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Biomedical subjects

W L Clarke

Publications and source records attributed to W L Clarke.

At least 55 records · Page 3Linked to original sources
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

Evaluation of a new system for self blood glucose monitoring.

A new combination reflectance meter/visually interpretable system (Glucometer II/Glucostix, Ames Division, Miles Laboratories, Elkhart, IN) has been designed for self blood glucose monitoring. Performance evaluation of this system demonstrates a linear relationship between meter-determined blood glucose values and laboratory-determined whole blood glucose values (y = 0.95x + 2.86, r = 0.97). In addition, 95% of visually interpreted blood glucose values are within one color block of YSI comparative values. Error grid analysis, a new method for determining the clinical accuracy of patient-determined blood glucose results, demonstrated that components of this new system produce clinically accurate blood glucose results.

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

Teenage relationships and sex education.

Most of the consequences of early intercourse affect the woman and much research has focused upon her. As part of a study on teenage pregnancy, where 137 women were interviewed, 46 men were also interviewed. They were less likely to have had teaching about sex from parents and were subject to less parental supervision than the women. Both sexes had had similar experience of school sex education. Just under half of the men started having intercourse before 16 years. Over half of both sexes were initiated by an experienced partner and for 15/25 (60%) of the men this was within the first month of a relationship. Most men had had several partners and 27/99 (27%) of teenage women at least three, most in the context of stable relationships. 'Serial monogamy' exposes each partner indirectly to their partners previous partners (with the associated medical risks). Education must help teenagers make decisions about sexual involvement that take account of these facts and the implications for their own future health and happiness.

Adolescent↗
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↗
PubMed1986

Failure to detect the "dawn phenomenon" in nondiabetic subjects with markedly different patterns of nocturnal growth hormone secretion.

Overnight serum insulin and plasma glucose concentrations were measured every 20 min from midnight to 0900 h in 13 nondiabetic subjects. Seven were normal men, and 6 had isolated GH deficiency. The pre-breakfast increase in serum insulin concentrations ("dawn phenomenon") did not occur in either group of individuals, and a progressive decline in serum insulin concentrations occurred particularly in the dawn hours (0600-0900 h). The GH secretory patterns were strikingly different in the two groups, with normal spontaneous GH peaks mostly between 0100-0200 h in the normal subjects vs. virtually flat GH secretion in the isolated GH deficiency group. The absence of the dawn phenomenon in these nondiabetic subjects regardless of their GH secretory pattern suggests that the dawn phenomenon, as described in insulin-dependent diabetic patients, is not an exaggeration of normal circadian rhythmicity in insulin sensitivity.

Adolescent↗
PubMed1985

Outpatient pediatric diabetes--I. Current practices.

A survey of pediatric diabetologists in the U.S. was made in an attempt to define current outpatient practices in diabetes subspecialty clinics. Survey questions addressed clinic organization, health care team members, content of histories and physical examinations, use of laboratory studies, patient education, therapeutic recommendations, self-management practices and screening procedures used to identify early diabetes-related complications. The results of the survey suggested similar clinic organization and operation in most settings; a high degree of reliance on glycosylated hemoglobin determinations; a preference for the use of NPH insulin; and a lack of credence given urinary glucose determinations. Additionally, screening tests for the development of complications are not performed with regularity.

Adolescent↗
PubMed1984

Autoimmunity in congenital rubella syndrome.

Two hundred one deaf adolescents with congenital rubella syndrome and 83 age-matched deaf control subjects were evaluated for the presence of organ-specific antibodies directed against thyroid microsomes, thyroglobulin, pancreatic islets, adrenal cortex, and gastric parietal cells. Positive thyroid microsomal or thyroglobulin antibodies were found in 23.3% (47/201) of the rubella group and in 12.0% (10/83) of control subjects. Nine of 46 (19.6%) in the rubella group and two of nine (22.2%) control subjects with thyroid autoimmunity had thyroid gland dysfunction as indicated by elevated serum TSH concentrations. Neither islet cell nor adrenal cortical antibodies were detected in any subject tested; parietal cell antibodies were detected in 5.5% (8/146) of those in the rubella group and 8.8% (6/68) of control subjects tested, but occurred most frequently in subjects with thyroid autoimmunity (6/36, 16.7% vs 8/178, 4.5%; P less than 0.05). It is recommended that all patients with congenital rubella syndrome be screened for thyroid autoimmunity and that those with positive antibody titers be evaluated for the presence of thyroid dysfunction.

Adolescent↗
PubMed1984

The effect of exogenous growth hormone on insulin requirements during closed loop insulin delivery in insulin-dependent diabetes mellitus.

The amount of insulin required to maintain similar blood glucose concentrations during an eight hour infusion of either saline or growth hormone (2 micrograms/kg/hr) was determined in five fed, insulin-dependent diabetic subjects during closed-loop insulin delivery. Elevations of serum growth hormone concentrations to levels previously observed in poorly controlled diabetic subjects were not accompanied by differences in the amount of insulin required to maintain blood glucose concentrations at levels comparable to those observed during the saline infusion. Specifically, no early insulin-like nor late anti-insulin effects of physiologic increases in serum growth hormone concentrations (10.27 +/- 0.23 mg/ml vs 5.69 +/- 1.5 mg/ml, P less than 0.05) on mean hourly blood glucose levels or mean hourly insulin requirements were observed. These studies suggest that serum growth hormone concentrations similar to those observed in poorly controlled diabetics do not affect the insulin requirements of well-insulinized diabetic subjects.

Adolescent↗
PubMed1984

Diabetes today.

Explore the source record for details and available documents.

Blood Glucose↗
PubMed1983

Continuous subcutaneous insulin infusion systems. A new approach to management of type I diabetes.

Although continuous subcutaneous insulin infusion (CSII) is not presently the most feasible method of insulin delivery for most type I diabetic patients, unquestionably it is a major therapeutic advance in recent efforts to normalize blood glucose levels in such patients. In selected, highly motivated patients, CSII therapy has been shown to be safe, effective, and physiologically reasonable. Despite the failure of prolonged CSII therapy to reverse established microangiopathic complications in all cases, normoglycemia produced with CSII may reverse early complications and prevent or minimize their development in patients treated by this method from the onset of hyperglycemia. Understanding of the importance of continuous normoglycemia to the psychologic and physical well-being of type I patients should be greatly advanced by the development and use of CSII systems.

Blood Glucose↗
PubMed1983

Naloxone attenuates recovery from insulin-induced hypoglycemia in normal man.

The effect of the opioid antagonist, naloxone, on recovery of serum glucose concentrations from insulin-induced (0.1 U/kg) hypoglycemia was determined in five normal adult men. Each subject was studied on 2 separate days, at least 2 weeks apart, during an infusion of either normal saline (6.5 ml/h) or naloxone (0.8 mg/h). The order of the infusions was randomized and double blinded. Although glucose recovery was complete by 120 min after insulin administration during each study, the fractional rate of glucose recovery as determined by analysis of covariance was significantly slower during the naloxone infusions (P = 0.008). Plasma glucagon, serum cortisol, and serum GH concentrations were not different during glucose recovery on either study day. These studies suggest that endogenous opioids contribute to glucose recovery from insulin-induced hypoglycemia and therefore may be important to glucose homeostasis in normal man.

Blood Glucose↗
PubMed1983

The effect of hyperglucagonaemia on blood glucose concentrations and on insulin requirements during fasting in insulin dependent diabetes mellitus.

The effect of sustained hyperglucagonaemia on blood glucose concentrations and on insulin requirements was evaluated in 6 fasting insulin dependent diabetic subjects whose blood glucose concentrations were being controlled with a closed loop insulin infusion system. Subjects were iv infused initially with either saline or glucagon and subsequently with the other infusate. All determinations were performed following the period during which transient increases in glucagon stimulated glucose production have been reported to occur. Plasma glucagon concentrations were significantly higher during the glucagon study period (491 +/- 65 vs 70 +/- 13 pg/ml +/- SD, P less than 0.001) as were blood glucose concentrations (104 +/- 2 vs 84 +/- 7 mg/ml +/- SD, P less than 0.001) and insulin requirements (3.5 to 36.5 vs 0 to 2.3 mU/kg/h, P less than 0.05). Sustained hyperglucagonaemia continues to have an effect on glucose homeostasis for at least 2 h following the initiation of a continuous infusion.

Adult↗
PubMed1982

Organ-specific autoantibodies in children with common endocrine diseases.

Sera from 438 children were examined for autoantibodies to thyroid microsomes, thyroglobulin, pancreatic islet cells, gastric parietal cells, and adrenocortical cells by indirect hemagglutination and immunofluorescence techniques. A modification of the indirect hemagglutination technique allowed specific detection of low titers of antithyroidal antibodies. The subjects included a control group (117) with no known autoimmune disease, and children with disorders of the thyroid (88), insulin-dependent diabetes mellitus (201), Turner's Syndrome (24), and Addison disease (8). A subject's age at the time of disease onset and the race and sex were correlated with the prevalence of autoantibodies. The coincidence of autoantibodies to components of the thyroid with autoantibodies to gastric parietal cells was increased in children with disorders of the thyroid (94%, 18/19) over that observed in diabetes (29%, 4/14), Turner syndrome (0%), or Addison disease (0%), perhaps indicating different genetic propensities for the development of parietal cell antibodies in these groups. Islet cell antibodies were not found in subjects with Turner syndrome, nor were they more prevalent in white or black subjects with diabetes. The incidence of organ-specific autoantibodies in individuals without overt clinical disease may reflect an altered immunologic state that will lead eventually to autoimmune disease. Islet cell antibodies decline in prevalence in diabetes, whereas thyroid antibodies in disorders of the thyroid do not; this may reflect differences in the pathogenesis of these common autoimmune endocrine disorders in children.

Addison Disease↗