First test effect in intravenous glucose tolerance testing

AIMS

Intravenous glucose tolerance testing (IVGTT) is a common test of β-cell function in which a glucose load is administered and insulin and/or C-peptide responses are monitored. Since the first IVGTT may be more stressful and stress may alter β-cell secretion or hepatic insulin extraction, we asked whether there was a first test effect.

METHODS

Insulin and C-peptide responses were compared from two sequential IVGTTs performed within 6 months during staging for the Diabetes Prevention Trial-Type 1 (DPT-1) in 368 people at high risk for type 1 diabetes. Insulin data (1+3 min) were used because the first phase insulin response (and peak insulin concentration) occurs within this time frame. Areas under the curve (AUC) calculations represent early insulin or C-peptide responses from 0 through 10 min post-glucose challenge.

RESULTS

More than half of all subjects were found to have first test values lower than the second. This was true for all measures of both insulin and C-peptide but the frequency was significantly different only for insulin measures corrected for basal and for insulin AUC (p < 0.05). However, for subjects (n = 99) whose 1+3 min insulin response was <10th percentile on the first test, there was a significant increase on the second test (p < 0.05). The C-peptide: insulin ratio did not change significantly between tests, indicating that differences are due to changes in β-cell secretion rather than hepatic insulin uptake.

CONCLUSIONS

A statistically significant first test effect occurs during the IVGTT attributable to variations in insulin secretion rather than hepatic uptake.

Metabolic tests to determine risk for type 1 diabetes in clinical trials

AIMS

Evaluate the reproducibility and relationship of various metabolic tests conducted as part of the Diabetes Prevention Trial-type 1 diabetes.

METHODS

Coefficients of variation, intraclass correlation coefficients, and Pearson correlations between the same metabolic tests performed at different times as well as the different tests were determined.

RESULTS

Fasting samples on the same day had a coefficient of variation of < 10 for C-peptide, 11 for insulin, and 2 for glucose. Testing on separate days approximately doubled the variance. Stimulated insulin values had less variance than fasting values and there was only a moderate correlation between fasting and stimulated values on each test. While highly correlated, C-peptide values from mixed meal tolerance tests are significantly lower than that obtained during oral glucose tolerance tests (OGTTs). Neither peak nor area under the curve C-peptide on the oral glucose tolerance test was different between those with abnormal and normal glucose tolerance. Those with abnormal as compared with normal glucose tolerance had lower 30-min C-peptide and a longer time to peak C-peptide.

CONCLUSIONS

A large, multi-centre trial, with tests performed over a decade-long period, can provide robust data. C-peptide data from oral glucose tolerance tests and mixed meal tolerance tests differ; therefore, the same stimulation test should be used to evaluate changes in beta cell function over time. Worsening glucose tolerance is associated with lower C-peptide at 30 min and a delay in peak secretion on the oral glucose tolerance test. This Diabetes Prevention Trial-type 1 diabetes data can be used in planning parameters for future studies, including evaluation of new algorithms to determine risk of disease.

Factors affecting improved glycaemic control in youth using insulin pumps

AIMS

The purpose of this study was to evaluate factors associated with insulin pump therapy resulting in lower HbA(1c) levels in young people with Type 1 diabetes mellitus.

METHODS

Insulin pumps were downloaded from 150 youth (81 male), ages 5-20 years. Consecutive insulin pump downloads, 3 months apart, were available for 85 (43 male) of the 150 youth and changes in pump use were correlated with changes (≥0.5%, ≥ 6 mmol/mol) in HbA(1c) levels.

RESULTS

  Using cross-sectional data, lower HbA(1c) values correlated with use of more frequent daily insulin boluses (r=-0.46, P<0.0001) and more frequent blood glucose checks/day (r=-0.35, P<0.0001). Young people with HbA(1c) levels <7.5% (58 mmol/mol) vs. values of 7.5-9.0% (58-75 mmol/mol) or ≥ 9.0% (75 mmol/mol) tested blood glucose more frequently/day (P<0.0001), bolused more frequently/day (P<0.0001), reported more grams of carbohydrates eaten/day (P<0.05) and had a higher per cent bolus insulin/day (P<0.05) compared with the ≥9.0% of youth. Using longitudinal data, 48 of 85 patients had a change in HbA(1c) level of ≥0.5% (6 mmol/mol) between downloads (24 improved). Increased bolus insulin (OR=1.15, P=0.03) and time of temporary basal rate use (OR=1.017, P=0.01) predicted ≥0.5% (6 mmol/mol) decrease in HbA(1c) in logistic regression.

CONCLUSIONS

This study emphasizes the importance of blood glucose testing, of bolus insulin administration and of an increase in the time of temporary basal rate use in relation to improving glycaemic control.

Post-prandial glucose excursions following four methods of bolus insulin administration in subjects with type 1 diabetes

AIMS

To determine if one method of short-acting insulin bolus administration is superior to other methods in managing a meal high in carbohydrates, calories and fat.

METHODS

Nine subjects receiving continuous subcutaneous insulin infusion using insulin lispro (Humalog) agreed to consume the same meal high in carbohydrates, calories and fat on four occasions 1 week apart. They received the same dose of bolus insulin on each of the four occasions randomly assigned and beginning 10 min prior to the meal as either a single bolus, two separate boluses of one-half the same total dose (the second after 90 min), the entire bolus given as a square-wave (over 2 h) or a dual-wave (70% as a bolus and 30% as a square-wave over 2 h). Blood glucose levels were measured at -60 and -30 min and at zero time, and then every half-hour for 6 h using the Hemacue in the out-patient clinic.

RESULTS

Changes in blood glucose values from fasting were the lowest after 90 and 120 min (P < 0.01) when the dual wave was administered. When the dual or square-wave methods of insulin administration were used, subjects had significantly lower glucose levels after 4 h in comparison with when the single or double boluses were used (P = 0.04).

CONCLUSIONS

We conclude that the dual wave provided the most effective method of insulin administration for this meal. The dual- and square-wave therapies resulted in lower glucose levels 4 h after the meal in comparison with the single and double-bolus treatments.

Diabetic ketoacidosis with intracerebral complications

PURPOSE

To describe 11 instances of severe diabetic ketoacidosis (DKA) with secondary intracerebral complications (ICCs), nine of whom were treated early and showed complete recovery.

METHODS

Three hundred and eighty-one episodes of DKA were treated at Denver Children's Hospital (DCH) from January 1989 to December 1999. Nine instances of DKA with ICC were prospectively identified during this time period. Two additional occurrences were identified via a medical records search (total incidence, 2.9%). The signs, symptoms and laboratory values which led to their diagnosis and treatment are identified.

RESULTS

All nine children who received early treatment with i.v. mannitol showed complete recovery. An additional patient had central nervous system involvement upon arrival at our hospital and showed almost complete recovery. Another patient suffered a cardiorespiratory arrest before transfer to our hospital and died without being treated for cerebral edema.

CONCLUSION

Prevention of ICCs by the earlier diagnosis of diabetes and by being aware of possible risk factors for cerebral edema is the eventual goal. Based on our experience, mannitol should be given promptly for the treatment of ICCs indicated by the clinical course even if cerebral edema is not documented by a computed tomography (CT) scan.

Life with continuous subcutaneous insulin infusion (CSII) therapy: child and parental perspectives and predictors of metabolic control

OBJECTIVE

The purpose of this study was twofold (i): to evaluate metabolic control in patients receiving CSII therapy in a routine pediatric diabetes clinic by describing reasons for initiating therapy and daily management issues, including needle fear; and (ii) to assess the change in parental involvement and anxiety once their child initiated CSII therapy.

RESEARCH DESIGN AND METHODS

The study included 52 subjects (aged 7.6-23.6 yr) from a general pediatric diabetes clinic. Management issues were defined as diet, exercise, home blood glucose monitoring (HBGM) frequency, and self/staff assessment of needle fear. Characteristics were analyzed both according to a 0.5% change in HbA1c status (decreased vs. stable vs. increased) compared with pre-CSII therapy, and final HbA1c achieved (< or = 8.1 vs. > 8.1%).

RESULTS

The primary recommendation source for CSII use was most often the physician/diabetes team (48.1%), followed by a combination of the former with a personal referral source (32.7%). The most common reason (71.2%) for CSII initiation was a combination of wanting to achieve better metabolic control, dislike of insulin injections, and/or increased flexibility in daily living. Over one-quarter (26.9%) of subjects were identified as being needle-fearful, and this characteristic was predictive of final metabolic control (3/25 subjects </= 8.1% vs. 11/27 subjects > 8.1%, p = 0.03). On CSII therapy, dietary carbohydrate consistency was highly variable, and most subjects (65.3%) exclusively used an insulin to carbohydrate ratio for insulin bolus dosage calculation. The most common adjustment strategy (63.5%) for exercise was a combination of decreasing the insulin basal rate, disconnecting the pump, and/or eating extra carbohydrates. For the total cohort, the frequency of HBGM significantly increased on CSII therapy (4.31-4.85 tests/day, p = 0.02). Females did not have a significant change in HBGM frequency, while the youngest subjects had the highest HBGM frequency. Parental involvement and anxiety primarily stayed the same or decreased, regardless of the child's age (< or = 18 vs. > 18 yr) or metabolic control.

CONCLUSIONS

Analyses of the various characteristics identified only needle fearfulness as being predictive of poor metabolic control. Interestingly, poor control with CSII therapy did not result in a significant increase in parental involvement and/or anxiety.

The impact of the diabetes control and complications trial and humalog insulin on glycohemoglobin levels and severe hypoglycemia in type 1 diabetes

OBJECTIVE

This study was performed to determine the effects of the Diabetes Control and Complications Trial (DCCT) report in 1993 and the introduction of Lispro (Humalog) insulin in 1996 on glycemic control and on the number of severe hypoglycemic episodes in type 1 diabetic patients of various ages.

RESEARCH DESIGN AND METHODS

Diabetes care parameters and HbA1c data from 884 subjects with type 1 diabetes were entered into our database at the time of clinic visits from 1993 through 1998. In addition, a questionnaire was sent to all patients to validate the number of insulin injections per day, the incidence of severe hypoglycemic episodes (as defined by the DCCT), and the use of Humalog insulin. Data were divided into four age-groups: < 5, 5-12, 13-18, and > 18 years of age.

RESULTS

Longitudinal HbA1c levels declined significantly after the DCCT report in 1993-1996 (P < 0.001), but the number of severe hypoglycemic events increased (P < 0.001). A second decline in HbA1c levels was observed after the introduction of Humalog insulin in 1996 (P < 0.001). However, severe hypoglycemic episodes did not change (P = 0.26).

CONCLUSIONS

Administration of Humalog resulted in an additional reduction in HbA1c levels beyond the reduction in HbA1c values after the DCCT report. In contrast to the increase in severe hypoglycemic events after the DCCT results, the number of severe hypoglycemic episodes did not increase after the introduction of Humalog, despite a further decrease in HbA1c values.

Continuous subcutaneous glucose monitoring in children with type 1 diabetes

PURPOSE

To determine whether the use of continuous subcutaneous glucose monitoring will help in detecting unrecognized nocturnal hypoglycemia and in lowering hemoglobin A1c (HbA1c) levels (without increasing the risk for severe hypoglycemia) in children with type 1 diabetes.

METHODS

Eleven children with type 1 diabetes and HbA1c values consistently >8.0% were randomized either to the Continuous Glucose Monitoring System (CGMS) group or to the control group. The CGMS group used 6 3-day sensors within a 30-day period. Both groups self-monitored their blood glucose levels a minimum of 4 times daily. HbA1c levels were measured at the start, at 1-month, and after 3 months of study.

RESULTS

The 5 children using the CGMS had 17 asymptomatic episodes (85%) of glucose levels below 60 mg/dL (3.25 mmol/L) and 3 symptomatic episodes (15%) during the night in the study month. The 6 control children had 4 symptomatic nocturnal low episodes during the month. After the 30-day period of wearing the CGMS, the 5 children had a significantly lower mean HbA1c value compared with their initial value (mean +/- standard error of the mean [SEM] decrease =.36% +/-.07%). The mean decrease for the controls was.2% +/-.2%. After 3 months, 4 of the 5 children who used the CGMS continued to have lower HbA1c values in comparison to their initial values (mean +/- SEM decrease = 1.04% +/-.43%). Three of the 6 control participants also had lower HbA1c values at 3 months (mean +/- SEM decrease for the group =.62% +/-.44%). No severe hypoglycemic events occurred in either the CGMS or the control groups.

CONCLUSION

In this pilot trial, continuous subcutaneous glucose monitoring was helpful in detecting asymptomatic nocturnal hypoglycemia as well as in lowering HbA1c values without increasing the risk for severe hypoglycemia in children with type 1 diabetes.

First-phase insulin release during the intravenous glucose tolerance test as a risk factor for type 1 diabetes

OBJECTIVE

To determine the relationship between first-phase (1 minute + 3 minutes) insulin production during the intravenous glucose tolerance test (IV-GTT) and risk factors for developing type 1 diabetes.

STUDY DESIGN

Relatives of persons with type 1 diabetes (n = 59,600) were screened for islet cell antibodies (ICAs). Subjects who had positive screening results underwent IV-GTT (> or =2 times), repeat ICA screening, insulin autoantibody (IAA) screening twice, and an oral glucose tolerance test.

RESULTS

Of the 59,600 subjects in the study, 2199 (3.69%) had positive findings on initial ICA test. IV-GTTs were performed in 1622 subjects, with children <8 years having the lowest first-phase insulin release (FPIR) and subjects 8 to 20 years of age having the highest FPIR. The FPIR was lower for subjects with a confirmed positive ICA test result or a positive IAA test result, subjects with higher titers of ICA or IAA, and subjects who had an abnormal (impaired or diabetic) oral glucose tolerance test result.

CONCLUSION

FPIR in the IV-GTT correlates strongly with risk factors for development of type 1 diabetes.

Continuous subcutaneous insulin infusion therapy for children and adolescents: an option for routine diabetes care

OBJECTIVE

The purpose of this study was to determine the feasibility of continuous subcutaneous insulin infusion (CSII) (insulin pump) therapy in routine pediatric diabetes care by comparing the HbA(1c), body mass index (BMI), and hypoglycemic episodes before and after initiation of CSII therapy.

RESEARCH DESIGN AND METHODS

Data from 56 patients (7-23 years old) were collected during regularly scheduled visits at a frequency similar to non-CSII patients.

RESULTS

The data were analyzed for the entire cohort and 3 subgroups (decreased, stable, or increased HbA(1c)) stratified according to a >/=0.5% change in HbA(1c). The total cohort demonstrated a decrease in HbA(1c) from 8.5% to 8.3%. The decreased cohort (39.4% of the total cohort) demonstrated a significant decrease in HbA(1c) from 8.6% to 7.6%. The mean HbA(1c) of the stable cohort (41.0%) was 8.7%. The increased cohort (19.6%) had an increase in HbA(1c) from 7.8% to 8.8%. Thirty-six patients (64.3%) maintained or achieved a HbA(1c) <8.0% or achieved a HbA(1c) at least 1% lower than their pre-CSII level. Of concern, 6 patients (10.7%) demonstrated a clinically significant increase in HbA(1c) from 8.3% to 9.6%. For the entire cohort, the rate of severe hypoglycemia before and on CSII therapy was 12.3 and 9.5 events per 100 patient-years, respectively. A statistically significant proportion of patients reported a decrease in seizure frequency versus an increase (17.9% vs 1.8%) as well as a decrease in overall hypoglycemic frequency versus an increase (41.1% vs 17.9%). There was not a clinically significant increase in BMI, even in the decreased HbA(1c) cohort.

CONCLUSIONS

CSII therapy is an appropriate option for some children in routine pediatric diabetes care. It can effectively decrease the HbA(1c) and reduce hypoglycemic episodes, without producing an abnormal increase in BMI.

Impact of insulin lispro on HbA1c values in insulin pump users

AIM

To compare the therapeutic efficacy of the short-acting insulin analogue insulin lispro (Humalog) with that of buffered regular human insulin (Velosulin) in patients on insulin pump therapy.

PATIENTS AND METHODS

Sixty-two (45 women and 17 men) young patients with type 1 diabetes using insulin pump therapy were compared while using buffered regular human insulin for a mean +/- s.e.m. of 20.1+/-1.2 months or insulin lispro for a mean +/- s.e.m. of 19.7+/-0.5 months. The initial mean +/- s.e.m. age and duration of diabetes were 29.1+/-0.9 and 17.7+/-0.9 years, respectively. The mean HbA1c values, basal insulin dosages, premeal insulin dosages and number of low blood sugars were recorded during treatment with both insulins.

RESULTS

Mean +/- s.e.m. HbA1c values were significantly lower (p < 0.001; paired Wilcoxon t-test) during insulin lispro treatment (7.4+/-0.1%) as compared to treatment with buffered regular human insulin (7.9+/-0.1%). Total units of insulin (mean +/- s.e.m.)/kg/day was significantly (p = 0.03) lower (0.61+/-0.02) during the insulin lispro treatment period as compared to the buffered regular human insulin treated period (0.65+/-0.03). Total mean +/- s.e.m. (U/kg/day) of basal insulin administered per day was higher when patients received insulin lispro treatment (0.44+/-0.02 vs. 0.42+/-0.01 for buffered regular human insulin treated period; p = 0.002). The premeal insulin boluses (mean +/- s.e.m.) for the two treatment groups were significantly different with less insulin required for the insulin lispro treatment period for all three meals (p < 0.001, t-test). The number of mild/moderate and severe hypoglycaemic episodes were similar in the two groups.

CONCLUSION

We conclude that use of insulin lispro in pump therapy significantly lowers HbA1c values in comparison to therapy with buffered regular human insulin insulin without increasing hypoglycaemic episodes.

Correlation of fingerstick blood glucose measurements with GlucoWatch biographer glucose results in young subjects with type 1 diabetes

OBJECTIVE

The purpose of this study was to compare measurements of glucose obtained via iontophoretic extraction with the GlucoWatch automatic glucose biographer (Cygnus, Inc., Redwood City, CA) with capillary blood glucose values that were determined 1) in a controlled outpatient clinic setting and 2) in a home setting.

RESEARCH DESIGN AND METHODS

There were 76 GlucoWatch biographers used on 28 different young adults (21 women and 7 men) with type 1 diabetes (age 30.9 +/- 6.9 years and duration of diabetes 18.4 +/- 8.1 years [mean +/- SD]) in a controlled outpatient clinic setting. Some subjects participated on multiple days. Subjects wore two GlucoWatch biographers, each on the forearm (ventral aspect). Comparisons were made to HemoCue blood glucose analyzer (Aktiebolgat Leo, Helsingborg, Sweden) capillary blood glucose measurements. In addition, GlucoWatch biographers (one each day for 3 consecutive days) were used by 12 subjects (8 women, 4 men) in a home setting. Comparisons were made to capillary blood glucose values determined using the One Touch Profile meter (Johnson & Johnson, New Brunswick, NJ).

RESULTS

GlucoWatch biographer glucose values correlated well with capillary blood glucose values determined using the HemoCue analyzer in the clinic setting (r = 0.90, 1,554 paired data points) and using the One Touch Profile meter in the home setting (r = 0.85, 204 paired data points). When 36 subjects wore two biographers simultaneously, the correlation between the two biographers was r = 0.94. The error grid analysis demonstrated that > 96% of biographer glucose values determined in the clinic or home setting were in the clinically acceptable A and B regions.

CONCLUSIONS

This study confirms the accuracy and precision of glucose values as determined using the GlucoWatch biographer in clinic and home settings.

Effect of Bacillus Calmette-Guerin vaccination on new-onset type 1 diabetes. A randomized clinical study

OBJECTIVE

We undertook this study to test whether Bacillus Calmette-Guerin (BCG) vaccine preserves beta-cell function and increases the remission rate in children with new-onset type 1 diabetes.

RESEARCH DESIGN AND METHODS

This was a randomized double-blind placebo-controlled trial offered to children referred to the Barbara Davis Center for Childhood Diabetes or the Baystate Medical Center with a diagnosis of new-onset type 1 diabetes. There were 94 children aged 5-18 years who received either BCG or saline intradermally within 4 months of onset of symptoms and who were then evaluated at 3-month intervals for 2 years. The primary end point was remission, defined as insulin independence for 4 weeks. Secondary end points were C-peptide levels (fasting and in response to a mixed meal challenge), insulin dose, and HbA1c.

RESULTS

Of the patients, 47 were randomized to each arm; 7 in the placebo group and 9 in the BCG group did not complete 1 year of the study and are not included in the analysis. One patient from each group achieved remission. Fasting and stimulated C-peptide levels did not differ by treatment arm but declined in both groups and were lower initially and during the entire 2-year period in younger children. Insulin requirements and HbA1c levels did not differ in the two groups.

CONCLUSIONS

Vaccination with BCG at the time of onset of type 1 diabetes does not increase the remission rate or preserve beta-cell function.

Long-term efficacy of humalog in subjects with Type 1 diabetes mellitus

AIMS

To evaluate the long-term effectiveness of Humalog insulin in lowering post meal glucose excursions.

METHODS

Twenty young subjects with Type 1 diabetes mellitus (DM) who had received insulin-lispro (Humalog) for a least 1 year (mean +/- SD 1.8+/-1.6 years) were studied on two occasions, 3-14 days apart. They consumed a similar breakfast consisting of 450-600 kCal having fasted overnight. The same amount of human soluble Humulin Regular or Humalog insulin was given 10 min before the meal in a randomized, double-blind fashion.

RESULTS

Postprandial glucose excursions at 30, 60, and 120 min were significantly lower (P<0.001, ANCOVA) when subjects received Humalog as compared to human soluble insulin. Serum-free insulin levels were significantly higher (P<0.001, ANOVA) at 30 and 60 min when subjects received Humalog as compared with human soluble insulin. Humalog antibody levels after up to 5.4 years of receiving Humalog insulin were not elevated beyond the values at 1 year.

CONCLUSIONS

We conclude that Humalog insulin is effective in lowering postprandial glucose excursions even after up to 5.4 years of treatment.

Use of insulin lispro in the outpatient management of ketonuria

OBJECTIVE

To compare the effectiveness of the use of insulin lispro with the use of regular insulin in managing children with diabetes in outpatient settings.

DESIGN

In this prospective study, telephone records of 75 children treated for ketonuria were analyzed. Outcome was based on the number of successful home treatment episodes (hospitalization not required), the amount of insulin the patients needed, and the time to resolution of ketonuria.

RESULTS

Doses of supplemental insulin used to treat patients with both moderate and large urine ketone values were similar (P>.05) in the insulin lispro and regular insulin groups. Likewise, the time to resolution of moderate or large ketonuria was not statistically different (P>.05) between the 2 groups. No hospitalizations were required for any of the patients for whom management via telephone was attempted.

CONCLUSION

These data indicate that insulin lispro is an effective option for the outpatient management of ketonuria.

Dual-parameter model for prediction of type I diabetes mellitus

The recent cloning and recombinant expression of novel islet autoantigens [glutamic acid decarboxylase (GAD) 65 and islet-cell autoantibody 512 (ICA512)] has made possible the determination of whether the quantitative expression of autoantibodies to these molecules is correlated with age of diabetes onset and rate of progression to diabetes, similar to insulin autoantibodies (IAAs). We measured autoantibodies reacting with GAD65 (GAD65AA), ICA512 (ICA512AA), and insulin in patients who recently had received a diagnosis of diabetes and in first-degree relatives prospectively identified and then followed because of the expression of high titers of ICA. Levels of IAAs (but not GAD65AA or ICA512AA) correlated inversely with age at diagnosis of diabetes and directly with time to diabetes onset among the ICA-positive relatives. In multiple linear regression models, the level of IAAs remained a significant predictor of the time to diabetes after allowing for first-phase insulin secretion. The unique and dramatic association of IAAs with progression to diabetes suggests that IAAs contribute directly to disease pathogenesis or that levels of IAAs are influenced uniquely by the process, leading--at different rates in different prediabetic individuals--to type I diabetes. In addition, the linear regression model described (involving two variables, first-phase insulin secretion and levels of IAAs) aids in the prediction of time to diabetes among ICA-positive relatives.

Slicing the pie. Correlating HbA--values with average blood glucose values in a pie chart form

OBJECTIVE

The purpose of this study was to define the correlation between HbA1c values and the percentage of home blood glucose (HBG) measurements within given ranges in a pie chart in three age-groups of subjects with type 1 diabetes.

RESEARCH DESIGN AND METHODS

HbA1c values were compared with HBG measurements in subjects who did at least three blood glucose tests per day over 30 days in three age groups: 5-11, 12-16, and 17-35 years. The blood glucose values were arbitrarily divided into three groups, defined as the percentage of HBG measurements within, above, and below target range. Each range was then compared with the corresponding HbA1c value. Longitudinal data were also collected for 279 of the subjects after a mean of 139 days.

RESULTS

A strong correlation (P = 0.001) was found between HbA1c values and the average blood glucose, and also with the percentage of HBG measurements within, above, and below target range in each of the three age-groups (P < 0.001). Analyses of longitudinal data showed a strong correlation of the changes in HbA1c values to the changes in blood glucose values.

CONCLUSIONS

These data showed that a pie-shaped graph of the HBG data can be useful as a clinical parameter in helping patients and families attain desired HbA1c values.

Effectiveness of postprandial Humalog in toddlers with diabetes

OBJECTIVE

The purpose of this study was to determine whether postprandial administration of the new rapid-acting insulin analog Humalog could effectively reduce glucose excursions in children <5 years old.

DESIGN

Human Regular insulin given before a meal was compared with the same dose of Humalog after a meal of equal carbohydrate content in five toddlers with insulin-dependent (type 1) diabetes mellitus. In addition, the use of Humalog before a meal was compared with Humalog given after a meal of equal carbohydrate content in five other toddlers. The dose of long-acting insulin was not changed during the study period. Blood glucose levels were determined at fasting and at 1, 2, and 4 hours postprandially.

RESULTS

The 2-hour glucose excursions were significantly lower when postprandial Humalog administration was compared with preprandial Human Regular insulin administration. In contrast, glucose excursions were similar when Humalog was taken before or after the meal.

CONCLUSION

These data show that it is efficacious to give Humalog insulin postprandially in toddlers with type 1 diabetes, allowing increased safety for the young child. The insulin dose can be both matched to the actual food intake and timed to give families increased flexibility and control at mealtime.

24-hour ambulatory blood pressure and renal disease in young subjects with type I diabetes

Twenty-four hour ambulatory blood pressure (ABP) was evaluated in 150 teenage and young adults with insulin-dependent diabetes mellitus (IDDM) to define high-risk subjects who are likely to develop early diabetic nephropathy. Their age range was 16-28 years with diabetes of 3.5-25.8 years duration. All subjects had office blood pressure (BP) measured, wore an ABP monitor for 24 h, and collected two or more timed urine samples for albumin excretion rates (AERs). Eighty-six subjects had no elevation of AER (< 7.6 micrograms/min), 29 subjects had borderline elevations (7.6-20 micrograms/min), 24 subjects had microalbuminuria (20.1-200 micrograms/min), and 11 had macroalbuminuria (> 200 micrograms/min). Age, gender, duration of diabetes, and single office BP readings were similar in the four groups (p > 0.05, logistic regression). All 24-h ABP parameters were significantly higher in subjects with diabetes having AER values greater than 7.6 micrograms/min when compared with healthy age- and gender-matched nondiabetic controls (p < 0.05, Dunnett's t test). The percent of nighttime systolic and diastolic ABP readings above the 90th percentile of normal for age, gender, and race and the percent of readings in the hypertensive range (> 140/90) were significantly related with AERs (p < 0.01; logistic regression). A higher percentage of ABP values above the 90th percentile for age, gender, and ethnic group or of ABP readings above hypertensive levels (> or = 140/90) are associated with diabetic renal disease.

Altered immune response to insulin in newly diagnosed compared to insulin-treated diabetic patients and healthy control subjects

Insulin-dependent diabetes mellitus (IDDM) is the result of a T-cell mediated autoimmune beta-cell destruction, which is accompanied by autoantibodies. We analysed the cellular and humoral immune response to insulin and insulin peptides in patients with recent-onset IDDM, IDDM patients treated with insulin, non-diabetic first degree relatives and unrelated control subjects. There were no differences in T-cell reactivity to whole insulin or insulin peptides in general between age-matched groups of IDDM patients, relatives or healthy control subjects. In contrast to investigations in NOD mice, no immunodominant or disease-specific insulin peptide could be identified. Surprisingly, a positive correlation of T-cell responses to insulin with age was noticed (p < 0.005). This resulted in an inverse relation of insulin autoantibodies (IAA) and insulin reactive T-cells (p < 0.001) together with the well-described negative correlation of IAA with age. Interestingly, insulin-treated patients differed from age-matched recent-onset IDDM patients: first, simultaneous immune recognition of insulin with T-cells and IAA was only seen in patients treated for 6 months with insulin; second, insulin-treated patients rarely responded to whole insulin; third, they displayed less determinant spreading, and finally, recognition of multiple insulin peptides was not accompanied by crossreactivity to whole insulin. These distinct observations in insulin-treated IDDM patients, together with the inverse correlation between humoral and cellular responses to insulin, may result from activation or modulation of different T-cell subsets, and may be of relevance to insulin therapy trials, in which selective activation of non-destructive T-cell subsets may be a key to successful intervention.

24-h ambulatory blood pressure monitoring in healthy young adult Anglo, Hispanic, and African-American subjects

The purpose of this study was to compare office and 24-h ambulatory blood pressure (ABP) values for adolescent and young adult males and females of Anglo, Hispanic, and African-American descent. One hundred and eighteen healthy subjects (62 females, 56 males) participated, with an ethnic distribution of 50 Anglo, 32 Hispanic, and 36 African-American subjects. All subjects came to the clinic for height, weight, sitting blood pressure (BP), and to begin 24-h ABP monitoring using the SpaceLabs model 90207 automatic noninvasive monitor. The monitor recorded readings every 0.5 h from 06:00 to 22:00 and every hour at night from 22:00 to 06:00. Office systolic and diastolic BP values were higher for all males compared to all females. Mean 24-h, nighttime, and daytime systolic ABP values were also significantly higher for males compared to females. The 24-h mean and daytime systolic ABP values were significantly different by ethnic groups. The African-American subjects always had the highest readings. Mean 24-h diastolic ABP was also significantly different by ethnic groups, with the African-American subjects being higher than the Anglos or the Hispanics. Diastolic ABP (24-h mean, daytime, and nighttime) values (for all subjects combined) increased gradually and varied significantly with age. This study provides preliminary normative data about ABP in an understudied population (ie, teenagers and young adults of different ethnic backgrounds). It also shows that higher blood pressures are present among males and among subjects of African-American descent in the teenage and young adult population.

Lack of association between early exposure to cow's milk protein and beta-cell autoimmunity. Diabetes Autoimmunity Study in the Young (DAISY)

OBJECTIVE

To examine whether infant dietary exposure to cow's milk is associated with beta-cell autoimmunity (BCA), an early predictor of insulin-dependent diabetes mellitus (IDDM).

SETTING

Denver, Colo.

DESIGN

Cross-sectional with retrospective analysis.

PARTICIPANTS

Between January 1994 and December 1995, 253 children from 171 families of persons with IDDM were screened for BCA. All children were between the ages of 9 months and 7 years.

MAIN OUTCOME MEASURES

BCA was defined as elevated levels of insulin autoantibody, glutamic acid decarboxylase autoantibody, or insulinoma-associated islet tyrosine phosphatases autoantibody (IA-2) above the 99th percentile of 198 normal subjects.

RESULTS

Eighteen cases of BCA were detected; 153 unrelated autoantibody-negative children were selected from the cohort as controls. There were no differences in the proportion of cases and controls who were exposed to cow's milk or foods containing cow's milk or to cereal, fruit and vegetable, or meat protein by 3 months or by 6 months of age. Children with BCA were breast-fed for a slightly longer duration than controls (median duration 10 vs 8 months, P=.07).

CONCLUSIONS

These data suggest that early exposure to cow's milk or other dietary protein is not associated with BCA. This calls into question the importance of cow's milk avoidance as a preventive measure for IDDM.

Prediction of type I diabetes in first-degree relatives using a combination of insulin, GAD, and ICA512bdc/IA-2 autoantibodies

Islet cell antibodies (ICAs) are predictive of type I diabetes in first-degree relatives, but this immunohistochemical assay has proven difficult to standardize. As an alternative, we assessed the use of radioassays for antibodies against three molecularly characterized islet autoantigens, including ICA512bdc (amino acid residues 256-979 of the IA-2 molecule, incorporating the intracellular domain). We measured insulin autoantibodies (IAAs), GAD autoantibodies (GAAs), and ICA512bdc autoantibodies (ICA512bdcAAs) by radioassay, in addition to ICAs, in 882 first-degree relatives of patients with type I diabetes, 50 of whom later developed diabetes with a median follow-up of 2.0 years (maximum 11.3 years). The cutoff for each radioassay was determined by testing >200 control subjects. When autoantibody frequencies among the relatives were analyzed according to relationship to the proband, the offspring of diabetic fathers had a higher frequency of ICA5I2bdcAAs (P = 0.008), IAAs (P = 0.0001) and GAAs (P = 0.0001) than the offspring of diabetic mothers. ICA512bdcAAs and IAAs both showed a significant association with HLA-DR4-DQ8 (P = 0.0005). Among relatives developing diabetes, 98% had one or more of IAAs, GAAs, or ICA512bdcAAs, and 80% had two or more of these autoantibodies, compared with none of the control subjects. Using survival analysis to allow for different lengths of follow-up, there was a significant increase in the risk of diabetes with the number of these autoantibodies present, comparing zero, one, two, and three autoantibodies (P < 0.0001, log-rank test), and by Cox regression analysis, this was independent of ICAs and age. For relatives with two or more of these autoantibodies, the risk of diabetes within 3 years was 39% (95% CI, 27-52) and the risk within 5 years was 68% (95% CI, 52-84). Relatives with all three autoantibodies had a risk within 5 years estimated to be 100%. The presence of low first-phase insulin release further increased the risk for relatives with one or two autoantibodies. We conclude that the presence of two or more autoantibodies (out of IAAs, GAAs, and ICA512bdcAAs) is highly predictive of the development of type I diabetes among relatives.

Number of autoantibodies (against insulin, GAD or ICA512/IA2) rather than particular autoantibody specificities determines risk of type I diabetes

We previously evaluated radioassays for insulin autoantibodies (IAA), glutamate decarboxylase autoantibodies (GAA) and ICA512bdc autoantibodies (ICA512bdcAA) in the prediction of type I diabetes. Among first degree relatives, the five year risk of diabetes was 0% if no autoantibody was positive, 15% if only one was positive, 44% if two were positive and 100% if all three were positive. We measured IAA, GAA and ICA512bdcAA in 45 patients with new onset type I diabetes (sampled within 7 days of insulin therapy), 882 first degree relatives of patients with type I diabetes, and 217 control subjects. ICA512bdc is a construct of the ICA512/IA2 molecule (amino acid residues 256-979), including the intracellular domain. Based on receiver-operating characteristic plots, there was no significant difference between the three assays in their ability to discriminate between disease and control subjects. The upper limits of normal for the assays were determined as the 99th percentile of levels in the control subjects or higher. Using these cut-offs, 76% of new onset patients were positive for two or more autoantibodies, and 98% were positive for one or more. In comparison, none of 198 control subjects tested for all three assays were positive for more than one autoantibody. In relatives with a single autoantibody, or exactly two autoantibodies, there was no difference in diabetes-free survival according to which one of the autoantibodies was present (P = 0.70, logrank test), or which particular combination of autoantibodies was present (P = 0.56, logrank test) respectively. Our conclusions were as follows: the number of autoantibodies (counting IAA, GAA and ICA512bdcAA) is important in prediction, rather than the particular autoantibody specificities present. Among patients with new onset insulin-dependent diabetes, the absence of any of these autoantibodies justifies the consideration of non-autoimmune forms of diabetes in the differential diagnosis.

Pre-meal insulin analogue insulin lispro vs Humulin R insulin treatment in young subjects with type 1 diabetes

The present prospective one-year randomized study was conducted to compare soluble human insulin, with a new rapid-acting human insulin analogue, lispro, with respect to postprandial glucose excursions, frequency of hypoglycaemic episodes, glucose control, and long-term safety in 39 subjects (20 females, 19 males) with Type 1 diabetes. The duration of diabetes, gender distribution, and age were similar in the two groups. The total number of hypoglycaemic episodes was significantly less (p < 0.04, Wilcoxon rank sum test) in subjects receiving insulin lispro compared with regular human insulin over the 12-month period. The 2-h postprandial glucose excursion at 1 year was also significantly less (p < 0.05, ANOVA) in the group treated with insulin lispro. The reductions in the total number of hypoglycaemic episodes and in the postprandial glucose excursion with use of insulin lispro may be beneficial for the long-term management of subjects with Type 1 diabetes. However, the greatest benefit identified by the subjects receiving insulin lispro was the greater convenience of the rapid-acting analogue.

Sexual dimorphism in transmission of expression of islet autoantibodies to offspring

To help elucidate the mode of inheritance of insulin-dependent diabetes mellitus (IDDM), we measured GAD (glutamic acid decarboxylase) autoantibodies (GAD65Ab), insulin autoantibodies (IAA), and cytoplasmic islet cell autoantibodies (ICA) in 292 sequentially screened non-diabetic offspring of patients with IDDM. The prevalence of these islet autoantibodies was higher in offspring of diabetic fathers than in offspring of diabetic mothers. The prevalences of GAD65Ab, IAA, and ICA in the offspring of diabetic fathers were 11.5%, 10.8%, and 8.1% vs 2.1%, 1.4%, and 2.8%, respectively in the offspring of diabetic mothers (p < 0.002, p < 0.001, and p = 0.06 NS). Amongst autoantibody-positive relatives the IAA and ICA levels were significantly higher in offspring of diabetic fathers than of diabetic mothers (p < 0.002 and p < 0.01, respectively). The frequencies of these autoantibodies were equal in male and female offspring. We conclude that IDDM mothers transmitted islet autoimmunity less frequently to their offspring than IDDM fathers. Given the markedly lower frequency of autoantibodies in offspring of mothers, larger sample sizes will be required to determine whether islet autoantibodies are influenced by age of IDDM onset of mothers, maternal age of pregnancy, and presence of diabetes in these mothers prior to conception.

Exercise versus overnight albumin excretion rates in subjects with type 1 diabetes

Diabetic nephropathy is the leading cause of new cases of renal failure in the US and Europe. An elevated albumin excretion rate (AER) on an overnight urine sample is considered an early predictor of end-stage renal failure. An elevated AER on a post-exercise urine sample has previously been considered to be an even earlier marker of renal damage. In a longitudinal prospective study, 373 subjects with insulin-dependent (type 1) diabetes mellitus had a total of 714 renal evaluations, each of which included one exercise and two overnight urine collections for AER determinations. All subjects were at least 13 years old and had diabetes for at least 4 years. There was a strong correlation between exercise and overnight AERs (r = 0.74, P < 0.001). For the 60 subjects with an initial borderline increase of either overnight or exercise AER, the overnight AER values (7.6-20 micrograms/min) progressed first for 52% of subjects whereas the exercise AERs (41-114 micrograms/min) progressed first for 43% of subjects (5% had simultaneous elevations of both). For the 22 subjects in which an abnormal overnight (> 20 micrograms/min) or exercise (> 114 micrograms/min) value was detected first, 17 (77%) had an elevated exercise AER first, whereas only 4 (18%) had an elevated overnight AER first. This study shows that an increase of either the exercise or the overnight AER can occur first, dependent upon the level of abnormality being considered. The two tests correlate closely with one another.(ABSTRACT TRUNCATED AT 250 WORDS)

Final adult height and its relationship to blood glucose control and microvascular complications in IDDM

The effect of longitudinal blood glucose control on final adult height was evaluated in 181 subjects (94 women and 87 men) with IDDM. Diabetes onset was at a median age of 6.9 years with an interquartile range of 4.7 years. Longitudinal glycated haemoglobin values were determined over a mean period of 6.6 +/- 2.6 years during their growth phase. Serial eye and joint examinations and urinary albumin excretion rates were performed with final assessment being carried out at a mean age of 21.1 +/- 3.0 years. The mean adult height standard deviation score of the whole group was -0.22 +/- 1.15 and was reduced compared to the mean height of the general population and to the mean height of the subjects' parents and siblings. There was an inverse correlation with mean longitudinal glycated haemoglobin and final adult height (p < 0.01). There was also an inverse relationship between adult height and the severity of eye, kidney, and joint complications, but when controlled by glycated haemoglobin, this relationship only remained significant for eye complications. Final adult height is reduced in subjects with early onset IDDM who remain in poor blood glucose control during their growth period.

Oral contraceptives and renal and retinal complications in young women with insulin-dependent diabetes mellitus

OBJECTIVE

To evaluate the effects of oral contraceptives (OCs) as a possible risk factor for early diabetic renal and/or retinal complications.

DESIGN

A retrospective case-control study.

SETTING

A university hospital diabetes clinic.

PARTICIPANTS

Forty-three diabetic women who used OCs for 1 year or longer (mean, 3.4 years; range, 1.0 to 7.0 years) were compared with a computer-matched control group of 43 diabetic women who never used OCs.

MAIN OUTCOME MEASURES

Hemoglobin A1c levels, albumin excretion rates, and mean retinopathy scores.

RESULTS

The mean +/- SEM age and duration of diabetes were 22.7 +/- 0.5 years (range, 17.1 to 30.5 years) and 13.8 +/- 0.8 years, respectively, for the study group. The mean longitudinal hemoglobin A1c values were similar for study subjects and control subjects. The final mean albumin excretion rates, reflecting diabetic renal damage, and the mean eye grades were not significantly different between the groups.

CONCLUSIONS

The use of OCs among young women with insulin-dependent diabetes mellitus does not pose an additional risk for the development of early diabetic retinopathy and/or nephropathy.

Ethnic differences in human leukocyte antigen markers of susceptibility to IDDM

OBJECTIVE

To determine whether genetic differences explain the lower risk of developing insulin-dependent diabetes mellitus (IDDM) for Hispanic versus non-Hispanic white children in Colorado.

RESEARCH DESIGN AND METHODS

Hispanic (n = 62) and non-Hispanic white (n = 82) subjects with IDDM identified from the Colorado IDDM Registry and healthy, nondiabetic control subjects were recruited. Human leukocyte antigen (HLA) serologic typing and sequence-specific oligonucleotide typing of DQA1 and DQB1 alleles were performed.

RESULTS

HLA and allele associations with IDDM were similar in both ethnic groups. HLA-DR3 and HLA-DR4 were more common in IDDM subjects in both ethnic groups. Subjects with DQBl alleles encoding aspartic acid (Asp) in position 57 were less likely to have IDDM, irrespective of ethnic background. HLA-DR3 was less common among Hispanic subjects than non-Hispanic white control subjects (4.4 vs. 17.5%, Hispanics vs. non-Hispanic whites, P = 0.04).

CONCLUSIONS

These data suggest that the lower prevalence of HLA-DR3 in the Hispanic population, a pattern consistent with the presence of Amerindian admixture, may explain the lower rate of IDDM in the Hispanic population.

First-phase insulin release in normal children

Normal values for the first-phase insulin release during an intravenous glucose tolerance test are not yet well defined for children and adolescents. In this study, 69 normal subjects (aged 7 to 22 years) who had no family history of type I diabetes, a normal glycohemoglobin value, and a negative islet cell antibody test result underwent a standard intravenous glucose tolerance test. The mean (+/- SEM) first-phase insulin release increased with age and pubertal status: 7 to 10 years, 93 +/- 10.1 mIU/L; 11 to 15 years, 172.7 +/- 22.3 mIU/L; and 16 to 22 years, 163 +/- 28.5 mIU/L. The mean intraindividual variability in 11 subjects who underwent a second test was 23.6%. Acute stress, as estimated by observer assessment or by blood catecholamine levels, did not significantly correlate with first-phase insulin release. We conclude that first-phase insulin release is markedly lower in prepubertal children than in adolescents and young adults.

Angiotensin-converting enzyme inhibitor treatment for young normotensive diabetic subjects: a two-year trial

Microangiopathy characterizes both diabetic retinopathy and nephropathy. It is currently unclear which diabetic subjects should be treated with angiotensin-converting enzyme (ACE) inhibitors. A double-blind, placebo-controlled protocol was implemented using captopril to treat subjects with Type I diabetes, early diabetic nephropathy (albumin excretion rates, 20-200 micrograms/min), and normal blood pressures. After two years, the final eye grades were improved in two treated subjects but not in any of the controls. Three control and one treated subject showed worsening of their eye grade after two years (P < .001, by chi-square test). Significant differences in renal albumin excretion were not seen between the two groups. The distribution of changes in retinal grades in the treatment group compared with the placebo group was improved after two years. Studies of larger numbers of patients will be necessary to determine if ACE inhibitors should be used routinely in subjects with diabetic retinopathy and to determine which subjects are most likely to respond.

Factors influencing the onset and progression of diabetic retinopathy in subjects with insulin-dependent diabetes mellitus

BACKGROUND

The etiology of diabetic retinopathy is poorly understood. In the current study, factor associated with the onset and the progression or regression of retinopathy are evaluated.

METHODS

Two hundred seventy-seven subjects with insulin-dependent (type I) diabetes mellitus (IDDM) were evaluated longitudinally for retinal changes over a mean of 2.7 years. The multistate Markov model was used to analyze the influences of the duration of diabetes, a family history of hypertension, age, sex, cigarette smoking, systolic blood pressure, diastolic blood pressure, cholesterol levels, and longitudinal glycohemoglobin (GHb) values on the development and the progression or regression of retinopathy.

RESULTS

Univariate analysis confirmed that four factors were significantly associated with the etiology and the progression or regression of diabetic retinopathy: age, duration of diabetes, mean longitudinal GHb levels (all at P < 0.01), and diastolic blood pressure (P < 0.04). However, age was no longer significant when controlled by duration of diabetes. Cigarette smoking was only associated significantly with background retinopathy (stages 2 and 3). Systolic blood pressure, sex, a family history of hypertension, and cholesterol levels were not significantly associated with retinopathy.

CONCLUSIONS

The onset of diabetic retinopathy is associated with the duration of diabetes, mean longitudinal GHb levels, smoking, and diastolic blood pressure. A longer duration of diabetes, higher GHb values, and higher diastolic blood pressure levels are associated with an increased risk of progression and a decreased chance of regression of diabetic retinopathy.

Early exposure to cow's milk and solid foods in infancy, genetic predisposition, and risk of IDDM

Using a case-control study design, we examined the hypothesis that early exposure to cow's milk and solid foods increased the risk of IDDM. An infant diet history was collected from 164 IDDM subjects from the Colorado IDDM Registry with a mean birth year of 1973, and 145 nondiabetic population control subjects who were frequency matched to diabetic subjects on age, sex, and ethnicity. Early exposure was defined as exposure occurring before 3 mo of age. After controlling for ethnicity, birth order, and family income, more diabetic subjects were exposed early to cow's milk (OR 4.5, 95% CI 0.9-21.4) and solid foods (OR 2.5, CI 1.4-4.3) than control subjects. To examine this association while accounting for the genetic susceptibility to IDDM, we defined individuals as high and low risk by an HLA-DQB1 molecular marker. Early exposure to cow's milk was not associated with elevated risk for IDDM in low-risk individuals. Relative to unexposed low-risk individuals, early exposure to cow's milk was strongly associated in individuals with a high risK marker (OR 11.3, CI 1.2-102.0). Similar findings were observed for early exposure to solid foods. These data indicate that early exposure to cow's milk and solid foods may be associated with increased risk of IDDM. The inclusion of HLA-encoded risk in the analyses demonstrates the combined effect of genetic and environmental factors.

Clinical characteristics of IDDM in Hispanics and non-Hispanic whites. Little evidence of heterogeneity by ethnicity

OBJECTIVE

To compare the clinical characteristics of IDDM in HD and NHWD subjects in order to evaluate potential heterogeneity of IDDM by ethnicity.

RESEARCH DESIGN AND METHODS

HD subjects (n = 73) and NHWD subjects (n = 97) were recruited from the Colorado IDDM Registry. The registry included individuals who were Colorado residents, less than 18 yr old at diagnosis, placed on insulin within 2 wk of diagnosis, and had diabetes not secondary to other conditions. Residual beta-cell function was measured as the 1-h C-peptide response to a Sustacal challenge.

RESULTS

HD subjects were similar to NHWD subjects in insulin dose, HbA1, HLA-DR antigens, ICAs, and family history of IDDM. HD subjects were more likely to have a family history of NIDDM than NHWD subjects (11 vs. 3%, P = 0.03). HD girls had higher C-peptide levels (0.27 vs. 0.11 nm/L [0.83 vs. 0.33 ng/ml], P = 0.01), BMI (22.7 vs. 20.9 kg/m2 P = 0.04), subscapular skinfold thickness (18.9 vs. 15.0 mm, P = 0.04), and WHR (0.81 vs. 0.77, P = 0.03) than NHWD females. After controlling for diabetes duration, BMI, sex, and family history of NIDDM, residual beta-cell function was associated significantly with Hispanic ethnicity, although the term accounted for just 3% of the overall variability in C-peptide levels.

CONCLUSIONS

Little evidence of heterogeneity by ethnicity of IDDM patients in the Colorado IDDM Registry was found. Ethnic differences in C-peptide levels may be related to differences in body fat distribution in females rather than heterogeneity of the disease.

Outpatient management vs in-hospital management of children with new-onset diabetes

The long-term results of outpatient management of subjects with newly diagnosed insulin-dependent diabetes mellitus (IDDM) are unknown. The longest follow-up described to date is for only one year, a time when most children with IDDM still make endogenous insulin. In this study, 41 young subjects with IDDM, treated and educated in the outpatient setting (1980 to 1984), were compared to a group of 80 similar subjects who received their initial education as hospital inpatients. Long-term glycemic control, as measured by longitudinal glycohemoglobin (HbA1) values was not different in the two groups (p greater than .05). We conclude that outpatient education and management of newly diagnosed subjects with IDDM is as safe and effective as inpatient treatment.

Incidence of insulin-dependent diabetes mellitus in Colorado

We examined the incidence of insulin-dependent diabetes mellitus in children 0-17 years of age in Colorado from 1978 to 1988. Cases were ascertained from a statewide registry based on physician surveillance. A total of 1,376 children were diagnosed during this interval in a population averaging 860,000 children. The degree of ascertainment was estimated to be 93.3%. The age-adjusted incidence rate of insulin-dependent diabetes mellitus was 14.8/100,000 person-years. The rate was lower in individuals of Spanish origin (Hispanics) (8.7/100,000 person-years) compared with non-Hispanic individuals (15.5/100,000 person-years) (incidence rate ratio = 0.6, 95% confidence interval = 0.4-0.8). Incidence rates were higher in winter and lower in summer for children 5-17 years old. Children diagnosed before the age of 5 years showed no significant seasonal pattern, although peak incidences were observed in autumn and spring. No temporal trend in diabetes incidence was observed overall or by ethnic group. The increasing insulin-dependent diabetes incidence reported by registries in Europe during this time period was not observed in Colorado.

Elevation of resting and exercise blood pressures in subjects with type I diabetes and relation to albuminuria

The etiology of diabetic nephropathy is currently unknown, but blood pressure is believed an important risk factor. A total of 173 subjects with type I diabetes who participated in two or more exercise tests with simultaneous measurements of blood pressure (BP) and heart rate were studied. Subjects with diabetes had significantly elevated resting and exercise diastolic and systolic BPs when compared with controls. This was not related to the presence of albuminuria. During exercise, elevation of diastolic BP was present in 65 (38%) of the 173 test subjects. Elevated exercise diastolic BPs among the subjects with diabetes (excluding controls) was present only for subjects with elevated exercise and overnight albuminuria. It is concluded that factors other than early diabetic nephropathy are likely related to elevated resting and exercise BPs in subjects with diabetes compared with controls. Early renal damage, however, is related to further elevations in resting and exercise diastolic BPs within the group of subjects with diabetes.

Detection of cell-mediated immunity in type I diabetes mellitus

Type I insulin dependent diabetes mellitus (IDDM) is thought to result from chronic, cell-mediated, 'autoimmune' islet damage. Antibody testing is extensively used to define and follow the pre-diabetic population. However, the assay for cell mediated immunity (CMI) should be more predictive of impending disease. This report shows that it is possible to detect human islet reactive CMI in the IDDM patient. Groups of athymic CD-1 nu/nu mice were injected intraperitoneally with either mononuclear blood cells (MBCs) or plasma from 10 newly diagnosed Type I diabetic patients and 10 normal control subjects. Both glycemic control and histopathology were used to assay islet specific CMI in diabetic individuals. None of the injected mice showed any impairment of glycemic control. However, MBCs from six of 10 diabetic patients, but from none of the 10 normal subjects, induced significant mononuclear cell infiltrate in the pancreas of the recipient mice (P = 0.005). The infiltrate was focused on the islet tissue and no damage was seen in control tissues. No histological abnormalities were observed when plasma was transferred. We conclude that cellular reactivity seen in this model is tissue specific and disease associated. Our findings provide evidence that CMI to human islet tissue can be detected in IDDM patients.

Angiotensin-converting enzyme inhibitor therapy and diabetic retinopathy

This pilot project suggested that angiotensin-converting enzyme (ACE) inhibitors may have an effect on delaying or reversing diabetic retinopathy. One patient who had Grade 5 (preproliferative) retinopathy improved to Grade 2 (microaneurysms only) after two years of treatment. Of the 450 patients followed in our eye and kidney clinic, no other patient showed a similar reversal from Grade 5 retinopathy without treatment. Improvement by one or more grades was seen in three other patients with variable grades of retinopathy after a mean of 3.3 years of treatment. Improvement was not related consistently to a decrease in blood pressure (0 of 4), better glycemic control (2 of 4), or reduction in albumin excretion rate (0 of 4). Proper double-blind controlled studies are needed to prove the effect of ACE inhibitors on diabetic microangiopathy of the eye.

Accuracy of a filter paper method for measuring glycosylated hemoglobin

OBJECTIVE

To compare glycosylated hemoglobin (GH) results obtained by filter paper fingerstick collection and mailed for assay by affinity chromatography with results from a venous sample assayed by ion-exchange chromatography (HbA1) in a local laboratory.

RESEARCH DESIGN AND METHODS

Fifty-eight volunteer subjects with insulin-dependent diabetes mellitus (IDDM), aged 5-24 yr, included patients at a referral-based IDDM clinic and subjects in an ongoing research study. We obtained two blood samples from each subject. One was collected by fingerstick onto filter paper, the other by venipuncture into a vacutainer. We sent filter paper samples to the Diabetes Research Laboratory (Univ. of Missouri, Columbia, MO) for analysis. Vacutainer samples were sent to the Clinical Chemistry Department of the Clinical Laboratory, University of Colorado Health Sciences Center.

RESULTS

Results were highly correlated (r = 0.89, P = 0.0001). Fifty-nine percent were classified identically when results were normalized to SD units and grouped to suggest levels of clinical concern.

CONCLUSIONS

The filter paper method is a convenient, accurate measure of glycosylated hemoglobin in young people with IDDM. It should be considered a credible alternative research and clinical tool.

Increasing trend of outpatient management of children with newly diagnosed IDDM. Colorado IDDM Registry, 1978-1988

OBJECTIVE

To examine the management of newly diagnosed insulin-dependent diabetes mellitus (IDDM) in Colorado over time and to determine the prevalence of outpatient care at IDDM diagnosis on a statewide basis.

RESEARCH DESIGN AND METHODS

The Colorado IDDM Registry was used to assess medical care at the diagnosis of IDDM in 1182 patients less than 18 yr of age between 1978 and 1988.

RESULTS

Twenty-three percent of children with IDDM in Colorado reported never being hospitalized during the diagnosis period. Treatment of IDDM at diagnosis (outpatient vs. inpatient) did not differ by age, sex, or ethnicity/race. Patients living in rural counties were less likely to have been treated as outpatients at diagnosis than those living in urban counties. Physicians at specialized diabetes clinics (e.g., The Barbara Davis Center for Childhood Diabetes and The Childrens Hospital) were more likely to treat newly diagnosed children in an outpatient setting than physicians not affiliated with these clinics. The proportion of patients receiving only outpatient care at IDDM diagnosis increased from 6% in 1978 to 35% in 1988. This increase can be attributed to three factors: 1) an increase in the number of Colorado children diagnosed at The Barbara Davis Center, where outpatient care is strongly advocated; 2) a change in treatment practices at The Childrens Hospital away from routine hospitalization at onset; and 3) a steady increase in outpatient care for newly diagnosed diabetic children by physicians who were not affiliated with the aforementioned specialized diabetes clinics.

CONCLUSIONS

The relatively new practice of outpatient care at diagnosis of IDDM increased between 1978 and 1988 in Colorado, in both specialized diabetes clinics and physicians' practices not affiliated with specialized clinics.

Limited joint mobility in subjects with insulin dependent diabetes mellitus: relationship with eye and kidney complications

Three hundred and fifty seven subjects (178 males and 179 females) with insulin dependent diabetes mellitus were evaluated for the presence of limited joint mobility of the interphalangeal joints. Sixty six subjects (19%) had stage 1 and 26 subjects (7%) had stage 2 involvement of their interphalangeal joints. The presence of contractures was significantly related to mean longitudinal glycated haemoglobin (HbA1) concentrations, duration of diabetes, age of onset, mean longitudinal cholesterol concentrations and blood pressure. Limited joint mobility was also significantly associated with early diabetic retinopathy and raised albumin excretion rates. Limited joint mobility remained a significant factor in the logistic regression model for albuminuria and grade of retinopathy when controlled for smoking, cholesterol concentrations, duration of diabetes, age, gender, and blood pressure. However, limited joint mobility was only significantly associated with diabetic retinopathy when the effect of HbA1 concentrations was included in the multivariate model.

Borderline increases in albumin excretion rate and the relation to glycemic control in subjects with type I diabetes

We evaluated "borderline" increases in overnight albumin excretion rates (AERs)----i.e., those between the upper 95th percentile of normal (7.6 micrograms/min) and the lowest value currently considered predictive of nephropathy (30 micrograms/min)----to determine their importance and to see whether glucose control influenced subsequent changes in the "borderline" AER values. Between 1985 and 1990, we studied 190 subjects with insulin-dependent diabetes mellitus (Type I), analyzing a mean of 6.5 timed overnight urine samples collected per subject. Above-normal AERs were associated with a significantly (by ANOVA) higher mean age (P = 0.03), longer duration of diabetes (P = 0.0002), and greater mean glycohemoglobin values (P = 0.002). The transition rate between borderline and abnormal AERs was significantly higher (P less than 0.0001, chi-square test) than the direct transition rate between normal and abnormal AERs, thus showing the borderline AER to be a definite intermediate stage. Good and poor glucose control were clearly associated with improvement and worsening, respectively, of the borderline AER values (P = 0.032, chi-square test of trend). More attention to borderline AER values is clearly indicated.

The effect of sugar cereal with and without a mixed meal on glycemic response in children with diabetes

The effect of sucrose consumption on glycemic control in children with insulin-dependent diabetes mellitus is unclear. Eight young subjects, 7-16 years of age, with a duration of diabetes of 2-8 years participated in this study. All subjects consumed four different breakfasts--oatmeal (OM) alone, oatmeal-sucrose (OMS), oatmeal-protein (OMP), and oatmeal with protein and sucrose (OMPS)--on four different days. Addition of sucrose resulted in a slightly greater area under the tolerance curve in 50% of the subjects; however, in 38% of subjects, the area decreased. The peak glucose level was lowest for OM, but there was no statistical difference in the peak levels of the four test meals. The most significant effect on glucose response was a delay in the peak time when protein was added to the meals. Peak times for OM and OMS (mean of 38 min) when fed alone were significantly (p less than 0.05, ANOVA) shorter when compared to the peak time for OMP and OMPS (mean of 54 min). The average recovery time for OMP was longest. Other indices (tolerance index and change of rise in blood glucose) measured were not significantly different among the test meals. This study demonstrates that adding limited sucrose to OM cereal has little effect on the blood glucose response in children with diabetes. Addition of protein and fat clearly delays the glycemic response.

Use of the pen delivery system for intensive insulin therapy in college-age students with type I diabetes

The present report describes our experience with 16 adolescents and young adults with insulin-dependent diabetes mellitus (IDDM; Type I) who switched from two injections of insulin per day to the NovolinPen and four insulin injections a day. Their mean age at the initiation of therapy was 19.2 years with a duration of diabetes of 8.9 years. Sixteen random computer-matched (for age, sex, and duration of diabetes) controls who remained on two insulin injections a day were evaluated for comparison. Most subjects were preparing to leave home for college. After a minimum of 1 year of using the pen, the mean weight gain of the test subjects was significantly greater (P less than .05) than for the computer-matched controls. Glycemic control, as monitored by mean HbA1c values, were similar for the NovolinPen and the control groups (10.8 versus 10.9, respectively) after almost 2 years. The main advantage to the pen expressed by the users was a sense of freedom of lifestyle.

Prediction of the course of pre-type I diabetes

To increase knowledge on the predictability of the onset of insulin-dependent diabetes mellitus (IDDM; type I), we followed 38 subjects less than 18 years of age who had positive results on two or more islet-cell antibody tests and one identical twin who had positive results on one islet-cell antibody test. All 39 patients had longitudinal intravenous glucose tolerance tests to determine the first-phase insulin response (FPIR). Insulin dependence has developed in 10 untreated subjects less than 18 years of age. Of the 10 subjects, insulin dependence developed in eight a mean of 4.6 months after their FPIR fell to less than 30 microU/ml and a mean of 14 months after it fell to less than 46 microU/ml. Nine of the untreated subjects had an FPIR less than 67 microU/ml on at least two occasions and became insulin dependent a mean of 19 months after the value first fell below this level (95% confidence limit = 66.4% to 100%). All but one of the 10 subjects in whom IDDM developed initially had islet-cell antibody levels of greater than 80 JDF units. Insulin autoantibody values at onset were available for 9 of the 10 subjects and were positive (greater than 39 nU/ml) in six. We conclude that the combination of positive results on two islet-cell antibody tests and two diminished FPIRs (less than 67 microU/ml) in subjects less than 18 years of age reliably predicts the onset of IDDM. These data should permit intervention studies to be planned.

Prevention or delay of type 1 (insulin-dependent) diabetes mellitus in children using nicotinamide

A controlled trial of oral nicotinamide to prevent the onset of diabetes mellitus in high risk children was conducted in two centres. The selection criteria were age less than 16 years, islet cell antibody greater than or equal to 80 IUs, and first phase insulin release less than 5th percentile. All of eight untreated control subjects have developed diabetes, whereas only 1 of 14 treated children has diabetes to date. This data suggests that nicotinamide has an effect in preventing Type 1 (insulin-dependent) diabetes and that randomized controlled studies are now indicated.