The risk for diabetic nephropathy is low in young adults in a 17-year follow-up from the Diabetes Incidence Study in Sweden (DISS). Older age and higher BMI at diabetes onset can be important risk factors.

AIMS: The main objective of this study was to estimate the occurrence of diabetic nephropathy in a population-based cohort of patients diagnosed with diabetes as young adults (15-34 years). METHODS: All 794 patients registered 1987-1988 in the Diabetes Incidence Study in Sweden (DISS) were invited to a follow-up study 15-19 years after diagnosis, and 468 (58%) participated. Analysis of islet antibodies was used to classify type of diabetes. RESULTS: After median 17 years of diabetes, 15% of all patients, 14% T1DM and 25% T2DM, were diagnosed with diabetic nephropathy. Ninety-one percent had microalbuminuria and 8.6% macroalbuminuria. Older age at diagnosis (HR 1.05; 95% CI 1.01-1.10 per year) was an independent and a higher BMI at diabetes diagnosis (HR 1.04; 95% CI 1.00-1.09 per 1 kg/m²), a near-significant predictor of development of diabetic nephropathy. Age at onset of diabetes (p = 0.041), BMI (p = 0.012) and HbA1c (p < 0.001) were significant predictors of developing diabetic nephropathy between 9 and 17 years of diabetes. At 17 years of diabetes duration, a high HbA1c level (OR 1.06; 95% CI 1.03-1.08 per 1 mmol/mol increase) and systolic blood pressure (OR 1.08; 95% CI 1.05 1.12 per 1 mmHg increase) were associated with DN. CONCLUSIONS: Patients with T2DM diagnosed as young adults seem to have an increased risk to develop diabetic nephropathy compared with those with T1DM. Older age and higher BMI at diagnosis of diabetes were risk markers for development of diabetic nephropathy. In addition, poor glycaemic control but not systolic blood pressure at 9 years of follow-up was a risk marker for later development of diabetic nephropathy.

Assessment of beta-cell function in young patients with type 2 diabetes: arginine-stimulated insulin secretion may reflect beta-cell reserve.

OBJECTIVE: Simple methods for the evaluation of dynamic b-cell function in epidemiological and clinical studies of patients with type 2 diabetes (T2D) are needed. The aim of this study was to evaluate the dynamic beta-cell function in young patients with T2D with different disease durations and treatments. METHODS: Overall, 54 subjects with T2D from the Diabetes Incidence Study in Sweden (DISS) and 23 healthy control participants were included in this cross-sectional study. Beta-cell function was assessed by intravenous (i.v.) administration of arginine followed by i.v. glucose. The acute insulin and C-peptide responses to arginine (AIRarg and Ac-pepRarg, respectively) and to glucose (AIRglu and Ac-pepRglu, respectively)were estimated.Homeostasis model assessment of b-cell function(HOMA-b) andCpeptide assessments were also used for comparisons between patients with T2D and control participants. RESULTS: AIRarg and Ac-pepRarg, but not AIRglu and Ac-pepRglu, could differentiate between patients with different disease durations. AIRglu values were 89% (P < 0.001) lower and AIRarg values were 29% (P < 0.01) lower in patients with T2D compared with control participants. HOMA-b and fasting plasma C-peptide levels did not differ between the T2D and control groups. CONCLUSION: In young patients with T2D, the insulin secretory response to i.v. glucose is markedly attenuated, whereas i.v. arginine-stimulated insulin release is better preserved and can distinguish between patients with different disease duration and antidiabetic therapies. This suggests that the i.v. arginine stimulation test may provide an estimate of functional beta-cell reserve.

The gene responsible for familial hypocalciuric hypercalcemia maps to chromosome 3q in four unrelated families.

Familial hypocalciuric hypercalcemia (FHH) is an autosomal dominant syndrome of unknown aetiology characterized by lifelong elevation in serum calcium concentration and low urinary calcium excretion. These features suggest that the causal gene is important for maintenance of extracellular calcium homeostasis by the parathyroid gland and kidney. To identify the chromosomal location of FHH gene(s), we clinically evaluated 114 individuals in four unrelated affected families and performed linkage analyses. The disease gene mapped to the long arm of chromosome 3 in each family (combined maximum multipoint lod score = 20.67). We suggest that this is the predominant FHH locus and anticipate that identification of the FHH gene will improve our understanding of the molecular basis for physiologic and pathologic regulation of calcium.

Long-term detrimental consequences of the onset of type 1 diabetes on annual earnings--evidence from annual registry data in 1990-2005.

AIMS/HYPOTHESIS: Young adults in the early stages of their participation in the labour market may be particularly vulnerable to the effects of onset of a chronic disease. Our aim was to quantify the consequences of the onset of type 1 diabetes in young adults on annual earnings, using individual-level longitudinal data before and after the onset of diabetes. METHODS: The Econ-DISS database contains annual socioeconomic information for 1990-2005 from Statistics Sweden. Econ-DISS includes data for persons with diabetes onset at the age of 15-34 years between 1983 and 2005, registered in the national Diabetes Incidence Study in Sweden (DISS) database, and for controls. Considering the onset of type 1 diabetes as an unanticipated and significant life event, we compared the progression of annual earnings for 3,650 cases born between 1949 and 1970 before and after onset of diabetes with that of 14,629 controls. Possible confounders--education, participation in the labour market, sick leave and parental education--were analysed. RESULTS: We found no differences between the groups in annual earnings or participation in the labour market before onset of diabetes. After onset, persons with type 1 diabetes gradually lagged behind the controls. Their median annual earnings were lower in each year from 1995 to 2005 (p < 0.01). The difference in 2005 was euro (EUR) 1,411 (5.3%). Controlling for confounders, duration of type 1 diabetes > or = 10 years was associated with 4.2% (men) and 8.1% (women) lower average annual earnings for persons with upper secondary education only who were active in the labour market. CONCLUSION/INTERPRETATION: The onset of type 1 diabetes in young adults has long-term detrimental consequences on earnings that cannot be attributed to confounders.

Variable sensitivity to the glucocorticoid activity of cortisol in patients with primary adrenal insufficiency: assessment with ACTH profiles.

Our aim was to investigate the usefulness of circulating levels of adrenocorticotropic hormone (ACTH) and also salivary cortisol to monitor cortisone substitution in patients with Addison's disease. 13 patients with primary adrenal insufficiency (8 women and 5 men, age 44 ± 11 years) received 12.5 mg cortisone acetate orally at 16:00 h and 25 mg at 07:00 h. Blood samples for cortisol and ACTH analysis were drawn every hour for 24 h, and also every half hour between 07:00 and 12:00 h. Samples for salivary cortisol were collected in parallel. Total ACTH levels showed large inter-individual variations and a diurnal rhythm with a nadir in the early evening at 19:00 (median 19 ng/l, range 2-434 ng/l) and high levels in the early morning, with a peak around 07:30 (median 844 ng/l, range 45-2,249 ng/l). Plasma cortisol concentrations showed 2 peaks distinct in time, but variable in height, 1-2 h after intake of cortisone. Plasma cortisol correlated significantly with ln(ACTH) at 17:00 h (r=-0.56), at 10:00 h (r=-0.51), and at 10.30 h (r=-0.57). When tested at different time points, ln(ACTH) at 10:00 to 12:00 h was negatively correlated with plasma cortisol between 08:30 and 12:00 h. Plasma cortisol was highly correlated to ln(salivary cortisol) most of the time points measured, but 30-60 min after intake of cortisone acetate the correlation disappeared. In conclusion, the large interindividual variation in ACTH levels most likely indicates varying sensitivity to cortisol with a need for individualized dosing schemes. Furthermore ACTH-determinations may be useful for dose titration of cortisol.

Intraoperative muscle and fat metabolism in diabetic patients during coronary artery bypass grafting surgery: a parallel microdialysis and organ balance study.

BACKGROUND: Surgical trauma causes stress and inflammatory reactions with elevated serum free fatty acids (FFA) and glucose levels characteristic of intraoperative insulin resistance. Our aim was to compare microdialysis findings with those using the classical organ balance technique and to test the clinical feasibility of microdialysis during cardiac surgery. METHODS: Nine diabetic and nine non-diabetic patients, undergoing routine coronary artery bypass grafting surgery, were studied using both microdialysis and the organ balance technique in the brachio-radial muscle of the forearm, and microdialysis in the pre-pectoral fat tissue. Glucose, lactate, and glycerol were measured in arterial and venous plasma and in the microdialysate before administration of heparin, at the release of the aortic cross-clamp, and before transfer to the intensive care unit. RESULTS: Glucose release from the diabetic muscle at the last sampling time was detected. This was confirmed by a negative glucose A-I (arterial-interstitial difference) in the muscle. No differences were observed regarding lipolysis in the fat tissue in terms of A-I of glycerol. Intergroup differences were detected at the first sampling time, where arterial plasma glucose and plasma insulin levels were higher and muscle interstitial glucose lower in the diabetic patients. Plasma insulin was higher in the diabetic patients even at the final measurement time. CONCLUSIONS: In terms of lipolysis in the fat tissue and glucose transport in the muscle, the non-diabetic patients were metabolically 'diabetics' during surgery. Despite strict blood glucose control, disturbances in glucose homeostasis in the diabetic muscle persist. Microdialysis was easy to use during cardiac surgery.

Common variants in the TCF7L2 gene help to differentiate autoimmune from non-autoimmune diabetes in young (15-34 years) but not in middle-aged (40-59 years) diabetic patients.

AIMS/HYPOTHESIS: Type 1 diabetes in children is characterised by autoimmune destruction of pancreatic beta cells and the presence of certain risk genotypes. In adults the same situation is often referred to as latent autoimmune diabetes in adults (LADA). We tested whether genetic markers associated with type 1 or type 2 diabetes could help to discriminate between autoimmune and non-autoimmune diabetes in young (15-34 years) and middle-aged (40-59 years) diabetic patients. METHODS: In 1,642 young and 1,619 middle-aged patients we determined: (1) HLA-DQB1 genotypes; (2) PTPN22 and INS variable-number tandem repeat (VNTR) polymorphisms; (3) two single nucleotide polymorphisms (rs7903146 and rs10885406) in the TCF7L2 gene; (4) glutamic acid decarboxylase (GAD) and IA-2-protein tyrosine phosphatase-like protein (IA-2) antibodies; and (5) fasting plasma C-peptide. RESULTS: Frequency of risk genotypes HLA-DQB1 (60% vs 25%, p = 9.4 x 10(-34); 45% vs 18%, p = 1.4 x 10(-16)), PTPN22 CT/TT (34% vs 26%, p = 0.0023; 31% vs 23%, p = 0.034), INS VNTR class I/I (69% vs 53%, p = 1.3 x 10(-8); 69% vs 51%, p = 8.5 x 10(-5)) and INS VNTR class IIIA/IIIA (75% vs 63%, p = 4.3 x 10(-6); 73% vs 60%, p = 0.008) was increased in young and middle-aged GAD antibodies (GADA)-positive compared with GADA-negative patients. The type 2 diabetes-associated genotypes of TCF7L2 CT/TT of rs7903146 were significantly more common in young GADA-negative than in GADA-positive patients (53% vs 43%; p = 0.0004). No such difference was seen in middle-aged patients, in whom the frequency of the CT/TT genotypes of TCF7L2 was similarly increased in GADA-negative and GADA-positive groups (55% vs 56%). CONCLUSIONS/INTERPRETATION: Common variants in the TCF7L2 gene help to differentiate young but not middle-aged GADA-positive and GADA-negative diabetic patients, suggesting that young GADA-negative patients have type 2 diabetes and that middle-aged GADA-positive patients are different from their young GADA-positive counterparts and share genetic features with type 2 diabetes.

Gender differences and temporal variation in the incidence of type 1 diabetes: results of 8012 cases in the nationwide Diabetes Incidence Study in Sweden 1983-2002.

OBJECTIVES: To establish the gender difference amongst newly diagnosed type 1 diabetic patients aged 15-34 years, considering age at diagnosis, temporal trend and seasonal variation at time of diagnosis. STUDY DESIGN: A population-based prospective study with a mean annual population at risk of 2.3 million. SETTING: All departments of medicine, endocrinology and paediatrics and primary health care units in Sweden. SUBJECTS: Incident cases of diabetes aged 15-34 years at diagnosis 1983-2002. MEASURE INSTRUMENT: Basic characteristics of patients at diagnosis were reported by the diagnosing doctor on a standardized form. Level of ascertainment was estimated at 80-90%. RESULTS: Amongst all incident cases (n = 8012), 74% was diagnosed with type 1 diabetes. The mean annual incidence rate of type 1 diabetes was 12.7/100,000, in men 16.4/100,000 and in women 8.9/100,000. The incidence of type 1 diabetes decreased slowly by increasing age but was in all age groups higher in men, yielding an overall male/female ratio of 1.8. In both genders the incidence of type 1 diabetes decreased in average of 1.0% per year. A seasonal pattern with significantly higher incidence during January-March and lower during May-July was seen in both genders. CONCLUSIONS: A clear male predominance of type 1 diabetes was seen in all ages. The temporal trend and the seasonal pattern was similar in men and women. Hence, internal factors related to the gender rather than differences in the exposure to environmental factors seem to explain the consistent male-female bias in the postpubertal risk of developing type 1 diabetes.

Human microvascular endothelial cells are sensitive to IGF-I but resistant to insulin at the receptor level.

Human microvascular endothelial cells (HMVEC) are sensitive to IGF-I but insulin resistant and express several times more IGF-I receptors (IGF-IR) than insulin receptors (IR). Our aim was to investigate the mechanism of this insulin resistance in cultured HMVEC by studying receptor activation and signal propagation downstream. The IGF-IR beta-subunit and the IR beta-subunit were detected and found to co-precipitate. IRA was the major IR isoform expressed in HMVEC. IGF-I 10(-9) to 10(-8)M phosphorylated its cognate receptor beta-subunit. IGF-I also phosphorylated the IR beta-subunit at 10(-9)M. Phosphorylation of insulin receptor substrate 1 was obtained by IGF-I 10(-9) to 10(-8)M. Akt was phosphorylated by IGF-I at 10(-8) to 10(-7)M and by insulin 10(-7)M. IGF-I at 10(-8) to 10(-6)M significantly increased DNA-synthesis. We conclude that microvascular endothelial cells are sensitive to IGF-I but resistant to insulin due to a preponderance of IGF-I receptors and sequestration of insulin receptors into insulin/IGF-I hybrid receptors.

Overweight, hyperglycemia and tobacco use are modifiable risk factors for onset of retinopathy 9 and 17years after the diagnosis of diabetes - A retrospective observational nation-wide cohort study.

BACKGROUND: The aims of this study were to estimate the risk for diabetic retinopathy (DR) and to identify risk factors. We investigated a nationwide population-based cohort with diabetes diagnosed at age 15-34years. PATIENTS AND METHODS: Of 794 patients registered 1987-1988 in the Diabetes Incidence Study in Sweden (DISS) 444 (56%) patients with retinal photos available for classification of retinopathy participated in a follow-up study 15-19 (median 17) years after diagnosis. Mean age was 42.3±5.7years, BMI 26.1±4.1kg/m2, 62% were male and 91% had type 1 diabetes. A sub-study was performed in 367 patients with retinal photos from both the 9 and 17year follow up and the risk for development of retinopathy between 9 and 17years of follow up was calculated. RESULTS: After median 17years 324/444 (73%, 67% of T1D and 71% of T2D), had developed any DR but only 5.4% proliferative DR. Male sex increased the risk of developing retinopathy (OR 1.9, 95% CI 1.2-2.9). In the sub-study obesity (OR 1.2, 95% CI 1.04-1.4), hyperglycemia (OR 2.5, 95% CI 1.6-3.8) and tobacco use (OR 2.9, 95% CI 1.1-7.3) predicted onset of retinopathy between 9 and 17years after diagnosis of diabetes. CONCLUSION: The number of patients with severe retinopathy after 17years of diabetes disease was small. The risk of developing retinopathy with onset between 9 and 17years after diagnosis of diabetes was strongly associated to modifiable risk factors such as glycemic control, obesity and tobacco use.

Long-term improvement of glycemic control by insulin treatment in NIDDM patients with secondary failure.

OBJECTIVE: To evaluate the long-term efficacy of insulin treatment of patients with non-insulin-dependent diabetes mellitus (NIDDM) and secondary failure to oral hypoglycemic agents. RESEARCH DESIGN AND METHODS: Twenty-one NIDDM patients with secondary failure were studied while they were still on oral agents. Then they were switched to insulin treatment, and after a median of 27 months, a long-term evaluation was conducted. RESULTS: At the long-term evaluation, metabolic control was still markedly improved by insulin treatment, with reduction of HbA1c from 8.8 +/- 0.2 (mean +/- SE) to 6.9 +/- 0.3% (P < 0.0001), lowering of very-low-density lipoprotein (VLDL) cholesterol concentration from 0.97 +/- 0.3 to 0.69 +/- 0.1 mM (P < 0.03), and lowering of total triglycerides from 2.8 +/- 0.6 to 1.8 +/- 0.3 mM (P < 0.005), mainly due to reduction of VLDL triglycerides. Body weight increased during the first year, but not thereafter (71.3 +/- 2.5 kg during oral treatment, 78.9 +/- 2.9 and 79.8 +/- 3.2 kg after 12 and 36 months of insulin treatment, respectively). Blood pressure did not change. Fasting and postprandial insulin concentrations increased, and C-peptide concentrations were lowered. CONCLUSIONS: Improvements of glycemic control and lipoprotein concentrations in patients with NIDDM and secondary failure persist also after insulin treatment for 2-3 years in spite of weight gain and hyperinsulinemia.

Glycemic control and prognosis in type I diabetic patients with microalbuminuria.

OBJECTIVE: To investigate the course of microalbuminuria during the 1980s in type I diabetes patients. RESEARCH DESIGN AND METHODS: This was a 10-year follow-up of 109 patients in whom type I diabetes was diagnosed between 1961 and 1980 before 15 years of age and who were initially investigated between 1977 and 1983 after a diabetes duration of > or = 3 years. Microalbuminuria was defined as an albumin excretion rate (AER) of 20-200 micrograms/min in two of three consecutive urine samples. RESULTS: At the initial investigation, 81 patients had normal AER, 27 had microalbuminuria, and 1 had macroalbuminuria. Between 1989 and 1992, 99 (91%) patients were reinvestigated. Only 5 (19%) of the initially microalbuminuric patients developed macroproteinuria during the 10-year follow-up period, and in 15 (58%) patients, AER decreased to normal. Three (4%) of the normoalbuminuric patients developed microalbuminuria but none macroproteinuria. The initially microalbuminuric patients, in whom AER normalized, improved their glycemic control from 1980-1983 to 1989-1991 (mean +/- SE HbA1c 7.5 +/- 0.2 to 6.6 +/- 0.3%; P = 0.01). CONCLUSIONS: In the majority of patients with microalbuminuria in whom it is possible to obtain good glycemic control, microalbuminuria will disappear and the risk of developing nephropathy will be markedly reduced.

Effect of conventional and intensified insulin therapy on free-insulin profiles and glycemic control in NIDDM.

OBJECTIVE: To investigate the effects on 24-h insulin and glucose profiles of two- and four-dose insulin regimens in patients with non-insulin-dependent diabetes mellitus (NIDDM) who have failed oral agent therapy. RESEARCH DESIGN AND METHODS: Ten patients with NIDDM and 10 matched nondiabetic control subjects took part in the study, a randomized crossover trial with 8-wk treatment periods. We determined 24-h profiles of blood glucose and free insulin in control subjects and patients when they were taking oral agents and at the end of each treatment period. The two-dose regimen was mixed (15% regular, 85% NPH) insulin given before breakfast and dinner, and the four-dose regimen was regular insulin given before meals and NPH given at 2200. RESULTS: Patients taking oral agents had higher mean blood glucose than control subjects (mean +/- SE 12.6 +/- 0.6 vs. 4.5 +/- 0.1 mM, P less than 0.0001) and similar 24-h insulin concentrations but lower postprandial insulin concentrations (at breakfast, 87.6 +/- 13.8 vs. 228.6 +/- 29.4 pM, P less than 0.01). Mean 24-h insulin concentrations were the same on two- and four-dose regimens, and both regimens caused basal hyperinsulinemia. Glycemic control also improved. Postprandial insulin peaks were higher at lunch and dinner on the four-dose regimen, and postprandial blood glucose was lower. Fasting proinsulin was elevated in patients compared with the control subjects (25.1 +/- 4.7 pM vs. 5.0 +/- 0.9 pM, P less than 0.001) and was suppressed to normal during insulin treatment. CONCLUSIONS: Two- and four-dose insulin regimens can achieve similar glycemic control. Both regimens cause basal hyperinsulinemia but normalize the hyperproinsulinemia observed during failure of oral agent therapy. Four-dose insulin regimens offer few advantages to the glycemic control achieved with two-dose regimens but may be more physiological.

Comparisons of studies on diabetic complications hampered by differences in GHb measurements.

OBJECTIVE: To compare glycated hemoglobin (GHb) values of the relationship between glycemic control and complications of diabetes from laboratories involved in long-term studies (Steno, Oslo, Stockholm, Diabetes Control and Complications Trial, and Linköping.) RESEARCH DESIGN AND METHODS: Blood samples were collected from 25 subjects selected to represent the clinically relevant measurement range. Fresh whole-blood samples were distributed and analyzed within 4 days of sample collection. Pretreatment of samples and analyses of GHb were performed according to the routine method of each study's central or reference laboratory. Results from each laboratory were compared with the group mean, i.e., the mean of all results for each sample. RESULTS: Regression analyses with the group mean values as independent variables and results from each laboratory as dependent variables showed that Oslo's result had a slope significantly different from the group mean. Laboratories used by the DCCT, Oslo, and Steno studies gave, on average, 0.4, 0.4, and 0.7% higher HbA1c readings than the group mean, respectively, while HbA1c results from Linköping and Stockholm were, on average, 0.6 and 1.0% lower, respectively. CONCLUSIONS: There were large differences in GHb values among laboratories participating in studies of diabetic complications. The present data offer a guide to the comparison of results from the studies and underscores the need for standardization of GHb measurements.

Family characteristics and life events before the onset of autoimmune type 1 diabetes in young adults: a nationwide study.

OBJECTIVE: To elucidate whether family characteristics and stressful life events were associated with onset of autoimmune type 1 diabetes in young adults. RESEARCH DESIGN AND METHODS: This investigation was based on a nationwide study (Diabetes Incidence Study in Sweden) of newly diagnosed patients aged 15-34 years. Patients clinically classified as type 1 diabetic with antibodies to islet cells and/or to GAD65 were compared with age- and sex-matched control subjects via questionnaire. The questionnaire covered diabetes heredity, social environment, educational level, and life events experienced during the 12 months before diagnosis. RESULTS: The rate of response was 82% for the diabetic patients and 65% for the control subjects. Questionnaires from 349 diabetic patients and 979 control subjects were considered. Diabetes in relatives was more frequent in the patients (odds ratio [OR]2.6) who were born in Sweden and whose mothers were of Swedish origin. No major stress factors were detected in the diabetic patients; however, in comparison with the control subjects, the diabetic patients had experienced fewer conflicts with their parents and had less often broken contacts with friends. CONCLUSIONS: Young adults with recent-onset type 1 diabetes were more exposed to heredity for diabetes, but no major prediabetic stress factors were detected. Our study does not directly support the concept that psychosocial stressful life events are involved in the development of autoimmune type 1 diabetes in young adults.

Islet cell and glutamic acid decarboxylase antibodies present at diagnosis of diabetes predict the need for insulin treatment. A cohort study in young adults whose disease was initially labeled as type 2 or unclassifiable diabetes.

OBJECTIVE: To clarify the predictive value of islet cell antibody (ICA) and GAD65 antibody (GADA) present at diagnosis with respect to the need for insulin treatment 6 years after diagnosis in young adults initially considered to have type 2 or unclassifiable diabetes. RESEARCH DESIGN AND METHODS: The patient material was representative of the entire Swedish population, consisting of patients who were 15-34 years old at diagnosis of diabetes in 1987-1988 but were not considered to have type 1 diabetes at onset. At follow-up, 6 years after the diagnosis, it was noted whether the patient was treated with insulin. The presence of ICA was determined by an immunofluorescence assay, and GADAs were measured by a radioligand assay. RESULTS: Six years after diagnosis, 70 of 97 patients were treated with insulin, and 27 of 97 patients were treated with oral drugs or diet alone. At diagnosis, ICAs and GADAs were present in 41 (59%) of 70 patients and 41 (60%) of 68 patients, respectively, of those now treated with insulin, compared with only 1 (4%) of 26 patients and 2 (7%) of 27 patients who were still not treated with insulin. For either ICA or GADA, the corresponding frequencies were 50 (74%) of 68 for patients who were later treated with insulin and 3 (12%) of 26 for those who were still not treated with insulin, respectively. The sensitivity for later insulin treatment was highest (74%) for the presence of ICA or GADA, and the specificity was highest (100%) for ICA and GADA. The positive predictive value was 100% for the combination of ICA and GADA, 98% for ICA alone, and approximately 95% for GADA alone. CONCLUSIONS: Determination of the presence of ICA and GADA at diagnosis of diabetes improves the classification of diabetes and predicts the future need of insulin in young adults.

Vascular endothelial growth factor and transforming growth factor-beta1 regulate the expression of insulin-like growth factor-binding protein-3, -4, and -5 in large vessel endothelial cells.

We investigated the effect of diabetes-associated growth factors on the expression of insulin-like growth factor-I (IGF-I) and IGF-binding proteins (IGFBPs) in cultured endothelial cells from bovine aorta. Gene expression was measured by solution hybridization, and proteins were measured by enzyme-linked immunosorbent assay, RIA, or Western blot. The cells expressed messenger RNA (mRNA) for IGFBP-2 through -6 and IGFBP-2 through -5 proteins were detected in conditioned medium. Vascular endothelial growth factor inhibited IGFBP-3 mRNA (P < 0.01) and protein expression and increased IGFBP-5 mRNA (P < 0.001) and protein. Transforming growth factor-beta1 inhibited IGFBP-3 (P < 0.01), IGFBP-4 (P < 0.01), and IGF-I mRNA expression, whereas at the protein level only IGFBP-3 was significantly decreased. IGF-I, insulin, or angiotensin II did not affect IGF-I or IGFBP mRNA expression. At the protein level, IGF-I clearly increased IGFBP-5 levels in conditioned medium. In conclusion, vascular endothelial growth factor and transforming growth factor-beta1 regulate IGFBP expression in bovine aortic endothelial cells. These observations provide a new aspect of regulation for the IGF-system in macrovascular endothelium, with possible implications for subendothelial smooth muscle cells and development of diabetic angiopathy.

Prognostic factors for the course of beta cell function in autoimmune diabetes.

This study presents a 2-yr follow-up of 281 patients, aged 15-34 yr, diagnosed with diabetes between 1992 and 1993. At diagnosis, 224 (80%) patients were positive for at least one of the following autoantibodies: islet cell antibodies (ICAs), glutamic acid decarboxylase antibodies (GADAs), or tyrosine phosphatase antibodies (IA-2As); the remaining 57 (20%) patients were negative for all three autoantibodies. At diagnosis, C-peptide levels were lower (0. 27; 0.16-0.40 nmol/L) in autoantibody-positive patients compared with autoantibody-negative patients (0.51; 0.28-0.78 nmol/L; P: < 0. 001). After 2 yr, C-peptide levels had decreased significantly in patients with autoimmune diabetes (0.20; 0.10-0.37 nmol/L; P: = 0. 0018), but not in autoantibody-negative patients. In patients with autoimmune diabetes, a low initial level of C-peptide (odds ratio, 2. 6; 95% confidence interval, 1.7-4.0) and a high level of GADAs (odds ratio, 2.5; 95% confidence interval, 1.1-5.7) were risk factors for a C-peptide level below the reference level of 0.25 nmol/L 2 yr after diagnosis. Body mass index had a significant effect in the multivariate analysis only when initial C-peptide was not considered. Factors such as age, gender, levels of ICA or IA-2A or insulin autoantibodies (analyzed in a subset of 180 patients) had no effect on the decrease in beta-cell function. It is concluded that the absence of pancreatic islet autoantibodies at diagnosis were highly predictive for a maintained beta-cell function during the 2 yr after diagnosis, whereas high levels of GADA indicated a course of decreased beta-cell function with low levels of C-peptide. In autoimmune diabetes, an initial low level of C-peptide was a strong risk factor for a decrease in beta-cell function and conversely high C-peptide levels were protective. Other factors such as age, gender, body mass index, levels of ICA, IA-2A or IAA had no prognostic importance.

Influence of oxygen tension of the metabolism of vascular smooth muscle: demonstration of a Pasteur effect.

The influence of variations of oxygen tension on the metabolism of bovine mesenteric arteries was studied in vitro. Glucose uptake, lactate production, glycogen content, adenosine triphosphate (ATP), creatine phosphate (CrP) and incorporation of [14C]leucine into protein were determined. The mesenteric arteries were suspended in Krebs-Henseleit bicarbonate buffer which was aerated with a gas mixture containing 5% CO2,O-95% O2 and N2 to 100%. Reduction of the O2 concentration of the gas phase from 95-20% resulted in little metabolic change. A further reduction from 20-0% O2 increased the lactate production 4-fold, indicating a marked Pasteur effect. At 0% O2 the glucose uptake was moderately increased and the glycogen content was decreased. The tissue level of CrP was reduced at a low oxygen tension and at 0% O2 the ATP content was also lowered. The incorporation of leucine into proteins was reduced at 0% O2.

Effect of different insulin regimens on plasma lipoprotein and apolipoprotein concentrations in patients with non-insulin-dependent diabetes mellitus.

The effect of insulin treatment with 2 different insulin regimens on the plasma concentrations of lipoproteins and apolipoproteins A1 and B was studied in 10 patients with non-insulin-dependent diabetes mellitus (NIDDM) and secondary failure to oral hypoglycaemic agents. The investigation was performed as a randomized crossover study with treatment periods of 8 weeks. Insulin was given either as mainly intermediate acting insulin before breakfast and dinner (2-dose insulin) or as regular insulin preprandially with intermediate acting insulin at bedtime (4-dose insulin). A similar improvement in glycaemic control was obtained with both insulin regimens. On treatment with oral agents the patients were found to have higher total plasma triglycerides and lower plasma high density lipoprotein (HDL) cholesterol than a matched non-diabetic control group. Insulin treatment almost completely normalized these lipid disturbances by reducing mean total plasma triglycerides with 36% and increasing plasma HDL cholesterol with 20% on 2-dose and 17% on 4-dose. The triglyceride concentration in the very low density lipoprotein (VLDL) fraction was reduced. Mean plasma low density lipoprotein (LDL)-cholesterol was not affected by any treatment. There was an increase of similar magnitude in both HDL2 and HDL3 concentrations but only the change in the HDL3 subfraction was statistically significant. Mean plasma apolipoprotein A1 concentration increased with 9% (P less than 0.05) while there was no significant change in the plasma apolipoprotein B concentration. The changes in the plasma concentrations of lipoproteins and apolipoproteins A1 and B were almost identical on 2- and 4-dose insulin.(ABSTRACT TRUNCATED AT 250 WORDS)