Incidence of prolonged QTc and severe hypoglycemia in type 1 diabetes: the EURODIAB Prospective Complications Study

AIMS

To assess the independent role of severe hypoglycemia on 7-year cumulative incidence of prolonged QTc in a large cohort of patients with type 1 diabetes.

METHODS

People with type 1 diabetes recruited by the EURODIAB Prospective Complications Study who had normal QTc were examined at baseline and after 7 years with standardized methods (n = 1415; mean age ± SD 32.1 ± 9.6 years; diabetes duration 14.2 ± 8.8 years). Hypoglycemic episodes were assessed by a questionnaire. QTc was calculated according to Bazett's formula. In logistic regression analysis, we examined the role of severe hypoglycemia (none, 1-2, or 3 and more episodes/year) on the cumulative incidence of prolonged QTc, independently of age, sex, HbA1c, blood pressure, BMI, physical activity, distal symmetrical and autonomic neuropathy.

RESULTS

In total, 264/1415 (17%) patients had incident prolonged QTc. Compared to those with persistently normal QTc, a greater proportion of incident cases had 3 and more hypoglycemic episodes at baseline (16.3 vs 11.2%, p = 0.03) and after 7 years (15.2 vs 9.6%, p = 0.01). In logistic regression analysis, 3 or more episodes of severe hypoglycemia at baseline did not increase cumulative incidence of prolonged QTc (OR 1.34, 95% CI 0.88-2.03). By contrast, severe hypoglycemia at the follow-up examination was associated with higher incidence of QTc prolongation (OR 1.68, 1.09-2.58), which reverted to not significant after adjustment for diabetic neuropathy.

CONCLUSIONS

Severe hypoglycemia was not associated with incidence QTc prolongation in type 1 diabetic patients from the EURODIAB PCS.

Unhealthy dietary patterns associated with inflammation and endothelial dysfunction in type 1 diabetes: the EURODIAB study

BACKGROUND AND AIMS

A healthy diet has been inversely associated with endothelial dysfunction (ED) and low-grade inflammation (LGI). We investigated the association between nutrient consumption and biomarkers of ED and LGI in type 1 diabetes.

METHODS AND RESULTS

We investigated 491 individuals. Nutrient consumption and lifestyle risk factors were measured in 1989 and 1997. Biomarkers of ED (von Willebrand factor, soluble vascular cell adhesion molecule-1 and soluble endothelial selectin) and LGI (C-reactive protein, interleukin 6 and tumour necrosis factor α) were measured in 1997 and averaged into Z-scores. The nutrient residual method was used to adjust individual nutrient intake for energy intake. Data were analysed with generalised estimation equations. We report increments/decrements in nutrient consumption, averaged over time, per +1 standard deviation (SD) of 1997 ED or LGI Z-scores, after adjustment for sex, age, duration of diabetes, investigation centre, body mass index, energy intake, smoking behaviour, alcohol consumption, and each of the other nutrients. One SD elevation in ED Z-score was associated with a diet lower in fibre [β(95%CI);-0.09(-0.18;-0.004)], polyunsaturated fat [-0.18(-0.31;-0.05)] and vegetable protein [-0.10(-0.20;-0.001)]. For the LGI Z-score results showed associations with fibre [-0.09(-0.17;-0.01)], polyunsaturated fat [-0.14(-0.24;-0.03)] and cholesterol [0.10(0.01; 0.18)].

CONCLUSION

In type 1 diabetes, consumption of less fibre, polyunsaturated fat and vegetable protein, and more cholesterol over the study period was associated with more ED and LGI. Following dietary guidelines in type 1 diabetes may reduce cardiovascular disease risk by favourably affecting ED and LGI.

Association of physical activity with all-cause mortality and incident and prevalent cardiovascular disease among patients with type 1 diabetes: the EURODIAB Prospective Complications Study

AIMS/HYPOTHESIS

The aim of this study was to examine the association of physical activity (PA) with all-cause mortality and incident and prevalent cardiovascular disease (CVD) among patients with type 1 diabetes.

METHODS

The EURODIAB Prospective Complications Study is a cohort including 3,250 male and female patients with type 1 diabetes (mean age 32.7 ± 10.2 years) from 16 European countries, of whom 1,880 participated in follow-up examinations. In analysis 1 (longitudinal), the association of baseline PA (based on the reported number of hours per week spent in mild, moderate and vigorous PA) with all-cause mortality and incident CVD was examined by performing survival analysis. In analysis 2 (cross-sectional), we focused on the association between PA at follow-up (data on sports, walking distance and regular bicycling) and prevalent CVD by performing logistic regression analysis. Adjustments were made for age, sex, BMI, smoking, consumption of alcohol, consumption of certain nutrients and diabetic complications.

RESULTS

Analysis 1 (longitudinal): participation in moderate or vigorous PA once a week or more was borderline inversely associated with all-cause mortality (men and women combined) (HR 0.66, 95% CI 0.42, 1.03) and incident CVD (women only) (HR 0.66, 95% CI 0.40, 1.08). No association was found in men. Analysis 2 (cross-sectional): total PA (indexed by sports, walking, bicycling) and distance walked were inversely associated with prevalent CVD (OR(totalPA) 0.66, 95% CI 0.45, 0.97; and OR(walking) 0.61, 95% CI 0.42, 0.89).

CONCLUSIONS/INTERPRETATION

PA showed a borderline inverse association with both all-cause mortality (both sexes) and incident CVD (women only) in patients with type 1 diabetes. Since this is an under-researched clinical population, future longitudinal studies with objective PA measurements are needed to expand on these results.

Dietary saturated fat and fibre and risk of cardiovascular disease and all-cause mortality among type 1 diabetic patients: the EURODIAB Prospective Complications Study

AIMS/HYPOTHESIS

Low adherence to recommendations for dietary saturated fatty acid (SFA) and fibre intake in patients with type 1 diabetes mellitus may heighten their increased risk of cardiovascular disease (CVD) and mortality. We examined the relationship of SFA and total, soluble and insoluble fibre with incident CVD and all-cause mortality in type 1 diabetic patients.

METHODS

A prospective cohort analysis was performed in 2,108 European type 1 diabetic patients aged 15-60 years who were free of CVD at baseline and enrolled in the EURODIAB Prospective Complications Study (51% male). Diet was assessed from a standardised 3 day dietary record. HR were calculated using Cox proportional hazards models.

RESULTS

During a mean follow-up of 7.3 years, 148 incident cases of fatal and non-fatal CVD and 46 all-cause deaths were documented. No statistically significant association was found between SFA and CVD and all-cause mortality. Total dietary fibre, per 5 g/day, was associated with lower all-cause mortality risk (HR 0.72; 95% CI 0.55, 0.95). This association was stronger for soluble fibre (per 5 g/day, HR 0.34; 95% CI 0.14, 0.80) compared with insoluble fibre (per 5 g/day; HR 0.66; 95% CI 0.45, 0.97). Similar results were found for the association with CVD.

CONCLUSIONS/INTERPRETATION

This study suggests that reported dietary SFA is not significantly associated with CVD and all-cause mortality in type 1 diabetic patients. On the contrary, higher dietary fibre consumption, especially soluble fibre, within the range commonly consumed by type 1 diabetic patients, may contribute to the prevention of CVD and all-cause mortality in type 1 diabetic patients.

Exposure to candesartan during the first trimester of pregnancy in type 1 diabetes: experience from the placebo-controlled DIabetic REtinopathy Candesartan Trials

AIMS/HYPOTHESIS

The teratogenic consequences of angiotensin-converting enzyme inhibitors angiotensin receptor blockers (ARBs) during the second and third trimesters of pregnancy are well described. However, the consequences of exposure during the first trimester are unclear, especially in diabetes. We report the experience from DIRECT (DIabetic REtinopathy and Candesartan Trials), three placebo-controlled studies designed to examine the effects of an ARB, candesartan, on diabetic retinopathy.

METHODS

Over 4 years or longer, 178 normotensive women with type 1 diabetes (86 randomised to candesartan, 32 mg once daily, and 92 assigned to placebo) became pregnant (total of 208 pregnancies).

RESULTS

More than half of patients were exposed to candesartan or placebo prior to or in early pregnancy, but all discontinued it at an estimated 8 weeks from the last menstrual period. Full-term pregnancies (51 vs 50), premature deliveries (21 vs 27), spontaneous miscarriages (12 vs 15), elective terminations (15 vs 14) and other outcomes (1 vs 2) were similar in the candesartan and placebo groups. There were two stillbirths and two 'sick babies' in the candesartan group, and one stillbirth, eight 'sick babies' and one cardiac malformation in the placebo group.

CONCLUSIONS/INTERPRETATION

The risk for fetal consequences of ARBs in type 1 diabetes may not be high if exposure is clearly limited to the first trimester. Long-term studies in fertile women can be conducted with ARBs during pregnancy, provided investigators diligently stop their administration upon planning or detection of pregnancy.

TRIAL REGISTRATION

ClinicalTrials.gov DIRECT-Prevent 1 NCT00252733; DIRECT-Protect 1 NCT00252720; DIRECT-Protect 2 NCT00252694.

FUNDING

The study was funded jointly by AstraZeneca and Takeda.

Helping students become the medical teachers of the future--the Doctors as Teachers and Educators (DATE) Programme of Barts and the London School of Medicine and Dentistry, London

CONTEXT

In the United Kingdom (UK), learning about teaching is an integral part of the General Medical Council's recommendations for the undergraduate medical curriculum. Yet often, implementing this aspect of learning presents a challenge to curriculum organisers in terms of content, timing and student interest. PROGRAMME OBJECTIVES AND STRUCTURE: The Doctors as Teachers and Educators (DATE) programme was set up at Barts and the London School of Medicine and Dentistry specifically to meet the requirements for development in teaching. Although largely practical, the two-day programme offers an introduction to educational theory and the teaching requirements for junior doctors in training. The methods used are lectures and group work within plenary sessions, followed by small group micro-teaching sessions. The DATE programme has now been undertaken by over 900 graduates.

EVALUATION METHODS

We evaluated the Date programme by means of end-of-course questionnaires completed by two cohorts of students during the 2007/8 academic year and through the use of Nominal Group Technique in 2008/9. In line with the goals of the evaluation, the data on students' views were analysed to elicit self-reported learning and develop the programme.

RESULTS

Response rates of the two cohorts to the surveys were high (80% and 98%). Nearly 100% of the students reported through the survey that they had gained confidence in teaching. In the nominal groups, students indicated that they had gained insight into educational principles like student-centredness and gained an appreciation for the nature of educational evidence and scholarship. They challenged the curriculum organisers to achieve an appropriate balance between theory and practice.

CONCLUSIONS

A programme about teaching at the undergraduate medical level can be well-received by students; the DATE model could be transferred to other international contexts.

Progression to microalbuminuria in type 1 diabetes: development and validation of a prediction rule

AIMS/HYPOTHESIS

Microalbuminuria is common in type 1 diabetes and is associated with an increased risk of renal and cardiovascular disease. We aimed to develop and validate a clinical prediction rule that estimates the absolute risk of microalbuminuria.

METHODS

Data from the European Diabetes Prospective Complications Study (n = 1115) were used to develop the prediction rule (development set). Multivariable logistic regression analysis was used to assess the association between potential predictors and progression to microalbuminuria within 7 years. The performance of the prediction rule was assessed with calibration and discrimination (concordance statistic [c-statistic]) measures. The rule was validated in three other diabetes studies (Pittsburgh Epidemiology of Diabetes Complications [EDC] study, Finnish Diabetic Nephropathy [FinnDiane] study and Coronary Artery Calcification in Type 1 Diabetes [CACTI] study).

RESULTS

Of patients in the development set, 13% were microalbuminuric after 7 years. Glycosylated haemoglobin, AER, WHR, BMI and ever smoking were found to be the most important predictors. A high-risk group (n = 87 [8%]) was identified with a risk of progression to microalbuminuria of 32%. Predictions showed reasonable discriminative ability, with c-statistic of 0.71. The rule showed good calibration and discrimination in EDC, FinnDiane and CACTI (c-statistic 0.71, 0.79 and 0.79, respectively).

CONCLUSIONS/INTERPRETATION

We developed and validated a clinical prediction rule that uses relatively easily obtainable patient characteristics to predict microalbuminuria in patients with type 1 diabetes. This rule can help clinicians to decide on more frequent check-ups for patients at high risk of microalbuminuria in order to prevent long-term chronic complications.

ANTI-HSP60 and ANTI-HSP70 antibody levels and micro/ macrovascular complications in type 1 diabetes: the EURODIAB Study

OBJECTIVES

The heat shock proteins 60 and 70 (HSP60, HSP70) play an important role in cytoprotection. Under stress conditions they are released into the circulation and elicit an immune response. Anti-HSP60 and anti-HSP70 antibody levels have been associated with cardiovascular disease. Type 1 diabetes is associated with a greatly increased risk of micro- and macrovascular complications. Therefore, we investigated whether anti-HSP60 and anti-HSP70 antibody levels were associated with micro- and macrovascular complications in type 1 diabetic patients.

DESIGN

A cross-sectional nested case-control study from the EURODIAB Study of 531 type 1 diabetic patients was performed.

SUBJECTS

Cases (n = 363) were defined as those with one or more complications of diabetes; control subjects (n = 168) were all those with no evidence of any complication. We measured anti-HSP60 and anti-HSP70 antibody levels and investigated their cross-sectional associations with diabetic complications.

RESULTS

Anti-HSP70 antibody levels were significantly greater in control than in case subjects, whereas anti-HSP60 antibody levels were similar in the two groups. In logistic regression analysis, anti-HSP70 levels in the upper quartiles were associated with a 47% reduced odds ratio of micro/macrovascular complications, independently of conventional risk factors, markers of inflammation and endothelial dysfunction [odds ratio (OR) = 0.53, 95% confidence intervals (CI): 0.28-1.02].

CONCLUSIONS

In this large cohort of type 1 diabetic subjects, we found an independent and inverse association between serum anti-HSP70 antibody levels and diabetic micro/macrovascular complications. This suggests that anti-HSP70 antibody levels may be a novel marker of protection from chronic diabetic complications.

Levels of soluble receptor for AGE are cross-sectionally associated with cardiovascular disease in type 1 diabetes, and this association is partially mediated by endothelial and renal dysfunction and by low-grade inflammation: the EURODIAB Prospective Complications Study

AIMS/HYPOTHESIS

Plasma soluble receptor for AGE (sRAGE) may reflect the activity of the AGE-RAGE axis, which has been proposed as a potential mechanism linking hyperglycaemia to vascular complications in diabetes. We have therefore investigated: (1) whether sRAGE is associated with greater prevalence of cardiovascular disease (CVD) and microvascular complications in type 1 diabetic individuals; and (2) the extent to which any such associations are explained by markers of endothelial and renal dysfunction and inflammation.

METHODS

The study included 477 individuals (234 women; mean age 42 +/- 10 [SD] years) from the EURODIAB Prospective Complications Study. We used linear regression analyses to investigate the differences in sRAGE levels between individuals with and without vascular complications. All analyses were adjusted for age, sex, HbA(1c), duration of diabetes and other risk factors.

RESULTS

Individuals with CVD (n = 116) had higher levels of sRAGE than those without CVD or any microvascular complications (n = 178): beta = 0.15 (95% CI 0.04-0.27). Further adjustments for markers of endothelial (beta = 0.13 [0.02-0.24]) and renal dysfunction (beta = 0.10 [-0.01, 0.20]) and inflammation (beta = 0.12 [0.01-0.23]) attenuated these differences; altogether these variables explained about 50% of the association between sRAGE and prevalent CVD. sRAGE levels tended to be higher in the presence and across the levels of severity of albuminuria (p for trend = 0.087) and retinopathy (p for trend = 0.057); adjustments for endothelial and renal dysfunction and inflammation also attenuated these differences.

CONCLUSIONS/INTERPRETATION

sRAGE is associated with greater prevalence of CVD in type 1 diabetic individuals, and these associations may be partly explained by endothelial and renal dysfunction and low-grade inflammation.

Alcohol consumption and risk of microvascular complications in type 1 diabetes patients: the EURODIAB Prospective Complications Study

AIMS/HYPOTHESIS

The aim of this study was to investigate the association between alcohol consumption and risk of microvascular complications (retinopathy, neuropathy, nephropathy) in type 1 diabetes mellitus patients in the EURODIAB Prospective Complications Study.

METHODS

The EURODIAB Prospective Complications Study is a follow-up study including 3,250 type 1 diabetes mellitus patients from 16 different European countries. We investigated the cross-sectional association between moderate alcohol consumption and risk of retinopathy, neuropathy and nephropathy among 1,857 of these patients.

RESULTS

We documented 304 cases of proliferative retinopathy, 660 cases of neuropathy and 157 cases of nephropathy (macroalbuminuria). Alcohol consumption was associated with risk of proliferative retinopathy, neuropathy and macroalbuminuria in a U-shaped fashion. Moderate consumers (30-70 g alcohol per week) had a lower risk of microvascular complications with odds ratios of 0.60 (95% CI 0.37-0.99) for proliferative retinopathy, 0.61 (0.41-0.91) for neuropathy and 0.36 (0.18-0.71) for macroalbuminuria in multivariate-adjusted models. These results were similar when excluding patients who had been advised to drink less alcohol because of their health. The relation was most pronounced for alcohol consumption from wine. Drinking frequency was significantly, inversely associated with risk of neuropathy, but a similar trend was visible for proliferative retinopathy and macroalbuminuria. Alcohol consumption was not associated with occurrence of ketoacidosis or hypoglycaemic attacks.

CONCLUSIONS/INTERPRETATION

Consistent with its effects on macrovascular complications, moderate alcohol consumption is associated with a lower risk of all microvascular complications among type 1 diabetes patients.

Antibodies to periodontal pathogens and coronary artery calcification in type 1 diabetic and nondiabetic subjects

BACKGROUND AND OBJECTIVE

The aim of this study was to examine whether serum immunoglobulin G (IgG) levels to Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans are higher in type 1 diabetic patients than in controls and are associated with coronary artery calcification, a measure of atherosclerosis.

MATERIAL AND METHODS

One-hundred and ninety nine type 1 diabetic patients (mean age 38 +/- 4 years) and 201 age- and gender-matched nondiabetic subjects had coronary artery calcification, as measured by electron beam computed tomography. Serum IgG levels to P. gingivalis W50 and to A. actinomycetemcomitans HK1651 whole cells were measured by enzyme-linked immunosorbent assay.

RESULTS

A similar proportion of diabetic patients (29%) and controls (31%, p = 0.7) had elevated serum IgG to periodontal bacteria, defined as being above the median antibody level for both microorganisms. Elevated antibody levels were associated with higher systolic blood pressure (p = 0.02) and an increased odds of coronary artery calcification in all subjects combined (odds ratio = 1.7, p = 0.047) and in diabetic subjects examined separately (odds ratio = 2.01, p = 0.027). Association of serum IgG levels with coronary artery calcification was independent of social class, lipids and antibody levels to other microorganisms, but not systolic blood pressure (odds ratio = 1.4, p = 0.1 on adjustment for blood pressure). There was no association between serum IgG level and vascular endothelial function.

CONCLUSION

Elevated levels of serum IgG to P. gingivalis and A. actinomycetemcomitans are associated with coronary artery atherosclerosis. This may reflect a direct role for periodontal infection or a role for the host response to infection in coronary atherosclerosis, particularly in patients with type 1 diabetes.

Relationship between plasma sialic acid and fibrinogen concentration and incident micro- and macrovascular complications in type 1 diabetes. The EURODIAB Prospective Complications Study (PCS)

AIMS/HYPOTHESIS

Type 1 diabetes is associated with an increased risk of vascular complications. This increased risk could be explained by sialic acid and/or fibrinogen. It is also not clear what explains the abolition of sex-related differences affecting risk of CHD in the presence of type 1 diabetes. Therefore, we examined whether fibrinogen and sialic acid are related to incident micro- and macrovascular complications in patients with type 1 diabetes.

METHODS

A subset (n=2329) of the EURODIAB Prospective Complications Study was analysed. Sialic acid and fibrinogen concentrations were measured at baseline. The main outcomes after 7 years were development of albuminuria, retinopathy, neuropathy and CHD.

RESULTS

Univariable and multivariable models using Cox proportional survival analyses showed that an SD unit increase in sialic acid and fibrinogen levels was significantly associated with CHD in men only. Adjusted standardised hazard ratios (sHRs) were 1.50 (95% CI 1.05-2.15) and 1.40 (95% CI 1.06-1.86) for sialic acid and fibrinogen, respectively. Initial associations between (1) sialic acid and incident retinopathy [standardised odds ratio (sOR) men 1.68, 95% CI 1.10-2.57], (2) fibrinogen and retinopathy (sOR women 1.37, 95% CI 1.06-1.78) and (3) sialic acid and neuropathy (sOR men 1.37, 95% CI 1.06-1.77) were shown, but became non-significant in multivariable models.

CONCLUSIONS/INTERPRETATION

Sialic acid and fibrinogen are strong predictors of CHD in men with type 1 diabetes, beyond the effect of established risk factors. The associations found with microvascular complications were not independent of other risk factors.

Cost-effectiveness of primary prevention of cardiovascular disease with atorvastatin in type 2 diabetes: results from the Collaborative Atorvastatin Diabetes Study (CARDS)

AIMS/HYPOTHESIS

We estimated the cost-effectiveness of atorvastatin treatment in the primary prevention of cardiovascular disease in patients with type 2 diabetes using data from the Collaborative Atorvastatin Diabetes Study (CARDS).

SUBJECTS AND METHODS

A total of 2,838 patients, who were aged 40 to 75 years and had type 2 diabetes without a documented history of cardiovascular disease and without elevated LDL-cholesterol, were recruited from 32 centres in the UK and Ireland and randomly allocated to atorvastatin 10 mg daily (n = 1,428) or placebo (n = 1,410). These subjects were followed-up for a median period of 3.9 years. Direct treatment costs and effectiveness were analysed to provide estimates of cost per endpoint-free year over the trial period for alternative definitions of endpoint, and of cost per life-year gained and cost per quality-adjusted life-year (QALY) gained over a patient's lifetime.

RESULTS

Over the trial period, the incremental cost-effectiveness ratio (ICER) was estimated to be 7,608 pounds per year free of any CARDS primary endpoint; the ICER was calculated to be 4,896 pounds per year free of any cardiovascular endpoint and 4,120 pounds per year free of any study endpoint. Over lifetime, the incremental cost per life-year gained was 5,107 pounds and the cost per QALY was 6,471 pounds (costs and benefits both discounted at 3.5%).

CONCLUSIONS/INTERPRETATION

Primary prevention of cardiovascular disease with atorvastatin is a cost-effective intervention in patients with type 2 diabetes, with the ICER for this intervention falling within the current acceptance threshold ( 20,000 pounds per QALY) specified by the National Institute for Health and Clinical Excellence (NICE).

Weight gain is associated with improved glycaemic control but with adverse changes in plasma lipids and blood pressure isn Type 1 diabetes

AIMS

To assess the effects of weight gain on metabolic control, plasma lipids and blood pressure in patients with Type 1 diabetes.

METHODS

Patients in the EURODIAB Prospective Complications Study (n = 3250) were examined at baseline and 1800 (55%) were re-examined a mean of 7.3 years later. Patients had Type 1 diabetes, defined as a diagnosis made before age 36 years and with a need for continuous insulin therapy within a year of diagnosis. Patients were aged 15-60 years at baseline and were stratified for age, sex and duration of diabetes.

RESULTS

The change in HbA(1c) from baseline to follow-up examination was significantly more favourable in those who gained 5 kg or more during follow-up ('marked weight gain') than in patients who gained less or no weight or lost weight ('less or no weight gain'). In those with marked weight gain, there was a significantly greater rise in plasma triglycerides and total cholesterol and significantly less favourable changes in low-density lipoprotein and high-density lipoprotein cholesterol compared with those with less or no weight gain, with or without adjustment for HbA(1c). Systolic and diastolic blood pressure also rose significantly more in the group with marked weight gain.

CONCLUSION

Weight gain in patients with Type 1 diabetes has adverse effects on plasma lipids and blood pressure, despite a small improvement in glycaemic control.

All-cause mortality rates in patients with type 1 diabetes mellitus compared with a non-diabetic population from the UK general practice research database, 1992-1999

AIMS/HYPOTHESIS

We compiled up to date estimates of the absolute and relative risk of all-cause mortality in patients with type 1 diabetes in the UK.

MATERIALS AND METHODS

We selected patients with type 1 diabetes (n=7,713), and for each of these diabetic subjects five age- and sex-matched control subjects without diabetes (n=38,518) from the General Practice Research Database (GPRD). Baseline was 1 January 1992; subjects were followed until 1999. The GPRD is a large primary-care database containing morbidity and mortality data of a large sample representative of the UK population. Deaths occurring in the follow-up period were identified.

RESULTS

The study comprised 208,178 person-years of follow-up. The prevalence of type 1 diabetes was 2.15/1,000 subjects in 1992 (mean age 33 years, SD 15). Annual mortality rates were 8.0 per 1,000 person-years (95% CI 7.2-8.9) in type 1 diabetic subjects compared with 2.4 per 1,000 person-years (95% CI 2.2-2.6) in those without diabetes (hazard ratio [HR]=3.7, 95% CI 3.2-4.3). The increased mortality rates in patients with type 1 diabetes were apparent across all age-bands. The HR was higher in women (HR=4.5, 95% CI 3.5-5.6 compared with non-diabetic women) than men (HR=3.3, 95% CI 2.7-4.0), such that the sex difference (p<0.0001) in mortality in the non-diabetic population was abolished (p=0.3) in the type 1 diabetic patients. The predominant cause of death in patients with type 1 diabetes was cardiovascular disease.

CONCLUSIONS/INTERPRETATION

Despite advances in care, UK mortality rates in the past decade continue to be much greater in patients with type 1 diabetes than in those without diabetes.

Rapid emergence of effect of atorvastatin on cardiovascular outcomes in the Collaborative Atorvastatin Diabetes Study (CARDS)

AIMS/HYPOTHESIS

The aim of this study was to determine the pattern of the effect of the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor atorvastatin on cardiovascular events in patients with type 2 diabetes and no prior history of cardiovascular disease (CVD).

MATERIALS AND METHODS

A post hoc analysis of data from the Collaborative Atorvastatin Diabetes Study (CARDS), a randomised, placebo-controlled trial of 2,838 patients with type 2 diabetes, was performed. Patients received atorvastatin (10 mg daily) or placebo and were evaluated for cardiovascular and other outcomes over a median follow-up period of 3.9 years. Cox proportional hazards modelling was carried out, and the hazard ratios calculated for various times after randomisation to treatment were investigated.

RESULTS

A reduction in the primary endpoint of major CVD events was apparent and statistically significant as soon as 18 months after treatment initiation. The effect of atorvastatin on CHD events was apparent by 6 months, and at 1 year was similar to the 37% relative risk reduction observed at trial closure.

CONCLUSIONS/INTERPRETATION

Atorvastatin alters the pathogenesis of CVD rapidly, such that the effect on cardiovascular events is apparent within months of initiation of therapy.

Is pregnancy a risk factor for microvascular complications? The EURODIAB Prospective Complications Study

AIMS

To examine the long-term influence of pregnancy on the development and progression of microvascular complications in Type 1 diabetes.

METHODS

In the EURODIAB Prospective Complications Study (PCS), 793 women potentially child bearing at baseline completed the follow-up (7.3 years) and 163 (21%) gave birth during the follow-up period. We compared risk factors [mean levels of age, duration of diabetes, HbA(1c), systolic blood pressure (SBP) and proportion giving birth] between those that did or did not develop microvascular complications during the follow-up period.

RESULTS

For the 425 childless women at baseline, 102 gave birth during follow-up. HbA(1c) was a significant risk factor for progression to microalbuminuria but age, duration of diabetes, systolic blood pressure or giving birth were not. Duration of diabetes and high HbA(1c) were significant risk factors for progression to proliferative retinopathy, whereas giving birth was not. Similar results were obtained for progression to any form of retinopathy. Giving birth was not significantly related to the incidence of neuropathy. Similar results were obtained for women with children at baseline giving birth during follow-up (n = 61/368).

CONCLUSIONS

In this European study, having a first or another pregnancy did not seem to be a risk factor for long-term progression of any microvascular complication. This is in accordance with the findings of the Diabetes Control and Complications Trial (DCCT).

Plasma homocysteine and microvascular and macrovascular complications in type 1 diabetes: a cross-sectional nested case-control study

OBJECTIVES

To examine the independent relationship between plasma total homocysteine (tHcy) and microvascular and macrovascular complications.

DESIGN

We performed a cross-sectional nested case-control study from the EURODIAB Prospective Complications Study.

SETTING

A hospital-based multicentre study at 24 centres in 13 European countries.

SUBJECTS

A total of 533 type 1 diabetic patients, diagnosed at <36 years of age. Cases (n=359) were defined as those with one or more complications of diabetes and control subjects (n=174) were all those with no evidence of any complication. Main outcome measures. Retinopathy, albumin excretion rate (AER), glomerular filtration rate (GFR) estimated by Cockcroft-Gault formula, hypertension and cardiovascular disease (CVD) were assessed.

RESULTS

In unadjusted models, tHcy (per 5 micromol L(-1)) was significantly associated with nonproliferative retinopathy (OR=1.45, 95% CI: 1.10-1.91), proliferative retinopathy (OR=1.74, 95% CI: 1.34-2.27), macroalbuminuria (OR=1.90, 95% CI: 1.49-2.42), hypertension (OR=2.23, 95% CI: 1.69-2.93) and CVD (OR=1.59, 95% CI: 1.18-2.14). In multivariate models, tHcy was significantly related to macroalbuminuria (OR=1.66, 95% CI: 1.24-2.24) and hypertension (OR=1.57, 95% CI: 1.19-2.07), independent of age, sex, diabetes duration, GFR, microvascular and macrovascular complications and cardiovascular risk factors. There was a significant relationship between tHcy and decreased GFR, independent of established risk factors. The relationship between tHcy and retinopathy was not independent of albuminuria or GFR. The initial positive relationship with CVD was explained by cardiovascular risk factors.

CONCLUSION

In this large study of European type 1 diabetic subjects, increased concentrations of tHcy were independently related to macroalbuminuria, renal function and hypertension, which suggests that tHcy might play an important role in the pathogenesis of vascular complications in type 1 diabetes.

Markers of inflammation are cross-sectionally associated with microvascular complications and cardiovascular disease in type 1 diabetes--the EURODIAB Prospective Complications Study

AIMS/HYPOTHESIS

The pathogenesis of vascular complications in type 1 diabetes is poorly understood, but may involve chronic, low-grade inflammation. We investigated the association of markers of inflammation with vascular complications in type 1 diabetes.

METHODS

A cross-sectional nested case-control study of the follow-up data of the EURODIAB Prospective Complications Study. This study included 543 individuals (278 men) with type 1 diabetes diagnosed at <36 years of age. Cases (n=348) had complications of diabetes, controls (n=195) had no complications.

RESULTS

C-reactive protein, interleukin-6 and tumour necrosis factor-alpha levels, which were combined in an inflammatory marker Z-score, were associated with albuminuria, retinopathy and cardiovascular disease. Calculated means (95% confidence intervals) of the marker Z-score were -0.15 (-0.22 to -0.07), 0.10 (-0.05 to 0.25), and 0.28 (0.15 to 0.41), p for trend <0.0001, in individuals with normo-, micro- and macroalbuminuria; -0.23 (-0.33 to -0.13), 0.14 (0.02 to 0.25) and 0.20 (0.07 to 0.32), p for trend <0.0001, in individuals with no, non-proliferative and proliferative retinopathy; and -0.28 (-0.39 to -0.18) and 0.06 (-0.08 to 0.20), p<0.001, in individuals without and with cardiovascular disease. Per 1 SD increase of the inflammatory marker Z-score, GFR decreased by -4.6 (-6.6 to -2.6) ml per min per 1.73 m(2) (p<0.001).

CONCLUSIONS/INTERPRETATION

We have shown that markers of inflammation are strongly and independently associated with microvascular complications and cardiovascular disease in type 1 diabetes. These data suggest that strategies to decrease inflammatory activity may help to prevent the development of vascular complications in type 1 diabetes.

Risk factors for cardiac autonomic neuropathy in type 1 diabetes mellitus

AIMS/HYPOTHESIS

Cardiac autonomic neuropathy (CAN) is associated with increased morbidity and mortality in type 1 diabetes. Apart from glycaemic control, risk factors for CAN have not been extensively studied.

METHODS

As part of the EURODIAB Prospective Complications Study, CAN--defined as either a loss of heart rate variability or postural hypotension on standing--was assessed at baseline and follow-up (7.3+/-0.6 years from baseline) in patients with type 1 diabetes.

RESULTS

Follow-up measurements were available for 956 participants without CAN at baseline (age at baseline 31.3+/-8.9 years, duration of diabetes 13.5+/-8.3 years). During follow-up, 163 (17%) subjects developed CAN, yielding an incidence of 23.4 per 1,000 person-years. Blood pressure, weight, the presence of cardiovascular disease, albuminuria, distal symmetrical polyneuropathy (DSP) and retinopathy at baseline were associated with the incidence of CAN after adjustment for sex, duration of diabetes and HbA(1)c. In a multivariate regression model, baseline factors associated with an increased risk of developing CAN were age [odds ratio (OR)=1.3 per decade, 95% CI 1.1-1.7], HbA(1)c (OR=1.2 per percentage point, 95% CI 1.1-1.4), systolic blood pressure (OR=1.1 per 10 mmHg, 95% CI 1.0-1.3), feeling faint on standing (OR=2.0, 95% CI 1.2-3.2), DSP (OR=1.9, 95% CI 1.2-3.0) and retinopathy (OR=1.7, 95% CI 1.1-2.6).

CONCLUSION/INTERPRETATION

This study confirms the importance of exposure to hyperglycaemia as a risk factor for CAN. A small set of variables, including HbA(1)c, hypertension, DSP and retinopathy, predict the risk of CAN. Clinical trials are needed to address the impact of intensive antihypertensive treatment on CAN in type 1 diabetes.

Baseline characteristics in the Collaborative AtoRvastatin Diabetes Study (CARDS) in patients with Type 2 diabetes

AIM

To describe baseline characteristics of patients in the Collaborative AtoRvastatin Diabetes Study (CARDS), a randomized, placebo-controlled trial of lipid lowering with atorvastatin 10 mg daily for the primary prevention of major cardiovascular events in patients with Type 2 diabetes.

METHODS

The main eligibility criteria were Type 2 diabetes, age 40-75 years, no previous history of coronary heart disease, stroke or other major cardiovascular events, a documented history of at least one of retinopathy, micro- or macroalbuminuria, hypertension or current smoking, LDL-cholesterol < or = 4.14 mmol/l and triglycerides < or = 6.78 mmol/l.

RESULTS

Randomization of 2838 persons (909 women) into CARDS was completed in June 2001. At entry, mean age was 62 years, 12% were over 70 years old and median duration of diabetes was 6 years. Median fasting lipid levels were total cholesterol 5.4 mmol/l, LDL-cholesterol 3.1 mmol/l, HDL-cholesterol 1.4 mmol/l and triglyceride 1.7 mmol/l. There was a documented history of retinopathy in 30% of patients, micro/macroalbuminuria in 11% (additionally 17% had micro/macroalbuminuria based on two elevated pretreatment measurements of albumin-creatinine ratios), hypertension in 79% and 23% were current smokers.

CONCLUSION

CARDS will contribute importantly to the evidence for the macrovascular and microvascular benefits of lipid lowering with atorvastatin in patients with Type 2 diabetes. The results are likely to have important implications for the management of patients.

The effect of atorvastatin on serum lipids, lipoproteins and NMR spectroscopy defined lipoprotein subclasses in type 2 diabetic patients with ischaemic heart disease

The effect of statin therapy on subclasses of LDL, VLDL and HDL lipoproteins is unclear. We compared changes in serum lipids, apolipoproteins and nuclear magnetic resonance (NMR) spectroscopy measured lipoprotein subclass concentration and average particle size over a minimum 6 months treatment period of atorvastatin 10 mg vs. placebo in 122 men and women. All subjects had type 2 diabetes and a modest dyslipidaemia (mean LDL-cholesterol 3.2 mmol/l and median triglycerides 1.8 mmol/l) and had a previous myocardial infarction. Compared with placebo, atorvastatin therapy was associated with a greater decrease in medium VLDL (median within person change -13.4 vs. -5.9 nmol/l, P<0.001 adjusted for baseline level), small VLDL (median change -17.8 vs. -8.1 nmol/l, P=0.002), large LDL (mean within person change -167.9 vs. -48.6 nmol/l, P<0.001) and medium LDL (median within person change -101.8 vs. -22.3 nmol/l, P=0.017). Atorvastatin therapy was also associated with a greater increase in large HDL than placebo (median change 1.40 vs. 0.80 micromol/l, P=0.02) and there was little change in small HDL so that average HDL particle size increased significantly with atorvastatin (P=0.04). In addition to reducing levels of (enzymatically measured) triglyceride, LDL-cholesterol and apolipoprotein B in diabetic patients, atorvastatin significantly reduces NMR measured medium and small VLDL and large and medium LDL, and increases large HDL.

Autonomic neuropathy is associated with increased cardiovascular risk factors: the EURODIAB IDDM Complications Study

AIMS

To assess the prevalence of and risk factors for autonomic neuropathy in the EURODIAB IDDM Complications Study.

METHODS

The study involved the examination of randomly selected Type I (insulin-dependent) diabetic patients from 31 centres in 16 European countries. Neuropathic symptoms and two tests of autonomic function (changes in heart rate and blood pressure from lying to standing) were assessed and data from 3007 patients were available for the present analysis. Autonomic neuropathy was defined as an abnormality of at least one of the tests.

RESULTS

The prevalence of autonomic neuropathy was 36% with no sex differences. The frequency of one and two abnormal reflex tests was 30% and 6%, respectively. The R-R ratio was abnormal in 24% of patients while 18% had orthostatic hypotension defined as a fall in systolic blood pressure > 20 mmHg on standing. Significant correlations were observed between autonomic neuropathy and age (P < 0.01), duration of diabetes (P < 0.0001), HbA1c (P < 0.0001), diastolic blood pressure (P < 0.05), lower HDL-cholesterol (P < 0.01), the presence of retinopathy (P < 0.0001) and albuminuria (P < 0.0001). New associations have been identified from the study: the strong relationship of autonomic neuropathy to cigarette smoking (P < 0.01), total cholesterol/HDL-cholesterol ratio (P < 0.05) and fasting triglyceride (P < 0.0001). As a key finding, autonomic neuropathy was related to the presence of cardiovascular disease (P < 0.0001). All analyses were adjusted for age, duration of diabetes and HbA1c. However, data have been only partly confirmed by logistic regression analyses. Frequency of dizziness on standing up was 18%, while only 4% of patients had nocturnal diarrhoea and 5% had problems with bladder control.

CONCLUSION

Cardiovascular reflex tests, even in the form of the two tests applied, rather than a questionnaire, seem to be appropriate for the diagnosis of autonomic neuropathy. The study has identified previously known and new potential risk factors for the development of autonomic neuropathy, which may be important for the development of risk reduction strategies. Our results may support the role of vascular factors in the pathogenesis of autonomic neuropathy.

Trends in hypertension management in Type I diabetes across Europe, 1989/1990 - 1997/1999

AIMS/HYPOTHESIS

Our aim was to examine the change in the management of hypertension in patients with Type I (insulin-dependent) diabetes mellitus in Europe, between 1989-1990 and 1997-1999.

METHODS

Seven-year changes in hypertension treatment and control (defined as blood pressure <130/85 mmHg) were examined in a large sample of Type I diabetic patients recruited from 26 centres involved in the EURODIAB Prospective Complications Study. Hypertension was defined as a systolic and/or diastolic blood pressure greater than 140 and/or 90 mmHg respectively, and/or use of blood pressure lowering drugs.

RESULTS

Of 1866 Type I diabetic patients, 412 had hypertension at baseline and 631 at follow-up. A greater proportion of hypertensive patients were treated at follow-up (69% vs 40%, p<0.0001), which persisted after adjustment for age or centre. Of those who were treated, a modest increase in the proportion of those controlled for hypertension was found (41% vs 32%, p=0.048), which disappeared after adjustment for age. Among hypertensive patients with albuminuria, the proportions treated also increased, from 35% to 76% ( p<0.0001) in microalbuminuric and 64% to 95% ( p<0.0001) in macroalbuminuric patients. Control of hypertension in albuminuric patients did not change significantly and was below 50%. The use of more than one anti-hypertensive drug increased over a 7-year period, from 19% to 33% ( p<0.0001), and a marked increase was shown in the proportion of those taking an ACE inhibitor (from 57% to 82%, p<0.0001).

CONCLUSION/INTERPRETATION

The management of hypertension in Type I diabetic patients across Europe has improved over a 7-year follow-up period. Optimal levels of blood pressure treatment and optimal levels of control have not yet been achieved.

Design of the Collaborative AtoRvastatin Diabetes Study (CARDS) in patients with type 2 diabetes

BACKGROUND

There are few data on the role of lipid lowering in the primary prevention of coronary heart disease (CHD) in diabetic patients. This paper describes the design of a collaborative clinical trial between Diabetes UK, the NHS Research and Development Directorate and Pfizer UK, that addresses this question.

METHODS

The Collaborative AtoRvastatin Diabetes Study (CARDS) is a multicentre, randomized, placebo-controlled, double-blind clinical trial of primary prevention of cardiovascular disease in patients with Type 2 diabetes. The primary objective is to investigate whether treatment with the hydroxymethylglutaryl coenzyme A reductase inhibitor, atorvastatin, reduces the incidence of major cardiovascular events. At entry patients have at least one other risk factor for CHD in addition to diabetes, namely current smoking, hypertension, retinopathy, or micro- or macroalbuminuria. At randomization patients have been selected for a serum low-density lipoprotein (LDL) cholesterol concentration < or = 4.14 mmol/l (160 mg/dl) and triglycerides < or = 6.78 mmol/l (600 mg/dl). Randomization was completed in June 2001. Patients will be followed until 304 primary endpoints have accrued (expected date early 2005). The trial includes 2838 men and women aged 40-75 years. This report describes the design and administration of the study and reviews the evidence to date of the effectiveness of lipid-lowering therapy in Type 2 diabetes.

CONCLUSIONS

The case for lipid-lowering therapy for the primary prevention of CHD in diabetes has not been demonstrated. CARDS will provide essential information on the extent of any benefits and adverse effects of lipid-lowering therapy in diabetic patients without prior CHD.

Elevated expression of axin2 and hnkd mRNA provides evidence that Wnt/beta -catenin signaling is activated in human colon tumors

Genetic studies have identified mutations in key regulators of the Wnt/beta-catenin pathway in a variety of cancers, most frequently in colon cancers. However, whether the pathway is activated in clinical cancer samples is not easily determined, and therefore it is useful to find markers that could be surrogates to show activation of the Wnt/beta-catenin pathway. Gene expression profiles were analyzed in SW620, a colon cancer cell line in which beta-catenin levels are stabilized as a consequence of truncated adenomatous polyposis coli and were compared with profiles of the same cells transfected with antisense oligodeoxynucleotides. Treatment of cells with beta-catenin antisense oligodeoxynucleotides resulted in a decrease in the levels of axin2 and human naked cuticle (hnkd) mRNAs. Interestingly, the proteins encoded by both of these mRNAs are known inhibitors of the beta-catenin pathway. In 30 human cell lines derived from different origins, axin2 and hnkd were expressed only in human colon cancer cell lines that are known to have activating mutations in the Wnt/beta-catenin pathway. Further, levels of both axin2 and hnkd mRNA were also found to be elevated in about 65% of laser microdissected cells from human colon tumors compared with laser microdissected cells of normal morphology from the same patient samples. The increased expression of axin2 and hnkd correlated with truncations in adenomatous polyposis coli in the same patient samples. These results reveal that it is possible to detect activation of a carcinogenic pathway in human cancer samples with specific markers.

Differing associations of lipid and lipoprotein disturbances with the macrovascular and microvascular complications of type 1 diabetes

OBJECTIVE

Cardiovascular disease (CVD) is increased in patients with type 1 diabetes, but lipid and lipoprotein patterns remain favorable. In contrast, nephropathy is associated with an adverse distribution. We compared the associations and predictive power of lipid and lipoprotein disturbances with these complications.

RESEARCH DESIGN AND METHODS

A nested case-control study from the EURODIAB cohort of 140 case subjects with evidence of at least one complication and 84 control subjects with no complications were analyzed. Conventional and unconventional lipid and lipoprotein fractions, including apolipoprotein (apo)-A1, lipoprotein (Lp)-A1, LpA1/A2, apoB, and LDL particle size were measured centrally.

RESULTS

CVD was only associated with increased LDL cholesterol (3.6 vs. 3.0 mmol/l, P = 0.02). In contrast, albuminuria was associated with elevated cholesterol, triglyceride, LDL, and apoB and with diminished LDL particle size. No disturbances in HDL and related lipoproteins were noted. In normoalbuminuric patients, CVD was not associated with any significant changes in lipids. CVD in macroalbuminuric patients was associated with increased triglyceride level (2.37 vs. 1.07 mmol/l, P = 0.001; P = 0.02 for CVD/albuminuria interaction) and LDL cholesterol (5.4 vs. 3.3 mmol/l, P = 0.005; P = 0.004 for interaction). Independent associations were observed for total cholesterol and for LDL particle size and albuminuria.

CONCLUSIONS

Abnormalities in lipid and lipoprotein disturbances are more closely related to albuminuria than to CVD in patients with type 1 diabetes. Measurement of conventional parameters provide sufficient risk information. ApoB and LDL particle size offer limited extra information. HDL metabolism remains undisturbed in the presence of complications. These changes reflect associations with glycemic control, which is the key to understanding lipid and lipoprotein disturbances.

Risk factors for progression to proliferative diabetic retinopathy in the EURODIAB Prospective Complications Study

AIMS/HYPOTHESIS

Proliferative diabetic retinopathy (PDR), a leading cause of blindness, cannot be totally prevented by optimizing metabolic and blood pressure control and responds to no specific treatment other than partially destructive retinal photocoagulation. Recognizing risk factors using large-scale epidemiological studies could help identify targets for treatment. The EURODIAB Prospective Complications Study (PCS) includes the largest cohort so far of patients with Type I (insulin-dependent) diabetes mellitus.

METHODS

Baseline data were collected between 1989 and 1991 on 3250 patients who were recalled for follow-up. Physical examination, biochemical tests and assessment of complications were done on both occasions. In particular, 1249 patients had retinal photographs taken both basally and after an average of 7.3 years.

RESULTS

Proliferative retinopathy had developed in 157 patients (cumulative incidence 17.3/1000 patient-years; 95%-CI: 13.6-21.1). HbA(1c) (standardized regression estimate--SRE = 3.03, CI 2.49-3.69), diabetes duration (1.71, 1.42-2.06), age at diagnosis < 12 (1.66, 1.11-2.50), diastolic blood pressure less than or equal to 83 (1.50, 1.03-2.20) and waist-to-hip ratio (1.50, 1.03-2.20) were all independent predictors for progression to PDR when entered simultaneously into a logistic regression model. Including retinopathy at baseline maintained the effects of metabolic control and pre-pubertal onset only. Including the albumin excretion rate maintained the effect of control but reduced SRE for pre-pubertal onset to 1.49 (0.94-2.33). There was no evidence for a threshold effect for HbA(1c)concentrations at baseline and progression to proliferative retinopathy.

CONCLUSION/HYPOTHESIS

Metabolic control and duration of diabetes are strong indicators of progression to proliferative retinopathy. Onset of diabetes before puberty could be an additional independent risk factor.

Factors associated with plasma lipids and lipoproteins in type 1 diabetes mellitus: the EURODIAB IDDM Complications Study

AIM

To assess the determinants and prevalence of hyperlipidaemia in Type 1 diabetic patients in the EURODIAB IDDM Complications Study.

METHODS

Standardized questionnaire data were obtained and anthropometric and biochemical measurements performed on 3159 Type 1 diabetic patients, randomly selected from 31 diabetes clinics. Plasma lipid levels were determined centrally, using enzymatic methods

RESULTS

Plasma total cholesterol, high-density lipoprotein cholesterol (HDL-C), and HDL subfractions were higher in women than in men, while plasma triglycerides were higher in men (P < 0.001). Total cholesterol, low-density lipoprotein cholesterol (LDL-C) and HDL-C and HDL-C subfractions were, as expected, significantly associated with age and HbA1c in both sexes. Age and HbA1c adjusted values of triglyceride, total cholesterol, LDL-C, HDL-C and HDL3-C in men and triglyceride and HDL2-C in women showed significant associations with central obesity, measured as the waist to hip ratio (WHR). Current smokers had lipid profiles characteristic of insulin resistance in comparison to nonsmokers. Significant positive associations were observed between hypertension and plasma triglycerides, total cholesterol and LDL-C in men and women. In men, degree of physical activity was negatively associated with triglyceride and positively related to HDL-C and HDL3-C. The prevalence of LDL-hypercholesterolaemia (LDL-C > 3.35 mmol/L) was 45% in men and in women, while plasma triglyceride levels > 1.7 mmol/L were observed in 12% of men and 8% of women.

CONCLUSION

The results of this study indicate that lipid levels in Type 1 diabetic patients are strongly influenced by smoking habit and central obesity in a way that is characteristic of the insulin resistance syndrome.

Risk factors, ethnic differences and mortality associated with lower-extremity gangrene and amputation in diabetes. The WHO Multinational Study of Vascular Disease in Diabetes

AIMS/HYPOTHESIS

We aimed to examine geographic differences, risk factors and mortality associated with amputation.

METHODS

Data from 10 of the original 14 centres of the WHO Multinational Study of Vascular Disease in Diabetes were used. This included 3443 men and women aged 35 to 55 years at baseline.

RESULTS

Incidences of amputation, adjusted for sex and duration in Type I (insulin-dependent) diabetes mellitus, were 31.0, 8.2, 3.5 and 1.0 per 1,000 person years in the American Indian, Cuban, European and East Asian centres respectively. In Type II (non-insulin-dependent) diabetes mellitus, incidences of amputation were 9.7, 2.0, 2.5 and 0.7 per 1000 person years in the American Indian, Cuban, European and East Asian centres respectively. Key risk factors for amputation included glucose, triglyceride, and retinopathy, and were similar for American Indians and Europeans. The age, duration and sex adjusted relative risk for amputation in American Indians compared with Europeans was 11.48 (95% CI 3.56, 36.98) in Type I diabetes and 3.86 (95 % CI 2.36, 6.32) in Type II diabetes. Adjusting for heart disease, retinopathy, proteinuria, glucose, blood pressure and triglyceride attenuated these relative risks to 10.83 (95 % CI 3.20, 36.65) and 3.15 (1.91, 5.20) in Type I and Type II diabetes respectively. Amputation doubled mortality rates in all groups.

CONCLUSION/INTERPRETATION

Vascular complications and their risk factors are themselves risk factors for amputation in both Type I and Type II diabetes and are common to several geographical regions worldwide. However, reasons for differences between geographical regions and the degree to which different health care systems could be responsible is not clear.

Increased urinary albumin excretion and its associations in the WHO Multinational Study of Vascular Disease in Diabetes

AIM/HYPOTHESIS

We aimed to determine variations in the prevalence of increased urinary albumin excretion, associated risk factors and complications in patients with diabetes participating in the WHO Multinational Study of Vascular Disease in Diabetes follow-up.

METHODS

Urinary albumin to urinary creatinine ratios were measured centrally in 2,033 of the 2,550 (79.7%) re-examined patients from eight centres in seven countries and the frequency of microalbuminuria and macroalbuminuria and their associations with risk factors and complications were examined.

RESULTS

Macroalbuminuria prevalence (overall 15.6%) varied tenfold (3-37%) among centres, was higher in American Indian and Asian centres and not clearly related to type of diabetes. Microalbuminuria (overall 19.7 %) varied less (12-31%). Increased albumin excretion was related overall to baseline fasting plasma glucose in the pooled group in whom it was measured and to increased arterial pressure, insulin use, coronary heart disease, lower extremity amputation, retinopathy and stroke in most centres.

CONCLUSION/INTERPRETATION

Centres varied widely in the prevalence of increased albumin excretion but associations with risk factors and vascular complications were generally similar in most centres and in both major types of diabetes with ethnic and genetic differences probably contributing.

Risk factors for cardiovascular mortality and morbidity: the WHO Mutinational Study of Vascular Disease in Diabetes

AIMS/HYPOTHESIS

We aimed to examine the associations between classic cardiovascular risk factors and diabetes specific factors and the incidence of fatal and non-fatal end-points in a large cohort of diabetic patients.

METHODS

A cohort of 4,743 diabetic patients participating in the WHO Multinational Study of Vascular Disease in Diabetes (WHO MSVDD) has been followed up for about 12 years and the incidence of fatal and non-fatal cardiovascular disease outcomes assessed.

RESULTS

The importance of blood pressure, serum cholesterol and proteinuria as predictors for cardiovascular disease mortality, fatal and non-fatal myocardial infarction and stroke is confirmed for patients with Type I (insulin-dependent) and Type II (non-insulin-dependent diabetes mellitus. Serum triglyceride was associated with cardiovascular disease death in Type II diabetes and in women with Type I diabetes and with MI incidence in Type II diabetes and stroke in Type II diabetic women. Fasting plasma glucose was associated with cardiovascular disease death, incidence of myocardial infarction and stroke in Type II diabetes only. In Type II diabetes, multivariate analysis confirmed that fasting plasma glucose was related to cardiovascular disease mortality independent of other risk factors. The independent relation of triglyceride to cardiovascular disease death was statistically significant only for Type II diabetic men. The presence of retinopathy was related to cardiovascular disease death and incidence of myocardial infarction in both types of diabetes and to stroke in Type II diabetes.

CONCLUSION/INTERPRETATION

This large cohort study shows that the assessment of cardiovascular disease risk in diabetes must include 'diabetes-related' variables such as glycaemic control, proteinuria and retinopathy, as well as the classic risk factors, blood pressure, smoking and dyslipidaemia. [Diabetologia

Mortality and causes of death in the WHO Multinational Study of Vascular Disease in Diabetes

AIMS/HYPOTHESIS

We aimed to examine the mortality rates, excess mortality and causes of death in diabetic patients from ten centres throughout the world.

METHODS

A mortality follow-up of 4713 WHO Multinational Study of Vascular Disease in Diabetes (WHO MSVDD) participants from ten centres was carried out, causes of death were ascertained and age-adjusted mortality rates were calculated by centre, sex and type of diabetes. Excess mortality, compared with the background population, was assessed in terms of standardised mortality ratios (SMRs) for each of the 10 cohorts.

RESULTS

Cardiovascular disease was the most common underlying cause of death, accounting for 44 % of deaths in Type I (insulin-dependent) diabetes mellitus and 52 % of deaths in Type II (non-insulin-dependent) diabetes mellitus. Renal disease accounted for 21% of deaths in Type I diabetes and 11% in Type II diabetes. For Type I diabetes, all-cause mortality rates were highest in Berlin men and Warsaw women, and lowest in London men and Zagreb women. For Type II diabetes, rates were highest in Warsaw men and Oklahoma women and lowest in Tokyo men and women. Age adjusted mortality rates and SMRs were generally higher in patients with Type I diabetes compared with those with Type II diabetes. Men and women in the Tokyo cohort had a very low excess mortality when compared with the background population.

CONCLUSION/INTERPRETATION

This study confirms the importance of cardiovascular disease as the major cause of death in people with both types of diabetes. The low excess mortality in the Japanese cohort could have implications for the possible reduction of the burden of mortality associated with diabetes in other parts of the world.

Risk factors for renal failure: the WHO Mulinational Study of Vascular Disease in Diabetes

AIMS/HYPOTHESIS

We aimed to examine risk factors for, and differences in, renal failure in diabetic patients from 10 centres.

METHODS

Risk factors for renal failure were examined in 3,558 diabetic patients who did not have renal disease at baseline in the WHO Multinational Study of Vascular Disease in Diabetes (WHO MSVDD).

RESULTS

In 959 subjects with Type I (insulin-dependent) diabetes mellitus and 2,559 with Type II (non-insulin-dependent) diabetes mellitus, the average follow-up was 8.4 years (+/- 2.7). By the end of the follow-up period 53 patients in the Type I diabetic group and 134 patients in the Type II diabetic group had developed renal failure (incidence rate 6.3:1,000 person years). Increasing age and duration of diabetes were associated with renal failure in Type II and Type I diabetes. In Type II diabetes duration of diabetes was a more important risk factor than age. In both Type I and Type II diabetic retinopathy and proteinuria were strongly associated with renal failure. Systolic blood pressure was associated with renal failure in Type I but not in Type II diabetic patients. ECG abnormalities at baseline, self-reported smoking and cholesterol were not associated with renal failure. Triglycerides were measured in a subset of centres. Among those with Type II, but not Type I diabetes, triglycerides were associated with renal failure independently of systolic blood pressure, proteinuria or retinopathy. In Type II diabetes fasting plasma glucose was associated with renal failure independently of other risk factors.

CONCLUSION/INTERPRETATION

We have confirmed the role of proteinuria and retinopathy as markers of renal failure and the importance of hyperglycaemia in renal failure in Type I and Type II diabetes. Plasma triglycerides seem to be an important predictor of renal failure in Type II diabetes. In Type I diabetes systolic blood pressure is an important predictor of renal failure.

Follow-up of the WHO Multinational Study of Vascular Disease in Diabetes: general description and morbidity

AIMS

The incidence of retinal, renal and cardiovascular complications and their relation to baseline risk factors was documented in this follow-up study of 10 of the 14 original centres of the WHO Multinational Study of Vascular Disease in Diabetes (WHO MSVDD).

METHODS

The incidence of specified items of vascular disease and some associated risk factors was ascertained after 7 to 9 years (11-12 years in Oklahoma, USA) follow-up, re-using baseline examination methodology in 3165 patients (66.9 %) and, through secondary information in 717 (15.2%) of the 4729 original patients, of whom 540 (11.4%) had died and 307 (6.5 %) were untraceable.

RESULTS

During follow-up, approximately one third of the patients developed hypertension and one third started insulin. Coronary heart disease incidence varied 10 to 20-fold among centres as did limb amputation rates. Inter-centre differences in incident retinopathy and severe visual impairment were smaller but incident clinical proteinuria and renal failure varied markedly. Vascular disease incidence of all categories was high in Native Americans though coronary heart disease incidence was relatively low in Pima Indians and absolutely low in Hong Kong and Tokyo patients. Specific vascular events and their relation with baseline risk factors are analysed in accompanying papers, summarised in the Epilogue.

CONCLUSION/INTERPRETATION

These 10 centres reported very different incidence rates of vascular complications. Observer variation, selection biases and competing causes of mortality contributed to these differences but their validity is supported by the more objective outcome indicators. The following papers also suggest that baseline factors such as raised arterial pressure, cholesterol and fasting glucose (in the centres where it was measured) were important and potentially reversible predictors of risk.

Blood pressure response to standing in the diagnosis of autonomic neuropathy: the EURODIAB IDDM Complications Study

Autonomic neuropathy is associated with poor prognosis. Cardiovascular reflexes are essential for the diagnosis of autonomic nerve dysfunction. Blood pressure response to standing is the most simple test for the evaluation of sympathetic integrity, however it is still discussed which diagnostic criteria of abnormal response should be considered as optimal. The EURODIAB IDDM Complications Study involved the examination of randomly selected Type 1 diabetic patients from 31 centres in 16 European counties. Data from 3007 patients were available for the present evaluation. Two tests of autonomic function (response of heart rate /R-R ratio/ and blood pressure from lying to standing) just as the frequency of feeling faint on standing up were assessed. R-R ratio was abnormal in 24% of patients. According to different diagnostic criteria of abnormal BP response to standing (>30 mmHg, >20 mmHg, and >10 mmHg fall in systolic BP), the frequency of abnormal results was 5.9%, 18% and 32%, respectively (p < 0.001). The frequency of feeling faint on standing was 18%, thus, it was identical with the prevalence of abnormal blood pressure response to standing when >20 mmHg fall in systolic blood pressure was considered as abnormal. Feeling faint on standing correlated significantly with both autonomic test results (p < 0.001). A fall >20 mmHg in systolic blood pressure after standing up seems to be the most reliable criterion for the assessment of orthostatic hypotension in the diagnosis of autonomic neuropathy in patients with Type 1 diabetes mellitus.

Microalbuminuria in type 1 diabetes: rates, risk factors and glycemic threshold

BACKGROUND

The occurrence of microalbuminuria in type 1 diabetes is strongly predictive of renal and cardiovascular disease and is still likely to occur despite improvements in glycemic control. A better understanding of microalbuminuria is required to inform new interventions. We determined the incidence and risk factors for microalbuminuria [albumin excretion rate (AER) 20 to 200 microg/min] in the EURODIAB Prospective Complications Study.

METHODS

This is a seven-year follow-up (between 1988 and 1991) of 1134 normoalbuminuric men and women (aged 15 to 60) with type 1 diabetes from 31 European centers. Risk factors and AER were measured centrally.

RESULTS

The incidence of microalbuminuria was 12.6% over 7.3 years. Independent baseline risk factors were HbA1c (7.1 vs. 6.2%, P = 0.0001) and AER (9.6 vs. 7.8 microg/min, P = 0.0001) and, independent of these, fasting triglyceride (0.99 vs. 0.88 mmol/L, P = 0.01), low-density lipoprotein cholesterol (3.5 vs. 3.2 mmol/L, P = 0.02), body mass index (24.0 vs. 23.4 kg/m2, P = 0.01), and waist to hip ratio (WHR; 0.85 vs. 0.83, P = 0.009). Triglyceride and WHR risk factors were nearly as strong as AER in predicting microalbuminuria (standardized regression effects of 1.3 for triglyceride and WHR and 1.5 for AER). Blood pressure at follow-up, but not at baseline, was also raised in those who progressed. There was no evidence of a threshold of HbA1c on microalbuminuria risk.

CONCLUSIONS

The incidence of microalbuminuria in patients with type 1 diabetes remains high, and there is no apparent glycemic threshold for it. Markers of insulin resistance, such as triglyceride and WHR, are strong risk factors. Systemic blood pressure is not raised prior to the onset of microalbuminuria.

The association of heart-rate variability with cardiovascular risk factors and coronary artery calcification: a study in type 1 diabetic patients and the general population

OBJECTIVE

To examine the association of heart-rate variability with cardiovascular risk factors and coronary calcification in type 1 diabetic and nondiabetic subjects without a history of cardiovascular disease. Reduced heart-rate variability is associated with increased risk of coronary events. Whether it is associated with coronary atherosclerosis is unknown.

RESEARCH DESIGN AND METHODS

Power spectral analysis was used to define heart-rate variability in a cross-sectional study of 160 type 1 diabetic patients and 163 randomly selected nondiabetic adults from the general population aged 30-55 years. Coronary artery calcification was measured using electron beam-computed tomography.

RESULTS

Reduced heart-rate variability was associated with similar risk factors in the diabetic and nondiabetic subjects, namely higher HbA(1c), triglycerides, systolic blood pressure, BMI, and albumin excretion rate. Reduced heart-rate variability was significantly associated with coronary artery calcification in all subjects (odds ratio per tertile lower total power = 1.5, P = 0.01). This association was not independent of blood pressure or BMI (odds ratio on adjustment = 1.3, P = 0.1).

CONCLUSIONS

Reduced heart-rate variability clusters with other cardiovascular disease risk factors, especially those that are more common in the insulin resistance syndrome, and is associated with increased coronary calcification in asymptomatic young adults. Whether reduced heart-rate variability leads to other risk factor disturbances or mediates the effects of other risk factors on atherosclerosis deserves further study.

Circulating plasma vascular endothelial growth factor and microvascular complications of type 1 diabetes mellitus: the influence of ACE inhibition

AIMS

To determine whether circulating plasma vascular endothelial growth factor (VEGF) is elevated in the presence of diabetic microvascular complications, and whether the impact of angiotensin-converting enzyme (ACE) inhibitors on these complications can be accounted for by changes in circulating VEGF.

METHODS

Samples (299/354 of those with retinal photographs) from the EUCLID placebo-controlled clinical trial of the ACE inhibitor lisinopril in mainly normoalbuminuric non-hypertensive Type 1 diabetic patients were used. Albumin excretion rate (AER) was measured 6 monthly. Geometric mean VEGF levels by baseline retinopathy status, change in retinopathy over 2 years, and by treatment with lisinopril were calculated.

RESULTS

No significant correlation was observed between VEGF at baseline and age, diabetes duration, glycaemic control, blood pressure, smoking, fibrinogen and von Willebrand factor. Mean VEGF concentration at baseline was 11.5 (95% confidence interval 6.0--27.9) pg/ml in those without retinopathy, 12.9 (6.0--38.9) pg/ml in those with non-proliferative retinopathy, and 16.1 (8.1--33.5) pg/ml in those with proliferative retinopathy (P = 0.06 for trend). Baseline VEGF was 15.2 pg/ml in those who progressed by at least one level of retinopathy by 2 years compared to 11.8 pg/ml in those who did not (P = 0.3). VEGF levels were not altered by lisinopril treatment. Results were similar for AER.

CONCLUSIONS

Circulating plasma VEGF concentration is not strongly correlated with risk factor status or microvascular disease in Type 1 diabetes, nor is it affected by ACE inhibition. Changes in circulating VEGF cannot account for the beneficial effect of ACE inhibition on retinopathy.

Lipid transfer protein activities in type 1 diabetic patients without renal failure and nondiabetic control subjects and their association with coronary artery calcification

This study examined the role of cholesteryl ester transfer (CET), cholesteryl ester transfer protein (CETP) activity, and phospholipid transfer protein (PLTP) activity in the increased prevalence of coronary artery calcification (CAC) in diabetic subjects compared with nondiabetic subjects and in the loss of the sex difference in CAC in diabetes. CETP activity, PLTP activity, and CET were measured in 195 type 1 diabetic subjects without renal failure and 194 nondiabetic control subjects of similar age (30-55 years) and sex distribution (50% female). CAC was quantified with electron beam computed tomography. CETP activity was higher in diabetic subjects (mean 84 arbitrary units [AU]) than in nondiabetic subjects (80 AU, P = 0.028). PLTP activity was also higher in diabetic subjects (96 AU) than in nondiabetic subjects (81 AU, P < 0.001). However, CET was lower in diabetic men (geometric mean 32 nmol. ml(-1).h(-1)) than nondiabetic men (37 nmol.ml(-1).h(-1), P = 0.004) and did not differ between diabetic (30 nmol. ml(-1).h(-1)) and nondiabetic (32 nmol.ml(-1).h(-1), P = 0.3) women. CETP and PLTP activities were not associated with CAC. CET was positively associated with CAC in both diabetic and nondiabetic subjects (odds ratio per 10 nmol.ml(-1).h(-1) increase in CET in all subjects = 1.4, P = 0.001). The prevalence of CAC was similar in diabetic (51%) and nondiabetic (54%, P = 0.7) men but was much higher in diabetic (47%) than nondiabetic (21%, odds ratio 3.6, P < 0.001) women so that there was no sex difference in CAC in diabetic subjects. The odds of CAC in diabetic women compared with nondiabetic women was altered little by adjustment for CETP activity, PLTP activity, or CET (odds ratio on adjustment 3.7, P < 0.001). The greater effect of diabetes on CAC in women than in men, i.e., the loss of the sex difference in CAC, was independent of CETP and PLTP activity and CET. In conclusion, among both diabetic and nondiabetic subjects, higher cholesteryl ester transfer is a risk factor for CAC. However, abnormalities in cholesteryl ester transfer or lipid transfer protein activities do not underlie the increased CAC risk in diabetic women compared with nondiabetic women or the loss of the sex difference in CAC in diabetes.

Glycemic index in the diet of European outpatients with type 1 diabetes: relations to glycated hemoglobin and serum lipids

BACKGROUND

Little is known about the variation of the glycemic index (GI) in the diet of European outpatients with type 1 diabetes and how the GI of a commonly consumed diet is associated with metabolic control.

OBJECTIVE

The present study examined the calculated dietary GI of European outpatients with type 1 diabetes for possible relations to glycated hemoglobin (Hb A(1c)) and serum lipid concentrations.

DESIGN

The relation of the GI (calculated from a 3-d dietary record) to Hb A(1c), serum cholesterol (total, LDL, and HDL), and fasting triacylglycerol was analyzed in 2810 people with type 1 diabetes from the EURODIAB Complications Study.

RESULTS

The GI was independently related to Hb A(1c) (P = 0.0001). Compared with the highest GI quartile (median GI: 89), adjusted Hb A(1c) in the lowest GI quartile (median GI: 75) was 11% lower in patients from southern European centers and 6% lower in patients from northern, western, and eastern European centers. Of the serum lipids, only the HDL cholesterol in patients from these European centers was independently related to the GI (P = 0.002). In southern European centers, the consumption of pasta, temperate-climate fruit, white bread, and potatoes largely determined the patients' dietary GI, whereas in the northern, western, and eastern European centers, consumption of bread, potatoes, and temperate-climate fruit was most relevant.

CONCLUSIONS

This study in European patients with type 1 diabetes showed that a lower dietary GI is related to lower Hb A(1c) concentrations, independently of fiber intake. The consumption of bread and pasta had the biggest effect on the overall dietary GI of European outpatients.

Markers of insulin resistance are strong risk factors for retinopathy incidence in type 1 diabetes

OBJECTIVE

To determine the incidence of retinopathy and the relative importance of its risk factors in type 1 diabetes.

RESEARCH DESIGN AND METHODS

This is a 7.3-year follow-up of 764 of 1,215 (63%) people with type 1 diabetes across Europe, aged 15-60 years at baseline with no retinopathy (the EURODIAB Prospective Complications Study). Retinal photographs were taken at baseline and follow-up and risk factors were assessed to a standard protocol.

RESULTS

Retinopathy incidence was 56% (429/764, 95% CI 52-59%). Key risk factors included diabetes duration and glycemic control. We found no evidence of a threshold effect for HbA1c on retinopathy incidence. Univariate associations were observed between incidence and albumin excretion rate, cholesterol, triglyceride, fibrinogen, von Willebrand factor, gamma-glutamyltransferase, waist-to-hip ratio, and insulin dose. No associations were observed for blood pressure, cardiovascular disease, or smoking. Independent risk factors, as assessed by standardized regression effects, were HbA1C (1.93, P = 0.0001), duration (1.32, P = 0.008), waist-to-hip ratio (1.32, P = 0.01), and fasting triglyceride (1.24, P = 0.04).

CONCLUSIONS

Retinopathy incidence in type 1 diabetes remains high. Key risk factors include diabetes duration and glycemic control, with no evidence of a threshold for the latter. Other independent risk factors, such as waist-to-hip ratio and triglyceride levels, both markers of insulin resistance, were strongly related to incidence.

Relationship between plasma sialic acid concentration and microvascular and macrovascular complications in type 1 diabetes: the EURODIAB Complications Study

OBJECTIVE

To test the hypothesis that an increased plasma concentration of sialic acid, a marker of the acute-phase response, is related to the presence of diabetic micro- and macrovascular complications in type 1 diabetes.

RESEARCH DESIGN AND METHODS

We investigated the relationship between plasma sialic acid concentration and nephropathy, retinopathy, neuropathy, and coronary heart disease (CHD) in a cross-sectional survey of 1,369 people with type 1 diabetes. Subjects were participants in the EURODIAB IDDM Complications Study, which involved 31 centers in 16 European countries.

RESULTS

There was a significantly increasing trend of plasma sialic acid with severity of retinopathy (P < 0.001 in men) and with degree of urinary albumin excretion (P < 0.001 men, P < 0.01 women). Plasma sialic acid correlated with increasing plasma creatinine concentration (P < 0.009 men, P < 0.0002 women), and men with neuropathy had a higher plasma sialic acid concentration than those without (P < 0.006). There was no significant correlation between plasma sialic acid and CHD in either sex. Elevated plasma sialic acid concentrations were also associated with several risk factors for diabetic vascular disease: diabetes duration, HbA1c, plasma triglyceride and cholesterol concentrations, waist-to-hip ratio, hypertension and smoking (in men), and low physical exercise (in women). In multiple logistic regression analysis, plasma sialic acid was independently related to proliferative retinopathy and urinary albumin excretion rate in men.

CONCLUSIONS

We conclude that an elevated plasma sialic concentration is strongly related to the presence of microvascular complications in type 1 diabetes, especially retinopathy and nephropathy. Further study of acute-phase response markers and mediators as indicators or predictors of diabetic microvascular complications is therefore justified.

Plasma lipids and urinary albumin excretion rate in Type 1 diabetes mellitus: the EURODIAB IDDM Complications Study

AIMS

To examine the relationship between increased urinary albumin excretion rate and fasting plasma lipids among male and female respondents to the EURODIAB IDDM Complications Study, and attempt to explain inconsistencies in previous reports.

METHODS

A cross-sectional study of 3250 randomly selected Type 1 diabetic patients from 31 diabetes clinics in 16 European countries was carried out between 1989 and 1990. Plasma lipids and urinary albumin were measured centrally. The present analysis was confined to the subgroup of 2205 patients attending after a 10-12 h overnight fast. Mean age was 33 years (SD 10) and mean duration of Type 1 diabetes mellitus was 15 years (SD 9).

RESULTS

The prevalence of microalbuminuria (24-h urinary albumin excretion rate 20-200 microg/min) was 21.7% (95% confidence interval 19.9-23.5) and macroalbuminuria (24-h urinary albumin excretion rate > 200 microg/min) 7.8% (6.6-9.0). In comparison to patients with normal urinary albumin excretion rate (< 20 microg/min), and after controlling for age, sex, glycaemic control, duration of diabetes and current smoking, macroalbuminuria was associated with significantly (P<0.01) increased fasting plasma triglycerides, cholesterol, LDL-cholesterol, cholesterol:HDL-cholesterol ratio and, in women, reduced HDL-cholesterol. In men and women with microalbuminuria, the only significant association was with increased plasma triglycerides.

CONCLUSIONS

These data confirm that there is an association between fasting plasma lipids and increasing urinary albumin excretion rate in European Type 1 diabetic patients. In microalbuminuric patients, however, the association was weaker than previously reported and partly explained by confounding factors.

A locus influencing total serum cholesterol on chromosome 19p: results from an autosomal genomic scan of serum lipid concentrations in Pima Indians

A genome-wide linkage study was analyzed to identify loci that influence serum lipid concentrations in Pima Indians. Linkage analyses were conducted for total cholesterol measured in 998 siblings from 292 nuclear families, for total triglycerides in 547 siblings from 188 families, and for high density lipoprotein (HDL) cholesterol in 590 siblings from 201 families. Genotypes were generated for 516 autosomal microsatellite markers. Multipoint variance components methods were used to assess linkage. The strongest evidence for linkage with total cholesterol was on chromosome 19p (lod score 3.89), in the vicinity of the marker D19S1034, which is near the low density lipoprotein receptor gene. The strongest evidence for linkage with HDL cholesterol was on chromosome 3q (lod score 2.64) near D3S3053. For triglycerides, the strongest evidence for linkage was on chromosome 2p near D2S1788 (lod score 1.70) and on chromosome 3p near D3S2406 (lod score 1.77). This genomic scan provides evidence for a locus influencing total cholesterol concentration on chromosome 19p. It also suggests a locus influencing HDL cholesterol on chromosome 3q.

The effect of type 1 diabetes mellitus on the gender difference in coronary artery calcification

OBJECTIVES

To examine whether the gender difference in coronary artery calcification, a measure of atherosclerotic plaque burden, is lost in type 1 diabetic patients, and whether abnormalities in established coronary heart disease risk factors explain this.

BACKGROUND

Type 1 diabetes abolishes the gender difference in coronary heart disease mortality because it is associated with a greater elevation of coronary disease risk in women than men. The pathophysiological basis of this is not understood.

METHODS

Coronary artery calcification and coronary risk factors were compared in 199 type 1 diabetic patients and 201 nondiabetic participants of similar age (30 to 55 years) and gender (50% female) distribution. Only one subject had a history of coronary disease. Calcification was measured with electron beam computed tomography.

RESULTS

In nondiabetic participants there was a large gender difference in calcification prevalence (men 54%, women 21%, odds ratio 4.5, p < 0.001), half of which was explained by established risk factors (odds ratio after adjustment = 2.2). Diabetes was associated with a greatly increased prevalence of calcification in women (47%), but not men (52%), so that the gender difference in calcification was lost (p = 0.002 for the greater effect of diabetes on calcification in women than men). On adjustment for risk factors, diabetes remained associated with a threefold higher odds ratio of calcification in women than men (p = 0.02).

CONCLUSIONS

In type 1 diabetes coronary artery calcification is greatly increased in women and the gender difference in calcification is lost. Little of this is explained by known coronary risk factors.

Differences in HDL-cholesterol:apoA-I + apoA-II ratio and apoE phenotype with albuminuric status in Type I diabetic patients

AIMS/HYPOTHESIS

To examine whether the HDL-cholesterol:apoA-I + apoA-II ratio and the epsilon2 allele are related to albuminuria at baseline and whether they are risk factors for progression of albuminuria in a cohort study of patients with Type I (insulin-dependent) diabetes mellitus.

METHODS

At baseline, the study cohort comprised 617 patients, aged 15-60 years, from seven European diabetic centres of the EURODIAB study. Albumin excretion rate, measured in a central laboratory, was categorised as normoalbuminuria at 20 microg/min or less, microalbuminuria between 20 and 200 microg/min or macroalbuminuria at 200 microg/min or over. Of the 250 patients who were normoalbuminuric at baseline and had follow-up albuminuria measurements, 34 patients were defined as early progressors.

RESULTS

At baseline, the mean HDL-cholesterol:apoA-I + apoA-II ratio was lower in macroalbuminuric patients (0.79, 95 % CI:0.74-0.83) compared with normoalbuminuric (0.88, 95 % CI:0.87-0.90) patients (p = 0.0002, adjusted for age and sex). At follow-up, 34 patients who progressed from normoalbuminuria to microalbuminuria or macroalbuminuria also had a slightly lower baseline ratio (0.85, 95% CI:0.80-0.89) than those 216 who remained normoalbuminuric (0.89, 95 % CI:0.87-0.92) (adjusted p = 0.08). Neither of these relations were independent of LDL-cholesterol or fasting triglyceride. There was no association of the epsilon2 allele with albuminuria either at baseline (OR = 1.4, 95% CI:0.7-2.8) or with progression of albuminuria (OR = 0.4, 95 % CI:0.1-3.5).

CONCLUSION/INTERPRETATION

There is an inverse relation of HDL-cholesterol:apoA-I + apoA-II ratio with albuminuria at baseline. This lower ratio in microalbuminuric or macroalbuminuric patients could contribute to the increased risk of cardiovascular disease associated with nephropathy. There is weak evidence that HDL-composition is a risk factor for progression of albuminuria and no association of the epsilon2 allele with diabetic nephropathy.

Methods of assessing the quality of diabetes care

To monitor the progress of the improvement of diabetes care several methods are available such as clinical databases, epidemiological studies, and mortality and morbidity statistics. Developments in information technology have made clinical databases such as the DiabCare System a method of high potential because of high generalisability and the potential participation of many clinicians. Epidemiological studies utilize standardized methods to assess disease outcomes and to quantify risk factors. For example, the EURODIAB IDDM Complications Study indicated that life-style factors may have a direct influence on the risk of complications: 21% of 272 patients aged 15-19 years were smokers, rising to above 30% in those aged 20 and above (n = 1,193). This was associated with poor glycemic control in all age groups. Mortality and mortality statistics have the problem of under-ascertainment but they still provide evidence for substantial excess rates in young IDDM subjects with wide regional variations. Thus, for analysing the outcomes of improvements in the quality of care all available information sources have to be utilized, taking care to assess their accuracy and generalisibility.

Organization and sequences of p-hydroxybenzaldehyde dehydrogenase and other plasmid-encoded genes for early enzymes of the p-cresol degradative pathway in Pseudomonas putida NCIMB 9866 and 9869

The gene (designated pchA) encoding the aldehyde dehydrogenase that is required to metabolise the p-hydroxybenzaldehyde produced by the degradation of p-cresol in Pseudomonas putida NCIMB 9866 and 9869 has been identified on plasmids pRA4000 and pRA500, respectively. The gene lies immediately upstream of the pchC and pchF genes encoding the subunits of p-cresol methylhydroxylase (PCMH), the preceeding enzyme in the p-cresol degradative pathway. In pRA500 the latter genes are followed by the genes encoding the alpha (pcaG) and beta (pcaH) subunits of protocatechuate-3,4-dioxygenase, whereas in pRA4000 the genes encoding PCMH are followed by an open reading frame encoding a protein that is similar to the maturase-related protein of P. alcaligenes. A gene, designated pchX, that encodes a protein of unknown function was identified between the pchC and pchF genes in both plasmids.