Examining the Behaviour subscale of the Hypoglycaemia Fear Survey: an international study.

AIMS: The Hypoglycemia Fear Survey (HFS)-II Behaviour and Worry subscales were developed to measure behaviours and anxiety related to hypoglycaemia in diabetes. However, previous studies found lower reliability in the HFS Behaviour subscale and inconsistent relationships with glucose control. The purpose of this study was to conduct extensive analyses of the internal structure of the HFS Behaviour subscale's internal structure and its relationships with diabetes outcomes, including HbA1c and episodes of severe hypoglycaemia. METHODS: HFS-II survey data from 1460 adults with Type 1 diabetes were collected from five countries. This aggregated sample underwent exploratory factor analysis and item analysis to determine the internal structure of the survey and subscales. RESULTS: A three-factor solution showed the best fit for the HFS, with two subscales emerging from the HFS Behaviour representing tendencies towards (1) maintenance of high blood glucose and (2) avoidance of hypoglycaemic risks by other behaviours, and a third single HFS Worry subscale. Subscale item analysis showed excellent fit, separation and good point-measure correlations. All subscales demonstrated acceptable (0.75) to excellent (0.94) internal reliability. HbA(1c) correlated with Maintain High Blood Glucose subscale scores, r = 0.14, P < 0.001, and severe hypoglycaemia frequency correlated with all subscales. CONCLUSIONS: The HFS Worry subscale measures one construct of anxiety about various aspects of hypoglycaemia. In contrast, the HFS Behaviour subscale appears to measure two distinct aspects of behavioural avoidance to prevent hypoglycaemia, actions which maintain high blood glucose and other behaviours to avoid hypoglycaemic risk. These results demonstrate the clinical importance of the HFS Behaviour subscales and their differential relationships with measures of diabetes outcome such as HbA1c .

Toxicological assessment of a particulate yeast (1,3/1,6)-beta-D-glucan in rats.

This study investigates the toxicity of WGP 3-6, a yeast-derived beta-glucan ingredient, during single-dose acute and sub-chronic toxicity studies in rats. For the acute study, Fisher-344 rats were administered WGP 3-6 via gavage at a dose of 2000 mg/kg body weight, and any evidence of toxicity was monitored over a 14-day period. WGP 3-6 was well tolerated, indicating that the LD(50) value is greater than 2000 mg/kg body weight. For the sub-chronic study, Fisher-344 rats (10/sex/group) were randomly allocated to receive daily gavage treatment with WGP 3-6 at doses of 0, 2, 33.3, or 100 mg/kg body weight. Control and high-dose satellite recovery groups of each sex also were included. Full toxicological monitoring and endpoint investigations were performed throughout and upon completion of the study. No negative effects on animal weights or food consumption attributable to WGP 3-6 were evident at any dose. In addition, no mortality, clinical pathology, functional/behavioral, microscopic, or gross observations indicating toxicity were observed. Sporadic changes in some biochemical and hematological parameters were observed; however, since the effects were within the physiological ranges in historical controls, were not dose-responsive, or were not observed in both sexes, they were determined to be of no toxicological significance. In conclusion, no adverse or toxic effects were observed after subchronic oral administration of 2, 33.3, or 100mg/kg body weight/day of WGP 3-6 in Fisher-344 rats, and therefore, a no observed adverse effect level (NOAEL) of 100 mg/kg body weight/day, the highest dose tested, was determined.

Self-treatment of hypoglycemia while driving.

OBJECTIVE: While it is clear that progressive diabetic hypoglycemia leads to neuroglycopenia, which impairs driving, it is not clear what contributes to patients' detection and subsequent self-correction of hypoglycemia/driving impairments. Drivers with Type 1 Diabetes Mellitus (T1DM) who did and did not engage in self-treatment during experimental hypoglycemia driving are compared physiologically and psychologically. METHOD: 38 drivers with T1DM drove a sophisticated driving simulator during euglycemia and progressive hypoglycemia. Subjects were continually monitored for driving performance, EEG activity and whether they self-treated with a glucose drink. Every 5 min measures were taken of blood glucose (BG) and epinephrine levels, perceived neurogenic and neuroglycopenic symptoms and driving ability. For the four weeks prior to this hospital study, subjects participated in a field study. Using a hand-held computer just prior to routine self-measurements of BG, subjects rated neurogenic and neuroglycopenic symptoms and made judgements about BG level and ability to drive as they did in the hospital. RESULTS: Drivers who did and did not self-treat did not differ in terms of their pre-hospital exposure to hypoglycemia, their depth and rate of BG fall during experimental testing, or their epinephrine response to hypoglycemia. Subjects who self-treated detected more neurogenic and neuroglycopenic symptoms than those who did not self-treat. They also experienced less EEG defined neuroglycopenia during the progressive hypoglycemic drive as compared to those who did not self-treat. Perceived need to self-treat and EEG parameters correctly classified 88% of those who did treat from those who did not self-treat. Further, subjects who self-treated were more aware of hypoglycemia and when not to drive while hypoglycemic in the field study. CONCLUSION: There is a narrow window between a patient's detection of hypoglycemic symptoms and the need to self-treat, and neuroglycopenia, which impairs self-treatment. Consequently, drivers with T1DM should be vigilant for signs of hypoglycemia and driving impairment (e.g. trembling, uncoordination, visual difficulties) and encouraged to treat themselves immediately when they suspect hypoglycemia while driving.

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.

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.

The EEG consistency index as a measure of ADHD and responsiveness to medication.

The primary diagnostic procedure for Attention-Deficit/Hyperactivity Disorder (ADHD) is the clinical interview, because psychological, neuropsychological, and neurological tests to date have not had sufficient specificity. Currently, there is no objective means to measure severity of ADHD, or the extent to which it is benefited by various dosages of medication. We recently reported that a certain EEG profile, the Consistency Index, occurring during the transition between two easy cognitive tasks clearly differentiated ADHD from non-ADHD boys between the ages of 8 and 12. The current study replicated this with older males (19-25) using different tasks, and a double blind, placebo versus Ritalin controlled crossover design. Seven ADHD subjects were found to have a significantly lower Consistency Index than 6 non-ADHD males while transitioning from 2 Simple tasks during placebo condition, while only the ADHD subjects demonstrated a significant improvement in their Consistency Index while on Ritalin. Similar but nonsignificant trends were observed while transitioning across Hard tasks.

Progressive hypoglycemia's impact on driving simulation performance. Occurrence, awareness and correction.

OBJECTIVE: Progressive hypoglycemia leads to cognitive-motor and driving impairments. This study evaluated the blood glucose (BG) levels at which driving was impaired, impairment was detected, and corrective action was taken by subjects, along with the mechanisms underlying these three issues. RESEARCH DESIGN AND METHODS: There were 37 adults with type 1 diabetes who drove a simulator during continuous euglycemia and progressive hypoglycemia. During testing, driving performance, EEG, and corrective behaviors (drinking a soda or discontinuing driving) were continually monitored, and BG, symptom perception, and judgement concerning impairment were assessed every 5 min. Mean +/- SD euglycemia performance was used to quantify z scores for performance in three hypoglycemic ranges (4.0-3.4, 3.3-2.8, and <2.8 mmol/l). RESULTS: During all three hypoglycemic BG ranges, driving was significantly impaired, and subjects were aware of their impaired driving. However, corrective actions did not occur until BG was <2.8 mmol/l. Driving impairment was related to increased neurogenic symptoms and increased theta-wave activity. Awareness of impaired driving was associated with neuroglycopenic symptoms. increased beta-wave activity, and awareness of hypoglycemia. High beta and low theta activity and awareness of both hypoglycemia and the need to treat low BG influenced corrective behavior. CONCLUSIONS: Driving performance is significantly disrupted at relatively mild hypoglycemia, yet subjects demonstrated a hesitation to take corrective action. The longer treatment is delayed, the greater the neuroglycopenia (increased theta), which precludes corrective behaviors. Patients should treat themselves while driving as soon as low BG and/or impaired driving is suspected and should not begin driving when their BG is in the 5.0-4.0 mmol/l range without prophylactic treatment.

Effect of stimulant medication on driving performance of young adults with attention-deficit hyperactivity disorder: a preliminary double-blind placebo controlled trial.

Driving performance of adult males with attention-deficit hyperactivity disorder (ADHD) was compared with matched controls in a double-blind (Ritalin vs. placebo) cross-over design, using a high-fidelity driving simulator. Seven ADHD and six non-ADHD drivers (mean age 22) were screened to rule out comorbidity and assess for ADHD, and then admitted to the General Clinical Research Center to control diet and sleep before testing. At 0800 and 1530, subjects consumed either a placebo or Ritalin pill in a counter-balanced manner, and at 0930 and 1700, subjects drove the simulator. After both drives, subjects rated their driving performance. Compared with non-ADHD subjects, ADHD subjects had more career driving accidents (p < .04) and motor vehicle violations (p = .059), drove worse on the simulator under placebo condition (p < .05), demonstrated significant improvement under the Ritalin condition (p < .05), rated themselves as driving poorer during the placebo condition (p = .05), and tended to perceive their driving to be better during the Ritalin condition (p = .07). This would suggest that individuals with ADHD should have the therapeutic benefit of a stimulant medication when operating a vehicle.

Review of the treatment literature for encopresis, functional constipation, and stool-toileting refusal.

This review summarizes the literature on randomized, controlled, published studies involving medical, behavioral, psychological, and biofeedback treatments for encopresis/functional constipation and stool-toileting refusal in preschool-age and school-age children. Nine such studies were located in the literature involving school-age children. No randomized, controlled treatment studies involving preschool-age children have been published. This review revealed no evidence to support the routine use of psychotherapy or anal sphincter biofeedback in the treatment of pediatric fecal elimination dysfunctions, beyond those benefits derived from a comprehensive medical-behavioral intervention. Further, this review indicated that paradoxical constriction of the External Anal Sphincter does not influence the treatment outcome of either biofeedback or medical-behavioral interventions. There are remarkably few controlled treatment outcome studies in this most important clinical area. More research is needed that employs standard treatment outcome variables.

Motivating signage prompts safety belt use among drivers exiting senior communities.

Senior drivers are vulnerable to automobile crashes and subsequent injury and death. Safety belts reduce health risks associated with auto crashes. Therefore, it is important to encourage senior drivers to wear safety belts while driving. Using an AB design, replicated five times, we evaluated the short- and long-term effects of a sign with the message "BUCKLE UP, STAY SAFE" attached to a stop sign at the exits of five different senior communities. Safety belt use was stable during two pretreatment assessments averaged across the five sites and 250 drivers (72% and 68% usage), but significantly increased following installation of these signs (94% usage). Six months after installation of the signs, the effect persisted (88% usage). Use of such signs may be a cost-effective way of promoting safety belt use.

Factors associated with nocturnal hypoglycaemia among patients with type 2 diabetes new to insulin therapy: experience with insulin lispro.

AIM: To identify factors associated with nocturnal hypoglycaemia in patients with type 2 diabetes who were new (< 2 months therapy) to insulin therapy. METHODS: A randomised, multicentre, 12-month parallel open-label study compared the clinical safety and efficacy of insulin lispro with regular human insulin. A cohort of North American patients completed a health-related quality of life (HRQOL) questionnaire which included questions related to the Health Beliefs Model (HBM). Measurements of hypoglycaemia rate and short-and long-term glucose control assessed clinical safety and efficacy. Three hundred and sixty-five type 2 diabetic patients were enrolled in the study, and 195 North American patients completed the HRQOL questionnaire. RESULTS: After adjustment for demographic and psychological factors, the study population demonstrated lower nocturnal hypoglycaemia risk with insulin lispro. Higher nocturnal hypoglycaemia risk was associated with reduced body mass index (b.m.i.), lower age, and basal ultralente insulin therapy. The associated hypoglycaemia risk was lower with increased alcohol consumption. Patients who completed the HRQOL survey demonstrated higher risk for nocturnal hypoglycaemia if they: (1) had more troublesome hyperglycaemia symptoms in the week before starting insulin; (2) were more confident in their ability to control their diabetes; or (3) thought that diabetes control did not offer a clear health benefit. Nocturnal hypoglycaemia risk was inversely associated with fear of hypoglycaemia. CONCLUSIONS: Type 2 diabetic patients new to insulin therapy demonstrated lower risk of nocturnal hypoglycaemia with insulin lispro. Practitioners should consider patient characteristics and psychological factors that may predispose type 2 diabetes patients to nocturnal hypoglycaemia when initiating insulin therapy.

Issues for the coming age of continuous glucose monitoring.

PURPOSE: This article reports the results of a symposium in which diabetes educators considered and discussed issues that are likely to arise when continuous glucose monitoring (CGM) becomes available and readily accessible. METHODS: Fifteen certified diabetes educators and 5 others with complementary expertise participated in a discussion based on their responses to 11 questions designed to elicit perspectives on issues related to CGM. Issues for discussion and debate include those related to patient acceptance and lifestyle, implications for professional practice and reimbursement, concerns about professional liability, use of CGM data by insurers and payers, and CGM data transfer. RESULTS: Educators offered varied and sometimes conflicting responses to CGM-related issues. CONCLUSIONS: Awareness of CGM-related issues will likely become an important part of diabetes professional development and perspectives in practice. Identifying and framing the issues before the new technologies become available allow diabetes educators to participate proactively in structuring the emerging policies, procedures, and standards of care.

Biopsychobehavioral model of severe hypoglycemia. II. Understanding the risk of severe hypoglycemia.

OBJECTIVE: To evaluate the clinical/research utility of the biopsycho-behavioral model of severe hypoglycemia in differentiating patients with and without a history of severe hypoglycemia and in predicting occurrence of future severe hypoglycemia. RESEARCH DESIGN AND METHODS: A total of 93 adults with type 1 diabetes (mean age 35.8 years, duration of diabetes 16 +/- 10 years, HbA1 8.6 +/- 1.8%), 42 of whom had a recent history of recurrent severe hypoglycemia (SH) and 51 who did not (NoSH), used a handheld computer for 70 trials during 1 month recording cognitive-motor functioning, symptoms, blood glucose (BG) estimates, judgments concerning self-treatment of BG, actual BG readings, and actual treatment of low BG. For the next 6 months, patients recorded occurrence of severe hypoglycemia. RESULTS: SH patients demonstrated significantly more frequent and extreme low BG readings (low BG index), greater cognitive-motor impairments during hypoglycemia, fewer perceived symptoms of hypoglycemia, and poorer detection of hypoglycemia. SH patients were also less likely to treat their hypoglycemia with glucose and more likely to treat with general foods. Low BG index, magnitude of hypoglycemia-impaired ability to do mental subtraction, and awareness of neuroglycopenia, neurogenic symptoms, and hypoglycemia correlated separately with number of SH episodes in the subsequent 6 months. However, only low BG index, hypoglycemia-impaired ability to do mental subtraction, and awareness of hypoglycemia entered into a regression model predicting future severe hypoglycemia (R2 = 0.25, P < 0.001). CONCLUSIONS: Patients with a history of severe hypoglycemia differed on five of the seven steps of the biopsychobehavioral model of severe hypoglycemia. Helping patients with a recent history of severe hypoglycemia to reduce the frequency of their low-BG events, become more sensitive to early signs of neuroglycopenia and neurogenic symptoms, better recognize occurrence of low BG, and use fast-acting glucose more frequently in the treatment of low BG, may reduce occurrence of future severe hypoglycemia.

The perception of safe driving ability during hypoglycemia in patients with type 1 diabetes mellitus.

PURPOSE: Insulin-induced hypoglycemia and its sequelae of cognitive impairment may place patients with type 1 diabetes at risk when driving and when making decisions about driving. Little is known about the factors that influence judgments of safe driving ability during hypoglycemia in these patients. PATIENTS AND METHODS: Thirty men and 30 women with uncomplicated type 1 diabetes (age [mean +/- SD] 33 +/- 9 years, duration 9 +/- 3 years, hemoglobin A1c level 8.7% +/- 1.0%) underwent a stepped hypoglycemic insulin clamp. Serum glucose levels were reduced from 120 mg/dL to 80, 70, 60, 50, and then 40 mg/dL during 190 minutes. At each glucose plateau, patients completed a symptom questionnaire and neuropsychological test, estimated their glucose level, and reported whether they could drive safely. RESULTS: The proportion of patients judging that they could drive safely decreased as serum glucose levels decreased from 70% at 120 mg/dL to 22% at 40 mg/dL. Men and middle-aged patients were more likely to consider it safe to drive during hypoglycemia than women and those under 25 years of age. Those who were symptomatic and those who recognized hypoglycemia were less likely to report safe driving ability during hypoglycemia. Most patients who were cognitively impaired appeared to recognize this and reported that they could not drive safely at a serum glucose level of 40 mg/dL. CONCLUSIONS: Adults with type 1 diabetes need educational reinforcement of safe driving habits, particularly to check glucose levels before driving. Glucose levels less than 70 mg/dL should be treated before driving. This information is as important for middle-aged, experienced drivers as it is for younger, inexperienced drivers.