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Biomedical subjects

E A Gale

Publications and source records attributed to E A Gale.

At least 55 records · Page 3Linked to original sources

The 'dawn phenomenon' in adolescents with insulin dependent diabetes mellitus: possible contribution of insulin-like growth factor binding protein-1.

OBJECTIVE: Insulin resistance increases during adolescence, and is exaggerated in patients with insulin dependent diabetes mellitus (IDDM). A relative deficiency of insulin-like growth factor-I (IGF-I) may contribute to this increased insulin requirement. Two mechanisms have been proposed: (a) increased GH secretion, caused by failure of IGF feedback control, leading to increased insulin resistance and (b) lack of insulin-like action of the IGFs which is reinforced by high plasma levels of IGFBP-1, an inhibitor of IGF action. The contribution of these two mechanisms to the 'dawn phenomenon' is assessed. DESIGN: The two possible mechanisms were studied during the dawn rise of glucose in pubertal adolescent patients with IDDM. Two overnight studies were performed in each subject. Patients remained on the same insulin regimen throughout. SUBJECTS: Twenty-two diabetic adolescent subjects, aged (mean +/- SEM) 14.0 +/- 0.4 years, duration of IDDM 7.9 +/- 0.8 years, were recruited. Pubertal status was: group 1 (breast stage 1-2; testicular volume < 4-8 ml) 3 male and 4 female, group 2 (breast stage 3; testicular volume 10-12 ml) 0 male 4 female, group 3 (breast stage 4-5; testicular volume 15-25 ml) 4 male and 7 female. Height standard deviation score (mean +/- SD) (-0.02 +/- 0.99) and daily insulin dose (50.4 +/- 3.1 U/day) did not change between studies. There were no differences in HbA1 (study A 11.26 +/- 0.45%, study B 11.09 +/- 0.42%). METHODS: The subjects were admitted for the two studies 0.3 +/- 0.03 years apart. Blood samples were taken via an indwelling cannula every 20 minutes between 1900 and 0700 h. MEASUREMENTS: GH was assayed every 20 minutes, IGFBP-1, glucose and free insulin every hour and IGF-I at 0700 h. GH, IGFBP-1, IGF-I and free insulin were measured by radioimmunoassay. IGFBPs were also analysed by Western ligand blotting techniques. GH profiles were analysed by Pulsar and results compared by paired Student's t-test. The relations between the dawn rise in glucose and the changes in IGFBP-1, GH and free insulin were examined by multiple linear regression analysis. RESULTS: Serum IGFBP-1 levels rose overnight in the two studies (study A, from 9 +/- 1 at 2200 to 59 +/- 9 micrograms/l at 0700 h; study B, from 10 +/- 1 at 2100 to 64 +/- 14 micrograms/l at 0700 h) whilst insulin levels fell from 47 +/- 5 at 2200 to 16 +/- 2 mU/l at 0700 h (study A) and from 45 +/- 5 at 2000 to 14 +/- 2 mU/l at 0700 h (study B). Glucose levels fell from 16.0 +/- 1.0 to 9.3 +/- 0.9 mmol/l at 0400 h, and then rose to 11.9 +/- 1.1 mmol/l at 0700 h during study A, and from 13.4 +/- 1.3 to 10.1 +/- 1.1 mmol/l at 0400 h and then rose to 13.5 +/- 1.0 mmol/l at 0700 h during study B. There were no differences in GH secretion between studies (mean GH levels (mean +/- SD) (study A, 15.7 +/- 6.6 mU/l; study B, 16.2 +/- 7.1 mU/l; correlation within subjects between studies r = 0.77, P < 0.001), sum of GH peaks (study A, 189.9 +/- 90.3 mU/l; study B, 185.8 +/- 100.2 mU/l; r = 0.57, P = 0.006)). Mean GH levels varied with pubertal stage (group 1, 12.1 +/- 1.5 mU/l; group 2, 23.3 +/- 2.1 mU/l; group 3, 15.3 +/- 1.2 mU/l). Serum IGF-I levels were not different (study A, 203 +/- 12 micrograms/l; study B, 218 +/- 13 micrograms/l). REGRESSION ANALYSIS: The change in plasma glucose between 0200 and 0700 h in both studies related to free insulin, IGFBP-1 and the sum of the GH levels over the preceding hour (log glucose = 7.87 + 5.32 log IGFBP-1 (P = 0.0001) - 5.05 log free insulin (P = 0.0001) - 1.44 log GH (P = 0.004); R2 = 72%). Mean overnight GH levels did not predict the morning rise in plasma glucose. CONCLUSION: The morning rise of IGFBP-1 and plasma glucose appear to be related in this group of subjects with IDDM and this was a consistent finding in the two studies. This relation was additive to the effect of insulin deficiency.

Adolescent↗

Slow metabolic deterioration towards diabetes in islet cell antibody positive patients with autoimmune polyendocrine disease.

We studied metabolic progression to IDDM in a cohort of adults who are ICA-positive and have associated autoimmune endocrine disease or circulating organ-specific autoantibodies (the Polyendocrine Study). Of the 186 individuals recruited 27 developed overt diabetes after a median follow-up of 4.5 years (range 0.4-12). Of these, eight patients did not require insulin treatment until at least 6 months after clinical diagnosis, with an interval of 1.8 years (1.2-5.7). An IVGTT was performed in 38 subjects and 23 had sequential studies. Of the initial 38 subjects six developed diabetes and only three showed a loss of FPIR to glucose (below the first percentile of a normal control group) before clinical onset of the disease. An additional three subjects showed a loss of the FPIR, and all still have normal glucose tolerance after median follow-up of 28 months (22-95). A "whole" or "mixed" pattern of islet cell staining was found in five of the six patients who developed diabetes and antibodies against an islet 37 k-antigen were detectable in four patients, all of whom required insulin soon after diagnosis. A beta-cell "selective" ICA staining pattern was seen in 14 of 17 subjects who did not develop diabetes and the "mixed" pattern in only three. None of this group had detectable 37 k-antibodies. We conclude that metabolic deterioration is slow in polyendocrine patients, and that the IVGTT has less prognostic significance in this group than in first degree relatives of patients with IDDM.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Presentation and progress of childhood diabetes mellitus: a prospective population-based study. The Bart's-Oxford Study Group.

We surveyed the clinical presentation, initial management and subsequent course of a prospectively registered, population-based cohort of 230 patients with Type 1 (insulin-dependent) diabetes mellitus diagnosed before age 21 years in the Oxford Regional Health Authority area in 1985 and 1986. Clinical details from the time of diagnosis were available on 219 patients. Thirty-four (16%) were in severe ketoacidosis with pH less than 7.10 or plasma bicarbonate less than 10 mmol/l, and 21 (10%) had mild to moderate ketoacidosis with pH 7.10-7.35 or plasma bicarbonate 10-21 mmol/l. One child died in ketoacidosis. Presentation in severe ketoacidosis was most common in children under age 5 years (p < 0.05), and ketoacidosis of any degree was less frequent in older children (0.05 < p < 0.01) and those with a parent or sibling with diabetes (p < 0.01). Within 4 years of diagnosis, 55 of 211 patients (26%) experienced severe hypoglycaemia, which in 31 (15%) led to one or more admissions. Readmission for unstable glycaemic control excluding acute hypoglycaemia occurred at least once within 1 year of diagnosis in 13% and within 4 years in 28%, and was more common in girls, in children aged less than 10 years at diagnosis, and those with a history of severe hypoglycaemia. A second cohort of 97 similar patients was recruited in 1990. The rates of admission at diagnosis (79%), severe ketoacidosis (13%) and mild to moderate ketoacidosis (13%) did not differ from the 1985/1986 cohort.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Do we know how to screen for gestational diabetes? Current practice in one regional health authority.

To review current practice for screening and diagnosis of gestational diabetes (GDM) in the North East Thames health region, clinical directors and other relevant individuals in all 17 obstetric units within NE Thames were interviewed personally. Additional information was obtained from local midwives, diabetologists, and chemical pathologists. Thirteen centres had a formal policy for screening and diagnosis of GDM. One centre ran two policies. Six of 18 centres performed a routine blood glucose (BG) screen on all pregnant women, proceeding to OGTT either on the basis of raised BG alone (3 centres), or on the basis of raised BG and/or clinical risk factors (3 centres). Of the remainder, 10 performed a diagnostic test (OGTT or equivalent) in all those with risk factors, and 2 via an intermediate screening BG. The choice and interpretation of screening and diagnostic tests varied considerably. Six centres used random BG, with cut-off ranging from > 5.8 mmol l-1 to > 9.0 mmol l-1, one used a single fasting BG > 5.0 mmol l-1, and another a 50 g oral glucose challenge (1 h level > 8.0 mmol l-1). Diagnosis of GDM was based on a 75 g (13 centres) or a 50 g OGTT (2 centres), while 1 used a standard mixed meal, and another a timed post-prandial glucose sample. Timing of tests ranged from booking to 36 weeks gestation and the diagnostic cut-off levels for GDM varied (fasting: 5.0-8.0 mmol l-1; 2 h: 6.0-10.1 mmol l-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes, Gestational↗

New approach for in vivo detection of insulitis in type I diabetes: activated lymphocyte targeting with 123I-labelled interleukin 2.

Insulitis is considered the histopathological hallmark of type I (insulin-dependent) diabetes. In the non-obese diabetic (NOD) mouse, diabetes has never been observed in the absence of insulitis. The in vivo detection of insulitis could be of relevance for early prediction of diabetes. As approximately 15% of islet-infiltrating lymphocytes express interleukin 2 receptors, we have labelled recombinant interleukin 2 with 123I and used this radiopharmaceutical to detect insulitis by gamma camera imaging. We studied 71 prediabetic NOD and 27 normal Balb/c mice. Labelled alpha-lactalbumin was used as the control protein. In the first set of experiments we studied the tissue distribution of radiolabelled interleukin 2 in isolated organs from animals sacrificed at different time points. Higher radioactivity was detected in the pancreas of NOD mice injected with labelled interleukin 2, as compared to NOD mice receiving labelled alpha-lactalbumin (p < 0.003 at 20 min: p < 0.001 at 40 min; p < 0.001 at 60 min) or Balb/c mice injected with labelled interleukin 2 (p < 0.05 at 40 min; p < 0.001 at 60 min). In another set of experiments, gamma camera images have been acquired after injection of 123I-labelled interleukin 2. Radioactivity in the pancreatic region of prediabetic NOD and Balb/c mice showed similar kinetics to those observed by single organ counting, with higher accumulation in the pancreatic region of NOD mice (p < 0.04 after 22-45 min in NOD mice vs Balb/c mice).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Combined analysis of autoantibodies improves prediction of IDDM in islet cell antibody-positive relatives.

Prediction of insulin-dependent diabetes mellitus (IDDM) is still largely based on islet cell antibodies (ICAs), but it may be improved by combined analysis with other humoral markers. We examined autoantibodies to insulin (IAAs), glutamic acid decarboxylase (GAD), and M(r) 37,000 and M(r) 40,000 fragments of islet antigens (37 and 40 kDa) together with ICA subtypes in 101 family members with ICAs > or = 10 Juvenile Diabetes Foundation units (JDF U) followed for up to 14 years, of whom 18 have developed IDDM. Life-table analysis showed a 43% risk of IDDM within 10 years for those with ICAs > or = 10 JDF U, rising to 53% for those with ICAs > or = 20 JDF U. The risk for ICAs > or = 10 JDF U was 62% in the family members in the youngest age quartile (< 13.2 years) and fell with increasing age to 4% in those > 40.7 years of age (P = 0.03). ICAs > or = 10 JDF U combined with IAAs gave a risk of 84% (P = 0.03 compared with IAA-), and ICAs > or = 10 JDF U combined with GAD antibodies gave a risk of 61% (P = 0.018). The risk for ICAs > or = 10 JDF U with antibodies to 37-kDa antigen was 76% (P < 0.0001). Risk increased with the number of autoantibodies, from 8% for ICAs alone to 88% with > or = 3 autoantibodies (14 cases detected) (P < 0.0001). The increased risk associated with multiple antibodies was observed independent of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Double blind clinical and laboratory study of hypoglycaemia with human and porcine insulin in diabetic patients reporting hypoglycaemia unawareness after transferring to human insulin.

OBJECTIVES: To compare awareness of hypoglycaemia and physiological responses to hypoglycaemia with human and porcine insulin in diabetic patients who reported loss of hypoglycaemia awareness after transferring to human insulin. DESIGN: Double blind randomised crossover study of clinical experience and physiological responses during slow fall hypoglycaemic clamping with porcine and human insulin. SETTING: Clinical investigation unit of teaching hospital recruiting from diabetes clinics of five teaching hospitals and one district general hospital. SUBJECTS: 17 patients with insulin dependent diabetes mellitus of more than five years' duration who had reported altered hypoglycaemia awareness within three months of transferring to human insulin. MAIN OUTCOME MEASURES: Glycaemic control and frequency of hypoglycaemic episodes during two months' treatment with each insulin. Glucose thresholds for physiological and symptomatic responses during clamping. RESULTS: Glycaemic control did not change with either insulin. 136 hypoglycaemic episodes (eight severe) were reported with human insulin and 149 (nine severe) with porcine insulin (95% confidence interval -4 to 2.5, p = 0.63). 20 episodes of biochemical hypoglycaemia occurred with human insulin versus 18 with porcine insulin (-0.8 to 1, p = 0.78). During controlled hypoglycaemia the mean adrenaline response was 138 nmol/l/240 min for both insulins; neurohormonal responses were triggered at 3.0 (SE 0.2) versus 3.1 (0.2) mmol/l of glucose for adrenaline and 2.5 (0.1) versus 2.5 (0.1) mmol/l for subjective awareness. CONCLUSIONS: These data suggest that human insulin per se does not affect the presentation of hypoglycaemia or the neurohumoral, symptomatic, and cognitive function responses to hypoglycaemia in insulin dependent diabetic patients with a history of hypoglycaemia unawareness.

Adult↗

Nicotinamide and insulin secretion in normal subjects.

Nicotinamide has been given both before and after clinical onset of Type 1 (insulin-dependent) diabetes mellitus in an attempt to prolong beta-cell survival. Nicotinic acid, structurally similar to nicotinamide, induces insulin resistance and increases insulin secretion in healthy individuals. It is not known if nicotinamide has similar effects. Since insulin secretion, as measured by the acute insulin response to intravenous glucose, is used to predict diabetes and to monitor therapy, the effects of nicotinamide must be established before trials in individuals at high risk of progression to Type 1 diabetes can be interpreted. Intravenous tolerance tests were performed according to the ICARUS standard protocol in 10 healthy, adult subjects (age 32 +/- 5.7 years) before and after 14 days of treatment with nicotinamide 25 mg.kg-1.day-1. The acute insulin response after nicotinamide did not differ from the control study, whether measured as the incremental 0-10 min insulin area (278 +/- 142 vs 298 +/- 130 mU.l-1.10 min-1) or as the 1 +/- 3 min insulin level (78 +/- 39 vs 81 +/- 44 mU/l). The late insulin response was equally unaffected, as were basal insulin (5.2 +/- 1.6 vs 5.6 +/- 2.1 mU/l) and glucose (5.0 +/- 0.4 vs 4.9 +/- 0.2 mmol/l) levels and glucose disposal rates (1.98 +/- 0.88 vs 2.04 +/- 0.68%/min). Nicotinamide does not affect insulin secretion and glucose kinetics in normal subjects, confirming its suitability for trials designed to delay or prevent the onset of Type 1 diabetes.

Adult↗

Tolbutamide reduces the incidence of diabetes mellitus, but not insulitis, in the non-obese-diabetic mouse.

The functional state of beta cells may influence the rate of their destruction in Type 1 (insulin-dependent) diabetes mellitus. We examined the effect of diazoxide, which inhibits insulin secretion, or tolbutamide, which stimulates insulin secretion, upon the incidence of diabetes in the non-obese-diabetic (NOD) mouse. Female mice were treated from 3-30 weeks of age with diet containing diazoxide 250 mg.kg-1 or tolbutamide 125 mg.kg-1. The cumulative incidence of diabetes at 35 weeks was similar in the diazoxide (16 of 24) and control (18 of 24) groups, but reduced in the tolbutamide group (10 of 23, p < 0.04 vs control group). In a second experiment, treatment was started from 9 weeks of age, by which time insulitis is already present. The cumulative incidence of diabetes at 35 weeks was 16 of 24 in controls, 15 of 24 on diazoxide and 11 of 24 on tolbutamide (p = NS vs control). A third experiment compared the effect of treatment from 3 weeks with control diet or diet containing tolbutamide 125 mg.kg-1 or 500 mg.kg-1. Diabetes was reduced by tolbutamide treatment, with a cumulative incidence of 25 of 31 in controls, 18 of 30 on tolbutamide 125 mg.kg-1 (p < 0.04) and 14 of 32 on 500 mg.kg-1 (p < 0.002), although the difference between the two treatment groups failed to reach statistical significance. A fourth experiment showed that treatment from 3-12 weeks with diazoxide 1000 mg.kg-1 increased the extent of insulitis compared with controls and animals treated with tolbutamide 500 mg.kg-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗

Can we really predict IDDM?

Risk of progression to IDDM has been assessed extensively in first-degree relatives of IDDM patients, and highly specific prediction is possible within a small subset of this population. Because approximately 90% of future cases will come from those who have no close relative with IDDM, prediction and intervention within the general population will become the main priority for the future. This review presents a decision tree analysis of risk of progression to IDDM, highlights the different prognosis of markers when applied to those with and without a family history of the disease, and proposes a strategy for disease prediction in the latter. Large collaborative studies in well-characterized populations will allow new predictive markers and models to be evaluated, and strategies of intervention to be tested with maximum efficiency and minimal delay.

Autoantibodies↗

Can islet cell antibodies predict IDDM in the general population?

OBJECTIVE: To evaluate the likely prognostic significance of ICAs in children with no family history of IDDM. RESEARCH DESIGN AND METHODS: We examined the prevalence of ICAs in 2925 English schoolchildren aged 9-13 yr and in 274 age-matched siblings of children with diabetes from the same region, and we compared the estimated risk of progression to diabetes within 10 yr in the two groups. RESULTS: ICAs were present at levels > or = 4 JDF U in 2.8% of schoolchildren and 6.6% of siblings and at > or = 20 JDF U in 0.8% of schoolchildren and 2.2% of siblings. Although ICAs are only 2-3 times more prevalent in siblings than schoolchildren, the estimated cumulative risk that siblings will progress to diabetes by age 21 is 13 times greater (2.8 vs. 0.21%). CONCLUSIONS: ICAs are unexpectedly prevalent in English schoolchildren, but only a small minority, with this evidence of immune activation directed against islet cells, will progress to diabetes. Although ICAs alone have limited predictive value in the general population, combining two or more predictive tests in series could achieve a level of prediction equivalent to that now obtained in first-degree relatives.

Adolescent↗

Comparison of bolus and infusion protocols for determining acute insulin response to intravenous glucose in normal humans. The ICARUS Group. Islet Cell Antibody Register User's Study.

OBJECTIVE: To help standardize methodology for intravenous glucose tolerance testing in preclinical IDDM by comparing a 30-s bolus and a 3-min infusion of glucose. RESEARCH DESIGN AND METHODS: We tested 20 healthy nondiabetic adults at four centers (in Seattle, Boston, Melbourne, and London). Each subject had four intravenous glucose tolerance tests (two bolus and two infusion). The acute insulin response to glucose was calculated as the mean of the 1' + 3', the mean of 1' to 10', or as the integrated area from 0 to 10'. Glucose and insulin profiles and intrasubject coefficient of variation were compared. RESULTS: With the infusion protocol, the 1' insulin was significantly higher, resulting in a higher acute insulin response to glucose when calculated as 1' + 3' (525 +/- 66 vs. 376 +/- 35 pM, P < 0.004). When calculated over 10 min, however, the acute insulin response to glucose was not different between protocols. In addition, the intrasubject coefficient of variation was significantly better when calculated over 10 min in both protocols, but no significant differences were noted between the bolus and infusion (infusion: AIRg [area from 0 to 10'] 10.4 +/- 2.1% vs. AIRg [1' + 3'] 14.9 +/- 2.8%, P < 0.007; bolus: AIRg [area from 0 to 10'] 14.6 +/- 2.8% vs. AIRg [1' + 3'] 19.8 +/- 3.5%, P < 0.007). Comparison of the insulin assays between the four centers showed close correlation and gave indistinguishable results in terms of within-subject coefficient of variation. Glucose profiles were similar in both protocols. Although the glucose values were lower with the bolus protocol from 4' to 40', the rate of fall from 10 to 30' (and thus the rate of glucose disposal) was indistinguishable between the two. CONCLUSIONS: These data suggest that neither protocol gives significant advantage over the other. However, to allow comparison of the acute insulin response to glucose between different protocols used in centers around the world, the ICARUS 3-min infusion protocol is recommended, with acute insulin response to glucose calculated over 10 min after the end of glucose administration; this reduces the within-subject coefficient of variation and provides similar acute insulin response to glucose with both protocols.

Adult↗

Incidence of childhood-onset insulin-dependent diabetes mellitus: the EURODIAB ACE Study.

EURODIAB ACE is a collaborative European study that was set up to assess incidence of childhood insulin-dependent diabetes mellitus (IDDM) in Europe, test the proposal of a south-north gradient, and to gather information to determine the causes and pathogenesis of the disease. Here, the basic epidemiological results are reported. Newly diagnosed cases of IDDM in children aged up to 15 years were identified prospectively in twenty-four geographically well-defined study regions in Europe and Israel (a total of 16.8 million children) during 1989 and 1990. 3060 cases were identified with estimated ascertainment rates exceeding 90% in all study regions. Age-standardised and sex-standardised incidence rates varied widely, ranging from 4.6 (northern Greece) to 42.9 (two regions in Finland) cases per 100,000 per year. Rates in southern Europe were generally higher than previously assumed, and there was an unexpectedly high incidence in Sardinia, which had the second highest rate (30.2 cases per 100,000 per year) recorded in Europe. Eastern European regions had generally low rates. The collaborative network now established provides a framework for further studies to examine the complex interaction between genetic and environmental factors in the cause and pathogenesis of IDDM.

Adolescent↗