Carbohydrate sources and glycaemic control in Type 1 diabetes mellitus. EURODIAB IDDM Complications Study Group

AIMS

Little information is available on the relationship between glycated haemoglobin levels and the source or amount of dietary carbohydrate. The present study compares the association of carbohydrate intake with HbA1c between European individuals with Type 1 diabetes mellitus injecting insulin once or twice per day and those with > or = 3 daily injections.

METHODS

The relation of carbohydrate intake (total, cereal, fruit, vegetable, milk, and potato carbohydrate assessed by a 3-day dietary record) to HbA1c was examined in 2084 patients (age 32.6 +/- 10.2 years, duration of diabetes 14.8 +/- 9.5 years) included in the EURODIAB Complications Study.

RESULTS

In both insulin injection regimens, an increased intake of total carbohydrate (% of energy) and a higher consumption of potato carbohydrates (g) were associated with higher levels of HbA1c, whereas an increased intake of vegetable carbohydrate (g) was inversely related to HbA1c. These tendencies were all more pronounced in persons with one or two daily insulin injections. Consumption of cereal and fruit carbohydrates (g) was not related to HbA1c, irrespective of the insulin injection regimen. A trend of HbA1c to increase with higher intakes of milk carbohydrate was confined to those with one or two insulin injections per day (test for interaction: P = 0.01).

CONCLUSIONS

In particular, subjects with only 1 or 2 daily insulin injections per day should receive specific advice to correctly consider milk and potato carbohydrates. On the other hand, people with Type 1 diabetes may profit from a higher consumption of vegetable carbohydrates for their levels of HbA1c.

Different risk factors of microangiopathy in patients with type I diabetes mellitus of short versus long duration. The EURODIAB IDDM Complications Study

AIMS/HYPOTHESIS

To identify factors associated with early development of and late protection from microvascular complications in subjects with Type I (insulin-dependent) diabetes mellitus.

METHODS

The frequency of microvascular complications and their relation to risk factors were studied in 300 Type I diabetic subjects with short duration of disease (< or = 5 years) compared with 1062 subjects with long duration (> or = 14 years). Microvascular disease was defined as the presence of either retinopathy (assessed from centrally-graded retinal photographs) or urinary albumin excretion rate of more than 20 micrograms/min.

RESULTS

The prevalence of microvascular disease was 25% in the short duration group. In the long duration group 18% had no evidence of microvascular complications. In the short duration group factors associated with early development of complications were cigarette smoking and a family history of hypertension. Subjects free of microvascular complications in spite of long duration of diabetes had better glycaemic control, lower blood pressure, better lipid profile and lower von Willebrand factor levels.

CONCLUSION/INTERPRETATION

At the early stages of Type I diabetes, cigarette smoking and genetic susceptibility to hypertension are important risk factors for microvascular complications. At a later stage, additional risk factors are poorer glycaemic control, higher blood pressure, and an unfavourable lipid profile possibly associated with endothelial dysfunction. Many of these factors are amenable to long-term intervention which should be started as soon as possible in the course of the disease.

Associations of fat and cholesterol intake with serum lipid levels and cardiovascular disease: the EURODIAB IDDM Complications Study

The EURODIAB IDDM Complications Study, a cross-sectional, clinic-based study examined the fat and cholesterol intakes of European individuals with type 1 diabetes for possible relations to serum lipid levels (total cholesterol, HDL- and LDL-cholesterol, fasting triglycerides) and to the prevalence of cardiovascular disease (past history or electrocardiogram abnormalities). Fat intake (total fat, saturated fat, cholesterol) from 2,868 subjects with type 1 diabetes (mean age 32.9 +/- 10.2 years (range: 14-61 years), mean diabetes duration 14.7 +/- 9.4 years (range: 1-56 years)) was assessed by a standardized 3-day dietary record at the Nutrition Co-Ordinating Centre (Düsseldorf). Serum lipid levels were determined in the central laboratory (London) by standard enzymatic methods. Energy-adjusted total and LDL-cholesterol levels increased significantly with higher intakes of total fat, saturated fat and cholesterol. However, these relations were largely explained by concomitant decreases in dietary fibre intake. For levels of HDL-cholesterol and triglycerides no independent associations were observed with fat or cholesterol intake. Increased intakes of total fat, saturated fat and cholesterol were also related to higher prevalences of cardiovascular disease. These associations were, however, no longer significant after adjustment for dietary fibre intake for which we previously demonstrated independent associations with the serum cholesterol pattern and CVD. Since higher fat intakes are commonly accompanied by lower carbohydrate and fibre intakes we conclude that restricted intakes of cholesterol, saturated fat and total fat combined with higher fibre intakes beneficially affect both the levels of total and LDL-cholesterol and the risk for cardiovascular disease in European individuals with type 1 diabetes.

Fiber intake, serum cholesterol levels, and cardiovascular disease in European individuals with type 1 diabetes. EURODIAB IDDM Complications Study Group

OBJECTIVE

A cross-sectional analysis of dietary fiber intake was performed in European type 1 diabetic patients enrolled in the EURODIAB IDDM Complications Study to explore its potential relationship to serum cholesterol levels and the prevalence of cardiovascular disease (CVD).

RESEARCH DESIGN AND METHODS

Dietary intake was assessed by a standardized 3-day dietary record. For analysis of fiber intake (total, soluble, and insoluble) and its associations with CVD (past history or electrocardiogram abnormalities), complete data were available from 1,050 male and 1,012 female individuals. Relationships of fiber intakes to serum cholesterol levels (total, HDL, and LDL cholesterol) were examined in 926 men and 881 women with type 1 diabetes.

RESULTS

Higher intakes of total fiber (g/day) were independently associated with significantly higher levels of HDL cholesterol in male (P = 0.01) and female individuals (P = 0.03). Fiber intakes of men with type 1 diabetes were also inversely related to ratios of total cholesterol to HDL cholesterol (P = 0.0001) and levels of LDL cholesterol (P = 0.0002). A protective effect of total fiber intake against CVD was observed for female subjects, where a significant trend was maintained after adjustment for potential confounders, including energy and saturated fat (P = 0.03 vs. P = 0.2 in men). Results were similar in separate analyses of soluble and insoluble fiber.

CONCLUSIONS

The present study demonstrates that higher fiber intakes are independently related to beneficial alterations of the serum cholesterol pattern in men and to a lower risk for CVD in European insulin-dependent women. Beneficial effects can already be observed for fiber amounts within the range commonly consumed by outpatients with type 1 diabetes.

The relation between QTc interval prolongation and diabetic complications. The EURODIAB IDDM Complication Study Group

The prevalence of QT interval prolongation is higher in people with diabetes and its complications. Sudden death has been reported as a common cause of death in insulin-dependent diabetic patients affected by autonomic neuropathy. It has been postulated that QT prolongation predisposes to cardiac arrhythmias and sudden death. In this analysis the prevalence of QT interval prolongation and its relation with diabetic complications were evaluated in the EURODIAB IDDM Complications Study (3250 insulin-dependent diabetic patients attending 31 centres in 16 European countries). Five consecutive RR and QT intervals were measured with a ruler on the V5 lead of the resting ECG tracing and the QT interval corrected for the previous cardiac cycle length was calculated according to the Bazett's formula. The prevalence of an abnormally prolonged corrected QT was 16% in the whole population, 11% in males and 21 % in females (p < 0.001). The mean corrected QT was 0.412 s in males and 0.422 s in females (p < 0.001). Corrected QT duration was independently associated with age, HbA1c and blood pressure. Corrected QT was also correlated with ischaemic heart disease and nephropathy but this relation appeared to be stronger in males than in females. Male patients with neuropathy or impaired heart rate variability or both showed a higher mean adjusted corrected QT compared with male patients without this complication. The relation between corrected QT prolongation and autonomic neuropathy was not observed among females. In conclusion we have shown that corrected QT in insulin-dependent diabetic female patients is longer than in male patients, even in the absence of diabetic complications known to increase the risk of corrected QT prolongation.

Prevalence and management of hypertension in type 1 diabetes mellitus in Europe: the EURODIAB IDDM Complications Study

AIM

To examine the prevalence of hypertension and the rates of hypertension awareness by investigating treatment and control among respondents to the EURODIAB IDDM Complications Study, and to explore the variation in hypertension management by age, sex and end-organ damage.

METHODS

A cross-sectional study, examining 3250 randomly selected Type 1 diabetic patients from 31 diabetes clinics in 16 European countries between 1989 and 1990. Mean age was 32.7 years (SD= 10.0) and mean duration of diabetes mellitus (DM) was 14.7 years (SD=9.3). Subjects were asked about a history of high blood pressure (BP) and current prescribed medications were recorded by the subject's physician. Hypertension was defined as having a systolic BP > or = 140 mmHg or diastolic BP > or = 90 mmHg or current use of antihypertensives. Control was defined as a BP < 130/85 mmHg.

RESULTS

Twenty-four per cent of subjects had hypertension, among whom fewer than one-half (48.5%) were aware of a previous diagnosis and a similar proportion (42.2%) were on treatment. Only 11.3% of those with hypertension were both treated and controlled. The majority (81%) of those receiving drug therapy for hypertension were on a single drug, most commonly an angiotensin-converting enzyme inhibitor (47%).

CONCLUSION

These data show the extent of undermanagement of hypertension in Type 1 DM across Europe prior to the publication of the St. Vincent Declaration and provide a useful baseline against which future improvements in the management of hypertension can be monitored.

Cardiovascular disease in insulin dependent diabetes mellitus: similar rates but different risk factors in the US compared with Europe

BACKGROUND

Cardiovascular disease (CVD) in insulin dependent diabetes mellitus (IDDM) has been linked to renal disease. However, little is known concerning international variation in the correlations with hyperglycaemia and standard CVD risk factors.

METHODS

A cross-sectional comparison was made of prevalence rates and risk factor associations in two large studies of IDDM subjects: the Pittsburgh Epidemiology of Diabetes Complications Study (EDC) and the EURODIAB IDDM Complications Study from 31 centres in Europe. Subgroups of each were chosen to be comparable by age and duration of diabetes. The EDC population comprises 286 men (mean duration 20.1 years) and 281 women (mean duration 19.9 years); EURODIAB 608 men (mean duration 18.1 years) and 607 women (mean duration 18.9 years). The mean age of both populations was 28 years. Cardiovascular disease was defined by a past medical history of myocardial infarction, angina, and/or the Minnesota ECG codes (1.1-1.3, 4.1-4.3, 5.1-5.3, 7.1).

RESULTS

Overall prevalence of CVD was similar in the two populations (i.e. men 8.6% versus 8.0%, women 7.4% versus 8.5%, EURODIAB versus EDC respectively), although EDC women had a higher prevalence of angina (3.9% versus 0.5%, P < 0.001). Multivariate modelling suggests that glycaemic control (HbA1c) is not related to CVD in men. Age and high density lipoprotein cholesterol predict CVD in EURODIAB, while triglycerides and hypertension predict CVD in EDC. For women in both populations, age and hypertension (or renal disease) are independent predictors. HbA1c is also an independent predictor-inversely in EURODIAB women (P < 0.008) and positively in EDC women (P = 0.03). Renal disease was more strongly linked to CVD in EDC than in EURODIAB.

CONCLUSIONS

Despite a similar prevalence of CVD, risk factor associations appear to differ in the two study populations. Glycaemic control (HbA1c) does not show a consistent or strong relationship to CVD.

Effect of angiotensin-converting enzyme (ACE) gene polymorphism on progression of renal disease and the influence of ACE inhibition in IDDM patients: findings from the EUCLID Randomized Controlled Trial. EURODIAB Controlled Trial of Lisinopril in IDDM

We examined whether the ACE gene insertion/deletion (I/D) polymorphism modulates renal disease progression in IDDM and how ACE inhibitors influence this relationship. The EURODIAB Controlled Trial of Lisinopril in IDDM is a multicenter randomized placebo-controlled trial in 530 nonhypertensive, mainly normoalbuminuric IDDM patients aged 20-59 years. Albumin excretion rate (AER) was measured every 6 months for 2 years. Genotype distribution was 15% II, 58% ID, and 27% DD. Between genotypes, there were no differences in baseline characteristics or in changes in blood pressure and glycemic control throughout the trial. There was a significant interaction between the II and DD genotype groups and treatment on change in AER (P = 0.05). Patients with the II genotype showed the fastest rate of AER progression on placebo but had an enhanced response to lisinopril. AER at 2 years (adjusted for baseline AER) was 51.3% lower on lisinopril than placebo in the II genotype patients (95% CI, 15.7 to 71.8; P = 0.01), 14.8% in the ID group (-7.8 to 32.7; P = 0.2), and 7.7% in the DD group (-36.6 to 37.6; P = 0.7). Absolute differences in AER between placebo and lisinopril at 2 years were 8.1, 1.7, and 0.8 microg/min in the II, ID, and DD groups, respectively. The significant beneficial effect of lisinopril on AER in the II group persisted when adjusted for center, blood pressure, and glycemic control, and also for diastolic blood pressure at 1 month into the study. Progression from normoalbuminuria to microalbuminuria (lisinopril versus placebo) was 0.27 (0.03-2.26; P = 0.2) in the II group, and 1.30 (0.33-5.17; P = 0.7) in the DD group (P = 0.6 for interaction). Knowledge of ACE genotype may be of value in determining the likely impact of ACE inhibitor treatment.

Relation of fibre intake to HbA1c and the prevalence of severe ketoacidosis and severe hypoglycaemia. EURODIAB IDDM Complications Study Group

The effect of dietary fibre intake on glycaemic control is still controversial. This study analysed the intake of natural dietary fibre in patients with Type I diabetes mellitus enrolled in the EURODIAB IDDM Complications Study to determine any associations with HbA1c levels and with the prevalence of severe ketoacidosis or severe hypoglycaemia. Dietary intake was assessed by a 3-day dietary record. The relation between intake of fibre (total, soluble and insoluble) and HbA1c was examined in 2065 people with Type I diabetes. Associations with severe ketoacidosis (requiring admission to hospital) and severe hypoglycaemia (requiring the help of another person) were analysed in 2687 people with Type I diabetes. Total fibre intake (g/day) was inversely related to HbA1c (p = 0.02), independently of carbohydrate intake, total energy intake and other factors regarding lifestyle and diabetes management. Severe ketoacidosis risk fell significantly with higher fibre intake (p = 0.002), with an adjusted odds ratio of 0.48 (95 % confidence interval 0.27 to 0.84) in the highest quartile ( > or = 23.0 g fibre/day) compared with the lowest quartile ( < or = 13.7 g fibre/day). The occurrence of severe hypoglycaemia was not related to fibre intake. Beneficial effects of fibre on HbA1c and the risk of severe ketoacidosis were particularly pronounced in patients from southern European centres. This study shows that higher fibre intake is independently related to a reduction in HbA1c levels in European people with Type I diabetes. Furthermore, increased fibre intake may reduce the risk of severe ketoacidosis. These beneficial effects were already observed for fibre intake within the range commonly consumed by people with Type I diabetes.

Parental history of hypertension and parental history of diabetes and microvascular complications in insulin-dependent diabetes mellitus: the EURODIAB IDDM Complications Study

Diabetic nephropathy clusters in families, suggesting an inherited predisposition. Parental history of hypertension and of Type 2 diabetes mellitus have been associated with nephropathy in offspring with Type 1 diabetes in some studies but not in others. The associations of parental history of hypertension and of diabetes with both albuminuria and proliferative retinopathy were studied in a large cross-sectional study of 3250 patients with Type 1 diabetes, from 16 European countries. Albuminuria was associated with hypertension in a parent (p < 0.01 in men, p < 0.05 in women), adjusted for age. Patients with a parental history of hypertension had a higher prevalence of hypertension (p < 0.001 in men, p < 0.01 in women) and a higher prevalence of parental diabetes (p < 0.001 in men, p < 0.001 in women). The association of albuminuria with parental hypertension was independent of parental diabetes in men but not women (OR = 1.28 in men p = 0.04, OR = 1.25 in women p = 0.09) and was not independent of hypertension in the patient him/herself in either sex. Albuminuria was associated with parental diabetes in women only (OR = 1.36, p = 0.04). This association was independent of both parental hypertension and hypertension in the patient herself. Proliferative retinopathy was not associated with parental hypertension or diabetes. The implications of these data are that both candidate genes for hypertension and Type 2 diabetes should be considered in the search for the genetic determinants of diabetic nephropathy.

Socioeconomic gradient in morbidity and mortality in people with diabetes: cohort study findings from the Whitehall Study and the WHO Multinational Study of Vascular Disease in Diabetes

OBJECTIVE

To assess whether the inverse socioeconomic mortality gradient observed in the general population persists in diabetic people.

DESIGN

The Whitehall cohort study and the London cohort of the WHO multinational study of vascular disease in diabetes.

SETTING

London.

SUBJECTS

17,264 male civil servants (17,046 without diabetes, 218 with diabetes) aged 40-64 examined in 1967-9, and 300 people with diabetes aged 35-55 from London clinics examined in 1975-7. Both cohorts were followed up until January 1995.

MAIN OUTCOME MEASURES

Mortality from all causes, cardiovascular disease, and ischaemic heart disease.

RESULTS

In both cohorts people in the lower social groups were older, had higher blood pressure, and were more likely to smoke. In the Whitehall study, the prevalence of heart disease was higher in the lowest social group compared with the highest group, by 6% among non-diabetic people (P = 0.0001) and by 14% among diabetic subjects (P = 0.02). In the WHO study proteinuria was more common in the lowest social group compared with the highest (27% v 15%, P = 0.01), as was retinopathy (54% v 48%, P = 0.5). There was a clear socioeconomic gradient in all cause mortality in both cohorts, with death rates being about twice as high in the lowest compared with the highest social groups. In the Whitehall study this gradient was similar in both diabetic and non-diabetic subjects, and it persisted for mortality from cardiovascular disease and from ischaemic heart disease. About half of the increased risk of death in the lowest social group was accounted for by blood pressure and smoking.

CONCLUSIONS

We confirm the existence of an inverse socioeconomic mortality gradient in diabetic people and suggest that this is largely due to conventional cardiovascular risk factors.

Effect of lisinopril on progression of retinopathy in normotensive people with type 1 diabetes. The EUCLID Study Group. EURODIAB Controlled Trial of Lisinopril in Insulin-Dependent Diabetes Mellitus

BACKGROUND

Retinopathy commonly occurs in people with type 1 diabetes. Strict glycaemic control can decrease development and progression of retinopathy only partially. Blood pressure is also a risk factor for microvascular complications. Antihypertensive therapy, especially with inhibitors of angiotensin-converting enzyme (ACE), can slow progression of nephropathy, but the effects on retinopathy have not been established. We investigated the effect of lisinopril on retinopathy in type 1 diabetes.

METHODS

As part of a 2-year randomised double-blind placebo-controlled trial, we took retinal photographs at baseline and follow-up (24 months) in patients aged 20-59 in 15 European centres. Patients were not hypertensive, and were normoalbuminuric (85%) or microalbuminuric. Retinopathy was classified from photographs on a five-level scale (none to proliferative).

FINDINGS

The proportion of patients with retinopathy at baseline was 65% (117) in the placebo group and 59% (103) in the lisinopril group (p = 0.2). Patients on lisinopril had significantly lower HbA1c at baseline than those on placebo (6.9% vs 7.3 p = 0.05). Retinopathy progressed by at least one level in 21 (13.2%) of 159 patients on lisinopril and 39 (23.4%) of 166 patients on placebo (odds ratio 0.50 [95% CI 0.28-0.89], p = 0.02). This 50% reduction was the same when adjusted for centre and glycaemic control (0.55 [0.30-1.03], p = 0.06). Lisinopril also decreased progression by two or more grades (0.27 [0.07-1.00], p = 0.05), and progression to proliferative retinopathy (0.18 [0.04-0.82], p = 0.03). Progression was not associated with albuminuric status at baseline. Treatment reduced retinopathy incidence (0.69 [0.30-1.59], p = 0.4).

INTERPRETATION

Lisinopril may decrease retinopathy progression in non-hypertensive patients who have type 1 diabetes with little or no nephropathy. These findings need to be confirmed before changes to clinical practice can be advocated.

Mortality and morbidity from diabetes in South Asians and Europeans: 11-year follow-up of the Southall Diabetes Survey, London, UK

Over 20% of middle aged and elderly South Asian people throughout the world have diabetes. The associated mortality and morbidity risks are unclear. We compared mortality and morbidity in a cohort of South Asian and European people with diabetes in London, UK, in an 11-year follow-up of a population-based sample of 730 South Asians (mean age 55 in 1984) and 304 Europeans (mean age 67 in 1984) with diabetes aged 30 years and above in 1984. By 1995, 242 (33%) of South Asians, and 172 (57%) of Europeans had died. The all-cause mortality rate ratio (South Asian versus European) was 1.50 (95% CI 0.72-3.12) for those aged 30-54 years at baseline. Ethnic differences in mortality rates were abolished or reversed in people aged 65 years and above at baseline. The mortality rate ratio for circulatory deaths was 1.80 (95% CI 1.03-3.16, p < 0.05) and for heart disease was 2.02 (95% CI 1.04-3.92, p < 0.05) in those aged 30-64 years at baseline. Seventy-seven per cent of South Asian deaths were caused by circulatory disease, compared with 46% of European deaths. South Asian survivors were 3.8 times (95% CI 1.8-8.0, p = 0.001) more likely to report a history of myocardial infarction than Europeans. South Asian adults with diabetes show a markedly increased predisposition to cardiovascular disease compared with Europeans, especially in younger people. This emphasizes the urgent need to reduce cardiovascular risk in this vulnerable group.

Which features of smoking determine mortality risk in former cigarette smokers with diabetes? The World Health Organization Multinational Study Group

OBJECTIVE

The effects of quitting smoking on mortality risk in individuals with diabetes is unknown and may differ from the benefits observed in the general population. We therefore determined the mortality risks in ex-smokers with diabetes, compared with subjects who have never smoked, by the number of years since quitting, the number of cigarettes smoked, and the number of years of smoking.

RESEARCH DESIGN AND METHODS

An international cohort study of 4,427 individuals with diabetes was studied. Baseline examinations were performed in 1975-1977 when smoking habits were determined by questionnaire. Mortality follow-up continued until 1988.

RESULTS

All-cause mortality risks were higher for recent quitters (1-9 years; relative risk [RR], 1.53 [95% CI 1.19-1.97]; P = 0.001) than for those who quit earlier (> or = 10 years; RR, 1.25 [95% CI 1.03-1.52]; P = 0.02), compared with subjects who have never smoked. These risks were highest in those who had smoked the longest (> or = 30 years: RR, 1.66 [95% CI 1.22-2.26]; P = 0.001; vs. 1-9 years: RR, 1.17 [95% CI 0.85-1.60]; P = 0.3). Risks were also highest in those who had smoked the most and least number of cigarettes. Adjustment for key confounders, which included a previous history of heart disease, proteinuria, and blood pressure, did not materially affect these relationships.

CONCLUSIONS

Quitting smoking does reduce mortality risk in ex-smokers with diabetes, but risks remain high several years after quitting and are highly dependent on the duration of smoking. Thus, individuals with diabetes who smoke should be encouraged to quit as soon as possible in the course of disease.

Fibrinogen and von Willebrand factor in IDDM: relationships to lipid vascular risk factors, blood pressure, glycaemic control and urinary albumin excretion rate: the EURODIAB IDDM Complications Study

The interrelationships between fibrinogen, von Willebrand factor, a marker of vascular endothelial cell damage, and serum lipids were explored in well-characterised subjects with insulin-dependent diabetes mellitus. The 2091 subjects were enrolled into a cross-sectional, clinic-based study of complications, from 16 European countries: the EURODIAB IDDM Complications study. The anticipated significant relationships between both plasma fibrinogen and plasma von Willebrand factor concentrations and age and glycaemic control, and between fibrinogen and body mass index, were noted. Fibrinogen, adjusted for age and glycated haemoglobin concentration, was also related to smoking habits and was higher in the quartiles with highest systolic and diastolic blood pressures. There was a clustering of vascular risk factors, with a positive relationship between plasma fibrinogen and serum triglyceride concentrations in both genders and between fibrinogen and total cholesterol in males. An inverse relationship between fibrinogen and high density lipoprotein cholesterol was also apparent in males. A prominent feature was a positive relationship between both fibrinogen and von Willebrand factor and albumin excretion rate (p < 0.001 and p < 0.003 respectively) in those with retinopathy but not in those without this complication. In view of previous observations on blood pressure and albuminuria in these subjects the findings are consistent with the hypothesis that microalbuminuria and increased plasma von Willebrand factor are due to endothelial cell perturbation in response to mildly raised blood pressure in subjects with retinopathy. Fibrinogen may also contribute to microvascular disease and its relationships to lipid vascular risk factors suggest a possible pathogenic role in arterial disease in diabetes.

Is autonomic neuropathy a risk factor for severe hypoglycaemia? The EURODIAB IDDM Complications Study

The hypothesis that diabetic patients with autonomic neuropathy are at increased risk of severe hypoglycaemia was examined in an epidemiological study of over 3000 IDDM patients in Europe (EURODIAB IDDM Complications Study). Autonomic function was assessed by two standard cardiovascular tests: change in heart rate and systolic blood pressure on standing. Severe hypoglycaemia was defined as an attack serious enough to require the help of another person. Compared to patients (68%) reporting no attacks in the last year, those reporting one or more attacks were older (34.0 +/- 10.7 vs 32.1 +/- 9.9 years, mean +/- SD, p < 0.0001), had had diabetes for a longer period (16.6 +/- 9.5 vs 13.8 +/- 9.1 years, p < 0.0001), had better glycaemic control (HbA1c 6.4 +/- 1.8 vs 6.9 +/- 1.9%, p < 0.0001) and were more likely (p = 0.002) to have abnormal responses to both autonomic tests (13.0 vs 7.7%). A single abnormal autonomic response was not associated with an increased risk of severe hypoglycaemia. The odds ratio for severe hypoglycaemia in people with abnormal responses to both autonomic tests, compared to those with normal responses, was 1.7 (95% confidence interval 1.3, 2.2) after controlling for age, duration of diabetes, glycaemic control and study centre. In conclusion, a combined autonomic deficit in heart rate and blood pressure responses to standing is associated with only a modest increase in the risk of severe spontaneous hypoglycaemia. Although the increase in risk is not large, severe hypoglycaemia was a frequently reported event in this study. IDDM patients with deficient autonomic responses who strive for tight glycaemic control may therefore be at particular risk of severe hypoglycaemia.

Prevalence of diabetic peripheral neuropathy and its relation to glycaemic control and potential risk factors: the EURODIAB IDDM Complications Study

The EURODIAB IDDM Complications Study involved the examination of 3250 randomly selected insulin-dependent diabetic patients, from 31 centres in 16 European countries. Part of the examination included an assessment of neurological function including neuropathic symptoms and physical signs, vibration perception threshold, tests of autonomic function and the prevalence of impotence. The prevalence of diabetic neuropathy across Europe was 28% with no significant geographical differences. Significant correlations were observed between the presence of diabetic peripheral neuropathy with age (p < 0.05), duration of diabetes (p < 0.001), quality of metabolic control (p < 0.001), height (p < 0.01), the presence of background or proliferative diabetic retinopathy (p < 0.01), cigarette smoking (p < 0.001), high-density lipoprotein cholesterol (p < 0.001) and the presence of cardiovascular disease (p < 0.05), thus confirming previous associations. New associations have been identified from this study - namely with elevated diastolic blood pressure (p < 0.05), the presence of severe ketoacidosis (p < 0.001), an increase in the levels of fasting triglyceride (p < 0.001), and the presence of microalbuminuria (p < 0.01). All the data were adjusted for age, duration of diabetes and HbA1c. Although alcohol intake correlated with absence of leg reflexes and autonomic dysfunction, there was no overall association of alcohol consumption and neuropathy. The reported problems of impotence were extremely variable between centres, suggesting many cultural and attitudinal differences in the collection of such information in different European countries. In conclusion, this study has identified previously known and new potential risk factors for the development of diabetic peripheral neuropathy.

Differences in mortality and morbidity in African Caribbean and European people with non-insulin dependent diabetes mellitus: results of 20 year follow up of a London cohort of a multinational study

OBJECTIVE

To examine differences in morbidity and mortality due to non-insulin dependent diabetes in African Caribbeans and Europeans.

DESIGN

Cohort study of patients with non-insulin dependent diabetes drawn from diabetes clinics in London. Baseline investigations were performed in 1975-7; follow up continued until 1995.

PATIENTS

150 Europeans and 77 African Caribbeans with non-insulin dependent diabetes.

MAIN OUTCOME MEASURES

All cause and cardiovascular mortality; prevalence of microvascular and macrovascular complications.

RESULTS

Duration of diabetes was shorter in African Caribbeans, particularly women. African Caribbeans were more likely than the Europeans to have been given a diagnosis after the onset of symptoms and less likely to be taking insulin. Mean cholesterol concentration was lower in African Caribbeans, but blood pressure and body mass index were not different in the two ethnic groups. Prevalence of microvascular and macrovascular complications was insignificantly lower in African Caribbens than in Europeans. 59 Europeans and 16 African Caribbeans had died by the end of follow up. The risk ratio for all cause mortality was 0.41 (95% confidence interval 0.23 to 0.73) (P = 0.002) for African Caribbeans v Europeans. This was attenuated to 0.59 (0.32 to 1.10) (P = 0.1) after adjustment for sex, smoking, proteinuria, and body mass index. Further adjustment for systolic blood pressure, cholesterol concentration, age, duration of diabetes, and treatment made little difference to the risk ratio. Unadjusted risk ratio for cardiovascular and ischaemic heart disease were 0.33 (0.15 to 0.70) (P = 0.004) and 0.37 (0.16 to 0.85) (P = 0.02) respectively.

CONCLUSIONS

African Caribbeans with non-insulin dependent diabetes maintain a low risk of heart disease. Management priorities for diabetes developed in one ethnic group may not necessarily be applicable to other groups.

International variations in cardiovascular mortality associated with diabetes mellitus: the WHO Multinational Study of Vascular Disease in Diabetes

The WHO Multinational Study of Vascular Disease in Diabetes was launched in 1975-77 to investigate international variations in the occurrence of different manifestations of vascular disease in subjects with insulin-dependent and non-insulin-dependent diabetes. A morbidity and mortality follow-up extending until January 1, 1988 was carried out in 10 centres, including five European centres (London, Switzerland, Berlin, Warsaw and Zagreb), two East Asian centres (Hong Kong and Tokyo), two Native American centres (Arizona and Oklahoma) and one Caribbean centre (Havana). Of a total of 4714 diabetic subjects (2310 men and 2404 women) aged between 35 and 55 years at baseline who were successfully followed up, 1266 were classified as having insulin-dependent diabetes and 3448 as having non-insulin-dependent diabetes. There was a large variation between the centres in ischaemic heart disease and cerebrovascular disease mortality rates for both insulin-dependent and non-insulin-dependent diabetic subjects, presumably reflecting in part differences between the background populations in mortality rates from these cardiovascular causes. The lowest ischaemic heart disease mortality rates for diabetic subjects were observed in Hong Kong and Tokyo centres, representing industrialized countries which have continued to have low ischaemic heart disease mortality rates. The importance of raised blood pressure and proteinuria as potentially modifiable cardiovascular risk factors in diabetic subjects was confirmed in this study.

Eye position and target amplitude effects on human visual saccadic latencies

Gaze shifts vary in the extent of eye and head contribution; a large amplitude and/or an eccentric ocular orbital starting position alter the participation of head movement in the shift. The interval between eye onset and head onset determines compensatory counterrolling before and after the shift and the extent of vestibular ocular reflex reduction during the shift. The latency of eye saccades in the head-fixed condition was measured with respect to target amplitude and orbital position in order to establish base-line operations of these two variables as they apply to the head-free condition. Eye movements were measured during single-step saccades in nine young adult humans. The target step, hereafter called a jump, started from three possible fixation lights; e.g., rightward saccades started from the midline (0 degree) or from -20 or -40 degrees left of the midline, with a maximum amplitude of 80 degrees. The latency of saccades starting from the primary position increased with jump amplitude (amplitude-latency relation). When the eye started eccentrically, the latency was decreased (orbital position-latency relation), with the largest jump amplitudes most affected. These changes can be related to active eye-head coordination. Thus, with a leftward maximal orbital eccentricity, compensatory eye rotation would be impossible with a rightward head movement; however, incorporating the orbital position-latency relation, the forward ocular saccade is expedited by 90 ms. Conversely, with a primary starting position, the ocular component of an 80 degrees gaze saccade could be slowed 125 ms by incorporating the amplitude-latency relation, thus facilitating a head contribution to the gaze shift. The orbital position and amplitude-latency relations were prominent in those subjects with habitually large head contributions to the gaze shift and minimal in individuals with typically small head contributions.

The relationship between socioeconomic status and diabetes control and complications in the EURODIAB IDDM Complications Study

OBJECTIVE

To determine whether there are socioeconomic differences in diabetes control and complications in people with IDDM.

RESEARCH DESIGN AND METHODS

We conducted a prevalence survey of 1,217 men and 1,170 women with IDDM age 25-60 years from European clinics. Age at completion of education defined socioeconomic status: < or = 14 years defined those with primary education; 15-18 years, as secondary education; and > 19 years, as college education. Glycemic control, lipids, diet, retinopathy, neuropathy, and heart disease were assessed centrally.

RESULTS

People with a primary education were older and had diabetes for longer than those with a college education. The mean percentage of HbA1c was worst in the primary-educated men (6.6 vs. 6.1%, P = 0.0007 for trend) and women (6.5 vs. 6.0%, P = 0.0007). Total cholesterol level was higher in primary-educated than in college-educated men (5.6 vs 5.3 mmol/l, P = 0.002), as was triglyceride level (1.23 vs. 1.02 mmol/l, P = 0.0001). College-educated people were the least likely to be current smokers (P < 0.0001), and were most likely to partake in vigorous exercise (P < 0.001). Surprisingly, There was little difference in the prevalence of heart disease by educational status in men, while it was highest in the least educated women, but proliferative retinopathy was more common in primary- than in college-educated men (16 vs 10%, P = 0.04) as was macroalbuminuria (15 vs 9%, P = 0.03). Glycemic control could not fully account for these differences.

CONCLUSIONS

Healthy lifestyles are more prevalent in better educated men and women with IDDM, but these are not reflected in heart disease prevalence in men. The lower prevalence of severe microvascular complications in better educated men, unaccounted for by better glycemic control, requires further investigation.

Excess mortality and its relation to hypertension and proteinuria in diabetic patients. The world health organization multinational study of vascular disease in diabetes

OBJECTIVE

To determine the extent that mortality in IDDM and NIDDM patients is in excess of that of the general population and examine its relation to hypertension and proteinuria in diabetic patients.

RESEARCH DESIGN AND METHODS

A stratified random sample of 4,714 diabetic patients aged 35-55 years participating in the World Health Organization Multinational Study of Vascular Disease in Diabetes has been followed up from 1975 to 1987. Excess mortality, compared with the background population, was assessed in terms of standardized mortality ratios (SMRs) for each of the 10 international cohorts. The relationship between excess mortality and proteinuria/hypertension was examined by diabetes type and sex.

RESULTS

SMRs were in general higher in patients with IDDM (ranging from 188 to 686 for men and from 336 to 790 for women) than with NIDDM (from 138 to 370 for men and from 126 to 435 for women). For both diabetes types and in both sexes, SMRs decreased with increasing age and increased with increasing diabetes duration. Patients with both hypertension and proteinuria experienced a strikingly high mortality risk: 11-fold for men with IDDM and 18-fold for women with IDDM and 5-fold for men with NIDDM and 8-fold for women with NIDDM. Even in the absence of proteinuria and hypertension, SMRs were significantly increased in both IDDM (284 men and 360 women) and NIDDM (192 men and 236 women) patients.

CONCLUSIONS

Considerable international differences were found not only in mortality rates for the two types of diabetes but also in the extent of excess mortality among centers. IDDM patients had a high excess mortality in comparison with the general population. The significant excess mortality was demonstrated even in patients without proteinuria and without hypertension for both sexes and diabetes types.

Ethnic differences in mortality from cardiovascular disease in the UK: do they persist in people with diabetes?

STUDY OBJECTIVE

To determine whether ethnic differences in cardiovascular disease mortality persist in people with non-insulin-dependent diabetes mellitus.

DESIGN

This was an ecological study in which routine mortality data from 1985-86, which coded all mentioned causes of death, provided the numerator. The UK population derived from 1981 census formed the denominator.

SETTING

United Kingdom.

PARTICIPANTS

Records of all deaths in people aged 45 years and above were extracted if diabetes was mentioned anywhere on the death certificate. The denominator was aged five years to approximate to the 1986 population. Mortality rates where a cardiovascular underlying cause was given were compared between South Asians, African-Caribbeans, and those born in England and Wales. The latter group formed the standard for directly standardised rate ratios.

MAIN RESULTS

Mortality from heart disease was approximately three times higher in diabetic South Asian born men and women than in those with diabetes born in England and Wales. This ethnic difference was greatest in the younger age group. Conversely, stroke mortality rates in African-Caribbeans were 3.5-4 times higher than those in the England and Wales population. Despite this high mortality from stroke, ischaemic heart disease death rates were not high in African-Caribbean men.

CONCLUSIONS

Ethnic differences in cardiovascular mortality persisted and were greater in those with diabetes. Thus the high risk of heart disease should be targeted for intervention in South Asians, and the high rates of stroke targeted in African-Caribbeans.

A comparison of renal disease across two continents; the epidemiology of diabetes complications study and the EURODIAB IDDM Complications Study

OBJECTIVE

To compare prevalence rates of increased albumin excretion in the Epidemiology of Diabetes Complications Study (EDC) (in the U.S.) to similar rates in the EURODIAB study (in Europe) and determine if any differences relate to hypertension, glycemic control, or smoking status.

RESEARCH DESIGN AND METHODS

The study population is made up of two epidemiological clinic-based IDDM populations with comparable ages (chi = 28 years, both studies), sex distribution (50% male, EURODIAB; 49% male, EDC), and duration characteristics. Comparison of two cross-sectional (prevalence) studies was made. Despite different laboratory assays, comparability was established for urinary albumin (r = 0.98) and GHb measures (r = 0.95). Hypertension was measured with an identical protocol. Renal status was determined by 24-h urine albumin excretion (< 20 micrograms/min normal, 20-200 micrograms/min microalbuminuria, > 200 micrograms/min macroalbuminuria) in EURODIAB. Identical cutoffs were used for EDC, though two of three samples (24-h, 4-h clinic, and/or overnight sample) had to be positive in one range. (Main findings are confirmed using only 24-h results from EDC.)

RESULTS

The prevalence of macroalbuminuria was higher in EDC (27%) than in EURODIAB (12%). Rates of microalbuminuria were similar (22 vs. 25%, respectively). These patterns were seen at all durations and ages and in both sexes. Controlling for glycemic control, hypertension, or smoking did not account for the higher rate in EDC, nor did exclusion of subjects with raised serum creatinine.

CONCLUSIONS

Advanced renal disease is more prevalent in IDDM in EDC (Pittsburgh, PA) than in Europe. This is not explained by hypertension, glycemic control, or smoking.

The use of the Micral-Test strip to identify the presence of microalbuminuria in people with insulin dependent diabetes mellitus (IDDM) participating in the EUCLID study

In IDDM, microalbuminuria (urinary albumin excretion rate (AER) of 20-200 micrograms/min) is a predictor of persistent proteinuria and diabetic nephropathy. Early intervention may prevent or reduce the rate of progression of renal complications. The Micral-Test strip can be used to establish a semi-quantitative estimate of AER. We assessed the field performance of the Micral-Test strip in detecting microalbuminuria in the EUCLID study, an European wide, 18 centre study of 530 IDDM participants, aged 20 to 59 years. People with macroalbuminuria were excluded. On entry, all participants had albumin concentrations from two overnight urine collections measured by a central laboratory, and the corresponding Micral-Test performed on the two collections locally. a cut off of > or = mg/l albumin from the first Micral-Test, to detect a centrally measured albumin concentration > or = 20 mg/l, yielded 29 (5.8%) false negative results and 58 (11.6%) false positive results (sensitivity 70%, specificity 87%). The mean AER, from two collections, was compared with the corresponding 'pooled' Micral-Test results (mean of the two readings). Receiver Operating Characteristic (ROC) curves were used to assess if there was a suitable 'pooled' Micral-Test result for screening microalbuminuria. A 'pooled' Micral-Test result (> or = 15 mg/l) was used to detect mean AER > or = 20 micrograms/min (sensitivity 78%, specificity 77%). This 'pooled cut-off' had already been used for screening on to the study and led to an over-estimate (154 vs. 77) of the true number of microalbuminuric participants on the study. In conclusion, our findings suggest that the Micral-Test strip is not an effective screening tool for microalbuminuria, using the 'pooled' result from two measurements did not improve the sensitivity of the test.

Comparison of horizontal head movements evoked by auditory and visual targets

Head movement propensity-the pattern of head saccades dependent on methods of target presentation-varies among individuals. The present group of 9 young adults was previously ranked in a visual saccadic task according to this propensity. The present report examines how and why this propensity changes if the saccades are made to auditory targets. 1) Spatially identical, interleaved, auditorily and visually elicited horizontal saccadic gaze shifts (jumps) differed in amplitude and in starting and/or ending position. The jumps were executed in two head movement modes: first, the non-aligned mode was a standard reaction-time single gaze step between two points. Second, the head-aligned mode required alignment of the head with the fixation (starting) point; thereafter both modes were identical. All results in the auditory task are expressed relative to the visual results. 2) In the non-aligned mode, head movement amplitudes were increased on average by 15% (for example, an 80 degrees jump elicited a 12 degrees larger head movement), and velocity decreased by 12%, reflecting the increased demands of the auditory task. More importantly, the differences between subjects was narrowed; that is, head movement propensity was homogenized in the auditory task. In the visual task, head-movers willingly move their heads off and across the midline, whereas non-movers are unwilling to leave the midline from eccentric starting points or to eccentric ending points. This is called the midline attraction effect and was previously linked to spatial reference frames. The homogenization in the auditory task was characterized by head-movers increasing, and non-movers decreasing, their midline attraction, suggesting altered spatial reference frames. 3) For heuristic purposes, the ideal head-mover is defined by a gain of 1.0 in the visual task, and by external earth-fixed reference frames. Similarly, the ideal non-mover has a gain of 0.0 and has a bias toward body (or some par of the body)-fixed reference frames. In the auditory task these gains (and reference frames) in head movers and non-movers are homogenized (close to 0.5), either by the participation of the head (movement of the ears in space) in sensory acquisition or by differences in central nervous processing of the two modalities, or both.

The cytochrome subunit is necessary for covalent FAD attachment to the flavoprotein subunit of p-cresol methylhydroxylase

When p-cresol methylhydroxylase (PCMH) is expressed in its natural host Pseudomonas putida, or when the genes of the alpha and beta subunits of the enzyme are expressed together in the heterologous host Escherichia coli, flavin-adenine dinucleotide (FAD) is covalently attached to Tyr384 of the alpha subunit and the correct alpha 2 beta 2 form of the enzyme is assembled. The apoflavoprotein has been expressed in E. coli in the absence of the beta cytochrome c subunit and purified. While noncovalent FAD binding to apoflavoprotein in the absence of the cytochrome subunit could not be directly demonstrated, circumstantial evidence suggests that this indeed occurs. Covalent flavinylation requires one molecule each of FAD and cytochrome for each flavoprotein subunit. The flavinylation process leads to the 2-electron-reduced form of covalently bound FAD, and the resulting alpha 2 beta 2 enzyme is identical to wild-type PCMH. This work presents clear evidence that covalent flavinylation occurs by a self-catalytic mechanism; an external enzyme or chaperon is not required, nor is prior chemical activation of FAD or of the protein. This work is the first to define the basic chemistry of covalent flavinylation of an enzyme to produce the normal, active species, and confirms a long standing, postulated chemical mechanism of this process. It also demonstrates, for the first time, the absolute requirement for a partner subunit in the post-translational modification of a protein. It is proposed that the covalent FAD bond to Tyr384 and the phenolic portion of this Tyr are part of the essential electron transfer path from FAD to heme.

The relationship between pregnancy and long-term maternal complications in the EURODIAB IDDM Complications Study

Pregnancy is believed to exacerbate diabetes complications, although the degree to which this occurs, and the advice that should be given to women contemplating pregnancy is unclear. We examined 776 nulliparous and 582 parous women with Type 1 diabetes from a cross-sectional study performed in 31 European centres. Glycaemic control was better in parous women. Age and duration adjusted prevalence of microalbuminuria was similar in parous and nulliparous women, but macroalbuminuria was lower in parous women (6% versus 10%, p < 0.0001). Prevalence of all retinopathy was lower in parous women (34% in women who had two or more pregnancies, 45% in women who had one), compared with 48% in nulliparous women (chi 2 for trend = 47.1, p < 0.0001). Proliferative retinopathy was lower in parous (8% and 7%, respectively) compared with nulliparous women (16%, chi 2 for trend = 52.2, p < 0.0001). These differences persisted when adjusted for glycaemic control. Excluding referrals for pregnancy, parous women were more likely to have been referred to the diabetes clinic with complications than nulliparous women (p = 0.001). It is unlikely that our findings can be explained by women with complications being advised against pregnancy, or by the better glycaemic control in parous women. Equivalent levels of microalbuminuria and background retinopathy in parous and nulliparous women suggests that pregnancy may not exacerbate these early complications.

Mortality and morbidity associated with body weight in people with IDDM. The WHO Multinational Study of Vascular Disease in Diabetes

OBJECTIVE

Strict glycemic control in people with insulin-dependent diabetes mellitus (IDDM) reduces the risk of microvascular complications, but improvements in control are also associated with weight gain. Fears about the mortality risks of obesity may limit the acceptability of tight control. Therefore, we examined morbidity and mortality risks associated with body weight in people with IDDM.

RESEARCH DESIGN AND METHODS

This was a cohort study of 644 men and 576 women with IDDM from nine centers worldwide. Baseline examinations were performed in 1975-1977, and mortality follow-up continued until 1988.

RESULTS

Body weight was positively associated with blood pressure and, in men, with cholesterol. Fasting blood glucose was higher in the most obese groups in women only. There were 204 deaths among the men and 148 among the women. There was a reverse J-shaped relationship between body weight and all-cause mortality, with the highest mortality rates occurring in the leanest body mass index (BMI) category. The age-, duration-, and center-adjusted mortality rate ratio (95% confidence interval) comparing BMI category < 20 kg/m2 with BMI category > or = 22 and < 24 kg/m2 was 2.64 (1.59-4.38) in men and 1.54 (0.77-3.06) in women. Additional adjustment for smoking, blood pressure, glucose, cholesterol, and proteinuria did not qualitatively alter these findings.

CONCLUSIONS

We conclude that except in very lean people with IDDM, body weight is not significantly associated with mortality. Thus, efforts to improve glycemic control should not be restricted by concerns about the effects of weight gain on mortality.

Mortality risk by body weight and weight change in people with NIDDM. The WHO Multinational Study of Vascular Disease in Diabetes

OBJECTIVE

Care guidelines for people with non-insulin-dependent diabetes mellitus (NIDDM) emphasize the importance of weight loss in reducing mortality risk. However, existing evidence regarding the relationship between weight and mortality and the effects of weight change is conflicting. We examined these relationships in the World Health Organization Multinational Study of Vascular Disease in Diabetes.

RESEARCH DESIGN AND METHODS

This was a cohort study of 1,416 men and 1,544 women. Baseline examinations were performed in 1975 through 1977, a morbidity follow-up was performed in 1983, and a mortality follow-up continued until 1988. Data were analyzed according to geographical groups: Europeans, East Asians, and Native Americans. The relationship between weight change and mortality was analyzed for Europeans only.

RESULTS

Generally, body mass index (BMI) was positively associated with age, blood pressure, and cholesterol but was negatively associated with duration of diabetes, prevalence of retinopathy, and use of insulin. There was no clear relationship between BMI and mortality across the geographical groups. In Europeans, weight loss in the leanest subjects at baseline (BMI < 26 kg/m2) was associated with a threefold increase in mortality risk compared with those who had maintained a steady weight (relative risk [RR] 3.05, 95% confidence interval [CI] 1.26-7.36). Only in the most obese group was weight loss associated with a reduction in mortality risk (BMI > 29 kg/m2, RR 0.84, 95% CI 0.40-1.74).

CONCLUSIONS

The positive association of BMI with age, blood pressure, and cholesterol and the negative association with duration of diabetes, retinopathy, and use of insulin may explain why there is no strong relationship between BMI and mortality in NIDDM. Weight loss, particularly in the relatively lean diabetic person, may be associated with an increased mortality risk.

The relationship between smoking and microvascular complications in the EURODIAB IDDM Complications Study

OBJECTIVE

To examine the relationship between smoking and both glycemic control and microvascular complications in patients with insulin-dependent diabetes mellitus (IDDM).

RESEARCH DESIGN AND METHODS

This was a prevalence survey of 3,250 men and women aged 15-60 years with IDDM from 31 diabetes centers in 16 European countries. Participants completed a questionnaire, had retinal photographs taken, and performed a 24-h urine collection. HbA1c, frequency of hypoglycemic and ketoacidotic episodes, urinary albumin excretion rates, and retinopathy were compared by smoking category.

RESULTS

The prevalence of smoking was 35% in men and 29% in women. Current smokers had poorer glycemic control and, among men, were more likely to have had a ketoacidotic episode than were those who never smoked. Ex-smokers had equivalent glycemic control and marginally more hypoglycemic episodes did than those who never smoked. Current smokers had a higher prevalence of microalbuminuria and total retinopathy than did those who never smoked. Ex-smokers had a higher prevalence of macroalbuminuria and proliferative retinopathy than did those who never smoked, but both had a similar prevalence of microalbuminuria. Adjustment for either current or long-term glycemic control could not fully account for these differences.

CONCLUSIONS

Smoking is associated with poorer glycemic control and an increased prevalence of microvascular complications compared with not smoking. Ex-smokers can achieve glycemic control equivalent to and have a prevalence of early complications similar to that of those who never smoked. We suggest that poorer glycemic control can account for some of the increased risk of complications in smokers, and that quitting smoking would be effective in reducing the incidence of complications. Urgent action is required to reduce the high smoking rates in people with IDDM.

Blood pressure, retinopathy and urinary albumin excretion in IDDM: the EURODIAB IDDM Complications Study

Several studies have shown an association between blood pressure and nephropathy, but few have been large enough to examine whether, or how, this relation is influenced by retinopathy. We have therefore examined the independent relations of blood pressure to urinary albumin excretion and retinopathy in a cross-sectional observational study of over 3000 insulin-dependent diabetic patients (the EURODIAB IDDM Complications Study). The relation of blood pressure to urinary albumin excretion differed strikingly between patients with (46%) and without (54%) retinopathy. In those with retinopathy, mean urinary albumin excretion rate was normal (< 20 micrograms/min) below median diastolic pressure (75 mmHg) and increased steeply (p < 0.001) with blood pressure above this level. However, in patients without retinopathy, mean albumin excretion rate was normal across the range of diastolic pressure. This finding could not be explained by differences in glycaemic control or duration of diabetes between patients with and without retinopathy. These data identify a subgroup of patients whose high risk of nephropathy may reflect abnormal renal vulnerability to mildly raised blood pressure. Retinopathy is a close correlate of this vulnerability. Detection of even mild retinopathy, together with raised blood pressure, may be important in assessing nephropathy risk.

Proteinuria and mortality in diabetes: the WHO Multinational Study of Vascular Disease in Diabetes

The relation between proteinuria and mortality was investigated in 1188 patients with Type 1 diabetes and 3234 patients with Type 2 diabetes, aged 35-55 at baseline and followed up for a mean of 9.4 +/- 3.1 years in the WHO Multinational Study of Vascular Disease in Diabetes. Baseline prevalence of light or heavy proteinuria was the same (25%) in both types of diabetes after adjustment for differences in diabetes duration. Compared with patients with no proteinuria, all cause mortality ratios were 1.5 (95% confidence interval 1.1-2.0) and 2.9 (2.2-3.8) for Type 1 patients with light and heavy proteinuria, respectively, and 1.5 (1.2-1.8) and 2.8 (2.3-3.4) for Type 2 patients, after adjustment for age, duration of diabetes, blood pressure, cholesterol, and smoking. Proteinuria was associated with significantly increased mortality from renal failure, cardiovascular disease, and all other causes of death. In both types of diabetes, the association was strongest for renal deaths, and of similar magnitude for cardiovascular and all other causes of death. In conclusion, proteinuria is a common, important, and rather non-specific risk factor for increased morbidity and mortality in diabetes. The relation of proteinuria to mortality is similar for both types of diabetes. The benefits and risks of proteinuria reduction should be examined in large randomized trials with clinical endpoints.

Cloning, sequencing, and expression of the structural genes for the cytochrome and flavoprotein subunits of p-cresol methylhydroxylase from two strains of Pseudomonas putida

The structural genes for the flavoprotein subunit and cytochrome c subunit of p-cresol (4-methylphenol) methylhydroxylase (PCMH) from Pseudomonas putida NCIMB 9869 (National Collection of Industrial and Marine Bacteria, Aberdeen, Scotland) and P. putida NCIMB 9866 were cloned and sequenced. The genes from P.putida NCIMB 9869 were for the plasmid-encoded A form of PCMH, and the genes from P.putida NCIMB 9866 were also plasmid encoded. The nucleotide sequences of the two flavoprotein genes from P.putida NCIMB 9869 and P.putida NCIMB 9866 (pchF69A and pchF66, respectively) were the same except for 5 bases out of 1,584, and the translated amino acid sequences were identical. The nucleotide sequences of the genes for the cytochrome subunits of PCMH from the two bacteria (pchC69A and pchC66) varied by a single nucleotide in their 303-base sequences, and the translated amino acid sequences differed by a single residue at position 41 (Asp in PchC69A and Ala in PchC66). Both cytochromes had 21-residue signal sequences, as expected for periplasmic proteins, and these sequences were identical. On the other hand, no signal sequences were found for the flavoproteins.pchF69A and pchC69A were expressed, separately or together, in Escherichia coli JM109 and P.putida RA4007, with active PCMH produced in both bacteria. The E. coli-expressed flavocytochrome was purified. Our studies indicated that the E.coli-expressed subunits were identical to the subunits expressed in P.putida NCIMB 9869: molecular weights, isoelectric points, UV-visible spectra, and steady-state kinetic parameters were the same for the two sets of proteins. The subunits readily associated upon mixing two crude extracts of E.coli, one extract containing PchC69A and the other containing PchF69A. The courses of association of PchC69A and PchF69A were essentially identical for pure E. coli-expressed subunits and pure P. putida 9869-expressed subunits. E. coli-expressed PchC69A and PchF69A contained covalently bound heme and covalently bound flavin adenine dinucleotide, respectively, as the proteins expressed in nature.

Microalbuminuria is not rare before 5 years of IDDM. EURODIAB IDDM Complications Study Group and the WHO Multinational Study of Vascular Disease in Diabetes Study Group

Microalbuminuria is thought to be rare in people with insulin-dependent diabetes mellitus (IDDM) for less than 5 years. We measured its prevalence in 733 clinic-attending IDDM patients with diabetes duration of 1-5 years in two large multicenter studies [EURODIAB IDDM Complications Study and the World Health Organization (WHO) Multinational Study]. We also compared characteristics of microalbuminuric patients with IDDM for 1-5 years versus more than 5 years' duration. Albumin excretion rate was measured from a timed 24-h urine collection in the EURODIAB Study. Proteinuria was measured by the salicylsulphonic acid test in the WHO Study. The prevalence of microalbuminuria (20-200 micrograms/min, EURODIAB) was 18% [95% confidence interval (CI) 13%-22%)]. The prevalence of light proteinuria was 15% (9%-20%, WHO study). Raised protein excretion was a consistent finding in 34 of the 36 centers. The increased cardiovascular risk (raised blood pressure and total cholesterol) associated with microalbuminuria in patients with IDDM for more than 5 years was also apparent in those with diabetes for 1-5 years. However, repeat urine testing suggested that microalbuminuria before 5 years was more likely to be transient or reversible. In conclusion, these two studies in 36 centers, which used different methods more than 10 years apart, show consistently that raised urinary albumin excretion occurs before 5 years of IDDM. The clinical significance of this needs to be examined by prospective observation.

Cloning, sequencing, expression, and regulation of the structural gene for the copper/topa quinone-containing methylamine oxidase from Arthrobacter strain P1, a gram-positive facultative methylotroph

Deoxyoligonucleotides corresponding to amino acid sequences of methylamine oxidase and polyclonal anti-methylamine oxidase antibodies were used to probe Arthrobacter strain P1 plasmid and chromosomal DNA libraries. Two open reading frames, maoxI and maoxII, which are greater than 99% homologous, were cloned from the chromosomal library. The deduced amino acid sequences of the coding regions are identical except for two residues near the C termini. On the other hand, the 5'- and 3'-flanking regions of maoxI and maoxII are quite different. While either gene could code for methylamine oxidase, the dissimilarity in the 5'-flanking regions indicates that the genes are differently regulated. It was determined that maoxII alone encodes methylamine oxidase. The tyrosyl residue which is converted to topa quinone in the mature enzyme was located by comparison with amino acid sequences at the cofactor sites in other copper/topa quinone-containing amine oxidase. Transcriptional start sites and possible regulatory elements were identified in the 5' region of maoxI and maoxII, and stem-loop structures were found in the 3'-flanking regions. High levels of methylamine oxidase are produced when Arthrobacter strain P1 is grown on methylamine alone or on glucose plus methylamine, but growth on LB medium plus methylamine resulted in very low production of the enzyme. Expression of maoxII from its own promoter in Escherichia coli grown on glucose or LB medium with or without methylamine gave the same level of production of methylamine oxidase.

Are the social relationships of young insulin-dependent diabetic patients affected by their condition?

In order to compare the social relationships of young adults with Type 1 diabetes with those of healthy controls, 80 young people aged 16-25 years were interviewed in-depth with a semi-structured questionnaire. Results demonstrated that subjects with diabetes had an equally high commitment to social arenas, but were significantly more likely to be socially isolated and were less likely to have very close relationships. Subjects had more attitudinal constraints with regard to having close relationships, and were more likely to report a fear of intimacy. They were less likely to have children, and many voiced their concerns regarding the impact their diabetes might have on both marriage and future parenthood. This study suggests that young adults with diabetes have more negative social experiences which may affect their feelings with regard to having close relationships. The absence of supportive relationships may impact on diabetes management; however this has yet to be fully ascertained in a young adult population.

Head movement propensity

In studies of human eye-head coordinated saccadic gaze shifts, different laboratories have found greatly different magnitudes of head movements for a given amplitude of gaze shift (head movement gain). The present study was conducted to examine why, and to quantify volitional head movements. Fixation/target lights were located at 20 degrees and 40 degrees on either side of a central light. There were two tasks or modes. In the non-aligned mode, gaze fixation (first light) was followed by a gaze step to the target (second light) accurately and quickly. In the head-aligned mode, the head was aligned within 3 degrees of the first fixation light (i.e., initial starting position) before the step sequence began. In both non-aligned and head-aligned modes, subject instructions pertaining to the second target light concerned only gaze; there was no requisite head position. The head movement propensity of nine subjects was ranked according to the mean gain (head/target amplitude) of two 40 degree jumps (0-40 degrees and -20 to +20 degrees) in the non-aligned mode. This ranking method clearly identified extreme head-movers and non-movers. The moderate movers were further characterized by three additional criteria, derived by comparing the gains in different jumps, which varied in starting position and amplitude. First, when the two 40 degree jumps were compared, typically the gain of non-movers was less in the symmetric jump (-20 to +20 degrees) with the gain of the head-movers was greater in the symmetric jump. Second, in the head-aligned mode the gain of non-movers progressively increased when the starting position was progressively moved eccentrically, whereas the gain of head-movers increased only slightly, if at all. Third, when the gains of two symmetric (40 degrees and 80 degrees) jumps were compared, the head-movers consistently had opposite trends from non-movers. These three comparative criteria and the initial criterion together define head movement propensity. To explain the above observations, three effects are proposed. First, a "midline-attraction" effect causes resistance to movement away from the midline in non-movers and an increase in movement amplitude if the jump starts eccentrically. Second, a "resetting" effect occurs when the eccentricity of the jump is varied; the stopping position is reset closer to the target. Third, an "awareness/arousal" effect increases the gain in the head-aligned mode due to the intrinsic nature of the alignment procedure.(ABSTRACT TRUNCATED AT 400 WORDS)

Education and employment experiences in young adults with type 1 diabetes mellitus

Educational attainment, employment experiences, and self-esteem were measured using semi-structured questionnaires in young adults with Type 1 diabetes mellitus and in a group of age/sex matched healthy controls. Results showed that subjects with diabetes and their matched controls obtained comparable qualifications at all levels. However, subjects with diabetes were less likely to feel competent with regard to their educational performance, and many of this group reported experiencing difficulties at school. There were no differences in the proportion of each group who had experienced unemployment, although this was explained more by social class and educational attainment. Whereas only a minority had decided to withhold information about their condition from their employers, one-third of those with diabetes had experienced health-related problems in obtaining employment. This study suggests that the educational achievements and employment experiences of young adults with diabetes may not differ from those of healthy controls. However subjective reports of difficulties in these areas may be associated with reduced self-esteem. Confirmation of these findings should be carried out in a larger sample, using a prospective design.

Recent trends in diabetes mortality in England and Wales

Trends in diabetes-related mortality in England and Wales between 1975-6 and 1985-6, and regional and ethnic differences in diabetes-related mortality in 1985-6, have been examined. Data from death certificates mentioning diabetes in 1975-6 were compared with those for 1985-6 for different age groups. Data for 1985-6 were also analysed for different regions of England and Wales, and for country of birth. Between 1975-6 and 1985-6, the age-standardized rate of mentioning diabetes rose by 2.7% (95% confidence interval 1.4%, 4.1%) in men of all ages, and fell by 11.7% (10.6, 12.8) in women of all ages. By contrast, the rate of mentioning diabetes in those below 45 years fell by 30.7% (23.0, 37.7) in men and by 26.7% (16.5, 35.6) in women. Deaths in which the underlying cause was ischaemic heart disease (IHD), and where diabetes was also mentioned on the death certificate, rose by 14.4% (11.5, 16.8) in men and did not change significantly in women of all ages, but fell by 18.4% (-35.1, +2.6) in men, and 23.5% (-49.1, +15.2) in women below age 45. This was less favourable than the trend in the general population, where IHD mortality fell by 9.7% in men and 8.3% in women of all ages, and by 31.1% (28.6, 33.5) in men and 40.5% (35.0, 45.5) in women under 45 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidemiology of hypertension in diabetic patients and implications for treatment

We review the epidemiology of hypertension in diabetic patients and discuss the implications for treatment. The relationship between coronary heart disease (CHD) mortality and blood pressure (BP) in the World Health Organization Multinational Study of Vascular Disease in Diabetics (WHO MSVDD) is evaluated. One thousand two hundred seventy-seven patients with insulin-dependent diabetes mellitus (IDDM) and 3463 patients with non-insulin-dependent diabetes mellitus (NIDDM), aged 35-55 yr at baseline, from 10 centers throughout the world were evaluated. CHD mortality after a follow-up of 6-7 yr was measured. Estimates of usual diastolic BP were made with data from the Framingham study. The relative risk (RR) of CHD death was plotted against usual diastolic BP for IDDM and NIDDM, and the shapes of the relationship were compared with a meta-analysis of nine prospective studies in nondiabetic populations. For the NIDDM group, the CHD RRs were significantly greater than 1.0 only for the uppermost diastolic BP category (RR 2.23, 95% confidence interval 1.14-4.40). For the IDDM group, the shape of the diastolic BP-CHD relationship was difficult to assess in view of the small number of events. In neither diabetic group was the evidence for a J-shaped relationship. Elevated BP is associated with increased cardiovascular/renal mortality in both types of diabetes. However, the efficacy of antihypertensive therapy in the prevention of these outcomes remains unclear. Prospective data from the WHO MSVDD do not provide clear evidence of benefit from treating diastolic BP less than 95-100 mmHg in NIDDM patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Incidence of macrovascular disease in diabetes mellitus: the London cohort of the WHO Multinational Study of Vascular Disease in Diabetics

We report on the incidence of new macrovascular disease among the 497 members of the London Cohort of the WHO Multinational Study of Vascular Disease in Diabetics (aged 35-54 years at recruitment) over a mean 8.33 year follow-up period. Overall at the end of the follow-up period the prevalence of macrovascular disease in the cohort was 45%; 43% of the subjects showed evidence of ischaemic heart disease, 4.5% of cerebrovascular disease and 4.2% of peripheral vascular disease. The incidence rates for new disease in those subjects who were free at baseline expressed per 1000 patient years of follow-up were: ischaemic ECG abnormality 23.6 (patients with insulin-dependent diabetes 19.8, patients with non-insulin-dependent diabetes 28.1), myocardial infarction 17.6 (patients with insulin-dependent diabetes 16.5, patients with non-insulin-dependent diabetes 18.8), all ichaemic heart disease 31.7 (patients with insulin-dependent diabetes 30.3, patients with non-insulin-dependent diabetes 33.4), cerebrovascular disease 5.9 and peripheral vascular disease 5.2. Incidence rates were generally similar among men and women except for myocardial infarction in patients with non-insulin-dependent diabetes where men had a significantly higher incidence rate. Macrovascular disease is a major problem in patients with diabetes and in this age group is mainly manifested as ischaemic heart disease.