Diana M Julian

Reduced Awareness of Hypoglycemia in Adults With IDDM: A prospective study of hypoglycemic frequency and associated symptoms

OBJECTIVE To prospectively evaluate the frequency and severity of hypoglycemic episodes in IDDM subjects who declare themselves to have reduced awareness of hypoglycemia, to validate their self-designations in their natural environment, and to determine objectively the presence or absence of autonomic and neuroglycopenic symptoms associated with their low blood glucose (BG) levels. RESEARCH DESIGN AND METHODS A total of 78 insulin-dependent diabetes mellitus (IDDM) subjects (mean age 38.3 ± 9.2 years; duration of diabetes 19.3 ± 10.4 years) completed two sets of assessments separated by 6 months. The assessments included reports of frequency and severity of low BG, symptoms associated with low BG, and a BG symptom/estimation trial using a hand-held computer (HHC). Diaries of hypoglycemic episodes were kept for the intervening 6 months. HbA1 levels were determined at each assessment. RESULTS Of the subjects, 39 declared themselves as having reduced awareness of hypoglycemia (reduced-awareness subjects). There were no differences between these reduced-awareness subjects and aware subjects with regard to age, sex, disease duration, insulin dose, or HbA1. During the HHC trials, reduced-awareness subjects were significantly less accurate in detecting BG < 3.9 mmol/l (33.2 ± 47 vs. 47.6 ± 50% detection, P = 0.001) and had significantly fewer autonomic (0.41 ± 0.82 vs. 1.08 ± 1.22, P = 0.006, reduced-awareness vs. aware) and neuroglycopenic (0.44 ± 0.85 vs. 1.18 ± 1.32, P = 0.004, reduced-awareness vs. aware) symptoms per subject. Prospective diary records revealed that reduced-awareness subjects experienced more moderate (351 vs. 238, P = 0.026) and severe (50 vs. 17, P = 0.0062) hypoglycemic events. The second assessment results were similar to the first and verified the reliability of the data. CONCLUSIONS IDDM subjects who believe they have reduced awareness of hypoglycemia are generally correct. They have a history of more moderate and severe hypoglycemia, are less accurate at detecting BG < 3.9 mmol/l, and prospectively experience more moderate and severe hypoglycemia than do aware subjects. Neither disease duration nor level of glucose control explains their reduced awareness of hypoglycemia. Reduced-awareness individuals may benefit from interventions designed to teach them to recognize all of their potential early warning symptoms.

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.

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.

Effects and Correlates of Blood Glucose Awareness Training Among Patients With IDDM

Whereas self-monitoring of blood glucose (SMBG) is the recommended source of information on which to make self-care decisions, patients frequently use estimates of their own blood glucose (BG). This study evaluated whether patients with insulin-dependent diabetes mellitus (IDDM) could learn to improve accuracy of BG estimations and whether this would lead to improved metabolic control. Subjects in BG awareness training improved both their BG-estimation accuracy and glycosylated hemoglobin (HbA1) compared with the control group. Initial BG-estimation accuracy was marginally associated with pretreatment HbA1 and months of previous SMBG experience. Posttreatment improvement was associated with pretreatment BGestimation accuracy and the ability to counterregulate to insulin-induced hypoglycemia.

The relationship between nonroutine use of insulin, food, and exercise and the occurrence of hypoglycemia in adults with IDDM and varying degrees of hypoglycemic awareness and metabolic control

The purpose of this study was to determine objectively the relationships between changes in the usual amount of insulin injected, food eaten, and exercise performed, and the subsequent occurrence of low blood glucose (<3.9mM) in adults with IDDM and varying degrees of hypoglycemic awareness and metabolic control. Subjects used a handheld computer to record whether their most recent insulin, food, and exercise had been omitted or were greater than, less than, or about the same as usual following every measured blood glucose level of <3.9mM and >5.6mM. Responses for each self-management behavior were compared for the two blood glucose ranges. Food was omitted more frequently prior to a low glucose reading and exercise was omitted more frequently prior to a high glucose reading. More insulin, less food, and more exercise each were associated with low glucose levels. These findings underscore the importance of traditional diabetes education.

Clarification of error-grid analysis.

Koschinsky et al. (1) reviewed the shortcomings of efforts to quantify accuracy of self-monitoring blood glucose (SMBG) devices. We concur with their conclusions that 7) linear regression, percent deviation, and correlational analyses are inappropriate; 2) many referencetest blood glucose readings across the entire range of hypo-, eu-, and hyperglycemia are required; 3) no clear distinctions exist between demarcations of acceptable and unacceptable blood glucose values within a clinically relevant range; and 4) evaluation schemes should be flexible enough to adjust to the needs of specific groups (2-7). Furthermore, as Koschinsky et al. point out with the error-grid analysis and as we point out herein with their acceptance analysis, any criteria will lead to decisions that may be unacceptable to some. Because of our common perspectives, it was surprising to read how these authors misrepresented the errorgrid analysis. They repeatedly state that the error grid considers B-zone (benign) errors as acceptable (Fig. 1). They cite several examples of reference-test B-zone blood glucose values (i.e., 150-40, 240-180, and 400-190 mg/dl). In fact, these examples are unacceptable by the error grid, the American Diabetes Association (ADA) (8), and others (9). The error-grid analysis only considers Azone values as acceptable. All examples given fall in the B zones. Although they are unacceptable, these examples do not put the patient at immediate clinical risk, as with C, D, and E zones. To summarize the error grid, A-zone values are acceptable, and any values outside the A zones are unacceptable. Any values that fall in zones C-E represent potential immediate clinical risk: C zones (correction errors) create a risk of overtreating euglycemia leading to potential hypoor hyperglycemia; D zones (detection errors) represent failure to detect immediate and significant hypoor hyperglycemia; E zones (erroneous treatment errors) may encourage treating hypoglycemia during actual hyperglycemia or vice versa. Unlike any other system, including that of Koschinsky et al. (1), the error-grid analysis differentiates and quantifies the type and significance of unacceptable and acceptable blood glucose tests. In contrast, Koschinsky et al.s acceptance analysis attempts to reduce clinical accuracy into a simplistic dichotomous variable: acceptable/unacceptable. This fails to recognize the clinical significance of different types of unacceptable tests. The analysis considers tests acceptable if they overestimate reference blood glucose as much as 57% in the hypoglycemic range and 85% in the hyperglycemic range, whereas test overestimates are considered good if differing from reference ^20% across the entire blood glucose range, similar to the error-grid analysis and others (9). Consequently their tolerance of acceptable tests is extremely liberal, their criteria for good has been reported repeatedly in the literature, and their scheme reflects basic percent deviation, a method they decry. Additionally, their scheme does not consider the clinical significance of the type of test errors made. They consider an instrument acceptable if 1 time in 20 it reads a reference test of 300-60 mg/dl. Such a 1:20 chance could lead to the lethal decision to inappropriately increase a patients insulin dose. Inversely, their method would consider a reference-test reading of 20-40 mg/dl unacceptable, when this unacceptable test result would lead to an acceptable clinical decision to elevate blood glucose. Koschinsky et al. (1) make a significant statement echoing our call for a standardized system for determining the accuracy of SMBC technology (2-7). We feel that