Hypoplasia of the pancreas in a patient with type I diabetes mellitus

Pancreatic hypoplasia is an uncommon developmental defect that has not been well documented in association with type I diabetes mellitus. We report the case of a patient with an atypical clinical onset of type I diabetes mellitus who died following pancreas transplantation. Autopsy showed the surprising finding of hypoplasia of the native pancreas with other features indicating the concurrence of type I diabetes mellitus. These findings lead to speculation about the occurrence and interaction of these two diseases in our patient.

Spontaneous whole blood platelet aggregation, hematological variables and complications in insulin-dependent diabetes mellitus: the Pittsburgh Epidemiology of Diabetes Complications Study

The role of platelet aggregation in the pathogenesis of diabetes complications remains unclear despite a number of reports suggesting associations in univariate analyses. The Pittsburgh Epidemiology of Diabetes Complications Study is a prospective study initiated in 1985 to determine risk factors for the development of complications in insulin-dependent diabetes mellitus (IDDM). This report focuses on the cross-sectional correlation between platelet count and aggregation and IDDM complications, in 563 participants aged 18 years and older seen at baseline. Spontaneous whole blood platelet aggregation (SWBPA) and other hematological variables [hematocrit, total platelet count (TPC), red blood cell count (RBC), fibrinogen and white blood cell count (WBC)] were evaluated as risk factors for IDDM complications (nephropathy, neuropathy, and retinopathy) in the baseline cross-sectional data of the Pittsburgh Epidemiology of Diabetes Complications Study. SWBPA was determined by a method based on the percentage fall in platelet count after shaking a fresh citrated blood sample kept at 37 degrees C. Subjects with chronic aspirin use or on dialysis were excluded from analysis. An increased TPC was observed in subjects with overt nephropathy (291.4 +/- 65.1 versus 261.2 +/- 64.9, p less than 0.001) compared with subjects without nephropathy. Similar results were found for proliferative retinopathy. The association with nephropathy (but not with retinopathy) persisted in multivariate analyses.(ABSTRACT TRUNCATED AT 250 WORDS)

Migrating a clinical laboratory information system between technologies

The technical revolution that has strongly driven events in the clinical laboratory for the last thirty years is now threatening to make obsolete what has become the central pillar of operation in many laboratories, the minicomputer-based laboratory information system. Some of its functions could easily be absorbed by the personal computers which are proliferating in the laboratory, but any single step leap between systems risks replacing order with chaos. Appropriate use of networking tools, together with essential software development, can provide a systematic migrational path for both the administrative and technical computer support from one environment to another without the trauma of a massive replacement step.

Familial and sporadic insulin-dependent diabetes: evidence for heterogeneous etiologies?

Heterogeneity within insulin-dependent diabetes mellitus (IDDM) has been hypothesized, but few studies have focused on differences which may exist between familial and sporadic IDDM cases. Presenting characteristics for 330 white, newly diagnosed IDDM cases were evaluated. Familial cases were older (10.2 +/- 5.1 years vs 7.9 +/- 4.2 years, P = 0.010) and had, on average, less severe metabolic disturbances at presentation, as demonstrated by lower mean hemoglobin A1 (12.6 +/- 2.4% vs 14.4 +/- 2.6%, P = 0.001) and mean insulin dose at discharge (0.62 +/- 0.35 U/kg/day vs 0.85 +/- 0.29 U/kg/day, P less than 0.001), and higher mean plasma bicarbonate concentrations (19.3 +/- 3.9 mmol/l vs 15.8 +/- 5.9 mmol/l, P = 0.023) and mean plasma C-peptide levels (0.35 +/- 0.36 pmol/ml vs 0.14 +/- 0.15 pmol/ml, P less than 0.001). Further analyses on a subset of IDDM cases (n = 100) indicated that initial differences in metabolic indices observed at diagnosis were no longer apparent at one-year post-diagnosis. These results suggest that the etiology of familial and sporadic IDDM is similar and that the less severe presentation observed at diagnosis in the familial cases may be due to earlier identification of the disease, reflecting increased parental knowledge of diabetic symptoms and/or frequent testing for diabetes.

The interface between epidemiology and molecular biology in the search for the causes of insulin-dependent diabetes mellitus

Epidemiological techniques have been utilized to accumulate new knowledge about insulin-dependent diabetes mellitus (IDDM), leading to important insights into the disease process and the alteration of these mechanisms when viewed from a geographic or population base. More recently, highly powerful and sophisticated techniques of molecular biology have been added to the research arsenal, extending the knowledge on the genetic basis for IDDM and the probable environmental factors involved. The development and growth of the new discipline of epidemiological genetics promises exciting new developments for the future of our field as well as that of other major medical problems having a genetic base, but significantly influenced by environmental factors. This review stresses the importance of carefully validated diabetes registries in the study of the epidemiology of IDDM. The Children's Hospital of Pittsburgh and the University of Pittsburgh Medical Center have spear-headed the development of such registries, worldwide. The first international meeting on IDDM epidemiology in 1983 gave as a result, i.e., the finding that there were truly remarkable differences in the risk of developing IDDM depending upon the geographic location of the individual. Later collaborative work via the Diabetes Epidemiology Research International (DERI) group has confirmed the previous finding and added the description of secular trends and epidemics of IDDM. It is remarkable that the incidence rate of IDDM in children below 15 years vary from 1/100,000/yr in the Orient to 35/100,000/yr in Finland. The epidemiological approach in the study of IDDM has also stimulated research into the various facets of the etiology of the disease, genetic factors, autoimmune mechanisms and environmental factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Cross-sectional and longitudinal relationship of sodium-lithium countertransport to insulin, obesity and blood pressure in healthy perimenopausal women

The objectives of this study were to assess the possible role of insulin as a regulator of red blood cell sodium-lithium countertransport and to examine the relationship of countertransport activity to change over time in insulin, blood pressure, and other variables. At baseline, countertransport was measured, and at baseline and after 2-3 years of follow-up, blood pressure, body mass index (BMI), lipids, fasting and two-hour plasma insulin and glucose were measured in 144 white healthy, premenopausal women, age 42-50 years. At baseline, using high and low categories of fasting insulin, triglycerides and BMI, countertransport was independently related to fasting insulin (P = 0.017), and triglycerides (P = 0.001), but not to BMI by analysis of variance. In similar analyses with fasting insulin, BMI, and countertransport, diastolic blood pressure was independently related only to countertransport (P = 0.003). Among the 73 who remained premenopausal after 2-3 year follow-up, baseline countertransport was significantly correlated with increases in fasting and two-hour insulin (r = 0.37, 0.38, P = 0.003, respectively), and these relationships remained significant after adjustment for change in BMI. Among subjects with high baseline countertransport, systolic blood pressure increased 5.6 mmHg compared with -2.2 mmHg with low countertransport, P = 0.001 after adjusting for baseline and change in BMI, triglycerides, and fasting and two-hour insulin. The data are consistent with a role for insulin and lipids in the regulation of sodium transport which may, in turn, play a role in blood pressure regulation. A relatively short follow-up in this healthy population suggests a relationship of baseline countertransport to changes in insulin metabolism, and blood pressure.

Cardiovascular disease and arterial calcification in insulin-dependent diabetes mellitus: interrelations and risk factor profiles. Pittsburgh Epidemiology of Diabetes Complications Study-V

Cardiovascular disease is a frequent complication of insulin-dependent diabetes mellitus (IDDM), but the prevalence, interrelations, and risk factors of its principal components (coronary, cerebrovascular, and lower-extremity arterial disease) and of medial arterial wall calcification are not well understood. To address these issues, data from the Epidemiology of Diabetes Complications Study (n = 657) baseline examination were examined. The term coronary heart disease (CHD) was applied to those with myocardial infarction or angina, whereas lower-extremity arterial disease (LEAD) was applied to those who had undergone amputation of a lower limb or who had an ankle to arm blood pressure ratio less than 0.8 at rest or after exercise. Calcification of the lower-extremity arteries was considered to be present if ankle pressure was more than 100 mm Hg higher than brachial pressure. Although the prevalence of CHD was low, LEAD was significantly more common in women than in men (p less than 0.01), whereas calcification was more frequent in men than in women (p less than 0.01). Ten percent of those with LEAD also had CHD, and 8% with LEAD had calcification. Modeling of potential risk factors (e.g., diabetes duration and glycosylated hemoglobin) revealed that duration, female gender, fibrinogen, low density lipoprotein cholesterol, high density lipoprotein cholesterol, and high density lipoprotein cholesterol to apolipoprotein A-I ratio were independent predictors of LEAD, whereas for CHD only, diabetes duration and hypertension contributed to CHD. Calcification revealed a mixed pattern, with duration, hypertension, and triglyceride to apolipoprotein A-I ratio being the statistically significant associated factors. The results suggest that although LEAD, CHD, and calcification often coexist, their risk factor profiles differ.

Human insulin use and hypoglycaemia: insights from the Pittsburgh Epidemiology of Diabetes Complications Study

Recently, concern has arisen that human (as opposed to beef or pork) insulin may cause more frequent and/or severe hypoglycaemia in association with reduced warning symptoms. This question was examined from questionnaire data of 628 Type 1 diabetic patients (mean age 28 years and duration of diabetes 19 years) participating in the baseline examination of a follow-up study of diabetes complications. Those using human insulin (n = 73) reported an insignificantly higher frequency of hypoglycaemic reactions in the last year than those using animal insulin (66 vs 55% with reactions at least monthly) and only a weak trend was seen overall for the prevalence of human insulin use to increase with increasing frequency of hypoglycaemia (p = 0.06). Hypoglycaemic reactions resulting in unconsciousness were too rare to permit analysis by type of insulin used. The prevalence of reduced awareness of hypoglycaemia was similar among human insulin users to that seen in animal insulin users (25 vs 19%, NS). However, prevalence of reduced awareness showed a strong relationship to current blood glucose in the animal (r = -0.18, p less than 0.001) but not human (r = -0.06, NS) insulin users. Excluding patients with autonomic symptoms or neuropathy did not alter the results, nor did excluding the 34 individuals taking more than three insulin injections per day. It is concluded that human insulin use is not associated with either any substantial increased frequency of hypoglycaemia or reduction in awareness of hypoglycaemia. However, human insulin use does appear to be associated with reduced awareness of hypoglycaemia in those whose blood glucose control is relatively poor.

Sexual dimorphism in insulin sensitivity in adolescents with insulin-dependent diabetes mellitus

Sex-related differences in insulin sensitivity were evaluated in male and female adolescents with insulin-dependent diabetes mellitus (IDDM). They were matched for age, pubertal staging, body mass index, and glycohemoglobin levels. During a 1.7 mU/kg.min hyperinsulinemic-euglycemic clamp, the insulin-mediated glucose disposal rate was lower (26.9 +/- 2.1 vs. 47.1 +/- 3.7 mumol/kg.min; P less than 0.001), and GH levels were higher (6.5 +/- 1.2 vs. 2.9 +/- 0.8 micrograms/L; P = 0.03) in females than in males. Plasma glucagon, cortisol, epinephrine, and norepinephrine levels during the clamp were similar in the two sexes, except for pancreatic polypeptide, which showed a tendency to be higher in females (19 +/- 4 vs. 11 +/- 1 pmol/L; P = 0.07). During insulin-induced hypoglycemia, the rate of drop in plasma glucose was faster (0.16 +/- 0.01 vs. 0.11 +/- 0.01 mmol/L.min; P = 0.001), and the rate of glucose recovery was slower in males than in females (0.04 +/- 0.01 vs. 0.06 +/- 0.01 mmol/L.min; P = 0.05). Plasma glucose concentrations were lower in males than in females (glucose nadir, 2.3 +/- 0.2 vs. 3.3 +/- 0.2 mmol/L; P = 0.002; glucose peak, 3.7 +/- 0.2 vs. 5.3 +/- 0.4 mmol/L; P = 0.002), with similar plasma free insulin concentrations. Despite a greater degree of hypoglycemia, GH responses were lower in males than in females. The remaining counterregulatory hormone responses were similar in both sexes. We conclude that there is a distinct sexual dimorphism in insulin sensitivity in adolescents with IDDM. This is likely to be due to sex-related differences in GH levels. Furthermore, male patients with IDDM are apt to develop greater degrees of hypoglycemia accompanied by lower GH responses.

Health, life, and automobile insurance characteristics in adults with IDDM

OBJECTIVE

To determine whether people with insulin-dependent diabetes mellitus (IDDM) were compromised in their access to insurance.

RESEARCH DESIGN AND METHODS

A case-control study of 158 people with IDDM and 158 nondiabetic siblings matched for age and sex was conducted to evaluate the health, life, and automobile insurance characteristics and history of people with IDDM.

RESULTS

Health insurance coverage (yes/no) among the IDDM and sibling control subjects was similar. More than 90% of the IDDM and control respondents had insurance through a private third-party source, and this insurance did not differ by type of plan, coverage, or premium. However, Medicare coverage was more common among the IDDM subjects and was associated with the presence of severe diabetic complications. IDDM subjects were also more likely to have been denied a health insurance policy by an insurer than were the control subjects (23 vs. 1%, P less than 0.001). Similarly, there was no difference between the IDDM and sibling control subjects in the number who had a life or automobile insurance policy. However, life and automobile insurance refusal was much more frequent among the IDDM respondents, more so for life (55 vs. 0%, P less than 0.001) than for automobile (12 vs. 4%, P less than 0.05) insurance.

CONCLUSIONS

These results suggest that access to insurance is severely compromised for people with IDDM. Although most of those with IDDM are able to find some form of insurance, it is evident that on average they must go to extra lengths to find it. These data and a changing insurance environment emphasize the need to reexamine, as a society, the importance of insurance for people with chronic disease, particularly IDDM.

The epidemiology of diabetes complications study. IV. Correlates of diabetic background and proliferative retinopathy

The roles of potential risk factors for background and proliferative retinopathy were evaluated in cross-sectional analyses from the Epidemiology of Diabetes Complications Study, Pittsburgh, Pennsylvania. This report presents results from the 657 insulin-dependent diabetic participants seen at the baseline examination (1986-1988). The presence of and severity of retinopathy were judged from stereoscopic photographs of three views of the ocular fundus using the modified Airlie House classification system. Fifty-three percent of the participants had background retinopathy, and 31% had proliferative retinopathy. Logistic regression analyses showed that among participants aged less than 18 years, those with background retinopathy were older and had higher levels of glycosylated hemoglobin compared with those without retinopathy. In the 18-29-year age group, participants with background retinopathy had a longer duration of diabetes, higher low density lipoprotein (LDL) cholesterol levels, and lower high density lipoprotein cholesterol levels and were more likely to have microalbuminuria compared with those without retinopathy. Participants aged 18-29 years with proliferative retinopathy had a longer duration of diabetes, higher diastolic blood pressure, and higher fibrinogen and LDL cholesterol levels than those with background retinopathy. In the age group greater than or equal to 30 years, diabetes duration, diastolic blood pressure, and fibrinogen, LDL cholesterol, and triglyceride levels were increased in participants with proliferative retinopathy versus those with background retinopathy. In a multivariate model of proliferative retinopathy, controlling for concurrent renal disease weakened the influence of blood pressure, fibrinogen, triglycerides, and LDL cholesterol and improved the overall fit of the model. These results suggest that diabetic nephropathy may contribute to the development of proliferative (but not background) retinopathy by increasing blood pressure and fibrinogen, by altering the lipoprotein profile, and possibly through other mechanisms.

Plasma catecholamine responses to hypoglycemia in children and adolescents with IDDM

OBJECTIVE

The goal of this study was to assess whether children and adolescents with insulin-dependent diabetes mellitus (IDDM) have decreased catecholamine responses to insulin-induced hypoglycemia as has been reported in adults and to explore the pathogenesis of the decreased response in terms of possible relationships to autonomic neuropathy or hyperinsulinism.

RESEARCH DESIGN AND METHODS

A before-and-after trial on the effects of 3 days of intensive insulin therapy was conducted on 60 subjects with IDDM (age 15.4 +/- 2.6 yr, duration of diabetes 7.8 +/- 3.5 yr). The control group consisted of 5 children with non-growth hormone-deficient short stature (age 14.8 +/- 3.2 yr). Hypoglycemia was induced with an intravenous insulin bolus (0.15-0.75 U/kg) after insulin withdrawal and 3 days of intensive insulin therapy in diabetic subjects on an inpatient basis to assess the role of hyperinsulinism in suppressing the catecholamine response to hypoglycemia. Control subjects were studied once and received an insulin bolus of 0.1 microU/kg. Autonomic neuropathy was assessed by computerized assessment of the basal R-R variation during inspiration and expiration and the pancreatic polypeptide response to hypoglycemia.

RESULTS

Basal plasma catecholamine levels were lower in diabetic subjects after intensive insulin therapy than in control subjects (P = 0.008). The peak and incremental catecholamine responses after insulin withdrawal and intensive insulin therapy in IDDM subjects were significantly decreased compared with control subjects (P less than 0.001). Peak catecholamine responses to hypoglycemia in IDDM were decreased after intensive insulin therapy (P = 0.002). This was particularly true in those with plasma glucose nadir levels of less than 2.2 mmol (P less than 0.001). The diminished catecholamine responses were primarily due to decreased peak epinephrine responses after intensive insulin therapy compared with insulin withdrawal (P = 0.011). There were no significant correlations between the catecholamine response to hypoglycemia and age, duration of diabetes, pancreatic polypeptide, or R-R interval.

CONCLUSIONS

These results suggest that children and adolescents with IDDM after insulin withdrawal have diminished catecholamine response to hypoglycemia compared with control subjects and indicate that short-term intensive insulin therapy diminishes this response further. Thus, hyperinsulinism may play a role in suppressing the catecholamine response to hypoglycemia. There is no evidence for a clinical or subclinical role of autonomic neuropathy to explain the altered catecholamine responses.

Measuring subclinical neuropathy: does it relate to clinical neuropathy? Pittsburgh epidemiology of diabetes complications study-V

We report results from 120 (25- to 34-year-old) participants in a neuropathy substudy of subjects with insulin-dependent diabetes mellitus (IDDM) taking part in a cohort follow-up study. Diabetic neuropathy was evaluated by quantitative sensory testing, nerve conduction studies, and clinical examination. Mean quantitative sensory thresholds differed significantly by clinical category of abnormal sensation and ankle reflex activity. Mean sural and peroneal amplitudes and conduction velocities were also significantly lower for subjects classified as having abnormal ankle reflex activity. Modeling potential correlates in logistic analyses showed glycemic control, triglyceride levels, and hypertension status to be independently associated with clinically overt neuropathy. Similar lipid and hemodynamic parameters were associated with abnormality by any single assessment method used to define neuropathy. Although follow-up is needed to resolve the best assessment methods for determining neuropathy, these results suggest that good glycemic control as well as control of blood pressure and lipids is advisible.

The investigation of age at onset as a risk factor for mortality in persons with insulin-dependent diabetes mellitus using Cox proportional hazards models

Proportional hazards models measuring the effect of age at onset of insulin-dependent diabetes mellitus on mortality risk are presented. The study population consisted of 924 insulin-dependent diabetic patients who were seen within 1 year of diagnosis at Children's Hospital of Pittsburgh between 1950 and 1981 and were more than 20 years old at follow-up. Age at diabetes onset was categorized as prepubertal or pubertal, defined by age. Individuals with pubertal onset of diabetes had a significantly higher risk of mortality compared with those with prepubertal onset by diabetes duration but not by attained age. It is proposed that age at onset is an independent determinant of mortality in diabetic individuals and may represent either heterogeneity within insulin-dependent diabetes mellitus with respect to long-term prognosis or an interactive effect of diabetes duration and puberty on prognosis.

Prevalence of complications in IDDM by sex and duration. Pittsburgh Epidemiology of Diabetes Complications Study II

The prevalence of and interrelationships among all four major complications of insulin-dependent diabetes mellitus (IDDM) and their risk factors are being examined in a large epidemiologic study of IDDM subjects diagnosed in childhood. This article focuses on the baseline prevalence of complications in the 657 subjects diagnosed between 1950 and 1980 and currently aged 8-48 yr, with a mean duration of 20 yr. In addition to background retinopathy being virtually universal after 20 yr of diabetes, proliferative retinopathy affects 70% of IDDM subjects after 30 yr duration. As with overt nephropathy, prevalence of proliferative retinopathy is marginally higher in females than in males at short durations; the previously reported male excess is limited to the subjects with IDDM of longer duration (greater than or equal to 25 yr). Somewhat different patterns of microalbuminuria are also seen by sex. Males show a threefold increase in prevalence from 10 to 25 yr duration, whereas females show a more constant prevalence across these durations. A further rise in microalbuminuria is seen in males but not females at greater than or equal to 30 yr duration, giving a combined prevalence of microalbuminuria and overt nephropathy at greater than or equal to 30 yr duration of 84% (males) and 59% (females). Distal symmetrical polyneuropathy shows a constant rise with duration and is only marginally higher in men. Prevalence of cardiovascular (coronary and cerebral) disease shows no sex difference, whereas peripheral vascular disease is particularly common in women after 30 yr duration (greater than 30%) compared with men (11%) when determined by ankle/arm blood pressure ratio less than 0.8 at rest or after exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetic autonomic neuropathy and cardiovascular risk. Pittsburgh Epidemiology of Diabetes Complications Study III

Diabetic autonomic neuropathy (DAN) has been shown to confer a high risk of mortality. The association between DAN and cardiovascular risk factors was examined in a well-defined cohort of 25- to 34-year-old insulin-dependent diabetes mellitus subjects (n = 168) with and without DAN as evaluated by heart rate response to deep breathing, standing, and the Valsalva maneuver. The autonomic tests were performed using both an office-based procedure and a method employed by the Diabetes Control and Complications Trial with analyses performed by the Diabetes Research and Analysis Association, Lexington, Ky. Good agreement was found between the procedures for the assessment modalities of heart rate response to deep breathing. Modeling potential correlates in logistic analyses, where heart rate response to deep breathing was the dependent variable, revealed hypertension status, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and gender (female) to be independent determinants of DAN. These results suggest that traditional cardiovascular risk factors are important correlates of DAN and may relate to both its cause and poor prognosis. Since these results are from a cross-sectional study, prospective follow-up of this cohort will be needed for confirmation.

Factors associated with avoidance of severe complications after 25 yr of IDDM. Pittsburgh Epidemiology of Diabetes Complications Study I

To identify characteristics associated with long-term avoidance of insulin-dependent diabetes mellitus (IDDM) complications, subjects taking part in an epidemiologic natural history study of childhood-onset IDDM, with a duration of disease greater than or equal to 25 yr, were studied. Nineteen percent of 175 subjects had avoided overt nephropathy, definite cardiovascular and peripheral vascular disease, clinical neuropathy, and proliferative retinopathy. Approximately half of the nonrenal complications occurred in the absence of renal disease. Subjects free of these advanced complications were characterized by a longer duration of disease (P less than 0.05), better lipid profile and blood pressure (P less than 0.01), and considerably lower glycosylated hemoglobin levels (P less than 0.001). Health-related behaviors, including recent medical contact, regular glucose monitoring, physical activity in youth, and avoidance of cigarette smoking, did not relate to complication status, although regular (at least weekly) alcohol consumption was more prevalent (P less than 0.05) in those without complications. We conclude that a lower mean glycosylated hemoglobin level is strongly related to the avoidance of all IDDM complications.

Cyclosporin therapy for prevention and cure of IDDM. Epidemiological perspective of benefits and risks

Cyclosporin and other immunosuppressive agents have been proposed as a preventive treatment against the development of insulin-dependent diabetes mellitus (IDDM) in relatives at increased risk for the disease, based on the understanding that its etiology is an ongoing process of autoimmune beta-cell destruction. We used an epidemiological approach to evaluate several recent trials of cyclosporin in newly diagnosed IDDM patients to determine the degree of benefit that is to be expected. We assessed these and other studies to estimate the potential adverse effects of such treatment, were it to be used in the future, either in newly diagnosed subjects or healthy high-risk relatives. Standard sample-size calculations were used to quantify the number of study subjects necessary to allow adequate statistical power to test the positive and negative effects of a future treatment (alpha = 0.05, beta = 0.20). The estimates were based on the data available from published studies of cyclosporin treatment. The importance of conducting an adequate trial of such a therapy, both from an ethical and a practical viewpoint, is discussed. Five small immunosuppression trials were evaluated. Remission rates in treated subjects exceeded those in control subjects by 15-59%. Variability in defining remission may account for the differences in rates across the studies. Estimates of the major beneficial and adverse effects of cyclosporin were derived from these trials and studies of patients who have undergone long-term immunosuppression. Indicators of kidney damage associated with cyclosporin treatment were reported in 5-47% of treated subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin-dependent diabetes mellitus mortality. The risk of cigarette smoking

The relation between cigarette smoking and mortality was examined prospectively in a population of adult insulin-dependent diabetes mellitus (IDDM) patients. In 1981, information on smoking history and other health and lifestyle factors was obtained by questionnaire from 93% of the 723 patients included in the Children's Hospital of Pittsburgh IDDM registry who were diagnosed between 1950 and 1964. Vital status as of January 1, 1988 was ascertained for 98% of the 548 patients who participated in the baseline survey and were alive as of January 1, 1982. Fifty-four cases died during the 6-year follow-up (32 male, 22 female). Proportional hazards analysis revealed that heavy smoking was a significant independent predictor of all-cause mortality among females but not males. The excess mortality in female diabetics was explained primarily by a marked excess risk of coronary heart disease mortality in smokers. These data strongly suggest that cigarette smoking, especially among diabetic females, should be avoided in order to improve longevity.

Evolution of the Pittsburgh studies of the epidemiology of insulin-dependent diabetes mellitus. Pittsburgh Diabetes Epidemiology and Etiology Research Group

The Pittsburgh project evaluating the epidemiology and etiology of insulin-dependent diabetes mellitus (IDDM) is currently one of the large ongoing studies of childhood diabetes. This paper traces the evolution of the project, from the initial basic epidemiologic approach in the early 1980s, to the current thrust where complex molecular genetic approaches are being incorporated into population-based research. The epidemiology models employed in the Pittsburgh project are similar to those that could be used in many areas of chronic disease research. The integration of immunogenetics into epidemiology produces a powerful approach for understanding the complex interaction of host susceptibility and environmental agents that contribute to the development of IDDM.

Demonstration of a dawn phenomenon in normal adolescents

To ascertain whether the dawn phenomenon occurs in normal adolescents and, if so, to determine its mechanism, we measured nocturnal plasma glucose, insulin, glucagon, growth hormone, cortisol, and adrenocorticotropic hormone (ACTH) levels between 01.00 and 08.00 h in 10 healthy adolescents. The prehepatic insulin secretion rate was calculated based on C peptide levels. The metabolic clearance rate of insulin (MCRI) was calculated as the ratio of mean insulin secretion rate to mean insulin concentration. There was no change in plasma glucose, insulin, and glucagon between 01.00-04.00 and 05.00-08.00 h (paired t test). The MCRI was higher at 05.00-08.00 h compared to 01.00-04.00 h (9.30 +/- 1.50 vs. 4.87 +/- 1.11 ml.kg-1.min-1; p = 0.008). The prehepatic insulin secretion increased at 05.00-08.00 h relative to 01.00-04.00 h (1.1 +/- 0.2 vs. 0.6 +/- 0.1 pmol.kg-1.min-1; p = 0.013). Similarly, cortisol and ACTH levels were higher at 05.00-08.00 versus 01.00-04.00 h (323 +/- 33 vs. 102 +/- 22 nmol/l, p less than 0.001; 3.6 +/- 0.5 vs. 1.8 +/- 0.4 pmol/l, p = 0.006, respectively). Growth hormone was higher at 01.00-04.00 versus 05.00-08.00 h (7.6 +/- 1.2 and 3.0 +/- 0.9 microgram/l; p = 0.019). ACTH correlated with MCRI (r = 0.66; p = 0.002) and prehepatic insulin secretion (r = 0.75; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Contribution of diabetes duration before puberty to development of microvascular complications in IDDM subjects

The contribution of diabetes duration, both pre- and postpuberty, to the development of microvascular complications and mortality in diabetic subjects was investigated in three study populations from the Children's Hospital of Pittsburgh Insulin-Dependent Diabetes Mellitus (IDDM) Registry. Life-table analyses by total and postpubertal IDDM duration were used to evaluate differences in the prevalence of microvascular complications and diabetes-related mortality in subjects diagnosed before and during puberty, as defined by an age at IDDM onset marker of 11 yr for girls and 12 yr for boys. The prevalence of retinopathy and overt nephropathy in 552 White adult diabetic subjects (population 1, mean IDDM duration 20.8 yr was significantly greater in subjects diagnosed during puberty compared with those diagnosed before puberty. However, similar analyses by postpubertal duration showed no difference in microvascular complication prevalence between the two groups. These findings did not appear to be due to a confounding effect of age. Additional analyses of 239 adolescent diabetic subjects (population 2, mean duration 8.3 yr) revealed the same trend for the prevalence of retinopathy. Finally, results concerning the risk of diabetes-related mortality in a cohort of 1582 subjects (population 3, mean duration 12.9 yr) indicated that postpubertal duration of IDDM may be a more accurate determinant of the development of microvascular complications and diabetes-related mortality than total duration, and it is suggested that the contribution of the prepubertal years of diabetes to long-term prognosis may be minimal.

Diabetes complications and glycemic control. The Pittsburgh Prospective Insulin-Dependent Diabetes Cohort Study Status Report after 5 yr of IDDM

The relationship between glycemic control and complications of insulin-dependent diabetes mellitus (IDDM) remains controversial. With the use of glycosylated hemoglobin (HbA1) to assess glycemic control from diagnosis onward, the Pittsburgh Prospective Insulin-Dependent Diabetes Mellitus Cohort Study prospectively evaluated 80 new cases of IDDM diagnosed at Children's Hospital of Pittsburgh. This study presents findings in 62 patients at 5 yr postdiagnosis. Only 7 patients, all girls, had any retinopathy (microaneurysms). These subjects had an elevated 5-yr mean HbA1 compared to those with no retinopathy (13.0 vs. 11.7%; P less than .05). Six female subjects who had an elevated albumin excretion rate (AER; greater than or equal to 20 micrograms/min) had a higher 5-yr mean HbA1 (13.3%) than the 26 subjects with AER less than 20 micrograms/min (11.8%; P less than .05). Current HbA1 was correlated with AER (r = +.36, P less than .05) and systolic blood pressure (r = +.49, P less than .01) in females. However, these associations were not observed in males. Positive correlations were found between HbA1 (5-yr mean and current) and serum triglyceride and cholesterol, but only in females was HbA1 inversely related to high-density lipoprotein cholesterol. However, HbA1 was independent of sex, HLA-DR type, and urine C-peptide status. Age adjustment did not change the above results. These analyses suggest that glycemic control is related to AER, systolic blood pressure, presence of microaneurysms, and serum triglyceride and cholesterol concentrations during the first 5 yr of IDDM. However, these associations appear to be predominant in girls.

Acute airway obstruction in achalasia. Possible role of defective belch reflex

Achalasia presenting as an acute airway obstruction is a rarely reported phenomenon. The pathophysiology of this dramatic complication of achalasia remains an enigma. Our patient with achalasia presented with an acute airway compromise necessitating emergent endotracheal intubation. We review the available literature on this interesting yet rare complication of achalasia. We also add some information to help elucidate the possible pathophysiologic mechanism of this emergency, proposing that specific upper esophageal sphincter manometry may indicate abnormality of the "belch reflex."