The predictive value of albuminuria for cardiovascular and renal disease. A 5-year follow-up study of 476 patients with type I diabetes mellitus

Early myocardial impairment in type 1 diabetes patients without known heart disease assessed with tissue Doppler echocardiography: The Thousand & 1 study

PURPOSE

Cardiovascular disease is the most common cause of mortality in type 1 diabetes; patients with albuminuria are at greatest risk. We investigated myocardial function and premature myocardial impairment in type 1 diabetes patients with and without albuminuria compared to controls.

METHODS

This study included a cross-sectional survey of 1093 type 1 diabetes patients from Steno Diabetes Center and 200 healthy controls. Conventional and tissue Doppler echocardiographic measurements were analysed in multivariable models in normoalbuminuria (n = 760), microalbuminuria (n = 227) and macroalbuminuria (n = 106). Investigators were blinded to degree of albuminuria.

RESULTS

For the type 1 diabetes patients, mean age was 49.6 years, 53% were men and mean diabetes duration was 25.5 years. In multivariable models systolic velocity s' did not differ between type 1 diabetes patients with normoalbuminuria and controls (β-coefficient [95% confidence interval]: -0.17 [-0.41; 0.08], p = 0.19), but was impaired between controls and microalbuminuria (-0.53 [-0.84; -0.23], p = 0.001) and macroalbuminuria (-0.59 [-0.96; -0.22], p = 0.002). Diastolic measurements (e', a', e'/a', and E/e') were all significantly impaired in type 1 diabetes, for example, e'/a': normoalbuminuria, microalbuminuria and macroalbuminuria versus controls: -0.38 [-0.52; -0.23], p < 0.001; -0.49 [-0.67; -0.32], p < 0.001; and -0.81 [-1.03; -0.59], p < 0.001. In age-related analyses, myocardial impairment occurred prematurely in type 1 diabetes compared to controls (e.g. E/e' = 8; 9.2 years [normoalbuminuria], 17.3 years [microalbuminuria] and 41.4 years [macroalbuminuria] prematurely, respectively).

CONCLUSION

In type 1 diabetes patients with albuminuria, both systolic and diastolic functions are impaired, whereas in patients without albuminuria only diastolic function is affected. Myocardial impairment is detectable many years prematurely in type 1 diabetes, especially in patients with albuminuria.

Nephropathy, but not retinopathy, is associated with the development of heart disease in Type 1 diabetes: a 12-year observation study of 462 patients

AIMS

To study the occurrence of heart disease and death in Type 1 diabetic patients and evaluate whether presence of microangiopathy, i.e. nephropathy and retinopathy, was associated with the outcome.

METHODS

A 12-year observation study of 462 Type 1 diabetic patients without a previous history of heart disease at baseline who were treated under routine care in a hospital out-patient clinic.

RESULTS

A total of 85 patients developed signs of heart disease, i.e. myocardial infarction (n = 41), angina (n = 23), and heart failure (n = 17) and 56 patients died. The mortality for patients without signs of heart disease during the observation period was 7.6% compared with 51% in patients with myocardial infarction (P < 0.001), 26% in patients with angina (P < 0.01) and 65% in patients with heart failure (P < 0.001). The relative risk for death was 9.0 (P < 0.001) and 2.5 (P < 0.05) times higher in patients with macroalbuminuria and microalbuminuria, respectively. The risk for cardiovascular death was 18.3 times (P < 0.001) higher in patients with macroalbuminuria compared with patients with normoalbuminuria. In patients with sight-threatening retinopathy, the relative risk for death was 7.0 times higher (P < 0.01) and the risk for coronary heart disease events 4.4 times higher (P < 0.05) compared with patients with no retinopathy. However, when retinopathy was adjusted for presence of macroalbuminuria, this association disappeared.

CONCLUSION

This study shows a high incidence of heart disease in patients with Type 1 diabetes. The worse prognosis was seen in patients with sight-threatening retinopathy and macroalbuminuria and microalbuminuria at baseline. Macroalbuminuria and microalbuminuria were independently associated with a high risk for heart disease and death while the association with sight-threatening retinopathy only occurred in the presence of nephropathy.

Urinary albumin excretion. An independent predictor of ischemic heart disease

Cross-sectional studies suggest that an increased urinary albumin excretion rate is associated with cardiovascular disease, dyslipidemia, and hypertension. The purpose of this study was to analyze prospectively whether the urinary albumin-to -creatinine (A/C) ratio can independently predict ischemic heart disease (IHD) in a population-based cohort. In 1983, urinary albumin and creatinine levels were measured, along with the conventional atherosclerotic risk factors, in 2085 consecutive participants without IHD, renal disease, urinary tract infection, or diabetes mellitus. The participants were followed up until death, emigration, or December 31, 1993. IHD was defined as a hospital discharge diagnosis or cause of death including the diagnoses ICD-8 and 410 to 414. Seventy-nine individuals developed IHD during the 21 130 person-years of follow-up. They were characterized by a preponderance of males and higher age, body mass index, blood pressure, lipoproteins, and proportion of current smokers. Microalbuminuria was defined as an A/C ratio) >90 percentile (>0.65 mg/mmol). When adjusted for other risk factors, the relative risk of IHD associated with microalbuminuria was 2.3 (95% CI, 1.3 to 3.9, P=0.002), and the 10-year disease-free survival decreased from 97% to 91% (P<0.0001) when microalbuminuria was present. An interaction between microalbuminuria and smoking was observed, and the presence of microalbuminuria more than doubled the predictive effect of the conventional atherosclerotic risk factors for development of IHD. It is concluded that microalbuminuria is not only an independent predictor of IHD but also substantially increases the risk associated with other established risk factors.

Nephropathy and hypertension in diabetes

The treatment of the patient with diabetes, with or without hypertension, is complex and challenging. Hyperglycemic treatment should ideally not only control blood glucose, but also prevent the chronic complications and associated metabolic derangements that can lead to increased morbidity and mortality. Hypertensive treatment should not only decrease blood pressure, but also reduce the risk of macrovascular and microvascular disease. The use of antihypertensive agents that improve insulin resistance, dyslipidemia, glycemic control, and nephropathy is preferred whenever possible. The real key to success in the care of the hypertensive diabetic patient is adequate screening and appropriate, early treatment. Currently, there is ample evidence to support the use of intensive management with the goal of near-normalization of blood glucose levels in most patients with diabetes. Similarly, aggressive treatment of hypertension is the current standard. Accomplishing these goals helps to prevent the development of chronic diabetic complications, including nephropathy. ESRD need not be the inevitable outcome for individuals with early diabetic nephropathy. Interventions currently available that are targeted at the known modifiable risk factors underlying the development and progression of diabetic nephropathy offer the best hope for reducing the incidence and severity of this complication. Prevention of the complications of diabetes, including nephropathy, must be the goal for the future on behalf of all those who now have diabetes.

Optimizing the assessment of the elderly patient with borderline hypertension: the Hypertension and Ambulatory Recording in the OLD (HAROLD) study

This article describes the objectives and protocol of the HAROLD study, a trial designed to assess whether home blood pressure (BP), 24-hour ambulatory BP, left ventricular structure and function, and albumin excretion rate are more accurate predictors of outcome than traditional sphygmomanometric BP in elderly subjects with borderline hypertension. Development of sustained hypertension (BP > or = 160/95 mmHg) and incidence of morbid events over a 5-year follow-up are considered soft and hard endpoints, respectively. Patients with blood pressure values between 140/90 and 159/94 mmHg after three months of observation and who have never been treated, are eligible for the study; these subjects must be 60 to 79 years old, and free from other important risk factors for atherosclerosis. Baseline exams, which include plasma renin and insulin, 24-hour urine collection for detection of microalbuminuria, and echo-doppler cardiac examination are repeated after three and five years follow-up, or when subjects develop sustained hypertension. To recruit a large enough number of subjects to allow a sufficient number of endpoints (over 1000 subjects), the study is conducted as a multicenter trial. Ninety Italian Hospital Centers have agreed to participate in the study.

The association between diabetic nephropathy and autonomic nerve function in type 1 diabetic patients

Diabetic cardiovascular autonomic neuropathy increases the risk of deterioration in renal function and is associated with increased mortality in patients with renal failure. Type 1 diabetic patients with long diabetes duration, matched for age (38 +/- 9 years) and diabetes duration (28 +/- 8 years) were studied regarding the association between cardiovascular autonomic nerve function and different degrees of diabetic nephropathy. Eighteen patients were normo- (< 30 mg/l), six micro- (30-300 mg/l), and 13 macroalbuminuric (> 300 mg/l) based on urinary albumin concentrations in three separate morning samples. They were compared with 33 control subjects with similar age. Autonomic nerve function was evaluated by measuring the response of heart rate to deep breathing and active standing. Beat-to-beat finger artery blood pressure (Finapres) was tested during active standing. During deep breathing both change in heart rate (17 +/- 11, 9 +/- 7 and 4 +/- 3 beats/min) and ratio between expiratory and inspiratory R-R intervals (1.32 +/- 0.24, 1.14 +/- 0.15 and 1.05 +/- 0.04) decreased from normo- over micro- to macroalbuminuria (p < 0.05 vs normoalbuminuric and control subjects [17 +/- 5 beats/min and 1.28 +/- 0.10, respectively]). Similar results were obtained during active standing with respect to change in systolic arterial blood pressure (3 +/- 8, 2 +/- 13 and -6 +/- 11 mmHg; p < 0.05 vs control subjects [8 +/- 11 mmHg]). However, the response of diastolic arterial blood pressure or mean heart rate to standing up did not differ between any of the groups. The ratio of maximum to minimum R-R interval during the dynamic response of heart rate to active standing decreased with the degree of nephropathy (1.27 +/- 0.17, 1.11 +/- 0.11 and 1.05 +/- 0.06) with significantly higher values in patients with normo- compared with patients with macroalbuminuria (p < 0.05). All patients groups had significantly lower values than control subjects (1.46 +/- 0.22, p < 0.05). The overshoot of the blood pressure after an initial fall during active standing decreased with the degree of diabetic nephropathy. In conclusion, type 1 diabetic patients with long duration of diabetes have signs of cardiovascular autonomic neuropathy, the severity of which is related to the degree of nephropathy.

The association between retinopathy, nephropathy, cardiovascular disease and long-term metabolic control in type 1 diabetes mellitus: a 5 year follow-up study of 442 adult patients in routine care

The aim of the present study was to examine mean HbA1c and blood pressure levels during a 5 year period in 442 type 1 adult diabetic patients in relation to the incidence and progression of retinopathy, nephropathy and to cardiovascular morbidity and mortality. The study showed, that in patients under routine care at a diabetic unit with four visits to the out-patient clinic per year, the intraindividual coefficient of variation for HbA1c values was 11 +/- 4% (mean +/- S.D.), and 7 +/- 3 and 8 +/- 2% for systolic and diastolic blood pressure, respectively. In 121 patients without retinopathy at entry, the 5 year incidence of any retinopathy was 47% (n = 57). Patients who developed retinopathy had higher mean HbA1c levels (P < 0.01), as well as mean systolic (P < 0.01) and diastolic (P < 0.05) blood pressure levels. In 123 patients with background retinopathy at entry, progression to severe retinopathy, i.e. clinically significant macular oedema, severe non-proliferative or proliferative retinopathy, occurred in 41% (n = 51). In those patients, the degree of metabolic control was worse (P < 0.001), the systolic (P < 0.05) and diastolic (P < 0.01) blood pressure levels were higher. The patients were stratified into four groups according to their urinary albumin concentration at entry: (1) normal albuminuria (< 12.5 mg/l), (2) borderline albuminuria (12.5-30 mg/l), (3) microalbuminuria (31-299 mg/l), i.c. incipient nephropathy and (4) clinical nephropathy (> or = 300 mg/l). An increase of urinary albumin concentration in patients who had normoalbuminuria or borderline albuminuria at entry was associated with mean HbA1c levels (r = 0.24, P < 0.01 and r = 0.27, P < 0.01, respectively). No such association was seen in patients with microalbuminuria or clinical nephropathy at entry. There was no association between the increase of urinary albumin level and mean systolic blood pressure levels in patients who had normoalbuminuria and microalbuminuria at entry. In contrast, there was an association between the increase of urinary albumin level in patients with borderline albuminuria (r = 0.36, P < 0.001), clinical nephropathy (r = 0.26, P < 0.05) and mean systolic blood pressure (P < 0.05). There was no association between the increase of urinary albumin levels and mean diastolic blood pressure in any of the albuminuria groups. As for the incidence of cardiovascular disease, renal insufficiency or death, the duration of diabetes (P < 0.01), urinary albumin concentration at entry (P < 0.001), mean systolic blood pressure (P < 0.05) and treatment with loop diuretics (P < 0.001) were but age, age at onset of diabetes, mean levels of HbA1c and diastolic blood pressure as well as treatment with beta- or Ca-blockers or ACE inhibitors were not related to these end-points. In conclusion, the present study showed that there was an association between the degree of metabolic control and both development and progression of retinopathy and progression of nephropathy of early stages in type 1 diabetic patients treated under routine conditions. Moreover, both the incidence and progression of retinopathy and progression of nephropathy at later stages were also associated with the long-term blood pressure levels. However, HbA1c levels were not associated with morbidity and mortality in cardiovascular disease or development of renal insufficiency.

Coronary artery disease in IDDM. Gender differences in risk factors but not risk

Insulin-dependent diabetes mellitus (IDDM) increases the risk of developing coronary artery disease (CAD) compared with that seen in the general population, while the sex differential in rates of CAD is considerably reduced in IDDM populations. To further our understanding of these observations, the effects of gender on baseline risk factors for CAD incidence were examined. Participants in the Pittsburgh Epidemiology of Diabetes Complications (EDC) Study were recruited from the Children's Hospital of Pittsburgh IDDM registry and had been diagnosed between 1950 and 1980. Subjects completed a series of questionnaires and were given a full clinical examination at baseline (1986 through 1988) and every subsequent 2 years. This report is based on the first 4 years of follow-up. Similar incidence rates of new CAD events were observed in men and women. In neither sex was glycemic control a predictor of later CAD. Sex-specific Cox proportional hazards models showed that for men, duration of IDDM, HDL cholesterol, fibrinogen, hypertension, and smoking were all significantly associated with the onset of CAD. Hypertension, fibrinogen, and smoking were all replaced by nephropathy when this latter variable was added to the model. For women, duration, hypertension, waist-hip ratio, physical activity, and depressive symptomatology were all significant independent predictors of CAD. Nephropathy status did not enter the model for women. While 4-year incidence of CAD in IDDM varies little by sex in this population, the predictive risk factors vary considerably. In particular, the effect of renal disease was stronger in men, while the cluster of physical activity, waist-to-hip ratio, and depressive symptomatology were more important in women. These results may help explain the relatively greater impact IDDM has on CAD risk for women and suggest new potential preventive approaches.

Cohort study of predictive value of urinary albumin excretion for atherosclerotic vascular disease in patients with insulin dependent diabetes

OBJECTIVE

To examine whether slightly elevated urinary albumin excretion precedes development of atherosclerotic vascular disease in patients with insulin dependent diabetes independently of conventional atherogenic risk factors and of diabetic nephropathy.

DESIGN

Cohort study with 11 year follow up.

SETTING

Diabetes centre in Denmark.

SUBJECTS

259 patients aged 19-51 with insulin dependent diabetes of 6-34 years' duration and without atherosclerotic vascular disease or diabetic nephropathy at baseline.

MAIN OUTCOME MEASURES

Baseline variables: urinary albumin excretion, blood pressure, smoking habits, and serum concentrations of total cholesterol, high density lipoprotein cholesterol, sialic acid, and von Willebrand factor.

END POINT

atherosclerotic vascular disease assessed by death certificates, mailed questionnaires, and hospital records.

RESULTS

Thirty patients developed atherosclerotic vascular disease during follow up of 2457 person year. Elevated urinary albumin excretion was significantly predictive of atherosclerotic vascular disease (hazard ratio 1.06 (95% confidence interval 1.02 to 1.18) per 5 mg increase in 24 hour urinary albumin excretion, P = 0.002). Predictive effect was independent of age; sex; blood pressure; smoking; serum concentrations of total cholesterol, high density lipoprotein cholesterol, sialic acid, and von Willebrand factor; level of haemoglobin A(lc); insulin dose, duration of diabetes, and diabetic nephropathy (hazard ratio 1.04 (1.01 to 1.08) per 5 mg increase

The prognostic value of albuminuria for the development of cardiovascular disease and retinopathy: a 5-year follow-up of 451 patients with type 2 diabetes mellitus

The aim of the present study was to evaluate the risk for vascular morbidity or death and retinopathy in relation to urinary albumin concentration. To that end, we performed a 5-year follow-up study of all type 2 diabetic patients attending the outpatient-clinic. A total of 444 (98.4%) out of 451 adult patients initially studied were evaluated for the degree of retinopathy and levels of HbA1c blood pressure, serum creatinine and urinary albumin. Vascular morbidity and causes of death were registered by one and the most severe event only. Forty-seven patients developed atherosclerotic vascular disease, i.e. myocardial infarction (n = 19), cerebrovascular disease (n = 20), or amputation (n = 8), and 42 died. The observed annual mortality rate was 22.1/1000 compared to an expected rate of 13.6/1000 for the general population with corresponding age and sex. Urinary albumin concentration was found to be a prognostic marker for the development of vascular disease and death in patients treated with insulin at baseline (P < 0.01), whereas this was not the case in patients treated with diet and/or oral agents at baseline. However, insulin treatment per se was not associated with an increased mortality or mortality or morbidity. Urinary albumin concentration was not correlated with incidence or progression of retinopathy regardless of type of diabetes treatment. In conclusion, this study showed that albuminuria was a prognostic factor for vascular morbidity and death in type 2 diabetic patients treated with insulin but not in patients treated with diet or oral agents. Furthermore, albuminuria was not a predictor for incidence or progression of retinopathy.

Medical status and complications in relation to periodontal disease experience in insulin-dependent diabetics

The aim of this study was to define a population of diabetics exhibiting an increased risk of developing severe periodontitis by comparing the medical status of 2 groups of diabetics, 1 with no/minor periodontal disease and 1 with severe periodontal disease. The case-control study consisted of 2 parts, a baseline study and a follow-up study. 39 case-control pairs were selected. They were adult, long-duration, insulin-dependent diabetics matched according to sex, age and diabetes duration. One individual in each pair (the CASE) exhibited severe periodontal disease while the other (the CONTROL) exhibited gingivitis or only minor alveolar bone loss. The median age of the cases was 58 years (range 36 to 70 years) and of the controls 59 years (range 37 to 69 years). The median disease duration in cases and controls was 24 years and 25 years, respectively. The median follow-up time was 6 years. The medical variables analysed were weight, insulin dose, systolic and diastolic blood pressure, vibratory threshold, triglycerides, total-cholesterol, HDL-cholesterol, creatinine, HbA1, proteinuria, ECG, retinopathy, stroke, transient ischemic attacks (TIA), angina, myocardial infarct, heart failure, hypertension, intermittent claudication, foot ulcer, death, cause of death, and smoking habit. Biochemical analyses and clinical variables used as a routine in the monitoring of diabetics failed to differentiate between diabetics with severe and minor periodontal disease. In the follow-up study, significantly higher prevalences of proteinuria and cardiovascular complications such as stroke, TIA, angina, myocardial infarct and intermittent claudication were found in the case group. An association between renal disease, cardiovascular complications and severe periodontitis seems to exist. This indicates that a closer cooperation between the diabetologist and the dentist is necessary in monitoring the diabetic patient.