression, anxiety, and marital conflict. However, spouses of patients with a recent history of SH showed significantly more fear of hypoglycemia, marital conflict about diabetes management, and sleep disturbances caused by hypoglycemia. Exploratory analyses of variance (ANOVAs) found no differences on psychometric measures between wives and husbands, with the exception that husbands of SH patients reported more sleep disturbance. Nondiabetic spouses, on average, showed greater fear of hypoglycemia than their diabetic partners. CONCLUSIONS: Although SH in IDDM patients can have a significant impact on the psychosocial status of their spouses, in this study the negative impact was restricted to areas of life that are directly related to diabetes and its management. Thus, SH per se is not necessarily associated with significant increases in spousal anxiety, depression, or marital conflict, but may be associated with types of diabetes-specific psychosocial distress that are not easily identified by traditional psychometric measures.

Adult↗
PubMed1997

A biopsychobehavioral model of risk of severe hypoglycemia.

Severe hypoglycemia (SH) is a significant problem for many patients with type I diabetes and presents a major barrier to optimal diabetes control. A critical task facing diabetes research is to understand, predict, and reduce the risk of SH in insulin-treated patients. The purpose of this article is to propose a biopsychobehavioral model of SH risk that integrates and extends previously proposed models. Current biological and psychological models of SH risk, which focus on hormonal counterregulation and symptom awareness, are reviewed. The limitations of these models are also discussed, including their failure to recognize important psychological and behavioral processes that contribute to SH risk. Specifically, the biopsychobehavioral model includes patients' decision-making, judgment, and behavioral responses as significant predictors of SH risk. The proposed model is comprised of seven steps: 1) physiological and behavioral precursors to low blood glucose (BG), 2) low BG occurrence, 3) hormonal and neurological responses to low BG, 4) awareness of symptoms caused by hormonal and neurological changes, 5) detection of low BG, 6) decision-making and judgment, and 7) behavioral response. The model has several advantages, including the ability to mathematically calculate the transitional probabilities from each step to the next as well as the ability to describe SH risk in both hypoglycemia-aware and hypoglycemia-unaware patients. Research findings supporting the biopsychobehavioral model are presented, and its empirical and clinical implications are discussed.

Behavior↗
PubMed1996

The frequency of severe hypoglycaemia in children with insulin-dependent diabetes mellitus.

The literature contains numerous reports of the frequency of severe hypoglycaemia in childhood insulin-dependent diabetes mellitus. Unfortunately, most of these data have been collected in such a manner as to make comparisons between them difficult. Most reports have used small, well-defined populations of children who were participants in larger, complex, clinical studies. Additional difficulties are encountered in the standardization of the definition of severe hypoglycaemia. Some studies have required that the child lose consciousness while others also included children who required assistance with treatment. Even when studies clearly define the representative nature of their patient population and include universally acceptable criteria for identifying a severe hypoglycaemic episode, the frequency of severe hypoglycaemia must be qualified. Severe hypoglycaemia is generated by a series of complex biological, psychological, and behavioural processes. Its frequency must be viewed not as a fixed value, but rather as a dynamic dependent variable.

Adolescent↗
PubMed1995

A multicenter evaluation of blood glucose awareness training-II.

OBJECTIVE: Blood glucose awareness training (BGAT) teaches individuals with insulin-dependent diabetes to more accurately estimate/detect their blood glucose (BG) fluctuations. It has not, however, consistently resulted in improved ability to detect low BG. To assess an enhanced version of BGAT (BGAT-II), with more focus on increasing sensitivity to low BG events, a multicenter study was undertaken. Following up on previous findings that BGAT is most effective with individuals who are least accurate in estimating BG, this study explicitly recruited subjects who did and did not report reduced awareness of hypoglycemia. RESEARCH DESIGN AND METHODS: Seventy-eight subjects from three research sites participated in a repeated baseline design. Subjects' BG estimation accuracy and BG profiles were assessed 6 months before, immediately before, and immediately after BGAT-II. RESULTS: Post-treatment, BGAT-II led to better overall accuracy in detecting BG fluctuations and better detection of both low and high BG levels. This was achieved while the number of low readings of self-monitoring of blood glucose (SMBG) was reduced. Reduction in the number of low SMBG events was significant only for subjects reporting awareness of hypoglycemia. Detection of low BG was significant only for subjects reporting reduced awareness of hypoglycemia. Both groups demonstrated equivalent improvements in detection of high BG levels. CONCLUSIONS: BGAT may be an effective behavioral strategy for reversing hypoglycemic unawareness and an adjunct to intensive insulin therapy to reduce the occurrence of severe hypoglycemia.

Adult↗
PubMed1994

Long-term follow-up evaluation of blood glucose awareness training.

OBJECTIVE: Blood glucose awareness training (BGAT) has been found effective in teaching individuals with insulin-requiring diabetes to improve their ability to better recognize blood glucose (BG) fluctuations. This study investigated whether subjects who underwent BGAT a mean of 4.9 years previously were superior to past control subjects in terms of their ability to recognize BG fluctuations, and whether past BGAT subjects had fewer automobile crashes and lost work days and better glycosylated hemoglobin than control subjects. Additionally, the beneficial effects of providing booster training to past BGAT subjects also was evaluated. RESEARCH DESIGN AND METHODS: This study followed up 28 past BGAT subjects. Half of these subjects (n = 14) received a simple booster-training program. Twelve previous control subjects also were evaluated. Booster subjects were given a BGAT diary to complete for 2 weeks before evaluation. Evaluation for all subjects included completion of a retrospective questionnaire on work and driving history, blood drawing for a glycosylated hemoglobin analysis, and having subjects estimate and measure their BG levels 50-80 times during a 3- to 4-week period during their daily routine. RESULTS: At long-term follow-up, BGAT subjects had significantly fewer automobile crashes than control subjects. BGAT subjects receiving booster training were significantly more accurate at estimating their BG levels and were more aware of hypoglycemia. Post hoc analyses indicated that the ability to accurately estimate BG fluctuations correlated positively with follow-up glycosylated hemoglobin and the number of hypoglycemic and hyperglycemic symptoms participants demonstrated. Both BGAT and control subjects demonstrated significantly improved glycosylated hemoglobin relative to baseline measures. CONCLUSIONS: These data suggest that BGAT has long-term benefits, which can be enhanced with booster training. Specifically, BGAT and simple booster training may result in reduction of severe hypoglycemic episodes and automobile crashes in the long term.

Accidents, Traffic↗
PubMed1993

Driving decrements in type I diabetes during moderate hypoglycemia.

Diabetic hypoglycemia produces cognitive-motor slowing, which is assumed to increase risk of automobile crashes. This study investigated driving decrements during and after hypoglycemia, and the patients' awareness of driving decrements. We used a randomized, single-blind, crossover design and conducted the study at the University of Virginia's General Clinical Research Center. We studied a volunteer sample of 27 consecutive adult type I diabetic patients who responded to newspaper ads. Two dropped out (final n = 25). Mean age (+/- SD) was 35.9 +/- 14 yr. Diabetes history was 14.6 +/- 10.5 yr, with HbA1 of 10.8 +/- 2.9%. Driving experience was 19 +/- 13.2 yr. Participants drove a state-of-the-art driving simulator on two consecutive days: Control day involved four euglycemia (mean blood glucose, 6.3 +/- 0.89 mM) driving tests; experimental day involved testing at euglycemia, mild hypoglycemia (mean blood glucose, 3.6 +/- 0.33 mM), moderate hypoglycemia (mean blood glucose, 2.6 +/- 0.28 mM), and again at euglycemia. Patients were blind to blood glucose manipulations and levels. Driving performance was not disrupted at mild hypoglycemia nor after recovery from moderate hypoglycemia. Moderate hypoglycemia disrupted steering, causing more swerving (P < 0.03), spinning (P < 0.03), time over midline (P < 0.05), and time off road (P < 0.01). It also resulted in an apparent compensatory slowing, with more very slow driving (P < 0.04). Global driving performance decrements were observed in 35% of the patients, only 50% of whom stated they would not drive under similar conditions. Driving decrements were unrelated to demographic, disease, or driving history variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Accidents, Traffic↗
PubMed1993

Perceived symptoms in the recognition of hypoglycemia.

For people with diabetes, detection of hypoglycemic symptoms is a critical tool for the recognition and treatment of hypoglycemia. This is not a simple process involving only the occurrence of a hypoglycemic-relevant physiological event, such as sweating. We propose a four-step biological and psychological model that leads to the accurate recognition of hypoglycemia through symptoms. The model illustrates both the chronic and transient modifiers that can enhance and interfere with recognition of hypoglycemia. Three common methods are used to investigate the occurrence and utility of hypoglycemic symptoms that relate to this model. This article reviews the advantages and disadvantages of these methods, providing previously unpublished illustrative data. The field study hit/false alarm approach was shown to be the most useful method. The relevance of this model and data to the concept of hypoglycemic awareness/unawareness and blood glucose awareness training is discussed.

Adult↗
PubMed1992

Major developments in behavioral diabetes research.

Over the past decade, there has been a major increase in behavioral diabetes research. This review focuses on 6 areas: self-treatment, psychosocial impact, diabetes-specific assessment, psychological stress, weight loss intervention, and neuropsychological effects. There has been great progress in identifying factors that predict self-treatment behaviors and psychological adjustment. This research has produced a number of diabetes-specific assessment tools. Psychological stress appears to affect both the etiology and the control of diabetes, but underlying mechanisms remain unclear. Weight loss studies demonstrate the potential benefits of behavioral interventions for diabetes management. Both acute and chronic abnormalities in diabetic blood glucose cause neuropsychological impairments and may cause permanent deficits. The challenge for the next decade is to translate these findings into interventions that improve quality of life and physical well-being for individuals with diabetes.

Adaptation, Psychological↗
PubMed1992

Fear of hypoglycemia: relationship to physical and psychological symptoms in patients with insulin-dependent diabetes mellitus.

Among diabetic patients, experience with hypoglycemia ranges from the unpleasant to the life threatening. The aversiveness of these episodes often results in fear. To examine the impact of hypoglycemia on fear, 69 patients with insulin-dependent diabetes mellitus completed the Behavior and Worry subscales of the Hypoglycemia Fear Survey along with measures of psychological symptoms, perceived stress, risk of future hypoglycemic episodes, and glycosylated hemoglobin. Behavior and Worry scores were positively related to psychological symptoms, perceived stress, and previous experiences with hypoglycemia. Fear was unrelated to glycosylated hemoglobin but was significantly higher for patients who had greater variability and lower mean daily blood glucose.

Adult↗