Increased mortality in a Danish cohort of young people with Type 1 diabetes mellitus followed for 24 years.

AIM: To determine the mortality rate in a Danish cohort of children and adolescents diagnosed with Type 1 diabetes mellitus compared with the general population. METHODS: In 1987 and 1989 we included 884 children and 1020 adolescents aged 20 years and under, corresponding to 75% of all Danish children and adolescents with Type 1 diabetes, in two nationwide studies in Denmark. Those who had participated in both investigations (n = 720) were followed until 1 January 2014, using the Danish Civil Registration System on death certificates and emigration. We derived the expected number of deaths in the cohort, using population data values from Statistics Denmark to calculate the standardized mortality ratio. Survival analysis was performed using Cox proportional hazards model. RESULTS: During the 24 years of follow-up, 49 (6.8%) patients died, resulting in a standardized mortality ratio of 4.8 (95% confidence interval 3.5, 6.2) compared with the age-standardized general population. A 1% increase in baseline HbA1c (1989), available in 718 of 720 patients, was associated with all-cause mortality (hazard ratio = 1.38; 95% confidence interval 1.2, 1.6; P < 0.0001). Type 1 diabetes with multiple complications was the most common reported cause of death (36.7%). CONCLUSION: We found an increased mortality rate in this cohort of children and adolescents with Type 1 diabetes compared with the general population. The only predictor for increased risk of death up to 24 years after inclusion was the HbA1c level in 1989. This emphasizes the importance of achieving optimal metabolic control in young people with Type 1 diabetes.

Effect of insulin analogues on frequency of non-severe hypoglycaemia in patients with type 1 diabetes prone to severe hypoglycaemia: The HypoAna trial.

AIM: Insulin analogues reduce the risk of hypoglycaemia compared with human insulin in patients with type 1 diabetes (T1D) and minor hypoglycaemia problems. The HypoAna trial showed that, in patients with recurrent severe hypoglycaemia, treatment based on insulin analogues reduces the risk of severe hypoglycaemia. The present study aims to assess whether this also applies to non-severe hypoglycaemia events during the day and at night. METHODS: This 2-year investigator-initiated multicentre, prospective, randomized, open, blinded endpoint (PROBE) trial involved patients with T1D and at least two episodes of severe hypoglycaemia during the previous year. Using a balanced crossover design, patients were randomized to basal-bolus therapy based on analogue (detemir/aspart) or human (NPH/regular) insulins. A total of 114 participants were included. Endpoints were the number of severe hypoglycaemic events and non-severe events, including documented symptomatic and asymptomatic episodes occurring during the day and at night (ClinicalTrials.gov number: NCT00346996). RESULTS: Analogue-based treatment resulted in a 6% (2-10%; P=0.0025) overall relative risk reduction of non-severe hypoglycaemia. This was due to a 39% (32-46%; P<0.0001) reduction of non-severe nocturnal hypoglycaemia, seen for both symptomatic (48% [36-57%]; P<0.0001) and asymptomatic (28% [14-39%]; P=0.0004) nocturnal hypoglycaemia episodes. No clinically significant differences in hypoglycaemia occurrence were observed between the insulin regimens during the day. The time needed to treat one patient with insulin analogues to avoid one episode (TNT1) of non-severe nocturnal hypoglycaemia was approximately 3 months. CONCLUSION: In T1D patients prone to severe hypoglycaemia, treatment with analogue insulin reduced the risk of non-severe nocturnal hypoglycaemia compared with human insulin.

Confidence bounds for nonlinear dose-response relationships.

An important aim of drug trials is to characterize the dose-response relationship of a new compound. Such a relationship can often be described by a parametric (nonlinear) function that is monotone in dose. If such a model is fitted, it is useful to know the uncertainty of the fitted curve. It is well known that Wald confidence intervals are based on linear approximations and are often unsatisfactory in nonlinear models. Apart from incorrect coverage rates, they can be unreasonable in the sense that the lower confidence limit of the difference to placebo can be negative, even when an overall test shows a significant positive effect. Bootstrap confidence intervals solve many of the problems of the Wald confidence intervals but are computationally intensive and prone to undercoverage for small sample sizes. In this work, we propose a profile likelihood approach to compute confidence intervals for the dose-response curve. These confidence bounds have better coverage than Wald intervals and are more precise and generally faster than bootstrap methods. Moreover, if monotonicity is assumed, the profile likelihood approach takes this automatically into account. The approach is illustrated using a public dataset and simulations based on the Emax and sigmoid Emax models.

Testing effect of a drug using multiple nested models for the dose-response.

During development of a drug, typically the choice of dose is based on a Phase II dose-finding trial, where selected doses are included with placebo. Two common statistical dose-finding methods to analyze such trials are separate comparisons of each dose to placebo (using a multiple comparison procedure) or a model-based strategy (where a dose-response model is fitted to all data). The first approach works best when patients are concentrated on few doses, but cannot conclude on doses not tested. Model-based methods allow for interpolation between doses, but the validity depends on the correctness of the assumed dose-response model. Bretz et al. (2005, Biometrics 61, 738-748) suggested a combined approach, which selects one or more suitable models from a set of candidate models using a multiple comparison procedure. The method initially requires a priori estimates of any non-linear parameters of the candidate models, such that there is still a degree of model misspecification possible and one can only evaluate one or a few special cases of a general model. We propose an alternative multiple testing procedure, which evaluates a candidate set of plausible dose-response models against each other to select one final model. The method does not require any a priori parameter estimates and controls the Type I error rate of selecting a too complex model.

Multinational study in children and adolescents with newly diagnosed type 1 diabetes: association of age, ketoacidosis, HLA status, and autoantibodies on residual beta-cell function and glycemic control 12 months after diagnosis.

OBJECTIVE: To identify predictors of residual beta-cell function and glycemic control during the first 12 months after the diagnosis of type 1 diabetes (T1D). SUBJECTS AND METHODS: Clinical information and blood samples were collected from 275 children. HbA1c, antibodies, HLA typing and mixed meal-stimulated C-peptide levels 1, 6, and 12 months after diagnosis were analyzed centrally. RESULTS: Mean age at diagnosis was 9.1 yr. DKA with standard bicarbonate <15 mmol/L was associated with significantly poorer residual beta-cell function 1 (p = 0.004) and 12 months (p = 0.0003) after diagnosis. At 12 months, the decline in stimulated C-peptide levels compared with the levels at 1 month was 69% in the youngest age group and 50% in patients 10 yr and above (p < 0.001). Stimulated C-peptide at 12 months was predicted by younger age (p < 0.02) and bicarbonate levels at diagnosis (p = 0.005), and by stimulated C-peptide (p < 0.0001), postmeal blood glucose (p = 0.0004), insulin antibodies (IA; p = 0.02) and glutamic acid decarboxylase antibodies (GADA; p = 0.0004) at 1 month. HbA1c at 12 months was predicted by HbA1c at diagnosis (p < 0.0001), GADA at 1 month (p = 0.01), and non-white Caucasian ethnicity (p = 0.002). CONCLUSIONS: Younger age, ketoacidosis at diagnosis, and IA and GADA 1 month after diagnosis were the strongest explanatory factors for residual beta-cell function at 12 months. Glycemic control at 12 months was influenced predominantly by ethnicity, HbA1c at diagnosis, and GADA at 1 month.

Relation of circulating concentrations of chemokine receptor CCR5 ligands to C-peptide, proinsulin and HbA1c and disease progression in type 1 diabetes.

Th1 related chemokines CCL3 and CCL5 and Th2 related CCL4 as ligands of the receptor CCR5 contribute to disease development in animal models of type 1 diabetes. In humans, no data are available addressing the role of these chemokines regarding disease progression and remission. We investigated longitudinally circulating concentrations of CCR5 ligands of 256 newly diagnosed patients with type 1 diabetes. CCR5 ligands were differentially associated with beta-cell function and clinical remission. CCL5 was decreased in remitters and positively associated with HbA1c suggestive of a Th1 associated progression of the disease. Likewise, CCL3 was negatively related to C-peptide and positively associated with the beta-cell stress marker proinsulin but increased in remitters. CCL4 associated with decreased beta-cell stress shown by negative association with proinsulin. Blockage of chemokines or antagonism of CCR5 by therapeutic agents such as maraviroc may provide a new therapeutic target to ameliorate disease progression in type 1 diabetes.

Impact of IDDM2 on disease pathogenesis and progression in children with newly diagnosed type 1 diabetes: reduced insulin antibody titres and preserved beta cell function.

AIMS/HYPOTHESIS: The insulin-dependent diabetes mellitus 2 gene (IDDM2) is a type 1 diabetes susceptibility locus contributed to by the variable number of tandem repeats (VNTR) upstream of the insulin gene (INS). We investigated the association between INS VNTR class III alleles (-23HphIA/T) and both insulin antibody presentation and residual beta cell function during the first year after diagnosis in 257 children with type 1 diabetes. MATERIALS AND METHODS: To estimate C-peptide levels and autoantibody presentation, patients underwent a meal-stimulated C-peptide test 1, 6, and 12 months after diagnosis. The insulin -23HphIA/T variant was used as a marker of class III alleles and genotyped by PCR-RFLP. RESULTS: The insulin antibody titres at 1 and 6 months were significantly lower in the class III/III and class I/III genotype groups than in the class I/I genotype group (p = 0.01). Class III alleles were also associated with residual beta cell function 12 months after diagnosis and independently of age, sex, BMI, insulin antibody titres, and HLA-risk genotype group (p = 0.03). The C-peptide level was twice as high among class III/III genotypes as in class I/I and class I/III genotypes (319 vs 131 and 166 pmol/l, p=0.01). Furthermore, the class III/III genotype had a 1.1% reduction in HbA(1)c after adjustment for insulin dose (p = 0.04). CONCLUSIONS/INTERPRETATION: These findings suggest a direct connection in vivo between INS VNTR class III alleles, a decreased humoral immune response to insulin, and preservation of beta cell function in recent-onset type 1 diabetes.

Prediction of severe hypoglycaemia by angiotensin-converting enzyme activity and genotype in type 1 diabetes.

AIMS/HYPOTHESIS: We have previously shown a strong relationship between high angiotensin-converting enzyme (ACE) activity, presence of the deletion (D) allele of the ACEgene and recall of severe hypoglycaemic events in patients with Type 1 diabetes. This study was carried out to assess this relationship prospectively. METHODS: We followed 171 adult outpatients with Type 1 diabetes in a one-year observational study with the recording of severe hypoglycaemia. Participants were characterised by serum ACE activity and ACE genotype and not treated with ACE inhibitors or angiotensin II receptor antagonists. RESULTS: There was a positive relationship between serum ACE activity and rate of severe hypoglycaemia with a 2.7 times higher rate in the fourth quartile of ACE activity compared to the first quartile (p=0.0007). A similar relationship was observed for the subset of episodes with coma (2.9 times higher rate in fourth quartile compared to first quartile; p=0.048). The impact of serum ACE activity was most pronounced in C-peptide negative subjects (4.2 times higher rate in fourth quartile compared to first quartile; p=0.003), and in this subgroup carriers of the D allele of the ACEgene had higher rates of severe hypoglycaemia compared to the group homozygous for the insertion (I) allele. In a multiple regression analysis high serum ACE activity and impaired awareness of hypoglycaemia were identified as the only significant predictors of severe hypoglycemia. CONCLUSION: High ACE activity and the presence of the D allele of the ACE gene predict a high rate of severe hypoglycaemia in Type 1 diabetes.

Good metabolic control is associated with better quality of life in 2,101 adolescents with type 1 diabetes.

OBJECTIVE: It is unclear whether the demands of good metabolic control or the consequences of poor control have a greater influence on quality of life (QOL) for adolescents with diabetes. This study aimed to assess these relations in a large international cohort of adolescents with diabetes and their families. RESEARCH DESIGN AND METHODS: The study involved 2,101 adolescents, aged 10-18 years, from 21 centers in 17 countries in Europe, Japan, and North America. Clinical and demographic data were collected from March through August 1998. HbA(1c) was analyzed centrally (normal range 4.4-6.3%; mean 5.4%). Adolescent QOL was assessed by a previously developed Diabetes Quality of Life (DQOL) questionnaire for adolescents, measuring the impact of diabetes, worries about diabetes, satisfaction with life, and health perception. Parents and health professionals assessed family burden using newly constructed questionnaires. RESULTS: Mean HbA(1c) was 8.7% (range 4.8-17.4). Lower HbA(1c) was associated with lower impact (P < 0.0001), fewer worries (P < 0.05), greater satisfaction (P < 0.0001), and better health perception (P < 0.0001) for adolescents. Girls showed increased worries (P < 0.01), less satisfaction, and poorer health perception (P < 0.01) earlier than boys. Parent and health professional perceptions of burden decreased with age of adolescent (P < 0.0001). Patients from ethnic minorities had poorer scores for impact (P < 0.0001), worries (P < 0.05), and health perception (P < 0.01). There was no correlation between adolescent and parent or between adolescent and professional scores. CONCLUSIONS: In a multiple regression model, lower HbA(1c) was significantly associated with better adolescent-rated QOL on all four subscales and with lower perceived family burden as assessed by parents and health professionals.

Persistent differences among centers over 3 years in glycemic control and hypoglycemia in a study of 3,805 children and adolescents with type 1 diabetes from the Hvidøre Study Group.

OBJECTIVE: Twenty-one international pediatric diabetes centers from 17 countries investigated the effect of simple feedback about the grand mean HbA(1c) level of all centers and the average value of each center on changes in metabolic control, rate of severe hypoglycemia, and insulin therapy over a 3-year period. RESEARCH DESIGN AND METHODS: Clinical data collection and determination of HbA(1c) levels were conducted at a central location in 1995 (n = 2,780, age 0-18 years) and 1998 (n = 2,101, age 11-18 years). RESULTS: Striking differences in average HbA(1c) concentrations were found among centers; these differences remained after adjustment for the significant confounders of sex, age, and diabetes duration. They were apparent even in patients with short diabetes duration and remained stable 3 years later (mean adjusted HbA(1c) level: 8.62 +/- 0.03 vs. 8.67 +/- 0.04 [1995 vs. 1998, respectively]). Three centers had improved significantly, four centers had deteriorated significantly in their overall adjusted HbA(1c) levels, and 14 centers had not changed in glycemic control. During the observation period, there were increases in the adjusted insulin dose by 0.076 U/kg, the adjusted number of injections by 0.23 injections per day, and the adjusted BMI by 0.95 kg/m(2). The 1995 versus 1998 difference in glycemic control for the seven centers could not be explained by prevailing insulin regimens or rates of hypoglycemia. CONCLUSIONS: This study reveals significant outcome differences among large international pediatric diabetes centers. Feedback and comparison of HbA(1c) levels led to an intensification of insulin therapy in most centers, but improved glycemic control in only a few.

Activity of angiotensin-converting enzyme and risk of severe hypoglycaemia in type 1 diabetes mellitus.

BACKGROUND: The insertion (I) allele of the angiotensin-converting-enzyme (ACE) gene occurs at increased frequency in endurance athletes. This association suggests that low ACE activity is favourable for performance in conditions with limited substrate availability. Such conditions occur in endurance athletes during competition and in diabetic patients during insulin-induced hypoglycaemia. Patients rely on preserved functional capacity to recognise hypoglycaemic episodes and avoid progression by self-treatment. We studied whether ACE activity is related to the risk of severe hypoglycaemia in type 1 diabetes. METHODS: Consecutive adult outpatients with type 1 diabetes, untreated with ACE inhibitors or angiotensin-II-receptor antagonists (n=207) reported their experience of mild and severe hypoglycaemia during the previous 1 year and 2 years. The patients were further characterised by diabetes history, degree of hypoglycaemia awareness, measurement of C-peptide, haemoglobin A(1c), and serum ACE concentrations, and determination of ACE genotype. FINDINGS: Patients with the DD genotype had a relative risk of severe hypoglycaemia in the preceding 2 years of 3.2 (95% CI 1.4-7.4) compared with those who had the II genotype. There was a significant relation between serum ACE activity and the rate of severe hypoglycaemia (relative risk per 10 U/L increment 1.4 [1.2-1.6]), corresponding to a 3.5 times higher risk for patients in the highest quartile than for those in the lowest quartile. Multiple regression analysis showed that the effect of the ACE genotype was explained by its influence on serum ACE activity and that the only other significant determinants of the risk of severe hypoglycaemia were the degree of hypoglycaemia awareness, b-cell function, and duration of diabetes of more than 20 years. INTERPRETATION: ACE activity is a clinically significant marker of the risk of severe hypoglycaemia in patients with type 1 diabetes, especially in those with impaired defence against hypoglycaemia. These findings need to be confirmed in prospective studies.

A 6-year nationwide cohort study of glycaemic control in young people with type 1 diabetes. Risk markers for the development of retinopathy, nephropathy and neuropathy. Danish Study Group of Diabetes in Childhood.

The study aimed to identify risk markers (present at the start of the study in 1989) for the occurrence and progression of microvascular complications 6 years later (in 1995) in a Danish nationwide cohort of children and adolescents with Type 1 diabetes (average age at entry 13.7 years). Probabilities for the development of elevated albumin excretion rate (AER), retinopathy, and increased vibration perception threshold (VPT) could then be estimated from a stepwise logistic regression model. A total of 339 patients (47% of the original cohort) were studied. Sex, age, diabetes duration, insulin regimen and dose, height, weight, HbA(1c), blood pressure, and AER were recorded. In addition, information on retinopathy, neuropathy (VPT), and anti-hypertensive treatment was obtained at the end of the study. HbA(1c) (normal range 4.3-5.8, mean 5.3%) and AER (upper normal limit <20 microg min(-1)) in two, timed overnight urine collections were analysed centrally. Eye examination was performed by two-field fundus photography. Determination of VPT was assessed by biothesiometry. Increased AER (> or =20 microg min(-1)) was found in 12.8% of the patients in 1995, and risk markers for this were increased AER and high HbA(1c), in 1989 (both p<0.001). Retinopathy was present in 57.8% of patients in 1995, for which the risk markers were long duration of diabetes (p<0.0001), age (p<0.01), and high HbA(1c) (p<0.0001) in 1989. Elevated VPT (>6.5 V) was found in 62.5% of patients in 1995, for which the risk markers were male sex (p<0.05), age (p<0.0001), and increased AER (p<0.05) in 1989. This study confirms that hyperglycaemia plays a major role for the development of microvascular complications in kidneys and eyes, and emphasises the need for optimal glycaemic control in children and adolescents with Type 1 diabetes.

Fisher information for two gamma frailty bivariate Weibull models.

The asymptotic properties of frailty models for multivariate survival data are not well understood. To study this aspect, the Fisher information is derived in the standard bivariate gamma frailty model, where the survival distribution is of Weibull form conditional on the frailty. For comparison, the Fisher information is also derived in the bivariate gamma frailty model, where the marginal distribution is of Weibull form.

Multi-state models: a review.

Multi-state models are models for a process, for example describing a life history of an individual, which at any time occupies one of a few possible states. This can describe several possible events for a single individual, or the dependence between several individuals. The events are the transitions between the states. This class of models allows for an extremely flexible approach that can model almost any kind of longitudinal failure time data. This is particularly relevant for modeling different events, which have an event-related dependence, like occurrence of disease changing the risk of death. It can also model paired data. It is useful for recurrent events, but has limitations. The Markov models stand out as much simpler than other models from a probability point of view, and this simplifies the likelihood evaluation. However, in many cases, the Markov models do not fit satisfactorily, and happily, it is reasonably simple to study non-Markov models, in particular the Markov extension models. This also makes it possible to consider, whether the dependence is of short-term or long-term nature. Applications include the effect of heart transplantation on the mortality and the mortality among Danish twins.

Plasma homocysteine concentration predicts mortality in non-insulin-dependent diabetic patients with and without albuminuria.

BACKGROUND: A high plasma total homocysteine (tHcy) concentration is a risk factor for cardiovascular disease in the nondiabetic population and in nondiabetic patients with end-stage renal disease. METHODS: We prospectively evaluated the impact of tHcy concentrations on mortality in 211 white non-insulin-dependent diabetic (NIDDM) patients of less than 70 years of age at entry (61 with microalbuminuria and 44 with macroalbuminuria). They were followed for a median of 6.4 (range 0.2 to 7.1) years. RESULTS: At the end of the follow-up period, 49 of 211 (23%) patients had died, 30 (61%) from cardiovascular disease. Univariate Cox survival analysis revealed that baseline tHcy level (1 micromol/liter) was associated with an increased all-cause mortality risk of 1.11 [95% confidence interval (CI) 1.08 to 1.15, P < 0.0001], and a cardiovascular mortality risk of 1.09 (CI 1.03 to 1.16, P < 0.01). The six-year cumulative all-cause mortality hazard was 44%, 14%, and 15% in the high (tHcy >/= 8.2 micromol/liter), the middle (tHcy 6. 2-8.1 micromol/liter), and the low (tHcy

Fundamentals of survival data.

Survival data stand out as a special statistical field. This paper tries to describe what survival data is and what makes it so special. Survival data concern times to some events. A key point is the successive observation of time, which on the one hand leads to some times not being observed so that all that is known is that they exceed some given times (censoring), and on the other hand implies that predictions regarding the future course should be conditional on the present status (truncation). In the simplest case, this condition is that the individual is alive. The successive conditioning makes the hazard function, which describes the probability of an event happening during a short interval given that the individual is alive today (or more generally able to experience the event), the most relevant concept. Standard distributions available (normal, log-normal, gamma, inverse Gaussian, and so forth) can account for censoring and truncation, but this is cumbersome. Besides, they fit badly because they are either symmetric or right skewed, but survival time distributions can easily be left-skewed positive variables. A few distributions satisfying these requirements are available, but often nonparametric methods are preferable as they account better conceptually for truncation and censoring and give a better fit. Finally, we compare the proportional hazards regression models with accelerated failure time models.

Insulin management and metabolic control of type 1 diabetes mellitus in childhood and adolescence in 18 countries. Hvidøre Study Group on Childhood Diabetes.

Insulin regimens and metabolic control in children and adolescents with Type 1 diabetes mellitus were evaluated in a cross-sectional, non-population-based investigation, involving 22 paediatric departments, from 18 countries in Europe, Japan, and North America. Blood samples and information were collected from 2873 children from March to August 1995. HbA1c was determined once and analysed centrally (normal range 4.4-6.3%, mean 5.4%). Year of birth, sex, duration of diabetes, height, body weight, number of daily insulin injections, types and doses of insulin were recorded. Average HbA1c in children under 11 years was 8.3 +/- 1.3% (mean +/- SD) compared with 8.9 +/- 1.8% in those aged 12-18 years. The average insulin dose per kg body weight was almost constant (0.65 U kg(-1) 24 h(-1)) in children aged 2-9 years for both sexes, but there was a sharp increase during the pubertal years, particularly in girls. The increase in BMI of children with diabetes was much faster during adolescence compared to healthy children, especially in females. Sixty per cent of the children (n = 1707) used two daily insulin injections while 37% (n = 1071) used three or more. Of those on two or three injections daily, 37% used pre-mixed insulins, either alone or in combination with short- and intermediate-acting insulin. Pre-adolescent children on pre-mixed insulin showed similar HbA1c levels to those on a combination of short- and long-acting insulins, whereas in adolescents significantly better HbA1c values were achieved with individual combinations. Very young children were treated with a higher proportion of long-acting insulin. Among adolescent boys, lower HbA1c was related to use of more short-acting insulin. This association was not found in girls. We conclude that numerous insulin injection regimens are currently used in paediatric diabetes centres around the world, with an increasing tendency towards intensive diabetes management, particularly in older adolescents. Nevertheless, the goal of near normoglycaemia is achieved in only a few.

[Significant risk factors for development of microalbuminuria and diabetic nephropathy in patients with non-insulin-dependent diabetes]. / Risikofaktorer af betydning for udvikling af mikroalbuminuri og diabetisk nefropati hos ikkeinsulinkraevende diabetikere.

Putative risk factors for the development of incipient diabetic nephropathy (persistent microalbuminuria) and overt diabetic nephropathy (persistent macroalbuminuria) were evaluated prospectively in Caucasian non-insulin dependent diabetic (NIDDM) patients. All NIDDM patients < 66 years, with normoalbuminuria (albumin excretion rate [AER] < 30 mg/24 h), attending our clinic during 1987 were identified (n = 191). The patients were followed for a median of 5.8 years. Fifteen of the 191 patients were lost to follow-up. Thirty-six of the remaining 176 patients developed persistent microalbuminuria (AER 30-299 mg/24 h) and five developed persistent macroalbuminuria (AER less than or equal to 300 mg/24 h) during follow-up. The five-year cumulative incidence of incipient diabetic nephropathy was 23% (95% confidence interval 17% to 30%). Baseline log10 AER, male gender, presence of retinopathy, S-cholesterol, HbA1c, and age was found to predict the development of incipient/overt diabetic nephropathy in these patients.

[Risk factors for mortality in patients with insulin-dependent diabetes]. / Risikofaktorer for død hos insulinkraevende diabetikere.

The prognostic significance of microalbuminuria, macroalbuminuria and other putative risk factors for mortality in insulin-dependent diabetic patients were evaluated in a 10 year prospective study. We identified 939 insulin-dependent diabetic patients; 593 patients had normoalbuminuria (< or = 30 mg/24 h), 181 had microalbuminuria (31-299 mg/24 h), and 165 had macroalbuminuria (> or = 300 mg/24 h). Fifteen percent of patients with normoalbuminuria, 25% with microalbuminuria and 44% with macroalbuminuria at baseline died during follow-up (p < or = 0.01). Significant predictors of all-cause mortality were male sex, age, height, smoking, low social class, urinary albumin excretion, hypertension, serum creatinine, and HbA1c. Age, smoking, microalbuminuria, overt nephropathy, and hypertension were significant predictors of cardiovascular mortality. The mortality in patients with microalbuminuria was only slightly increased compared to patients with normoalbuminuria. Median survival after onset of overt diabetic nephropathy was 13.9 (11.8 to 17.2) years. Abnormally elevated urinary albumin excretion and other potentially modifiable risk factors such as hypertension, smoking, poor glycaemic control and social class predicts increased mortality in insulin-dependent diabetic patients.

Significant reduction of the antiatherogenic effect of estrogen by long-term inhibition of nitric oxide synthesis in cholesterol-clamped rabbits.

The purpose of this study was to investigate whether endothelium-derived nitric oxide (NO) is involved in the plasma lipid-independent antiatherogenic effect of estrogen and levormeloxifene, a partial estrogen receptor agonist. 85 rabbits were ovariectomized and balloon-injured in the middle thoracic aorta. The rabbits were fed a cholesterol-enriched diet supplemented with 17beta-estradiol, levormeloxifene, or placebo, either alone, or together with 160 microg/ml NG-nitro- -arginine methyl ester (-NAME), an NO synthase inhibitor, in their drinking water for 12 wk. Plasma cholesterol was maintained at 25-30 mmol/liter by individualized cholesterol feeding. In the undamaged aorta, the extent of atherosclerosis in the estrogen group was only one-third that in the placebo group. Simultaneous administration of -NAME, however, significantly reduced the antiatherogenic effect of estrogen (P < 0.01). There was no significant difference between the placebo group given -NAME and the group treated with placebo alone. At the previously endothelium-denuded site, estrogen had no effect on atherosclerosis development, whereas -NAME combined with estrogen significantly increased atherogenesis (P < 0.05). The effects of levormeloxifene were almost similar to those of estrogen. Active vascular concentrations of -NAME were demonstrated in an additional study, in which maximal aortic/coronary endothelium-dependent relaxation was significantly inhibited in rabbits given -NAME. Thus, in this study a considerable part of the plasma lipid-independent antiatherogenic effect of estrogen was mediated through its effect on endothelial NO in cholesterol-fed rabbits. The results for levormeloxifene suggest a common mechanism of action for estrogen and partial estrogen receptor agonists on atherogenesis.