No signs of progressive beta cell damage during 20 years of prospective follow-up of autoantibody-negative diabetes

Both type 1 and type 2 diabetes are considered to be associated with different degrees of progressive beta cell damage. However, few long-term studies have been made. Our aim was to study the clinical course of 20 years of diabetes disease, including diabetes progression, comorbidity, and mortality in a prospectively studied cohort of consecutively diagnosed diabetic patients. Among all 233 patients diagnosed with diabetes during 1985-1987 in Malmö, Sweden, 50 of 118 surviving patients were followed-up after 20 years. The age at diagnose was 42.3 ± 23.1 and 57.5 ± 13.6 years for antibody-positive and antibody-negative patients, respectively. HbA1c and plasma lipids were analyzed with regard to metabolic control. Islet antibody-negative patients at diagnosis had highly preserved C-peptide levels after 20 years in contrast to antibody-positive patients (antibody negative: C-peptide 0 years 0.78 ± 0.47 and 20 years 0.70 ± 0.46 (nmol/l), P = 0.51 and antibody positive: C-peptide 0 years 0.33 ± 0.35 and 20 years 0.10 ± 0.18; P < 0.001. Islet antibodies but not age, BMI, or C-peptide at diagnosis were predictors of C-peptide levels at 20 years when analyzed by logistic regression (P < 0.05). HbA1c did not differ between the groups after 20 years. The 20-year mortality was higher among antibody-negative patients, dependent on the higher age at diagnosis in this group (number of deaths: antibody positive: 18 of 56 vs. antibody negative: 109 of 188, P < 0.001). Of the deceased, 79% had died from diseases or complications that may be associated with diabetes. We found no progressive beta cell damage in autoantibody-negative diabetes at a 20-year follow-up of the clinical course of diabetes.

Disturbed vibrotactile sense in finger pulps in patients with Type 1 diabetes--correlations with glycaemic level, clinical examination and electrophysiology

AIMS

In a cohort of men and women with Type 1 diabetes, prospectively followed for > 20 years, vibrotactile sense in fingers was investigated and related to neurophysiological tests, glycaemic level and clinical score.

METHODS

Out of 58 patients, diagnosed at the age of 15-25 years and recruited 1984-1985, 32 patients (13 women, median age 52 years, range 44-75 years; 19 men, median age 52 years, range 39-69 years; median duration 33.5 years, range 21-52 years) accepted follow-up in 2006. Vibration thresholds were measured in finger pulps of index and little fingers bilaterally at seven frequencies and related to results of touch (monofilaments), tactile discrimination (two-point discrimination test), electrophysiology (median nerve function), glycaemic level (HbA(1c) levels since 1984-1985) and a clinical score.

RESULTS

Vibrotactile sense was reduced in finger pulps, mainly in men, compared with an age- and gender-matched healthy control group with normal HbA(1c) . Vibration thresholds were increased, particularly at 250 and 500 Hz, in both index and little finger pulps. Touch and tactile discrimination correlated with vibration thresholds, but not with each other or with electrophysiology. HbA(1c) levels (at follow-up or mean values from five follow-ups since recruitment) did not correlate with any nerve function variables. Clinical scores correlated with vibrotactile sense, particularly at higher frequencies (> 125 Hz), but not with total Z-scores of electrophysiology. Duration of disease did not correlate with any variables.

CONCLUSIONS

Examination of vibration thresholds in index and little finger pulps may be valuable to detect neuropathy, where thresholds correlate with symptoms and tests.

Hyperproinsulinemia segregates young adult patients with newly diagnosed autoimmune (type 1) and non‐autoimmune (type 2) diabetes

OBJECTIVE

To investigate whether measurements of proinsulin and/or intermediate proinsulin degradation products could be used to differentiate between autoimmune (type 1) and non-autoimmune (type 2) diabetes in young adults.

MATERIAL AND METHODS

Total proinsulin, intact proinsulin and 32,33 split proinsulin concentrations were measured in 25 patients aged 15-34 years with type 1 diabetes, as defined by the presence of at least two positive islet autoantibodies, and in 23 antibody-negative patients of similar age with type 2 diabetes, at the time of clinical onset of diabetes and at 3-4 months thereafter. Comparisons were made with data from 25 healthy subjects matched for gender and age.

RESULTS

Plasma levels of total proinsulin, intact proinsulin and 32,33 split proinsulin were significantly increased 2-3-fold in the patients with newly diagnosed type 2 diabetes as compared with the controls, both in absolute terms (p<0.0001) and when related to circulating insulin (p<0.01-0.0002). In contrast, absolute proinsulin and 32,33 split proinsulin concentrations were significantly lower in patients with onset of type 1 diabetes than in controls. When proinsulin and split proinsulin release were related to plasma insulin, however, similar ratios were found in the type 1 diabetes patients and in controls. Using the 90th percentile for total proinsulin in the control group as the cut-off, the sensitivity and specificity for differentiation between autoimmune and non-autoimmune diabetes were 87% and 92%, respectively. At 3-4 months after clinical onset of diabetes, proinsulin secretion was still 2-3 times higher in type 2 than in type 1 diabetes patients (p<0.001).

CONCLUSIONS

Young adult patients with newly diagnosed type 2 diabetes display disproportionate hyperproinsulinemia, whereas proinsulin secretion appears to be normal in patients with clinical onset of type 1 diabetes. Evaluation of proinsulin and 32,33 split proinsulin concentrations may be useful as a diagnostic tool in differentiating between autoimmune and non-autoimmune diabetes in young adults, particularly in those lacking islet autoantibodies at diagnosis.

Sural nerve biopsy may predict future nerve dysfunction

OBJECTIVE

Sural nerve pathology in peripheral neuropathy shows correlation with clinical findings and neurophysiological tests. The aim was to investigate progression of nerve dysfunction over time in relation to a baseline nerve biopsy.

METHODS

Baseline myelinated nerve fiber density (MNFD) was assessed in sural nerve biopsies from 10 men with type 2 diabetes, 10 with impaired and 10 with normal glucose tolerance. Nerve conduction and quantitative perception thresholds were estimated at baseline and follow-up (7-10 years later).

RESULTS

Subjects with low MNFD (< or = 4700 fibers/mm(2)) showed decline of peroneal amplitude (P < 0.02) and conduction velocity (P < 0.04), as well as median nerve sensory amplitude (P < 0.05) and motor conduction velocity (P < 0.04) from baseline to follow-up. In linear regression analyses, diabetes influenced decline of nerve conduction. MNFD correlated negatively with body mass index (r = -0.469; P < 0.02).

CONCLUSION

Low MNFD may predict progression of neurophysiological dysfunction and links obesity to myelinated nerve fiber loss.

Growth hormone and endothelial function during exercise in diabetics with and without retinopathy

Changes in plasma growth hormone (GH), factor VIII related antigen (VIIIR:Ag), and plasminogen activator activity (PAA) during exercise were evaluated in 50 insulin-dependent diabetics. In patients with a short to moderately long duration of diabetes (5-19 years, mean 11), GH increased only in those with retinopathy. VIIIR:Ag and PAA increased most pronouncedly in retinopathy patients as well. In diabetics with long duration of the disease (21-49 years, mean 35), GH, VIIIR:Ag and PAA increased almost equally in those with and without retinopathy.

Autonomic neuropathy and toe circulation. A prospective study

Ankle and toe pressure ratios and toe temperature reactions to cold followed by indirect heating were evaluated in 23 diabetic patients with and without autonomic neuropathy (AN) in a first and in a second follow-up study after 5-7 years. In the first study, despite normal blood pressure ratios, AN patients, all with parasympathetic neuropathy, showed a markedly delayed increase in toe temperature after cooling followed by indirect heating. In the second study, most AN patients showed sympathetic neuropathy and had higher toe temperatures before cooling than those without AN. Parasympathetic neuropathy leads to increased sensitivity to cold in toe vessels and sympathetic neuropathy to vasodilation and increased toe temperatures.

Autonomic and peripheral nerve function in early diabetic neuropathy. Possible influence of a novel aldose reductase inhibitor on autonomic function

Autonomic and peripheral nerve functions as well as the possible short-term effect of a novel aldose reductase inhibitor (ARI) on neuropathy were evaluated in 30 male type I diabetics (age 25-44 years, mean 34; duration of diabetes 10-20 years, mean 34) with neurographic signs of peripheral neuropathy (PN). Autonomic neuropathy (AN) was established by the heart rate reactions to deep breathing (E/I ratio = vagal function) and to tilt (acceleration index = sympathetic and vagal functions; the brake index = vagal function). Twenty-nine patients, 13 with AN, completed the study. Among neurographic variables, only sural nerve function tests correlated with autonomic functions. Patients with AN showed significantly lower mean sensory action potential amplitudes (SAPA) sural, indicating axonal losses, than patients without AN (3.58 +/- 0.79 microV v. 7.34 +/- 1.12 microV; p less than 0.01). PN as measured by neurography did not improve during ARI treatment. On the other hand, vagal function (brake indices) improved (p less than 0.05) during ARI in AN patients.

Influence of autonomic neuropathy on leg circulation and toe temperature in diabetes mellitus

The relationship between neuropathy and peripheral circulation was assessed in 26 patients with a short to moderate duration (less than 20 years, mean 11 years) and in 26 patients with a long duration (greater than 20 years, mean 35 years) of diabetes mellitus. Peripheral nervous function was evaluated from measurements of vibration thresholds and ankle reflexes and autonomic nervous function from deep breathing, Valsalva, and tilt table tests. Peripheral circulatory tests included plethysmography, systolic blood pressure ratios, and thermography. A markedly delayed toe temperature increase after cooling followed by indirect heating occurred in diabetics of short duration with autonomic neuropathy (AN). Judging from blood flows and pressure ratios, functional vasospasm caused abnormal toe temperature reactions in short duration diabetics. No correlation existed between AN and abnormal toe temperature reactions in diabetics of long duration. Macroangiopathy rather than AN seemed to be responsible for abnormal toe temperature reactions in long duration diabetics. Thus, an abnormal toe temperature reaction indicates AN in patients with a short duration and macroangiopathy in patients with a long duration of diabetes.

Deep breathing, Valsalva, and tilt table tests in diabetics with and without symptoms of autonomic neuropathy

Autonomic neuropathy (AN) test results (Valsalva manoeuvre, deep breathing, and tilting) are frequently impaired in diabetics without symptoms of AN, particularly in those with peripheral neuropathy (PN). We have investigated 24 asymptomatic diabetics with PN, 17 diabetics with symptoms of AN and 24 healthy controls. The heart rate reactions to the three tests were impaired in both patient groups. The Valsalva manoeuvre could not distinguish between the patient groups. The heart rate reaction to deep breathing, estimated as the expiration/inspiration (E/I) ratio, was slightly more disturbed in patients with AN than those with PN (1.04 vs. 1.09, p less than 0.05) but the frequency of abnormally low E/I ratios was high in both groups (76.5 vs. 54.2%, NS). The immediate heart rate reaction to tilting, estimated as the brake index, clearly separated the patient groups. An abnormally low brake index was shown in 82.3% of AN patients and in 33.3% of PN patients (p less than 0.01). The study shows that the deep breathing test is sensitive for AN but an impaired immediate heart rate reaction to tilting is more specific for symptomatic AN.

Responses of plasma catecholamines to tilt in patients with diabetes mellitus

The immediate heart rate acceleration, blood pressure reaction, plasma adrenaline (PA), and plasma noradrenaline (PNA) responses to a 90 degrees and 2 sec tilt were evaluated in 13 male patients with type I diabetes. A disturbed immediate acceleration, as measured by a previously described acceleration index (AI), was found in 5 patients. All patients with normal AI but only one of those with abnormal AI showed an increase in PA during the first minute after tilt (p less than 0.02). A late diastolic blood pressure fall occurred in 6 patients and the fall was minor (5 mmHg) in 5 of these. Patients with a late diastolic blood pressure fall showed a significantly lower increase in PNA 1-8 min after tilt than those without (55 +/- 13% versus 163 +/- 24% (mean +/- SE), p less than 0.005). An abnormal immediate acceleration to tilt is associated with an impaired sympatho-adrenal reaction, and even a minor diastolic blood pressure fall indicates peripheral sympathetic denervation.

Autonomic neuropathy in type I diabetes: influence of duration and other diabetic complications

To evaluate the influence of duration on the development of autonomic neuropathy (AN) a group of type I diabetic patients (n = 58) who had been diagnosed between the ages of 15 and 25 years was investigated. The duration of diabetes varied from 2 months to 30 years (mean 13 years). AN tests included a deep breathing test (E/I ratio) and an orthostatic test on tilt table (acceleration and brake indices) and the results were corrected for age. A clear correlation between AN test and duration of diabetes was shown only for the E/I ratio (r = -0.44, p less than 0.001). On the other hand, deteriorations in the brake index were unrelated to the duration of diabetes and occurred early; 35% of the patients with a duration of 10 years or less showed an abnormal brake index. Autonomic test deviations were related to other diabetic complications. The E/I ratio and the acceleration index were especially low in patients with retinopathy as well as in patients with symptoms of AN if combined with peripheral neuropathy (PN). The brake index was low in patients with symptoms of AN independent of PN.

Hemoglobin A1c self-recording in the management of diabetes mellitus. A pilot study

HbA1c evaluates glycemic control 3-6 weeks retrospectively. To achieve improvements in glycemic control we have tested a patient-administered HbA1c control program in 12 (11 type I) diabetic patients. In the program, HbA1c was estimated once a month for 12 months and the results were mailed to the patient who recorded them in a specially designed HbA1c chart. The results in the probands were compared with 24 matched (22 type I) diabetic patients. The results showed that HbA1c fell significantly (p less than 0.01) during the year in the probands, from 8.84 +/- 1.12% to 7.48 +/- 0.95%, and was unchanged in the controls (8.41 +/- 1.78% and 8.17 +/- 1.74%, respectively). Accordingly, HbA1c self-recording improves glycemic control in diabetic patients.

Hand disorders, hand function, and activities of daily living in elderly men with type 2 diabetes

AIMS/HYPOTHESIS

This study aimed to examine hand disorders, symptoms, overall hand function, activities of daily living (ADLs), and life satisfaction in elderly men with type 2 diabetes mellitus (DM), impaired glucose tolerance (IGT), and normal glucose tolerance (NGT).

METHODS

Subjects were interviewed and evaluated with a battery of clinical and laboratory tests, including hand assessment, and a questionnaire.

RESULTS

HbA1c differed between groups (highest in DM, especially in long-term DM). Limited joint motion (LJM), for example, prayer sign and Dupuytren's contracture, was most common in individuals with DM, followed by individuals with IGT, as compared to those with NGT. Vibrotactile sense was impaired symmetrically in the index and little fingers in DM. However, there were no differences for sensibility, dexterity, grip strength, and cold intolerance between groups. Individuals with long-term (>15 years) DM were more affected regarding sensibility and ADL than individuals with short-term DM, who had more sleep disturbances. ADL difficulties were less among IGT subjects. Vibrotactile sense showed correlations with Semmes-Weinstein monofilament test and static two-point discrimination.

CONCLUSIONS/INTERPRETATION

Dupuytren's contracture and impaired vibrotactile sense in finger pulps occurred in patients with DM but not in those with IGT, although LJM occurred in both IGT and DM patients. A longer duration of DM was associated with more severe neuropathy and ADL difficulties. Life satisfaction was high, and hand disorders did not have a significant impact on ADL.

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.

Sequelae following sural nerve biopsy in type 1 diabetic subjects

OBJECTIVES

To detect post-operative sequelae of sural nerve biopsy.

MATERIALS AND METHODS

A questionnaire mailed to type 1 diabetic patients (n = 24; male/female 23/1; reply n = 23) 2 years after biopsy.

RESULTS

Type 1 diabetic patients (age 56 [11]; median [interquartile range]) had a long duration of diabetes (DM; 20 [19] years) and all had neuropathy. Three out of 24 patients developed infection (two superficial and one deep) and one had a post-operative bleeding. Less frequent pain among the patients were reported from one centre. About one-third or more of the patients still complained of pain, mostly mild, in the biopsy area and paraesthesia in the foot 2 years after surgery. More than two-thirds of the patients were reluctant for further biopsy; a crucial information in drug trial planning.

CONCLUSIONS

Sequelae of a sural nerve biopsy occur in type 1 DM. The risk for wound infections should be considered.

Effects of insulin vs. glibenclamide in recently diagnosed patients with type 2 diabetes: a 4-year follow-up

AIM

To compare effects of early insulin vs. glibenclamide treatment on beta-cell function, metabolic control and quality of life (QL) in recently diagnosed patients with type 2 diabetes.

METHODS

Forty-nine patients with type 2 diabetes diagnosed 0-2 years before inclusion were randomized to two daily injections of premixed 30% soluble and 70% NPH insulin or glibenclamide at six diabetic clinics in Sweden. C-peptide-glucagon tests were performed yearly after 3 days of withdrawal of treatment.

RESULTS

Thirty-four patients completed 4 years of study. Daily dose of insulin was increased from 20.4 +/- 1.8 U at year 1 to 26.1 +/- 2.9 U at year 4 (p = 0.005). Glibenclamide dosage increased from 2.7 +/- 0.4 mg at year 1 to 4.5 +/- 0.8 mg at year 4 (p = 0.02). Weight increased more in insulin than in glibenclamide treated (+4.4 +/- 0.8 vs. +0.3 +/- 1.0 kg, p < 0.005). Following short-term withdrawal of treatment, the C-peptide responses to glucagon were significantly higher in the insulin vs. glibenclamide group at years 1 (p < 0.01) and 2 (p < 0.02). HbA1c improved identical during the first year but thereafter deteriorated in the glibenclamide group (p < 0.005 for difference at year 4). Ratios of proinsulin to insulin were higher during treatment in glibenclamide- vs. insulin-treated patients after year 2. QL after 4 years as measured by the MOS 36-item Short-Form Health Survey (SF-36) form was not significantly altered.

CONCLUSIONS

In a 4-year perspective, beta-cell function deteriorated in both groups. However, deterioration occurred faster in the glibenclamide group, indicating that alleviating demands on secretion by insulin treatment is beneficial.

Number of islet autoantibodies present in newly diagnosed type 1 diabetes children born to non-diabetic mothers is affected by islet autoantibodies present at birth

OBJECTIVE

Cord blood islet autoantibodies in children born to mothers with type 1 diabetes may be associated with a reduced risk of islet autoimmunity and diabetes. The aim of this study was to investigate in children with type 1 diabetes but born to non-diabetic mothers whether islet autoantibodies at birth affected their presence at diagnosis.

PATIENTS AND METHODS

Serum samples at birth and at diagnosis were available from 141 children who developed type 1 diabetes between 1 and 19 yr of age (median 9.0 yr; male/female ratio 83/58). The samples were tested for autoantibodies against glutamic acid decarboxylase, insulinoma-associated antigen 2, and insulin as well as for islet cell antibodies. The human leukocyte antigen genotype was also determined.

RESULTS

The frequency of islet autoantibodies in the umbilical cord blood was 11% compared with 91% at diagnosis. Children with fewer islet autoantibodies at diagnosis were more likely to have had autoantibodies at birth (p = 0.02). Autoantibodies present in cord blood at birth were observed in 25% (3/12) of children with no islet autoantibodies at diagnosis, in 17% (7/42) of children with one or two antibodies at diagnosis, and in only 5% (4/86) of children with more than two antibodies, demonstrating an inverse relationship between autoantibodies at birth and at diagnosis (test for trend, p < 0.001).

CONCLUSIONS

Our preliminary data suggest that exposure to cord blood islet autoantibodies may influence the presence of islet autoantibodies at the time of diagnosis of type 1 diabetes and explain why some type 1 diabetes children are islet autoantibody negative at clinical diagnosis.

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.

Islet cell autoantibody levels after the diagnosis of young adult diabetic patients

AIMS

The aim was to determine the course of islet cell antibodies [glutamate decarboxylase (GADA), tyrosine phosphatase-like islet antigen 2 (IA-2A) and islet cell (ICA)] after the diagnosis of the diabetic patient.

METHODS

The Diabetes Incidence Study in Sweden (DISS) attempted to prospectively enrol all newly diagnosed diabetic patients aged 15-34 years during 1992 and 1993. C-peptide and autoantibody levels were determined from venous blood samples at diagnosis and again at yearly intervals for 6 years.

RESULTS

After the first year, the odds of remaining GADA positive decreased by 9% per year [odds ratio (OR) = 0.91, 95% confidence interval (CI) = 0.85-0.96] while the mean GADA index remained unchanged ( = 0.8, P = 0.37). There was no change in the percentage of subjects testing IA-2A positive after the first year ( = 0.1, P = 0.75). However, the mean index decreased 0.04 per year (95% CI: 0.03-0.05)-a 7.9% decline (95% CI: 5.4-10.4%). The odds of a subject testing positive for ICA decreased by 24% per year (OR = 0.76, 95% CI = 0.70-0.82). The mean ICA levels decreased 0.75 per year (95% CI: 0.66-0.84)-a 16.4% decline (95% CI: 14.1-18.6%). The rate of change in titres for all three autoantibodies was independent of gender, human leucocyte antigen genotype and C-peptide status.

CONCLUSIONS

GADA levels remained high while ICA levels declined. In contrast to a previous study, we found that the proportion of IA-2A subjects remaining positive did not decrease after the first year, while the average index decreased slightly.

Oesophageal dysmotility, delayed gastric emptying and gastrointestinal symptoms in patients with diabetes mellitus

AIMS

Gastroparesis is a common gastrointestinal complication in diabetes mellitus, whereas dysfunction in the other gastrointestinal organs has been less thoroughly investigated. Furthermore, it is not known whether there is any relationship between motility and dysmotility between these organs. The aim of this study was to examine whether diabetic patients with gastrointestinal symptoms also have motility disturbances in the oesophagus and stomach and, if so, whether there are any associations between these disturbances.

METHODS

Thirty-one patients with diabetes mellitus who complained of gastrointestinal symptoms were asked to complete a questionnaire about their symptoms. They were further investigated with oesophageal manometry and gastric emptying scintigraphy.

RESULTS

Fifty-eight per cent of the patients had abnormal oesophageal function, and 68% had delayed gastric emptying. Abdominal fullness was the only symptom that related to any dysfunction, and it was associated with delayed gastric emptying (P = 0.02). We did not find any relationship in motility or dysmotility between the oesophagus and the stomach.

CONCLUSION

Oesophageal dysmotility, as well as gastroparesis, are common in patients with diabetes who have gastrointestinal symptoms. It is important to investigate these patients further, to be able to reach an accurate diagnosis and instigate appropriate treatment. Our findings indicate that the oesophagus and the stomach function as separate organs and that pathology in one does not necessarily mean pathology in the other.

Subclinical sympathetic neuropathy appears early in the course of Crohn's disease

BACKGROUND

We have previously demonstrated that patients with Crohn's disease (CD) of long duration have signs of autonomic neuropathy. The aim of this study was to examine whether autonomic neuropathy is an early manifestation of CD, or a sign appearing late in the course.

METHODS

Twenty patients, median age 40 years, with a short duration of CD were included. Examination of autonomic reflexes included heart rate reaction to tilt (acceleration index - AI, brake index - BI) and heart rate variation to deep-breathing (expiration/inspiration index-E/I). Seven years later the same examinations were repeated, and in addition we examined the vasoconstriction response to indirect cooling by laser Doppler (vasoconstriction-index - VAC-index). The results were compared with healthy individuals.

RESULTS

There was no difference in the blood pressure between controls and the patients with CD at rest, but eight minutes after tilt, the systolic blood pressure was lowered in patients compared to controls, both at the first assessment (p = 0.016) and after seven years (p = 0.042). The change in systolic blood pressure between rest and eight minutes after tilt was not significant at the first assessment, while a significant change compared to controls was observed seven years later (p = 0.028). This indicates a progressive dysfunction. There were no differences in E/I, AI, BI or VAC indexes between patients and controls.

CONCLUSION

Patients with CD suffer from autonomic neuropathy early in their disease, suggesting involvement of many different organ systems in this entity.

Early changes in glomerular size selectivity in young adults with type 1 diabetes and retinopathy. Results from the Diabetes Incidence Study in Sweden

OBJECTIVE

To investigate the relationship between early-onset retinopathy and urinary markers of renal dysfunction.

RESEARCH DESIGN AND METHODS

The Diabetes Incidence Study in Sweden (DISS) aims to register all new cases of diabetes in young adults (15-34 years). In 1987-1988, 806 patients were reported and later invited to participate in a follow-up study focusing on microvascular complications after approximately 10 years of diabetes. In the present study, 149 patients with type 1 diabetes, completed eye examination, and urine sampling were included.

RESULTS

The patients with retinopathy (n=58, 39%) had higher HbA(1c) (P<.001) and urinary IgG2/creatinine (P<.05) and IgG2/IgG4 ratios (P<.05). Patients with maculopathy had the highest levels. No significant differences in urinary albumin/creatinine, glycosaminoglycans (GAGs)/creatinine, Tamm-Horsfall protein (THP)/creatinine, and IgG4/creatinine ratios were found. Women had higher urinary albumin/creatinine (P<.01) and urinary IgG2/creatinine ratios (P<.01) than men.

CONCLUSIONS

Young adults with type 1 diabetes and early-onset retinopathy had higher IgG2/creatinine and IgG2/IgG4 ratios than patients without retinopathy indicating that retinopathy is associated with a change in glomerular size selectivity. This was found in association with normal urinary albumin and THP excretion and may be suspected to reflect early general vascular changes.

Enteric ganglioneuritis and abnormal interstitial cells of Cajal: features of inflammatory bowel disease

BACKGROUND

An increased prevalence of irritable bowel syndrome (IBS) and disturbances in cardiac and blood pressure reflexes have been described in patients with Crohn's disease (CD) and ulcerative colitis (UC). These features could be due to abnormalities in the gastrointestinal neurotransmission. The aims of this study were to examine whether histopathologic changes in the enteric nervous system correlate with disturbances in cardiac and blood pressure reflexes and the occurrence of IBS- and dyspepsia-like symptoms in these patients.

METHODS

Thirty patients with CD and UC with bowel resection were examined by deep-breathing and orthostatic tests. The resection specimens were evaluated histologically regarding visceral neuro- or myopathy. All medical records were studied for treatment and clinical course.

RESULTS

Ganglioneuritis was observed in 11 of 19 patients with CD and in 5 of 11 with UC. Only patients with CD had ganglioneuritis in the small intestine. Moreover, in CD the interstitial cells of Cajal (ICCs) in the small bowel showed atrophy and vacuolar degeneration, along with a reduced number of cells (P = 0.005). In UC the colonic ICCs were hyperplastic (P = 0.05) without signs of degeneration. The indices of deep-breathing and orthostatic tests were impaired, except in CD with ganglioneuritis, who showed normal test values. There were no correlations between histopathologic alterations versus IBS and dyspepsia.

CONCLUSIONS

Visceral ganglioneuritis and pathologic ICCs were observed in patients with CD and UC. However, these histopathologic abnormalities could not be related to the clinical or autonomic features of the disease.

Reduced aortic wall stress in diabetes mellitus

OBJECTIVE

Most risk factors are similar for abdominal aortic aneurysm (AAA) and atherosclerosis, e.g. smoking, male gender, age, high blood pressure, hyperlipidemia. Diabetes mellitus however, is a risk factor for atherosclerosis, but diabetic patients seldom develop AAA. The reason for this discrepancy is unknown. Increased aortic wall stress seems to be an etiologic factor in the formation, growth and rupture of AAA in man. The aim of our study was to study the wall stress in the abdominal aorta in diabetic patients compared with healthy controls.

METHODS

39 patients with diabetes mellitus and 46 age - and sex matched healthy subjects were examined with B-mode ultrasound to determine the lumen diameter (LD) and intima-media thickness (IMT) in the abdominal aorta (AA) and the common carotid artery (CCA). Diastolic blood pressure (DBP) was measured non-invasively in the brachial artery. LaPlace law was used to calculate circumferential wall stress.

RESULTS

Age, DBP, and LD in the abdominal aorta were not significantly different in the diabetic patients compared to controls. IMT in the AA was larger in the diabetic patients, 0.89+/-0.17 vs 0.73+/-0.11 mm (p<.001). Accordingly aortic wall stress was reduced in the diabetics, 7.8+/-1.7 x 10(5) vs 9.7+/-1.9 x 10(5)dynes/cm(2) (p<.001).

CONCLUSIONS

Wall stress in the abdominal aorta is reduced in diabetes mellitus. This is mainly due to a thicker aortic wall compared to healthy controls. The reduced aortic wall stress coincides with the fact that epidemiological studies have shown a decreased risk of aneurysm development in diabetic patients.

Lower levels of plasma 25-hydroxyvitamin D among young adults at diagnosis of autoimmune type 1 diabetes compared with control subjects: results from the nationwide Diabetes Incidence Study in Sweden (DISS)

AIMS/HYPOTHESIS

Low plasma vitamin D concentrations may promote the development of type 1 diabetes. To test this hypothesis, we measured plasma 25-hydroxyvitamin D (25OHD) in young adults with type 1 diabetes.

METHODS

The nationwide Diabetes Incidence Study in Sweden (DISS) covers 15- to 34-year-old people with newly diagnosed diabetes. Blood samples at diagnosis were collected during the 2-year period 1987/1988. Patients with islet antibodies (islet cell antibodies, GAD antibodies or tyrosine phosphatase-like protein antibodies) were defined as having autoimmune type 1 diabetes. Plasma 25OHD was measured in samples taken from 459 patients at the time of diagnosis, and in 138 of these subjects 8 years later. The results were compared with age- and sex-matched control subjects (n=208).

RESULTS

At diagnosis, plasma 25OHD levels were significantly lower in patients with type 1 diabetes than in control subjects (82.5+/-1.3 vs 96.7+/-2.0 nmol/l; p<0.0001). Eight years later, plasma 25OHD had decreased in patients (81.5+/-2.6 nmol/l; p=0.04). Plasma 25OHD levels were significantly lower in diabetic men than in diabetic women at diagnosis (77.9+/-1.4 vs 90.1+/-2.4 nmol/l; p<0.0001) and at follow-up (77.1+/-2.8 nmol/l vs 87.2+/-4.5 nmol/l; p=0.048).

CONCLUSIONS/INTERPRETATION

The plasma 25OHD level was lower at diagnosis of autoimmune type 1 diabetes than in control subjects, and may have a role in the development of type 1 diabetes. Plasma 25OHD levels were lower in men than in women with type 1 diabetes. This difference may be relevant to the high incidence of type 1 diabetes among young adult men.

Islet antibodies associated with pancreatic B-cell dysfunction at and 3 years after diagnosis of diabetes in subjects aged 35-64 years old: degree of impairment less severe than in those aged 0-34 years old

AIMS

To determine differences in pancreatic B-cell function in relation to islet antibodies at diagnosis of diabetes and 3 years later in subjects aged 35-64 years old compared with those aged 0-34 years.

METHODS

From a population-based diabetes register, 46 (0-34 years old) and 323 (35-64 years old) incident diabetic patients were investigated at diagnosis and 3 years later. Islet cell antibodies (ICA, GADA and IA-2A) and fasting plasma C-peptide were measured.

RESULTS

Islet antibodies were found in 80% of the subjects aged 0-34 years and in 11% of those aged 35-64 years at diagnosis. ICA and GADA was the only combination of two islet antibodies detected in those aged 35-64 years and was, with or without IA-2A, associated with significantly lower median fasting C-peptide values than in those without or with only one antibody [0.35 nmol/l, interquartile range (IQR) 0.63 vs. 0.85 nmol/l, IQR 0.49; P = 0.0004]. However, fasting C-peptide in subjects aged 35-64 years old with multiple islet antibodies was higher than in those aged 0-34 years with islet antibodies (median 0 nmol/l, IQR 0.16, P = 0.0019). After 3 years' follow-up, fasting C-peptide was even lower in subjects aged 35-64 years old with three islet antibodies (median 0.14 nmol/l, IQR 0.27; P = 0.05).

CONCLUSIONS

Islet antibodies were common in adults at diagnosis of diabetes. The combination of ICA and GADA indicates impaired B-cell function at diagnosis of diabetes in those aged 35-64 years old.

Oesophageal dysmotility, delayed gastric emptying and autonomic neuropathy correlate to disturbed glucose homeostasis

AIMS/HYPOTHESIS

Among diabetic patients, glucose homeostasis may be affected by abnormal gastrointestinal motility and autonomic neuropathy. This study analysed whether oesophageal dysmotility, delayed gastric emptying or autonomic neuropathy affect glucose homeostasis.

MATERIALS AND METHODS

Oesophageal manometry and gastric emptying scintigraphy were performed in 20 diabetic patients. Heart-rate variation during deep breathing (expiration/inspiration [E/I] ratio) and continuous subcutaneous glucose concentrations for a period of 72 h were also monitored in the same patients.

RESULTS

Oesophageal dysmotility was found in eight of 14 patients. Eleven of 20 patients had delayed gastric emptying (abnormal gastric emptying half-time [T (50)]) and nine of 18 had an abnormal E/I ratio. Complaints of abdominal fullness were predictive of delayed gastric emptying. A low peristaltic speed of the oesophagus was associated with impaired T (50) (r ( s )=-0.67; p=0.02). One hour after breakfast, subcutaneous glucose levels decreased in patients with delayed gastric emptying but continued to rise in those with normal emptying. Consequently, the median glucose level 2.5 h after breakfast was lower in the former (9.1 [4.2-12.5] vs 14.3 [11.2-17.7] mmol/l; p<0.05). Glucose fluctuations during the 72 h were significantly higher in patients with an abnormal E/I ratio than in those with a normal E/I ratio (coefficient of variation: 41 [46-49] vs 28 [27-34]%; p=0.008).

CONCLUSIONS/INTERPRETATION

Abdominal fullness predicted delayed gastric emptying that was associated with diminished glucose uptake after breakfast. Low oesophageal peristaltic speed was associated with slow gastric emptying whereas parasympathetic neuropathy was associated with increased glucose variations.

HLA-DQB1 genotypes, islet antibodies and beta cell function in the classification of recent-onset diabetes among young adults in the nationwide Diabetes Incidence Study in Sweden

AIMS/HYPOTHESIS

The World Health Organization considers an aetiological classification of diabetes to be essential. The aim of this study was to evaluate whether HLA-DQB1 genotypes facilitate the classification of diabetes as compared with assessment of islet antibodies by investigating young adult diabetic patients.

SUBJECTS AND METHODS

Blood samples were available at diagnosis for 1,872 (90%) of the 2,077 young adult patients (aged 15-34 years old) over a 5-year period in the nationwide Diabetes Incidence Study in Sweden. Islet antibodies were measured at diagnosis in 1,869 patients, fasting plasma C-peptide (fpC-peptide) after diagnosis in 1,522, while HLA-DQB1 genotypes were determined in 1,743.

RESULTS

Islet antibodies were found in 83% of patients clinically considered to have type 1 diabetes, 23% with type 2 diabetes and 45% with unclassifiable diabetes. After diagnosis, median fpC-peptide concentrations were markedly lower in patients with islet antibodies than in those without (0.24 vs 0.69 nmol/l, p<0.0001). Irrespective of clinical classification, patients with islet antibodies showed increased frequencies of at least one of the risk-associated HLA-DQB1 genotypes compared with patients without. Antibody-negative patients with risk-associated HLA-DQB1 genotypes had significantly lower median fpC-peptide concentrations than those without risk-associated genotypes (0.51 vs 0.74 nmol/l, p=0.0003).

CONCLUSIONS/INTERPRETATION

Assessment of islet antibodies is necessary for the aetiological classification of diabetic patients. HLA-DQB1 genotyping does not improve the classification in patients with islet antibodies. However, in patients without islet antibodies, HLA-DQB1 genotyping together with C-peptide measurement may be of value in differentiating between idiopathic type 1 diabetes and type 2 diabetes.

Decreased heart rate variability may predict the progression of carotid atherosclerosis in type 2 diabetes

Heart rate variability (HRV), a measure of autonomic function, can predict survival outcomes. Cardiovascular disease is a known complication of diabetes, and we aimed to determine if autonomic dysfunction was associated with carotid artery atherosclerotic plaques in type 2 diabetic patients. We assessed frequency domain HRV from power spectral analysis of 24 h Holter ECG recordings, expiration/inspiration (E/I) ratio during deep breathing, acceleration index (AI) of R-R interval in response to head-up tilt, and the degree of carotid artery atherosclerosis in 61 type-2 diabetic patients (39 males, 45-69 years). Studies were carried out 5-6 years after diagnosis (baseline) and repeated 8 years after diagnosis (follow-up). At baseline, patients diagnosed with autonomic neuropathy, with abnormal E/I ratio and abnormal AI measurements, had decreased low frequency (LF) HRV. Baseline E/I ratio correlated with day (r = 0.34; P < 0.001) and night-time (r = 0.44; P < 0.001) LF power. Night-time HRV did not differ in patient with and without autonomic neuropathy. Reduced common carotid artery diameter and atherosclerotic intima-media thickness (IMT) both correlated with HRV at baseline. At follow-up, all HRV variables decreased significantly. Furthermore, patients with lower LF power at baseline, had a larger increase in the thickness of the carotid bulb intima-media at follow-up. Our results show that LF HRV power is associated with the extent and progression of carotid atherosclerosis in type 2 diabetes. A low LF HRV may predict the progression of atherosclerosis in these patients.

Excess mortality in incident cases of diabetes mellitus aged 15 to 34 years at diagnosis: a population-based study (DISS) in Sweden

AIMS/HYPOTHESIS

The objective of the study was to analyse the mortality, survival and cause of death patterns in incident cases of diabetes in the 15-34-year age group that were reported to the nationwide prospective Diabetes Incidence Study in Sweden (DISS).

MATERIALS AND METHODS

During the study period 1983-1999, 6,771 incident cases were reported. Identification of deaths was made by linking the records to the nationwide Cause of Death Register.

RESULTS

With an average follow-up of 8.5 years, resulting in 59,231 person-years, 159 deaths were identified. Diabetes was reported as the underlying cause of death in 51 patients (32%), and as a contributing cause of death in another 42 patients (26%). The standardised mortality ratio (SMR) was significantly elevated (RR=2.4; 95% CI: 2.0-2.8). The SMR was higher for patients classified by the reporting physician as having type 2 diabetes at diagnosis than for those classified as type 1 diabetic (2.9 and 1.8, respectively). Survival analysis showed significant differences in survival curves between males and females (p=0.0003) as well as between cases with different types of diabetes (p=0.005). This pattern was also reflected in the Cox regression model showing significantly increased hazard for males vs females (p=0.0002), and for type 2 vs type 1 (p=0.015) when controlling for age.

CONCLUSIONS/INTERPRETATION

This study shows a two-fold excess mortality in patients with type 1 diabetes and a three-fold excess mortality in patients with type 2 diabetes. Thus, despite advances in treatment, diabetes still carries an increased mortality in young adults, even in a country with a good economic and educational patient status and easy access to health care.

The influence of wavelength and probe configuration on findings of a skin vasoconstriction test when using laser Doppler perfusion devices

The aim of this study was to establish the degree to which a standardized test based on laser Doppler blood flow measurement is dependent on the particular equipment set-up being used. For this purpose, we examined finger skin blood flow with laser Doppler instruments in 20 healthy subjects. In laser Doppler perfusion monitoring (LDPM), we used a custom-made probe with two detecting fibers placed 0.25 and 1.2 mm from the illuminating fiber, respectively, and two laser Doppler perfusion imagers (LDPI) with a wavelength of 632.8 nm and 780 nm, respectively. Warming of the hand was achieved with a Peltier element, and reflex vasoconstriction was induced by immersing the other hand for 3 min into a water bath kept at 15 degrees C. As a measure for the change in skin blood flow, a vasoconstriction index (VAC: cooling/before cooling) was calculated and used for the comparison of the different devices. VAC values gathered around 0.6 for all devices. However, LDPI with a wavelength of 632.8 nm showed a slightly higher VAC index, and the difference was significant. We conclude that using a standardized test is the most appropriate for monitoring changes in blood flow rather than recording and comparing discrete values in intermittent recordings. Although a difference was noted when comparing the devices, different fiber separations and wavelengths seem then to be of little consequence.

Latent autoimmune diabetes in adults: definition, prevalence, beta-cell function, and treatment

Latent autoimmune diabetes in adults (LADA) is a disorder in which, despite the presence of islet antibodies at diagnosis of diabetes, the progression of autoimmune beta-cell failure is slow. LADA patients are therefore not insulin requiring, at least during the first 6 months after diagnosis of diabetes. Among patients with phenotypic type 2 diabetes, LADA occurs in 10% of individuals older than 35 years and in 25% below that age. Prospective studies of beta-cell function show that LADA patients with multiple islet antibodies develop beta-cell failure within 5 years, whereas those with only GAD antibodies (GADAs) or only islet cell antibodies (ICAs) mostly develop beta-cell failure after 5 years. Even though it may take up to 12 years until beta-cell failure occurs in some patients, impairments in the beta-cell response to intravenous glucose and glucagon can be detected at diagnosis of diabetes. Consequently, LADA is not a latent disease; therefore, autoimmune diabetes in adults with slowly progressive beta-cell failure might be a more adequate concept. In agreement with proved impaired beta-cell function at diagnosis of diabetes, insulin is the treatment of choice.

Autoantibodies to autonomic nerves associated with cardiac and peripheral autonomic neuropathy

OBJECTIVE

This study examines whether autonomic nerve autoantibodies (ANabs) are associated with development of autonomic neuropathy using a prospective study design.

RESEARCH DESIGN AND METHODS

A group of type 1 diabetic patients were followed prospectively with regard to autonomic nerve function on four occasions. At the third examination, 41 patients were tested for ANabs (complement-fixing autoantibodies to the sympathetic ganglion, vagus nerve, and adrenal medulla), and the results were related to cardiac autonomic nerve function (heart rate variation during deep breathing [expiration/inspiration ratio] and heart-rate reaction to tilt [acceleration and brake index]) and to peripheral sympathetic nerve function (vasoconstriction after indirect cooling [vasoconstriction index]).

RESULTS

ANabs were detected in 23 of 41 (56%) patients at the third examination. Compared with patients without ANabs (ANabs-), patients with ANabs (ANabs+) showed significantly higher frequencies of at least one abnormal cardiac autonomic nerve function test at the third examination (17 of 23 [74%] vs. 7 of 18 [39%]; P = 0.03) and fourth examination (15 of 21 [71%] vs. 4 of 16 [25%]; P < 0.01). In contrast, there was no similar difference at the first or second examination. The relative risk for ANabs(+) patients to develop cardiac autonomic neuropathy at follow-up was 7.5 (95% CI 1.72-32.80). The vasoconstriction index was more abnormal in ANabs+ than in ANabs- patients at the fourth examination (median 1.40 [interquartile range 1.58] vs. 0.35 [2.05]; P = 0.01).

CONCLUSIONS

ANabs were associated with future development of cardiac and peripheral autonomic neuropathy in diabetic patients, implying an etiological relationship between nervous tissue autoimmunity and these diabetes complications.

Changing associations between progressive cardiovascular autonomic neuropathy and carotid atherosclerosis with increasing duration of type 2 diabetes mellitus

To clarify associations between cardiovascular autonomic neuropathy (CAN) and the progression of carotid artery atherosclerosis in Type 2 diabetic patients, cardiovascular autonomic nerve function was related to carotid artery ultrasound in 61 Type 2 diabetic patients, 5 and 8 years after the diagnosis of diabetes. Between 5 and 8 years after diagnosis, age-adjusted acceleration index (AI) decreased (from -0.306+/-1.034 to -0.702+/-1.072; P=.0139), whereas age-adjusted expiration/inspiration (E/I) ratio was unchanged (-0.583+/-1.038 and -0.828+/-1.028; P=.1164). Intima-media thickness (IMT) increased in both the common carotid artery (CCA; from 0.854+/-0.219 to 0.913+/-0.241 mm; P<.0001) and the carotid bulb (from 1.789+/-0.714 to 2.128+/-0.881 mm; P<.0001), corresponding to a yearly IMT increase of 0.032+/-0.039 mm in the CCA and 0.146+/-0.204 mm in the carotid bulb. This value did not correlate with the AI or E/I ratios. In age-controlled partial correlation in the first examination, AI correlated inversely with mean (r=-.33, P=.018) IMT in the CCA, but not with IMT in the carotid bulb (r=-.14, P=.303). However, in contrast to the first examination, at follow-up, AI correlated inversely with the mean IMT of the carotid bulb (r=-.40, P=.007), lumen diameter of the CCA (r=-.31, P=.034), and plaque score (r=-.29, P=.041), but not with IMT of the CCA (r=-.04, P=.861). There were no correlations between the E/I ratio and carotid variables. In conclusion, CAN was associated with features of carotid atherosclerosis, which, in the carotid bulb, might affect baroreceptor function with the progression of Type 2 diabetes.

Increased aortic stiffness is persistent in type 1 diabetic women: a follow-up study

AIMS/HYPOTHESIS

We have previously reported that women, not men, with type 1 diabetes have increased aortic stiffness. Increased arterial stiffness may explain why diabetic women have a particularly high risk of developing cardiovascular complications. We have now followed up our previously investigated patients after 7 years, with a view to evaluating whether the sex difference was persistent, and also evaluating the degree of progression with time and the relationship between stiffness versus intima media thickness of the aorta.

METHODS

Stiffness (beta) of the abdominal aorta (echo-tracking sonography) and intima media thickness (B-mode ultrasound) were assessed in 23 women and 19 men with type 1 diabetes and compared with matched healthy individuals.

RESULTS

At follow-up, aortic stiffness was still higher (60%) (p=0.0016) in diabetic than in control women, whereas there was no similar difference (p=0.4) between diabetic and control men. No progression of stiffness had occurred over the 7 years. At follow-up, the intima media thickness was increased and the internal diameter of the aorta was decreased in diabetic men and women without any sex-related difference.

CONCLUSIONS/INTERPRETATION

The increased aortic stiffness that affects type 1 diabetic patients seems to be an early event that soon reaches a plateau without any further increase. Increased aortic stiffness in type 1 diabetic women seems to be a sex-specific functional disorder unrelated to the degree of underlying atherosclerosis.

Early parasympathetic neuropathy associated with elevated fasting plasma C-peptide concentrations and late parasympathetic neuropathy with hyperglycaemia and other microvascular complications

AIMS

To examine the relationship between parasympathetic neuropathy, hyperinsulinaemia, glycaemic control (HbA(1c)), and future diabetic complications.

METHODS

We assessed parasympathetic nerve function [expiration/inspiration (E/I) ratio], glomerular filtration rate (GFR), glycaemic control (HbA(1c)), fasting plasma (f-p-) C-peptide in 82 Type 2 diabetic patients (age 61 +/- 1 years) 5 and 12-15 years after diagnosis. Diabetic retinopathy was assessed 15 years after diagnosis.

RESULTS

High HbA(1c) values in the first study were associated with retinopathy (with 8.6 +/- 2.0 vs. without retinopathy 6.2 +/- 1.9%; P < 0.0001) and disturbed parasympathetic nerve function (low E/I ratio; r(s) = -0.41; P = 0.0061) in the second study, as well as with deteriorations in GFR between the first and second study (r(s) = 0.62; P < 0.0001). Patients with parasympathetic neuropathy in the first study had significantly higher f-p-C-peptide concentrations than those without 3 years (1.20 +/- 0.43 vs. 0.86 +/- 0.40 nmol/l; P = 0.0015) and 5 years (1.20 +/- 0.44 vs. 0.82 +/- 0.33 nmol/l; P < 0.0001), but not 15 years after diagnosis.

CONCLUSION

High HbA(1c) values 5 years after diagnosis of Type 2 diabetes were associated with retinopathy, disturbed parasympathetic nerve function, and deterioration in GFR 7-10 years later. Parasympathetic neuropathy 5 years after diagnosis was associated with high C-peptide concentrations. Parasympathetic nerve function has to be considered when beta-cell function is evaluated. Hyperglycaemia is an important factor for the development of complications in Type 2 diabetes.

Serum cystatin C advantageous compared with serum creatinine in the detection of mild but not severe diabetic nephropathy

OBJECTIVE

To determine whether serum cystatin C is more accurate than serum creatinine in the detection of diabetic nephropathy, also after adjustment for age.

METHODS

Forty-one patients with type 1 and 82 patients with type 2 diabetes were evaluated with serum creatinine, serum cystatin C, and (51)Cr-EDTA clearance (reference method). Cystatin C was measured by a particle-enhanced turbidimetric method and creatinine by an enzymatic method. Statistical estimations were performed both without and with age adjustment created by z-scores for (51)Cr-EDTA clearance, creatinine, and cystatin C. The cut-off levels for glomerular filtration rate (GFR) ((51)Cr-EDTA clearance) were 60 and 80 mL min(-1) 1.73 m(-2), respectively, in absolute values and 80, 90 and 95% CIs, respectively, in age-adjusted values (z-scores).

RESULTS

Estimations without age adjustment showed significantly (P = 0.0132) closer correlation for cystatin C (r = 0.817) versus (51)Cr-EDTA clearance as compared with creatinine (r = 0.678). However, when using age-adjusted values, the correlation for cystatin C and creatinine, respectively, versus (51)Cr-EDTA clearance did not differ. When comparing the diagnostic utilities for serum cystatin C versus serum creatinine in manifest renal impairment (GFR < 60 mL min(-1) 1.73 m(-2) or z-scores <-1.28 SD), there were no significant differences between the two markers whether age adjusted or not. However, for diagnosing mild nephropathy (GFR < 80 mL min(-1) 1.73 m(-2) or z-score -0.84 SD), serum cystatin C is significantly more useful.

CONCLUSIONS

Serum cystatin C performed better compared with serum creatinine even when measured enzymatically, to detect mild diabetic nephropathy. However, serum creatinine was as efficient as serum cystatin C to detect advanced diabetic nephropathy.

Sympathetic and parasympathetic neuropathy are frequent in both type 1 and type 2 diabetic patients

OBJECTIVE

The aim of this study was to evaluate the frequency of sympathetic versus parasympathetic neuropathy among type 1 and type 2 diabetic patients.

RESEARCH DESIGN AND METHODS

There were 43 patients with type 1 and 17 with type 2 diabetes who were investigated. Sympathetic nerve function was assessed by measurement of the vasoconstriction (VAC) index by laser Doppler perfusion imaging of a locally heated finger followed by indirect cooling. Parasympathetic nerve function was assessed by R-R interval variation during deep breathing as measured by the expiration/inspiration (E/I) ratio. Results were expressed as age-corrected z scores in SD; VAC index >1.64 SD and E/I ratio <-1.64 SD were considered abnormal.

RESULTS

VAC index was abnormal in 40% with type 1 and 41% with type 2 diabetes, whereas the E/I ratio was abnormal in 42% with type 1 and 65% with type 2 diabetes. There was a clear association between VAC index and E/I ratio among type 1 (rs=0.525; P=0.0002) but not among type 2 (rs=0.10) diabetic patients. Among type 2 diabetic patients, the degree of dysfunction was most severe regarding parasympathetic function (P=0.0167).

CONCLUSIONS

Sympathetic and parasympathetic neuropathy were frequent in both type 1 and type 2 diabetic patients. However, there was a difference between the two types of diabetes. Sympathetic and parasympathetic nerve functions correlated in type 1 but not in type 2 diabetic patients. The explanation for this discrepancy might be that parasympathetic nerve function was most severely affected among type 2 diabetic patients.

A 14-year prospective study of autonomic nerve function in Type 1 diabetic patients: association with nephropathy

AIMS

Prospective studies of autonomic nerve function are rare. We have followed the progression of autonomic dysfunction in relation to nephropathy over 14 years in Type 1 diabetic patients.

METHODS

Autonomic nerve function was assessed by heart-rate responses to deep breathing (E/I ratio) and tilting (acceleration and brake indices) and by the postural blood pressure reaction in 58 patients, 43 of whom were reassessed after 14 years. Nephropathy was evaluated by the degree of albuminuria (albuminuria > 20 micro g/min or > 0.03 g/24 h) and glomerular filtration rate ((51)Cr-EDTA plasma clearance). The acceleration index had deteriorated after 7 years (P = 0.0155), whereas the E/I ratio (P = 0.0070) and the diastolic postural blood pressure reaction (P = 0.0054) had deteriorated 14 years after the baseline examination (age-corrected values). All those with albuminuria at the third examination showed signs of autonomic neuropathy at baseline (10 of 10) compared with only nine of 22 without (P = 0.0016). Multiple regression analysis showed that the association between autonomic dysfunction and future albuminuria was due to the E/I ratio. In addition, individuals with an abnormal postural diastolic blood pressure fall (n = 7) at baseline showed a greater fall in glomerular filtration rate more than others 7-14 years later [29 (16.5) ml/min/1.72 m(2) vs. 11 (9) ml/min/1.72 m(2); P = 0.0074].

CONCLUSION

Autonomic nerve function had deteriorated after 14 years. Autonomic neuropathy and abnormal postural diastolic blood pressure falls at baseline were associated with future renal complications.

Plasma adiponectin and serum advanced glycated end-products increase and plasma lipid concentrations decrease with increasing duration of type 2 diabetes

OBJECTIVE

To prospectively follow the concentrations of plasma adiponectin (p-adiponectin) and serum advanced glycation end-products (s-AGE) in relation to plasma lipids and retinopathy over 3 years in type 2 diabetic patients.

DESIGN AND METHODS

P-adiponectin, s-AGE, plasma lipids and diabetic retinopathy were prospectively evaluated in 61 type 2 diabetic patients at baseline and at follow up 3 years later.

RESULTS

Mean p-adiponectin (from 8.84+/-5.14 to 11.05+/-6.16 microg/ml; P=0.006) and s-AGE (from 637+/-242 to 781+/-173 ng/ml; P<0.0001) concentrations had increased at follow up. In addition, HbA1c (7.7+/-1.7 to 7.4+/-1.4%; P=0.0045) and fasting C-peptide (1.00+/-0.38 to 0.81+/-0.35 nM; P=0.019) had decreased and all lipid variables had significantly improved at follow up. P-adiponectin correlated inversely with fasting C-peptide (r(s)=-0.273; P=0.045) and low-density lipoprotein (LDL)/high-density lipoprotein (HDL) ratio (r(s)=-0.362; P=0.011), and directly with plasma HDL cholesterol (r(s)=0.381; P=0.005) at follow up. Analysis of variance with adiponectin and s-AGE as dependent variables and fasting C-peptide, plasma HDL and plasma LDL cholesterol as covariates demonstrated that the increase in s-AGE was independent (P=0.001) and the increase in p-adiponectin dependent on covariate changes (P=0.862). There was a slight correlation between s-AGE at baseline versus the degree of retinopathy at follow up (r(s)=0.281; P=0.0499).

CONCLUSION

Both p-adiponectin and s-AGE increased during the 3 years. The increase in p-adiponectin was explained by improvements in insulin sensitivity and dyslipidaemia, whereas the increase in s-AGE was independent of changes in metabolic covariates. s-AGE increase when the duration of type 2 diabetes increases.

A 14-year prospective study of autonomic nerve function in Type 1 diabetic patients: association with nephropathy

AIMS

Prospective studies of autonomic nerve function are rare. We have followed the progression of autonomic dysfunction in relation to nephropathy over 14 years in Type 1 diabetic patients.

METHODS

Autonomic nerve function was assessed by heart-rate responses to deep breathing (E/I ratio) and tilting (acceleration and brake indices) and by the postural blood pressure reaction in 58 patients, 43 of whom were reassessed after 14 years. Nephropathy was evaluated by the degree of albuminuria (albuminuria > 20 micro g/min or > 0.03 g/24 h) and glomerular filtration rate ((51)Cr-EDTA plasma clearance). The acceleration index had deteriorated after 7 years (P = 0.0155), whereas the E/I ratio (P = 0.0070) and the diastolic postural blood pressure reaction (P = 0.0054) had deteriorated 14 years after the baseline examination (age-corrected values). All those with albuminuria at the third examination showed signs of autonomic neuropathy at baseline (10 of 10) compared with only nine of 22 without (P = 0.0016). Multiple regression analysis showed that the association between autonomic dysfunction and future albuminuria was due to the E/I ratio. In addition, individuals with an abnormal postural diastolic blood pressure fall (n = 7) at baseline showed a greater fall in glomerular filtration rate more than others 7-14 years later [29 (16.5) ml/min/1.72 m(2) vs. 11 (9) ml/min/1.72 m(2); P = 0.0074].

CONCLUSION

Autonomic nerve function had deteriorated after 14 years. Autonomic neuropathy and abnormal postural diastolic blood pressure falls at baseline were associated with future renal complications.

Achalasia: a vagal disease

BACKGROUND

Achalasia is considered to be a primary motor disorder of the oesophagus. However, there is increasing evidence to suggest extra-oesophageal involvement in this disease. Vagal disturbances at different levels and extra-oesophageal dysmotility have been reported in several studies. The aim of this study was to examine cardiovascular reflexes in patients with achalasia further to evaluate the involvement of the autonomic nervous system outside the oesophagus in this entity.

METHODS

Five patients (age range 38-58 years, median 45 years) diagnosed with achalasia were assessed for the autonomic nerve function by the heart rate reaction to deep breathing (E/I ratio) and to tilt (acceleration and brake index). The blood pressure reaction to tilt was also assessed. The results were compared with a control group comprising 56 healthy individuals (age range 16-59 years, median 40 years).

RESULTS

Patients with achalasia had a significantly decreased E/I ratio compared with controls (absolute values 1.13 (0.23) (median value (interquartile range)) versus 1.38 (0.14): P=0.0309, age corrected values -1.39 (1.49) versus -0.25 (1.20): P=0.0457). This reflects impairment of the vagus nerve. In contrast, sympathetic nerves were not affected, as the acceleration index and brake index and postural blood pressure reaction were not disturbed in patients.

CONCLUSION

Patients with achalasia have autonomic nerve dysfunction in the vagal nerve outside the oesophagus.

Normal weight promotes remission and low number of islet antibodies prolong the duration of remission in Type 1 diabetes

AIM

To identify clinical, immunological and biochemical factors that predict remission, and its duration in a large cohort of young adults with Type 1 diabetes mellitus (DM).

METHODS

In Sweden, 362 patients (15-34 years), classified as Type 1 DM were included in a prospective, nation-wide population-based study. All patients were followed at local hospitals for examination of HbA(1c) and insulin dosage over a median period after diagnosis of 5 years. Duration of remission, defined as an insulin maintenance dose </= 0.3 U/kg/24 h and HbA(1c) within the normal range, was analysed in relation to characteristics at diagnosis.

RESULTS

Remissions were seen in 43% of the patients with a median duration of 8 months (range 1-73). Sixteen per cent had a remission with a duration > 12 months. Among patients with antibodies (ab(+)), bivariate analysis suggested that adult age, absence of low BMI, high plasma C-peptide concentrations, lack of ketonuria or ketoacidosis at diagnosis and low insulin dose at discharge from hospital were associated with a high possibility of achieving remission. Multiple regression showed that normal weight (BMI of 20-24.9 kg/m(2)) was the only factor that remained significant for the possibility of entering remission. In survival analysis among ab(+) remitters, a low number of islet antibodies, one or two instead of three or four, were associated with a long duration of remissions.

CONCLUSION

In islet antibody-positive Type 1 DM, normal body weight was the strongest factor for entering remission, whilst a low number of islet antibodies was of importance for the duration.

CRP and IL-6 concentrations are associated with poor glycemic control despite preserved beta-cell function during the first year after diagnosis of type 1 diabetes

BACKGROUND

The role of non-specific inflammation in beta-cell loss in type 1 diabetes is unclear. In the present study, inflammatory markers were determined in patients with newly diagnosed disease and related to beta-cell function, glycemic control and autoimmunity.

METHODS

Ninety-seven adult patients with type 1 diabetes mellitus (80% islet antibody positives, ab(+)) were examined at diagnosis and 3, 6, 9 and 12 months after the start of insulin treatment. Plasma C-reactive protein (CRP), interleukin-6 (IL-6), C-peptide, islet autoantibodies, insulin requirement and HbA(1c) were assessed.

RESULTS

The concentrations of CRP were high-normal at diagnosis and did not change during the study period. A positive correlation between CRP at diagnosis and BMI was observed in ab(+) as well as in ab(-) cases. Detectable concentrations of IL-6 were found in 32% (157/485) of the samples and did not change during the study. Ab(-) patients had higher values of CRP at diagnosis and throughout the study compared to the ab(+). Among the ab(+) patients, CRP concentrations during the study were positively correlated to C-peptide at 12 months and an increase in HbA(1c) levels between 6 and 12 months. No associations between the presence or levels of islet autoantibodies and CRP were noted.

CONCLUSIONS

In type 1 diabetes, the islet destructive process and the development of beta-cell remission are not associated with changes in CRP or IL-6. Instead, elevated CRP concentrations are prevalent and seem to reflect insulin resistance, as positive associations to BMI, C-peptide and deterioration of glycemic control were observed.

Islet antibodies and remaining beta-cell function 8 years after diagnosis of diabetes in young adults: a prospective follow-up of the nationwide Diabetes Incidence Study in Sweden

OBJECTIVES

To establish the prevalence of remaining beta-cell function 8 years after diagnosis of diabetes in young adults and relate the findings to islet antibodies at diagnosis and 8 years later.

DESIGN

Population-based cohort study.

SETTING

Nationwide from all Departments of Medicine and Endocrinology in Sweden.

SUBJECTS

A total of 312 young (15-34 years old) adults diagnosed with diabetes during 1987-88.

MAIN OUTCOME MEASURE

Plasma connecting peptide (C-peptide) 8 years after diagnosis. Preserved beta-cell function was defined as measurable C-peptide levels. Three islet antibodies - cytoplasmic islet cell antibodies (ICA), glutamic acid decarboxylase antibodies and tyrosine phosphatase antibodies - were measured.

RESULTS

Amongst 269 islet antibody positives (ab+) at diagnosis, preserved beta-cell function was found in 16% (42/269) 8 years later and these patients had a higher body mass index (median 22.7 and 20.5 kg m-2, respectively; P = 0.0003), an increased frequency of one islet antibody (50 and 24%, respectively; P = 0.001), and a lower prevalence of ICA (55 and 6%, respectively; P = 0.007) at diagnosis compared with ab+ without remaining beta-cell function. Amongst the 241 patients without detectable beta-cell function at follow-up, 14 lacked islet antibodies, both at diagnosis and at follow-up.

CONCLUSIONS

Sixteen per cent of patients with autoimmune type 1 diabetes had remaining beta-cell function 8 years after diagnosis whereas 5.8% with beta-cell failure lacked islet autoimmunity, both at diagnosis and at follow-up.

Islet autoantibodies in cord blood from patients who developed type 1 diabetes mellitus at 15-30 years of age

Islet cell autoantibodies are early markers for type 1 diabetes. The aim of this study was to determine whether islet autoantibodies were present at birth in young adults who developed type 1 diabetes at 15-30 years of age. Cord blood sera from 30 patients who developed type 1 diabetes between 15 and 25 years of age and sera from 320 randomly selected control children were tested for islet cell antibodies (ICA) by indirect immunofluorescence and autoantibodies against the 65 kD isoform of glutamic acid decarboxylase (GADA), islet cell antigen-2 (IA-2A) and insulin (IAA) by radiobinding assays. The young adults who developed type 1 diabetes did not differ from controls in the cord blood prevalence of any of the four islet autoantibodies. This is in contrast to our previous findings that children who developed type 1 diabetes below 15 years of age had an increased prevalence of cord blood islet autoantibodies. Our present data suggest that, in contrast to children, pre- and perinatal risk factors are less likely to be involved in the development of type 1 diabetes in young adults.

Laser doppler perfusion monitoring of skin blood flow at different depths in finger and arm upon local heating

The purpose of the study was to elucidate the vasodilatory response to local heating of the skin at two depths in two locations. To accomplish this, we measured skin blood flow in 12 healthy subjects using laser Doppler perfusion monitoring. A probe with two fibers separated 0.14 mm (superficial) and 0.25 mm (deeper) from the illuminating fiber was first attached to the distal phalanx of the index finger and thereafter to the dorsal forearm skin. Local heating was caused with a thermostatic probe holder set at 40 degrees C. We studied the perfusion value and its two components, velocity and concentration. All registrations were also subjected to frequency analysis. Laser Doppler values were generally higher in the fingertip than in forearm skin. Heating caused increased values at both locations. Concentration increased relatively more than velocity and this was most obvious in the forearm. There were only slight differences in response between superficial and deeper vascular components. Frequency analysis revealed a peak in perfusion and velocity obviously related to the heartbeat. Movement of the column of blood thus reached the peripheral vascular network without changing concentration. We conclude that local heating increases skin blood flow in fingertip and forearm skin by different adjustments of blood cell concentration and velocity, presumably depending on differing vascular anatomy and physiological control, but differences are of a rather minor character. Furthermore, responses differ just slightly in superficial compartments as probed with fibers separated up to 0.25 mm.