Search PubMed⌕ Search

Biomedical subjects

W L Clarke

Publications and source records attributed to W L Clarke.

At least 19 recordsLinked to original sources
PubMed1992

Parental and professional estimates of self-care independence of children and adolescents with IDDM.

OBJECTIVE: To report the results of a survey of 490 parents of children with insulin-dependent diabetes mellitus (IDDM) regarding the children's mastery of 38 diabetes-care skills. Parental responses are contrasted with those of a previous survey in which 229 diabetes professionals estimated ages at which typical children with IDDM master the same skills. RESEARCH DESIGN AND METHODS: Parents were recruited at five pediatric endocrinology clinics with a response rate of 88.9%. RESULTS: For 33 of 38 skills, professionals' median mastery age estimates exceeded, by greater than or equal to 1 yr, the median ages that parents reported skill mastery by their estimates, children. Despite the parent-professional disagreement about mastery-age their survey responses yielded substantial agreement about the order of mastery of specific skills. The data also revealed two profiles of comparative results. For many items, parents reported earlier skill mastery, but parental and professional estimates eventually converged during adolescence. These skills consisted of rote, motoric acts, or more complex tasks for which errors yield relatively certain aversive consequences. For other skills, more professional estimated skill mastery among adolescents than did parents. These skills required substantial organization and self-regulation by the adolescent, involved treatment components for which the aversive consequences of errors are deferred and uncertain, or they were skills infrequently required of most patients with IDDM. CONCLUSIONS: The parent-professional discordance revealed by this survey illustrates the importance of clear specification of treatment responsibilities, careful monitoring of self-care competence, and periodic reeducation of children with IDDM.

Adolescent↗
PubMed1991

Multifactorial origin of hypoglycemic symptom unawareness in IDDM. Association with defective glucose counterregulation and better glycemic control.

To assess potential relationships between unawareness of hypoglycemic symptoms and both defective glucose counterregulation and therapy-associated altered glycemic thresholds, symptoms and hormonal responses to hypoglycemia were quantitated during standardized insulin infusion tests in 41 patients with insulin-dependent diabetes mellitus (IDDM). The glycemic thresholds for both neurogenic and neuroglycopenic symptoms (and those for both epinephrine and pancreatic polypeptide release) were at lower plasma glucose concentrations in both patients with defective (n = 9, 22%) and those with adequate glucose counterregulation and, among the latter, in patients with lower compared with higher glycosylated hemoglobin levels. The data are consistent with the concept that both defective glucose counterregulation and improved glycemic control contribute to excessive hypoglycemia in IDDM by reducing awareness of symptoms of developing hypoglycemia and by impairing physiological defenses against hypoglycemia. Thus, hypoglycemic symptom unawareness is multifactorial in origin and may be partly reversible.

Awareness↗
PubMed1991

Accuracy of blood glucose estimation by children with IDDM and their parents.

OBJECTIVE: To evaluate the accuracy of blood glucose symptom recognition and subjective blood glucose estimation in insulin-dependent diabetic (IDDM) children and their parents. RESEARCH DESIGN AND METHODS: Blood glucose estimation questionnaires were completed 4 times/day at home during routine activities. A sequential sample of 19 families, who attended a pediatric diabetes clinic, with IDDM children less than 12 yr old and IDDM duration of greater than or equal to 9 mo comprised the study. RESULTS: Error grid analysis showed that both children and parents demonstrated poor accuracy, making clinically significant errors as frequently as clinically accurate estimates. The most common error was the failure to detect extreme blood glucose levels, with a significant tendency to underestimate hyperglycemia. Children often reported hypoglycemia when blood glucose was hyperglycemic. Confidence in the ability to estimate blood glucose was unrelated to measured accuracy. CONCLUSIONS: IDDM children and their parents demonstrated a higher rate of blood glucose estimation errors than IDDM adolescents and adults in previous studies. Even in families who use self-monitoring of blood glucose frequently, self-reported ability to recognize symptoms and estimate blood glucose should be viewed with caution. Families with IDDM children need more education about errors in symptom recognition and blood glucose estimation. They should also be encouraged to use self-monitoring of blood glucose before treating children's reported hypoglycemic symptoms whenever possible.

Adult↗
PubMed1990

Environmental stress and blood glucose change in insulin-dependent diabetes mellitus.

Blood glucose (BG) response to psychological stress in insulin-dependent diabetes mellitus (IDDM) patients has not been firmly established. We report a study designed to address the gaps and methodological difficulties reviewed. Subjects with IDDM were exposed to two sessions (12 weeks apart) of two 20-min standardized stressors (active and passive) and a control condition administered in counterbalanced order. To measure BG response, subjects were connected to a glucose/insulin infusion system providing continuous BG measurement. Mood checklist measures were obtained at prestressor, poststressor, and recovery periods. During the first session of testing, the active stressor was associated with significantly more absolute change in BG response than the passive stressor. Results also indicate that IDDM subjects' BG response to this active stressor was idiosyncratic but significantly reliable over time.

Arousal↗
PubMed1990

Survey of diabetes professionals regarding developmental changes in diabetes self-care.

There are no empirically obtained data defining appropriate developmental expectations for the acquisition of self-care independence by children with insulin-dependent diabetes mellitus. This study surveyed diabetes professionals about their estimates of ages at which children typically master 38 diabetes skills. The 229 survey respondents represented a broad range of professions and clinical settings and had extensive experience as diabetes professionals. Mean mastery age estimates were less than 14 yr for the 38 skills assessed. Responses to each item were variable among respondents, with a mean SD of 2.1 yr in estimated mastery ages for all items. Estimated mastery ages were below the age ranges recommended by the American Diabetes Association for 14 of 20 comparable skills. Physicians generally expected the diabetes skills to be mastered at later ages than did nurses or other health-care professionals. There were no other consistent response patterns related to respondent characteristics, i.e., years of clinical experience, employment setting, current patient load, or method of survey distribution.

Adolescent↗
PubMed1989

Treatment of the young child with postoperative central diabetes insipidus.

A continuous intravenous infusion of aqueous vasopressin (dosage range, 1.0 to 3.0 mU/kg/h) was administered to two patients (respective ages, 2 weeks and 3 years 1 month) who had postoperative central diabetes insipidus to determine if this mode of therapy is helpful in the very young patient. In both patients the polyuria and serum hyperosmolality were corrected. These findings suggest that an intravenous infusion of aqueous vasopressin can provide satisfactory control of the polyuria and electrolyte disturbances found in young children with acute postoperative central diabetes insipidus.

Brain↗
PubMed1989

Stress in parents of children with diabetes mellitus.

The level of stress experienced in the parenting role by mothers of 49 children with insulin-dependent diabetes mellitus (IDDM) and its relationship to glycemic control was examined with the parenting stress index (PSI). A subsample of the research group of 25 children with diabetes (less than or equal to 11 yr old) was compared with an age-matched control group (n = 21) drawn from the original study of the PSI on total stress, parent- and child-domain, and subdomain scale scores. The two groups differed on one child-domain subscale, whereby children with diabetes are perceived by their mothers as more demanding than healthy controls. Three parent-subscale differences existed between the two groups, with mothers of children with diabetes reporting less attachment to their children, less spousal support, and poorer health. Analysis of the diabetes sample demonstrated significant stress on several of the child- and parent-domain subscales in a large proportion of the sample. Stress, at levels greater than or equal to 70th percentile of the control group, existed on the child scales of acceptability, mood, demanding behavior, and reinforcement for 51% of children with diabetes. Elevations associated with stress in the parenting role were evident on the scales associated with parental attachment, depression, and competence for 33% of parents. No differences in the level of glycosylated hemoglobin (HbA1) existed between children whose mothers reported high levels of stress in themselves and their children and those whose mothers reported little stress. Hierarchal regression analysis demonstrated a significant relationship between the child stress scale of distractibility, the use of self-monitoring blood glucose assessment, and low levels of HbA1.

Adult↗
PubMed1989

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 BG-estimation accuracy and the ability to counterregulate to insulin-induced hypoglycemia.

Blood Glucose↗
PubMed1988

Blood glucose discrimination training in insulin-dependent diabetes mellitus (IDDM) patients.

Self-management of insulin-dependent diabetes mellitus (IDDM) is dependent on a negative feedback loop of blood glucose (BG) fluctuations, which in turn directs treatment decisions to maintain normal BG. Although this feedback is typically accomplished by self-monitoring of blood glucose (SMBG), SMBG has limitations, and patients often rely on what their BG "feels" like. Two studies were performed to evaluate whether patients could learn to more accurately "feel"/discriminate their BG on the basis of internal cues or internal plus external BG cues. In Study I, BG Awareness Training significantly improved pre- to posttreatment BG estimation accuracy, relative to a control group. Study II replicated BG Awareness Training efficacy in improving BG estimation accuracy. Improvement in estimation accuracy was related only to initial accuracy; those who were initially less accurate improved the most. This improvement was represented in a 31% reduction in dangerous BG estimation errors and a 9% increase in accurate estimates. Resulting estimations were, however, still significantly less accurate than SMBG at the end of training.

Adult↗
PubMed1988

Metabolic and cutaneous events associated with hypoglycemia detected by sleep sentry.

Eighteen insulin-dependent diabetic subjects [age (mean +/- SD) 33.2 +/- 10.6 yr] participated in a study designed to determine the metabolic and cutaneous parameters associated with activation of the nocturnal hypoglycemia monitor Sleep Sentry. Plasma glucose, glucagon, epinephrine, norepinephrine, and pancreatic polypeptide concentrations were determined every 10 min during a 2-h constant intravenous insulin infusion (40 mU.kg-1.h-1). In addition, skin temperature and electrical conductance were monitored at the same time intervals, and subjects were asked to rate the degree to which they felt cold and/or sweaty. Ten of the subjects (alarmers) activated the device with a mean plasma glucose nadir of 52.8 +/- 13.8 mg/dl, whereas eight (nonalarmers) failed to do so despite a mean plasma glucose nadir of 50.5 +/- 8.2 mg/dl. There were no significant differences between alarmers and nonalarmers with respect to initial or nadir plasma glucose levels, rate of fall of plasma glucose, or changes in plasma epinephrine, norepinephrine, or pancreatic polypeptide concentrations. In addition, changes in skin temperature and conductance were similar in both groups as were descriptive variables including age, disease duration, gender, and level of glucose control. No subject reported an increase in coldness, whereas 80% of both groups reported an increase in sweatiness. Three subjects studied on more than one occasion over a year failed to exhibit consistent activation of the alarm. This study suggests that it may not be possible to identify patients for whom the Sleep Sentry would be a reliable addition to their self-management regimen and that physicians should exercise caution in recommending its use.

Adult↗
PubMed1978

Studies with a pancreatic beta cell simulator in the third trimester of pregnancies complicated by diabetes.

To determine the potential of an artificial pancreatic beta cell simulator as a therapeutic and research tool we have used the device for short-term monitoring and control of blood glucose concentrations in five pregnant patients with juvenile-onset diabetes (White's Class C) and three pregnant patients with maturity-onset diabetes (Class B). One patient with brittle juvenile-onset diabetes had successful control before, during, and after cesarean section. The other seven patients were studied during the third trimester of pregnancy and at least four weeks before delivery. Blood glucose control with Biostator regulation was excellent (mean, 96 mg. per deciliter; range, 85 to 107). The insulin requirements needed to achieve optimal glucose control with the Biostator were highly variable (range, 20 to 157 U. per 24 hours) but very similar to those previously calculated to provide optimal control by conventional means. Insulin requirements were unrelated to plasma growth hormone, placental lactogen, or glucagon concentrations. The greatest degree of insulin resistance was seen in obese patients with endogenous insulin-secretory capacity. This study indicates that a pancreatic beta cell simulator can normalize glucose concentrations and rapidly estimate daily insulin requirements in pregnant diabetic patients. In addition, the data suggest that exogenous insulin may indirectly suppress endogenous insulin secretion and thus contribute to the "insulin resistance" of obese patients with maturity-onset diabetes.

Adult↗
PubMed1978

The effect of hyperglucagonemia on blood glucose concentrations and on insulin requirements in insulin-requiring diabetes mellitus.

The effect of elevated glucagon concentrations on insulin requirements and on blood glucose concentrations was studied in five insulin-requiring diabetic subjects during feedback control of hyperglycemia with an automated glucose-controlled insulin infusion system (artificial endocrine pancreas) for six to eight hours. Two levels of hyperglucagonemia were induced by means of constant intravenous infusion. Raising plasma glucagon concentrations to levels reported in poorly controlled diabetics (450 to 665 pg. per milliliter) did not alter total insulin requirements or blood glucose concentrations. Higher glucagon concentrations (850 to 1,050 pg. per milliliter) caused a modest (26 per cent) increase in insulin requirements and only a slight increase in mean blood glucose concentrations. These studies demonstrate that the degree of hyperglucagonemia found most frequently in insulin-requiring diabetics does not increase insulin requirements or decrease insulin effectiveness in patients given insulin in amounts appropriate to maintain euglycemia.

Adult↗