Incident microalbuminuria and complement factor mannan-binding lectin-associated protein 19 in people with newly diagnosed type 1 diabetes

BACKGROUND

Evidence links the lectin pathway of complement activation to diabetic kidney disease. Upon carbohydrate-recognition by pattern-recognition molecules, eg, mannan-binding lectin (MBL), the MBL-associated serine protease (MASP-2) is activated and initiates the complement cascade. The MASP2 gene encodes MASP-2 and the alternative splice product MBL-associated protein 19 (MAp19). Both MAp19 and MASP-2 circulate in complex with MBL. We tested the hypothesis that MAp19 and MASP-2 concentrations predict the risk of incident microalbuminuria.

METHODS

Baseline MAp19 and MASP-2 were measured in 270 persons with newly diagnosed type 1 diabetes tracked for incidence of persistent microalbuminuria in a prospective observational 18-year-follow-up study.

RESULTS

Seventy-five participants (28%) developed microalbuminuria during follow-up. MBL-associated protein 19 concentrations were higher in participants that later progressed to microalbuminuria as compared with those with persistent normoalbuminuria (268 ng/mL [95% CI, 243-293] vs 236 ng/mL [95% CI, 223-250], P = .02). Participants with MAp19 concentration within the highest quartile of the cohort had an increased risk of microalbuminuria as compared with participants with MAp19 concentration within the combined lower 3 quartiles in unadjusted Cox analysis, hazard ratio 1.86 ([95% CI, 1.17-2.96], P = .009). This remained significant in adjusted models, eg, adjusting for age, sex, HbA_1c , systolic blood pressure, urinary albumin excretion, smoking, serum creatinine, and serum cholesterol. MBL-associated serine protease concentration was not associated with incidence of microalbuminuria.

CONCLUSIONS

In conclusion, the results show an association between baseline MAp19 concentration and the incidence of microalbuminuria in an 18-year-follow-up study on persons with newly diagnosed type 1 diabetes.

Comparing effects of insulin analogues and human insulin on nocturnal glycaemia in hypoglycaemia-prone people with Type 1 diabetes

AIMS

To assess the difference between analogue and human insulin with regard to nocturnal glucose profiles and risk of hypoglycaemia in people with recurrent severe hypoglycaemia.

METHODS

A total of 72 people [46 men, mean ± sd age 54 ± 12 years, mean ± sd HbA_1c 65 ± 12 mmol/mol (8.1 ± 1.1%), mean ± sd duration of diabetes 30 ± 14 years], who participated in a 2-year randomized, crossover trial of basal-bolus therapy with insulin detemir/insulin aspart or human NPH insulin/human regular insulin (the HypoAna trial) were studied for 2 nights during each treatment. Venous blood was drawn hourly during sleep. Primary endpoints were nocturnal glucose profiles and occurrence of hypoglycaemia (blood glucose ≤ 3.9 mmol/l).

RESULTS

During insulin analogue treatment, the mean nocturnal plasma glucose level was significantly higher than during treatment with human insulin (10.6 vs 8.1 mmol/l). The fasting plasma glucose level was similar between the treatments. Nocturnal hypoglycaemia was registered during 41/101 nights (41%) in the human insulin arm and 19/117 nights (16%) in the insulin analogue arm, corresponding to a hazard ratio of 0.26 (95% CI 0.14 to 0.45; P < 0.0001) with insulin analogue.

CONCLUSIONS

Treatment with insulin analogue reduces the occurrence of nocturnal hypoglycaemia assessed by nocturnal glucose profiles in people with Type 1 diabetes prone to severe hypoglycaemia. Nocturnal glucose profiles provide a more comprehensive assessment of clinical benefit of insulin regimens as compared to conventional recording of hypoglycaemia.

Plasma matrix metalloproteinases are associated with incident cardiovascular disease and all-cause mortality in patients with type 1 diabetes: a 12-year follow-up study

Background

Altered regulation of extracellular matrix remodeling by matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP) may contribute to vascular complications in type 1 diabetes. We investigated associations between plasma MMP-1, -2, -3, -9, -10 and TIMP-1, and cardiovascular events and all-cause mortality in type 1 diabetic patients.

Methods

We prospectively followed 337 type 1 diabetic patients [mean age 41.4 years (9.6), 39% female], 170 with and 167 without diabetic nephropathy, with median follow-up of 12.3 years. Survival analyses were applied to investigate differences in plasma MMP-1, -2, -3, -9, -10, and TIMP-1-levels in patients with and without a cardiovascular event and in those who died vs survivors. All analyses were adjusted for age, sex, duration of diabetes, HbA1c, nephropathy and for other conventional cardiovascular risk factors.

Results

After adjustment for potential confounders, higher MMP-2 plasma levels were significantly associated with higher incidence of cardiovascular events [HR 1.49 (95% CI 1.11; 1.99)], and higher plasma levels of MMP-1 [1.38 (1.07; 1.78)], MMP-2 [1.60 (1.19; 2.15)] and MMP-3 [1.39 (1.05; 1.85)] were associated with all-cause mortality. All associations were independent of low-grade inflammation and endothelial dysfunction as estimated by plasma markers. Associations between MMP-2 and cardiovascular events and between MMP-3 and mortality were attenuated after further adjustment for eGFR and changes in eGFR.

Conclusions

Higher levels of MMP-2 are associated with CVD and higher MMP-1, -2 and -3 with all-cause mortality. In addition, associations between MMP-2 and CVD, and MMP-3 and mortality were attenuated after adjustment for eGFR while both MMPs were associated with eGFR decline, indicating a possible mediating role of eGFR.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-017-0539-1) contains supplementary material, which is available to authorized users.

Is a reduction in albuminuria associated with renal and cardiovascular protection? A post hoc analysis of the ALTITUDE trial

AIMS

To investigate whether the degree of albuminuria reduction observed in the ALTITUDE trial is associated with renal and cardiovascular protection, and secondly, whether the reduction in albuminuria was too small to afford clinical benefit.

METHODS

In a post hoc analysis of the ALTITUDE trial in 8561 patients with type 2 diabetes and chronic kidney disease or cardiovascular disease we examined the effect of albuminuria changes at 6 months on renal and cardiovascular outcomes using Cox proportional hazard regression.

RESULTS

The median change in albuminuria in the first 6 months in the aliskiren arm of the trial was -12% (25th to 75th percentile: -48.7_to_ +41.9%) and 0.0% (25th to 75th percentile: -40.2_to_55%) in the placebo arm. Changes in albuminuria in the first 6 months were linearly associated with renal and cardiovascular endpoints: a >30% reduction in albuminuria in the first 6 months was associated with a 62% reduction in renal risk and a 25% reduction in cardiovascular risk compared with an increase in albuminuria. The association between changes at 6 months in albuminuria and renal or cardiovascular endpoints was similar in the two treatment groups (p for interaction >0.1 for both endpoints).

CONCLUSIONS

The addition of aliskiren to angiotensin-converting enzyme inhibitor/angiotensin receptor blocker therapy resulted in albuminuria changes that were associated with renal and cardiovascular risk changes. This did not translate into renal or cardiovascular protection because the overall reduction in albuminuria in the aliskiren arm was too small and nearly similar to that in the placebo arm.

Early renin-angiotensin system intervention is more beneficial than late intervention in delaying end-stage renal disease in patients with type 2 diabetes

AIMS

To develop and validate a model to simulate progression of diabetic kidney disease (DKD) from early onset until end-stage renal disease (ESRD), and to assess the effect of renin-angiotensin system (RAS) intervention in early, intermediate and advanced stages of DKD.

METHODS

We used data from the BENEDICT, IRMA-2, RENAAL and IDNT trials that assessed effects of RAS intervention in patients with type 2 diabetes. We built a model with discrete disease stages based on albuminuria and estimated glomerular filtration rate (eGFR). Using survival analyses, we assessed the effect of RAS intervention on delaying ESRD in early [eGFR>60 ml/min/1.73 m(2) and albumin:creatinine ratio (ACR) <30 mg/g], intermediate (eGFR 30-60 ml/min/1.73 m(2) or ACR 30-300 mg/g) and advanced (eGFR <30 ml/min/1.73 m(2) or ACR >300 mg/g) stages of DKD for patients in different age groups.

RESULTS

For patients at early, intermediate and advanced stage of disease, whose mean age was 60 years and who received placebo, the median time to ESRD was 21.4, 10.8 and 4.7 years, respectively. RAS intervention delayed the predicted time to ESRD by 4.2, 3.6 and 1.4 years, respectively. The benefit of early RAS intervention was more pronounced in younger patients; for example, for patients with a mean age of 45 years, RAS intervention at early, intermediate or advanced stage delayed ESRD by 5.9, 4.0 and 1.1 years versus placebo.

CONCLUSIONS

RAS intervention early in the course of proteinuric DKD is more beneficial than late intervention in delaying ESRD.

Pulse pressure is not an independent predictor of outcome in type 2 diabetes patients with chronic kidney disease and anemia--the Trial to Reduce Cardiovascular Events with Aranesp Therapy (TREAT)

Pulse pressure (PP) remains an elusive cardiovascular risk factor with inconsistent findings. We clarified the prognostic value in patients with type 2 diabetes, chronic kidney disease (CKD) and anemia in the Trial to Reduce cardiovascular Events with Aranesp (darbepoetin alfa) Therapy. In 4038 type 2 diabetes patients, darbepoetin alfa treatment did not affect the primary outcome. Risk related to PP at randomization was evaluated in a multivariable model including age, gender, kidney function, cardiovascular disease (CVD) and other conventional risk factors. End points were myocardial infarction (MI), stroke, end stage renal disease (ESRD) and the composite of cardiovascular death, MI or hospitalization for myocardial ischemia, heart failure or stroke (CVD composite). Median (interquartile range) age, gender, eGFR and PP was 68 (60-75) years, 57.3% women, 33 (27-42) ml min(-1) per 1.73 m2 and 60 (50-74) mm Hg. During 29.1 months (median) follow-up, the number of events for composite CVD, MI, stroke and ESRD was 1010, 253, 154 and 668. In unadjusted analyses, higher quartiles of PP were associated with higher rates per 100 years of follow-up of all end points (P⩽0.04), except stroke (P=0.52). Adjusted hazard ratios (95% confidence interval) per one quartile increase in PP were 1.06 (0.99-1.26) for MI, 0.96 (0.83-1.11) for stroke, 1.01 (0.94-1.09) for ESRD and 1.01 (0.96-1.07) for CVD composite. Results were similar in continuous analyses of PP (per 10 mm Hg). In patients with type 2 diabetes, CKD and anemia, PP did not independently predict cardiovascular events or ESRD. This may reflect confounding by aggressive antihypertensive treatment, or PP may be too rough a risk marker in these high-risk patients.

The methylglyoxal-derived AGE tetrahydropyrimidine is increased in plasma of individuals with type 1 diabetes mellitus and in atherosclerotic lesions and is associated with sVCAM-1

AIMS/HYPOTHESIS

Methylglyoxal (MGO) is a major precursor for advanced glycation end-products (AGEs), which are thought to play a role in vascular complications in diabetes. Known MGO-arginine-derived AGEs are 5-hydro-5-methylimidazolone (MG-H1), argpyrimidine and tetrahydropyrimidine (THP). We studied THP in relation to type 1 diabetes, endothelial dysfunction, low-grade inflammation, vascular complications and atherosclerosis.

METHODS

We raised and characterised a monoclonal antibody against MGO-derived THP. We measured plasma THP with a competitive ELISA in two cohort studies: study A (198 individuals with type 1 diabetes and 197 controls); study B (individuals with type 1 diabetes, 175 with normoalbuminuria and 198 with macroalbuminuria [>300 mg/24 h]). We measured plasma markers of endothelial dysfunction and low-grade inflammation, and evaluated the presence of THP and N (ε)-(carboxymethyl)lysine (CML) in atherosclerotic arteries.

RESULTS

THP was higher in individuals with type 1 diabetes than in those without (median [interquartile range] 115.5 U/μl [102.4-133.2] and 109.8 U/μl [91.8-122.3], respectively; p = 0.03). THP was associated with plasma soluble vascular cell adhesion molecule 1 in both study A (standardised β = 0.48 [95% CI 0.38, 0.58]; p < 0.001) and study B (standardised β = 0.31 [95% CI 0.23, 0.40]; p < 0.001), and with secreted phospholipase A2 (standardised β = 0.26 [95% CI 0.17, 0.36]; p < 0.001) in study B. We found no association of THP with micro- or macro-vascular complications. Both THP and CML were detected in atherosclerotic arteries.

CONCLUSIONS/INTERPRETATION

Our results suggest that MGO-derived THP may reflect endothelial dysfunction among individuals with and without type 1 diabetes, and therefore may potentially play a role in the development of atherosclerosis and vascular disease.

Urinary sulphate excretion and progression of diabetic nephropathy in Type 1 diabetes

AIMS

Hydrogen sulphide levels are reduced in many disease states, including diabetes and end-stage renal disease. We aimed to determine whether urinary sulphate excretion, as a proxy for hydrogen sulphide, was associated with progression of diabetic nephropathy.

METHODS

We conducted a post-hoc study of a prospective, randomized, controlled trial on the effect of a low vs. normal protein diet for 4 years, on decline of renal function in patients with Type 1 diabetes and diabetic nephropathy. We excluded patients with less than three measurements of glomerular filtration rate assessed by (51)Cr-EDTA plasma clearance (GFR) and less than 1 year of follow-up (n = 10), leaving 72 patients eligible for analyses. We studied both association of rate of decline in GFR and association of the combined endpoint of end-stage renal disease and death with baseline 24-h urinary sulphate excretion.

RESULTS

Sulphate excretion was significantly associated with the slope of GFR (rs = -0.28, P = 0.02). In a multivariate regression model, sulphate excretion was a significant determinant of decline in GFR, independent of age, gender, blood pressure, HbA1c , smoking, albuminuria, baseline GFR and diet group (P < 0.01). In addition, adjusted r(2) increased from 5% in a model with the aforementioned risk factors to 22% when sulphate excretion was included in the model. Cox regression revealed a hazard ratio of 0.34 (95% CI 0.13-0.88, P = 0.026) for each natural log unit increase in urinary sulphate excretion.

CONCLUSION

High urinary sulphate excretion was significantly associated with slower decline in (51)Cr-EDTA-assessed GFR in diabetic nephropathy, independent of known progression promoters.

A prediction of the renal and cardiovascular efficacy of aliskiren in ALTITUDE using short-term changes in multiple risk markers

INTRODUCTION

We recently developed and validated in existing trials a novel algorithm (PRE score) to predict long-term drug efficacy based on short-term (month-6) drug-induced changes in multiple risk markers. To show the value of the PRE score for ongoing and planned clinical trials, we here report the predicted long-term cardio-renal efficacy of aliskiren in type 2 diabetes, which was investigated in the ALTITUDE trial, but unknown at the time this study was conducted.

METHODS

We established the relation between multiple risk markers and cardio-renal endpoints (as defined in ALTITUDE) using a background database from past clinical trials. The short-term effect of aliskiren on multiple risk markers was taken from the AVOID trial. A PRE score was developed by multivariate Cox analysis in the background population and was then applied to the baseline and month-6 measurements of the aliskiren treatment arm of the AVOID trial to predict cardio-renal risk. The net risk difference at these time-points, after correction for placebo effects, was taken to indicate the estimated long-term cardio-renal risk change.

RESULTS

Based on the PRE score, we predicted that aliskiren treatment in ALTITUDE would confer a relative risk change of -7.9% (95% CI -2.5 to -13.4) for the cardio-renal endpoint, a risk change of -5.1% (-1.2 to -9.0) for the CV endpoint and a non-significant risk change of -19.9% (-42.1 to +2.1) for the renal endpoint.

CONCLUSIONS

PRE score estimations suggested that aliskiren has only a marginal additive protective effect on cardio-renal endpoints. These predictions were validated by the results of the ALTITUDE trial, confirming the potential of the PRE score to prospectively predict drug efficacy on cardio-renal outcomes.

Higher plasma high-mobility group box 1 levels are associated with incident cardiovascular disease and all-cause mortality in type 1 diabetes: a 12 year follow-up study

AIMS/HYPOTHESIS

This study aimed to investigate the associations of plasma levels of the pro-inflammatory cytokine high-mobility group box 1 (HMGB1) with incident cardiovascular disease (CVD) and all-cause mortality in patients with type 1 diabetes.

METHODS

We prospectively followed 165 individuals with diabetic nephropathy and 168 individuals with persistent normoalbuminuria who were free of CVD at study entry and in whom levels of HMGB1 and other cardiovascular risk factors were measured at baseline.

RESULTS

During the course of follow-up (median, 12.3 years [interquartile range, 7.8-12.5]), 80 patients died, 82 suffered a fatal (n = 46) and/or non-fatal (n = 53) CVD event. After adjustment for age, sex, case-control status and other risk factors, patients with higher levels of log(e) HMGB1 had a higher incidence of fatal and non-fatal CVD and all-cause mortality: HR 1.55 (95% CI 0.94, 2.48) and HR 1.86 (95% CI 1.18, 2.93), respectively. Further adjustments for differences in markers of low-grade inflammation, endothelial and renal dysfunction and arterial stiffness did not attenuate these associations because plasma levels of HMGB1 were not independently associated with these variables.

CONCLUSIONS/INTERPRETATION

In patients with type 1 diabetes, higher levels of plasma HMGB1 are independently associated with a higher risk of all-cause mortality and, to a lesser extent, with a higher incidence of CVD. Larger studies are needed to ascertain more definitely the role of HMGB1 in the development of vascular complications in diabetes.

SNP in the genome-wide association study hotspot on chromosome 9p21 confers susceptibility to diabetic nephropathy in type 1 diabetes

AIMS/HYPOTHESIS

Parental type 2 diabetes mellitus increases the risk of diabetic nephropathy in offspring with type 1 diabetes mellitus. Several single nucleotide polymorphisms (SNPs) that predispose to type 2 diabetes mellitus have recently been identified. It is, however, not known whether such SNPs also confer susceptibility to diabetic nephropathy in patients with type 1 diabetes mellitus.

METHODS

We genotyped nine SNPs associated with type 2 diabetes mellitus in genome-wide association studies in the Finnish population, and tested for their association with diabetic nephropathy as well as with severe retinopathy and cardiovascular disease in 2,963 patients with type 1 diabetes mellitus. Replication of significant SNPs was sought in 2,980 patients from three other cohorts.

RESULTS

In the discovery cohort, rs10811661 near gene CDKN2A/B was associated with diabetic nephropathy. The association remained after robust Bonferroni correction for the total number of tests performed in this study (OR 1.33 [95% CI 1.14, 1.56], p = 0.00045, p (36tests) = 0.016). In the meta-analysis, the combined result for diabetic nephropathy was significant, with a fixed effects p value of 0.011 (OR 1.15 [95% CI 1.02, 1.29]). The association was particularly strong when patients with end-stage renal disease were compared with controls (OR 1.35 [95% CI 1.13, 1.60], p = 0.00038). The same SNP was also associated with severe retinopathy (OR 1.37 [95% CI 1.10, 1.69] p = 0.0040), but the association did not remain after Bonferroni correction (p (36tests) = 0.14). None of the other selected SNPs was associated with nephropathy, severe retinopathy or cardiovascular disease.

CONCLUSIONS/INTERPRETATION

A SNP predisposing to type 2 diabetes mellitus, rs10811661 near CDKN2A/B, is associated with diabetic nephropathy in patients with type 1 diabetes mellitus.

Spironolactone diminishes urinary albumin excretion in patients with type 1 diabetes and microalbuminuria: a randomized placebo-controlled crossover study

AIMS

Adding aldosterone receptor blockade to standard renoprotective treatment may provide additional renoprotection in patients with overt nephropathy. We expected an impact of spironolactone in early diabetic nephropathy, and for this hypothesis we studied the effect on markers of glomerular and tubular damage in patients with Type 1 diabetes and persistent microalbuminuria.

METHODS

A double-blind, randomized, placebo-controlled crossover study in 21 patients with Type 1 diabetes and microalbuminuria using spironolactone 25 mg or placebo once daily, for 60 days added to standard antihypertensive treatment. After each treatment period, the primary endpoint were evaluated: urinary(u)-albumin excretion/24 hour(h) and secondary endpoints; 24 h blood pressure, glomerular filtration rate (GFR) and markers of tubular damage: urinary liver-type fatty-acid binding protein (LFABP), neutrophil gelatinase associated lipocalin (NGAL) and kidney injury molecule 1 (KIM1).

RESULTS

All patients completed the study. During spironolactone treatment, urinary albumin excretion rate was reduced by 60% (range 21-80%), from 90 mg/24 h to 35 mg/24 h (P=0.01). Blood pressure (24 h) did not change during spironolactone treatment (P>0.2 for all comparisons). The GFR (SD) decreased from 78 (6) mL/min/1.73 m(2) to 72 (6) mL/min/1.73 m(2) (P=0.003). Urinary liver-type fatty-acid binding protein, neutrophil gelatinase-associated lipocalin and kidney injury molecule 1 did not change during treatment (P>0.3 for all comparisons). Treatment was well-tolerated, but two patients had severe hyperkalaemia (plasma potassium = 5.7 mmol/l), which was sufficiently treated with diuretics and dietary intervention.

CONCLUSIONS

Spironolactone treatment in addition to standard renoprotective treatment lowers urinary albumin excretion in microalbuminuric patients with Type 1 diabetes, and thus may offer additional renoprotection independent of blood pressure.

Arterial stiffness and endothelial dysfunction independently and synergistically predict cardiovascular and renal outcome in patients with type 1 diabetes

AIMS

To evaluate whether pulse pressure alone or with placental growth factor as estimates of arterial stiffness and endothelial dysfunction, predicts mortality, cardiovascular disease and progression to end-stage renal disease in patients with Type 1 diabetes.

METHODS

Prospective, observational study, median (range) follow-up 8 (0-13) years, 900 patients with Type 1 diabetes, 458 with diabetic nephropathy, mean ± SD age 44 ± 11 years.

RESULTS

During follow-up, we recorded 178 (20%) all-cause deaths, 109 (12%) cardiovascular deaths, 213 (24%) cardiovascular events and 73 (16%) progressed to end-stage renal disease. Elevated pulse pressure predicted all-cause and cardiovascular mortality and cardiovascular events [Hazard Ratio (HR) (95% CI) per 10 mmHg increase]: HR 1.2 (1.1-1.3), 1.3 (1.2-1.5) and 1.2 (1.1-1.3), P<0.001 (adjusted for sex, age, HbA(1c) , cholesterol, diastolic blood pressure, creatinine, smoking, previous cardiovascular disease and nephropathy status). Furthermore, pulse pressure predicted the development of end-stage renal disease in patients with diabetic nephropathy: HR 1.2 (1.1-1.4), P=0.011 (adjusted for sex, age, HbA(1c) , cholesterol, diastolic blood pressure, previous cardiovascular disease and glomerular filtration rate). In a two-hit model, patients with pulse pressure and placental growth factor levels above the median vs. below the median had increased risk of all-cause and cardiovascular mortality, cardiovascular events and progression to end-stage renal disease: adjusted HRs 2.3 (1.2-4.2), 4.2 (1.6-11.0), 2.3 (1.3-4.1) and 3.5 (1.0-11.8),P<0.05.

CONCLUSIONS

Elevated pulse pressure independently predicts mortality, cardiovascular events and progression to end-stage renal disease in patients with Type 1 diabetes. Placental growth factor adds to the predictive value of pulse pressure on cardiovascular and renal outcome.

Insulin analogues and severe hypoglycaemia in type 1 diabetes

INTRODUCTION

The effect of insulin analogues on glycaemic control is well-documented, whereas the effect on avoidance of severe hypoglycaemia remains tentative. We studied the frequency of severe hypoglycaemia in unselected patients with type 1 diabetes treated with insulin analogues, human insulin, or mixed regimens.

METHODS

A questionnaire was posted from six Danish diabetes clinics to 6112 unselected patients with type 1 diabetes and filled in by 3861 patients (63.2%). Primary endpoint was number of episodes of severe hypoglycaemia in the preceding year. Mild hypoglycaemia was also reported.

RESULTS

The frequency of severe hypoglycaemic episodes per patient-year in patients receiving long-acting insulin analogues was 1.47±0.18 versus 1.09±0.10 in patients on long-acting human insulin (p=0.01). The frequency of severe hypoglycaemic episodes per patient-year was 1.09±0.11 in patients on short-acting insulin analogues versus 1.26±0.13 in patients on short-acting human insulin (p=0.15), which was statistically significant in an adjusted analysis.

CONCLUSIONS

Severe hypoglycaemia is more frequent in patients with type 1 diabetes treated with long-acting insulin analogues. Confounding by indication may be involved. Clinical intervention trials using insulin analogues in patients prone to severe hypoglycaemia are highly needed.

Evaluation of placental growth factor and soluble Fms-like tyrosine kinase 1 as predictors of all-cause and cardiovascular mortality in patients with Type 1 diabetes with and without diabetic nephropathy

AIMS

Placental growth factor is a vascular endothelial growth factor involved in angiogenesis, vascular inflammation and plaque formation. Soluble Fms-like tyrosine kinase 1 is a decoy receptor for placental growth factor, reducing its activity. The aim of this study is to evaluate the predictive value of placental growth factor and soluble Fms-like tyrosine kinase 1 in relation to all-cause and cardiovascular mortality and decline in kidney function in Type 1 diabetes.

METHODS

This was a prospective, observational follow-up study with 8 (0-13) years [median (range)] of follow-up, including patients with Type 1 diabetes, of whom 458 had diabetic nephropathy [278 men; age 42 ± 11 years (mean ± sd), diabetes duration 28 ± 9 years, glomerular filtration rate 76 ± 33 ml min(-1) 1.73 m(-2) ] and 442 had long-standing normoalbuminuria (234 men; age 45 ± 12 years, diabetes duration 28 ± 10 years).

RESULTS

Placental growth factor and soluble Fms-like tyrosine kinase 1 levels measured at baseline were higher in patients with diabetic nephropathy compared with patients with long-standing normoalbuminuria [median (range)] 15 (4-131) vs. 11 (7-64) ng/l, (P < 0.001) and 86 (42-3462) vs. 77 (43-1557) ng/l (P < 0.001), respectively. In patients with diabetic nephropathy, high levels of placental growth factor predicted all-cause and cardiovascular mortality [hazard ratio 1.94 (1.16-3.24) and hazard ratio 2.91 (1.45-5.85)] after adjustment for sex, age, smoking, systolic blood pressure, HbA(1c) , cholesterol, glomerular filtration rate and previous cardiovascular disease. High levels of placental growth factor predicted increased risk of end-stage renal disease [hazard ratio 2.77 (1.47-5.14)], but covariate adjustments attenuated the association [hazard ratio 1.89 (0.91-3.95)]. Among patients with long-standing normoalbuminuria, placental growth factor levels predicted fatal and non-fatal cardiovascular events [hazard ratio 1.97 (1.03-3.76)], but not all-cause mortality. Baseline soluble Fms-like tyrosine kinase 1 levels did not predict outcome in either group after adjustment.

CONCLUSION

Placental growth factor is elevated in patients with Type 1 diabetes and diabetic nephropathy and predicts all-cause and cardiovascular mortality, but not deterioration of kidney function.

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

AIMS/HYPOTHESIS

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

METHODS

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

RESULTS

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

CONCLUSIONS/INTERPRETATION

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

TRIAL REGISTRATION

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

FUNDING

The study was funded jointly by AstraZeneca and Takeda.

Retinal microaneurysm count predicts progression and regression of diabetic retinopathy. Post-hoc results from the DIRECT Programme

OBJECTIVE

To study the association between baseline retinal microaneurysm score and progression and regression of diabetic retinopathy, and response to treatment with candesartan in people with diabetes.

METHODS

This was a multicenter randomized clinical trial. The progression analysis included 893 patients with Type 1 diabetes and 526 patients with Type 2 diabetes with retinal microaneurysms only at baseline. For regression, 438 with Type 1 and 216 with Type 2 diabetes qualified. Microaneurysms were scored from yearly retinal photographs according to the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol. Retinopathy progression and regression was defined as two or more step change on the ETDRS scale from baseline. Patients were normoalbuminuric, and normotensive with Type 1 and Type 2 diabetes or treated hypertensive with Type 2 diabetes. They were randomized to treatment with candesartan 32 mg daily or placebo and followed for 4.6 years.

RESULTS

A higher microaneurysm score at baseline predicted an increased risk of retinopathy progression (HR per microaneurysm score 1.08, P < 0.0001 in Type 1 diabetes; HR 1.07, P = 0.0174 in Type 2 diabetes) and reduced the likelihood of regression (HR 0.79, P < 0.0001 in Type 1 diabetes; HR 0.85, P = 0.0009 in Type 2 diabetes), all adjusted for baseline variables and treatment. Candesartan reduced the risk of microaneurysm score progression.

CONCLUSIONS

Microaneurysm counts are important prognostic indicators for worsening of retinopathy, thus microaneurysms are not benign. Treatment with renin-angiotensin system inhibitors is effective in the early stages and may improve mild diabetic retinopathy. Microaneurysm scores may be useful surrogate endpoints in clinical trials.

A polymorphism in the gene encoding carnosinase (CNDP1) as a predictor of mortality and progression from nephropathy to end-stage renal disease in type 1 diabetes mellitus

AIMS/HYPOTHESIS

Homozygosity for a five leucine repeat (5L-5L) in the carnosinase gene (CNDP1) has been found to be cross-sectionally associated with a low frequency of diabetic nephropathy (DN), mainly in type 2 diabetes. We prospectively investigated in patients with type 1 diabetes whether: (1) 5L-5L is associated with mortality; (2) there is an interaction of 5L-5L with DN or sex for prediction of mortality; and (3) 5L-5L is associated with progression to end-stage renal disease (ESRD).

METHODS

In this prospective study in white European patients with type 1 diabetes, individuals with DN were defined by persistent albuminuria ≥ 300 mg/24 h. Controls without nephropathy were defined by persistent (>15 years) normoalbuminuria < 30 mg/24 h. Leucine repeats were assessed with a fluorescent DNA analysis system. Onset of ESRD was defined by need to start chronic dialysis or kidney transplantation.

RESULTS

The study involved 916 patients with DN and 1,170 controls. During follow-up for 8.8 years, 107 patients (14%) with 5L-5L died compared with 182 patients (13.8%) with other genotypes (p = 0.99). There was no significant interaction of 5L-5L with DN for prediction of mortality (p = 0.57), but a trend towards interaction with sex (p = 0.08). In patients with DN, HR for ESRD in 5L-5L vs other genotypes was not constant over time, with increased risk for 5L-5L beyond 8 years of follow-up (p = 0.03).

CONCLUSIONS/INTERPRETATION

CNDP1 polymorphism was not associated with mortality, and nor was there an interaction of this polymorphism with DN for prediction of mortality in patients with type 1 diabetes. CNDP1 polymorphism predicts progression to ESRD in patients with DN, but only late after baseline measurements.

Multifactorial treatment increases endothelial progenitor cells in patients with type 2 diabetes

AIMS/HYPOTHESIS

Endothelial progenitor cells (EPC) augment vascular repair and neovascularisation. Patients with type 2 diabetes have reduced EPC and increased risk of cardiovascular disease (CVD), which is reduced by multifactorial intervention. Our aim, therefore, was to evaluate in type 2 diabetic patients whether the numbers of EPC derived from peripheral blood mononuclear cells is influenced by a multifactorial treatment strategy.

METHODS

We enrolled 28 patients newly referred for initiation of multifactorial treatment, which consisted of improving glycaemic, lipid and blood pressure control, as well as antithrombotic therapy and lifestyle modification. EPC count was assessed by in vitro cultures at baseline and after 90 days of treatment. After 7 days in culture, we identified EPC by fluorescent staining of attached cells. Patients were treated with metformin, aspirin, statins and angiotensin II receptor blockers, and divided accordingly into groups of mono-, dual-, triple- or quadruple therapy.

RESULTS

After 90 days of treatment, glycaemic control improved and total cholesterol decreased. Multifactorial intervention for 90 days significantly increased EPC count in cultures by 35% (from 105 [SE 8] to 140 [11] cells per field [p = 0.002]). The change in EPC among patients with quadruple therapy was higher (63%) than in untreated patients (-32%, p = 0.043).

CONCLUSIONS/INTERPRETATION

Numbers of EPC derived from peripheral blood mononuclear cells increased significantly after multifactorial intervention in type 2 diabetic patients. It remains to be shown whether these changes contribute to the beneficial effects of multifactorial intervention on diabetic micro- and macroangiopathy.

Neutrophil Gelatinase-Associated Lipocalin (NGAL) and Kidney Injury Molecule 1 (KIM1) in patients with diabetic nephropathy: a cross-sectional study and the effects of lisinopril

AIMS

Our aim was to evaluate the markers of tubulointerstitial damage, neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule1 (KIM1) in Type 1 diabetic patients with different levels of albuminuria and in control subjects. In addition, the effect of renoprotective treatment on urinary NGAL was evaluated in diabetic nephropathy.

METHODS

This was a cross-sectional study in 58 normoalbuminuric (u-albumin <30 mg/24 h), 45 microalbuminuric (30-300 mg/24 h) and 45 macroalbuminuric (>300 mg/24 h) Type 1 diabetic patients and 55 non-diabetic control subjects. Furthermore, in a second study, urine-NGAL was measured in a randomized cross-over study of 56 Type 1 diabetic patients with diabetic nephropathy treated with lisinopril 20, 40 and 60 mg daily.

RESULTS

  Urine-NGAL levels were [geometric mean (95% CI)]: control subjects 74 (52-104) (pg/mmol creatinine), normoalbuminuric 146 (97-221), microalbuminuric 222 (158-312) and macroalbuminuric group 261 (175-390). Urine-NGAL increased significantly from the normo- to the micro- and further to the macroalbuminuric group (P<0.05). Urine-NGAL was higher in normoalbuminuric vs. control subjects (P<0.01). Plasma-NGAL was significantly higher in the normoalbuminuric and macroalbuminuric groups than in the control group. Urine-KIM1 was higher in all diabetic groups than in the control group (P<0.001), with no difference between diabetic groups. During lisinopril treatment, urine-NGAL was reduced (95% CI) 17% (11-50) (not significant).

CONCLUSIONS

Urine-NGAL and urine-KIM1 (u-KIM1) are elevated in Type1 diabetic patients, with or without albuminuria, indicating tubular damage at an early stage. Urine-NGAL increases significantly with increasing albuminuria. The ACE inhibitor lisinopril reduced urine-NGAL, but this was not statistically significant.

Optimal antiproteinuric dose of aliskiren in type 2 diabetes mellitus: a randomised crossover trial

AIM

The optimal antiproteinuric dose of aliskiren is unknown. This study compared the effect of placebo and increasing doses of aliskiren on urinary albumin excretion rate (UAER).

METHODS

The trial was a double-blind crossover design. Twenty-six patients with type 2 diabetes mellitus, hypertension and albuminuria were randomised to 2-month treatments with placebo or aliskiren 150 mg, 300 mg or 600 mg once daily, in random order. Primary endpoint was change in UAER; secondary endpoints included changes in 24-h BP, GFR, biomarkers and components of the renin-angiotensin-aldosterone system.

RESULTS

Placebo geometric mean UAER was 350 mg/day, mean 24-h BP was 137/81 (SD 12/9) mmHg, GFR was 85 (SD 26) ml min(-1) 1.73 m(-2). Aliskiren 150, 300 and 600 mg daily reduced UAER significantly by 36% (95% CI 17-51), 48% (33-60) and 52% (38-63) respectively (p < 0.001) compared with placebo. UAER reduction during the 600 mg dose was not significantly different from the 300 mg dose. Twenty-four-hour systolic BP was reduced by 4.5, 8.0 and 9.2 mmHg versus placebo, significant for 300 and 600 mg (p < or = 0.001). Twenty-four-hour diastolic BP was reduced by 3.0, 4.1 and 4.4 mmHg, significant versus placebo (p = 0.019, p = 0.001 and p < 0.001). GFR was reduced by 3.0, 5.1 and 6.5 ml min(-1) 1.73 m(-2). hsPRA was reduced by 63%, 70%, and 82% (p < 0.001 for all). Adverse events, most frequently dizziness and fatigue, occurred during all doses.

CONCLUSIONS

In patients with type 2 diabetes mellitus, hypertension and albuminuria there is no improved antiproteinuric effect when using 600 mg aliskiren daily compared with the maximal recommended antihypertensive dose of 300 mg.

TRIAL REGISTRATION

Clinicaltrials.gov NCT00464776

FUNDING

Novartis Pharma AG.

Telomere length predicts all-cause mortality in patients with type 1 diabetes

AIMS/HYPOTHESIS

Type 1 diabetic patients with diabetic nephropathy have increased mortality and morbidity compared with normoalbuminuric patients. Telomere length in proliferative cells is inversely related to the total number of cell divisions, and therefore to biological age. We aimed to evaluate differences in telomere length in patients with type 1 diabetes with or without diabetic nephropathy; we also evaluated the prognostic value of telomere length.

METHODS

In a prospective follow-up study, 157 type 1 diabetic patients with diabetic nephropathy and a control group of 116 patients with type 1 diabetes and normoalbuminuria were followed for 11.1 years (range 0.2-12.9). Telomere length was measured from DNA samples extracted from white blood cells at baseline.

RESULTS

The mean telomere length did not differ between patients with or without diabetic nephropathy, and was similar in men and women, but was inversely correlated with age and systolic blood pressure, p < 0.05. When dividing patients into tertiles after telomere length, 36 (37%) patients died in the tertile with the shortest telomere length, 24 (28%) died in the middle tertile, and 15 (17%) of patients in the tertile with the longest telomere length died, log rank test p = 0.017. After adjustment for traditional risk factors, telomere length was still predictive of all-cause mortality.

CONCLUSIONS/INTERPRETATION

In patients with type 1 diabetes we found no differences in telomere length between patients with or without diabetic nephropathy. We also found that telomere length was associated with all-cause mortality; however, confirmative studies are needed to verify our findings.

Effect of adjunct metformin treatment on levels of plasma lipids in patients with type 1 diabetes

BACKGROUND

In addition to its glucose-lowering effect, metformin treatment has been suggested to improve lipidaemia in patients with type 2 diabetes. In contrast, in patients with type 1 diabetes (T1DM), information about the effect of metformin treatment on lipidaemia is limited. In this study, we report the effect of a 1-year treatment with metformin vs. placebo on plasma lipids in T1DM patients and persistent poor glycaemic control.

METHODS

One hundred T1DM patients with haemoglobinA(1c) (HbA(1c)) > or =8.5% during the year before enrolment entered a 1-month run-in period on placebo treatment. Thereafter, patients were randomized (baseline) to treatment with either metformin (1000 mg twice daily) or placebo for 12 months (double masked). Patients continued ongoing insulin therapy and their usual outpatient clinical care. Outcomes were assessed at baseline and after 1 year.

RESULTS

After 1 year, in those patients who did not start or stop statin therapy during the trial, metformin treatment significantly reduced total and LDL cholesterol by approximately 0.3 mmol/l compared with placebo (p = 0.021 and p = 0.018 respectively). Adjustment for statin use or known cardiovascular disease did not change conclusions. In statin users (metformin: n = 22, placebo: n = 13), metformin significantly lowered levels of LDL and non-HDL cholesterol by approximately 0.5 mmol/l compared with placebo (adjusted for changes in statin dose or agent: p = 0.048 and p = 0.033 respectively). HbA(1c) (previously reported) was not significant different between treatments.

CONCLUSION

In patients with poorly controlled T1DM, at similar glycaemic levels, adjunct metformin therapy during 1 year significantly lowered levels of proatherogenic cholesterolaemia independent of statin therapy.

Aldosterone synthase (CYP11B2)­344T/C polymorphism and renoprotective response to losartan treatment in diabetic nephropathy

OBJECTIVE

It has been suggested that an aldosterone synthase gene polymorphism (CYP11B2 -344T/C) is predictive of the blood pressure lowering effect of angiotensin II receptor blockers in essential hypertension. We investigated whether this polymorphism is predictive of reductions in blood pressure and albuminuria and preservation of glomerular filtration rate (GFR) during short-term and long-term treatment with losartan in 57 hypertensive type-1 diabetic patients with diabetic nephropathy.

MATERIAL AND METHODS

After a 4-week washout period, patients received losartan (100 mg o.d.) and were followed for a mean follow-up of 36 months. At baseline, after 2 and 4 months, and every 6 months thereafter, GFR (51Cr-EDTA-clearance), albuminuria and 24-h blood pressure were determined. The CYP11B2 -344T/C polymorphism was determined by standard polymerase chain reaction (PCR).

RESULTS

The TT, CT and CC genotypes were found in 28 %, 58 % and 14 % of patients, respectively. At baseline albuminuria and blood pressure did not differ between genotype groups. Plasma aldosterone levels (geometric mean (95 % CI)) were similar at baseline: 87 (60-125), 77 (53-112), and 89 (49-161) pg mL(-1) and during follow-up (not significant). After initiation of losartan treatment, comparable mean (SE) reductions in blood pressure and albuminuria were seen in patients with TT, CT and CC genotypes (p >0.6 between groups). After long-term follow-up, there was a tendency towards a difference in systolic blood pressure reduction (p = 0.07, one-way ANOVA), suggesting a poorer response in patients with the CC genotype. No significant difference in rate of decline in GFR (median (range)) was seen between groups (TT, CT, CC): 4.2 (-1.0 to 16.0), 3.2 (-1.6 to 13.8) and 2.6 (-0.1 to 11.0) mL min(-1)year(-1), respectively (p = 0.5).

CONCLUSIONS

Compared to a previous smaller study of angiotensin II receptor blockade in essential hypertension, we could not confirm that CYP11B2 -344T/C genotypes contribute towards explaining the observed variability in response to treatment with angiotensin II receptor blockers, which could be due to lack of power.

The blood-retinal barrier permeability to fluorescein in juvenile diabetics treated with continuous subcutaneous insulin infusion

To determine possible quantitative changes of the blood-retinal barrier permeability in juvenile diabetics treated with continuous subcutaneous insulin infusion (CSII), we studied seven patients (three females and four males, mean age 36 years) with a mean duration of the disease of 19 years. The pump treatment was continued for seven to eight days and during the treatment mean blood glucose level decreased to near-normal values (before 13.7 mmol per liter - during 6.2 mmol per liter). There was no changes in retinal appearance during treatment. Determination of the blood-retinal barrier permeability showed no quantitative changes during the one week treatment with CSII (mean permeability before 7.6 10 divided by 7 cm/sec - mean permeability during 7.8 10 divided by 7 cm/sec). In order to quantitate possible long-term reversibility of break-down of the blood-retinal barrier we have design to extend the treatment period.

Sustained postprandial decrease in plasma levels of LDL cholesterol in patients with type-2 diabetes mellitus

OBJECTIVE

Low density lipoprotein cholesterol (LDL-C) is an independent and modifiable risk factor for development of cardiovascular disease (CVD). Postprandial lipid metabolism has been linked to CVD, but little is known about the postprandial LDL-C profile in patients with type-2 diabetes (T2DM). We aimed to study the postprandial levels of LDL-C in T2DM patients.

MATERIAL AND METHODS

After an overnight fast, 74 T2DM patients, mean age approximately 60 years, were served a standard fat-rich meal of 3515 kJ containing 54% fat, 13 % protein and 33 % carbohydrates. Only drinking water was allowed postprandially. Blood samples were drawn at times 0 (fasting), 1.5, 3.0, 4.5 and 6.0 h (postprandial). In all samples, LDL-C was measured with modified beta quantification (separation by ultracentrifugation followed by measurement of infranate high density lipoprotein cholesterol (HLD-C) using a homogeneous assay).

RESULTS

At all postprandial times, levels of LDL-C showed highly significant (p < 0.005) decreases compared to time 0 (mean [95% CI] maximum change in LDL-C levels at 3.0 h: -0.16 mmol/L [-0.12; -0.20]; p < 0.001). Independently of fasting LDL-C levels and ongoing statin therapy, LDL-C decreased significantly more in female compared to male patients postprandially (mean [95% CI] maximum unadjusted change versus time 0 in LDL-C for men [n=56] at 3.0 h: -0.14 mmol/L [-0.19; -0.10], p < 0.001; for women [n=18] at 4.5 h: -0.26 mmol/L [-0.35; -0.18], p < 0.001; -0.14 mmol/L [-0.24; -0.05], p = 0.005 between genders for the mean [95% CI] fasting adjusted difference at 4.5 h in the change versus time 0 in LDL-C; gender by time interaction: p = 0.007 (repeated measures mixed model)).

CONCLUSIONS

In T2DM patients served a fat-rich meal, levels of LDL-C decreased significantly more in women compared to men postprandially, irrespective of fasting levels or ongoing statin therapy. This might have implications in the atherosclerotic process and on any difference in the risk of CVD between genders.

A combined abnormality in heart rate variation and QT corrected interval is a strong predictor of cardiovascular death in type 1 diabetes

OBJECTIVE

Long-term diabetes is associated with excess morbidity and mortality, and cardiovascular autonomic neuropathy and QTc interval abnormalities are both predictive of early cardiovascular death in diabetes. We aimed to investigate the effect of these risk factors in a large cohort of type 1 diabetic patients followed prospectively for 10 years.

MATERIAL AND METHODS

Three-hundred-and-ninety-one type 1 diabetic mellitus patients (240 M and 151 F, age 41.8 years +/- 9.9 (mean +/-SD), duration of DM 27.3 years +/- 8.2) were followed in an outpatient setting.

RESULTS

Patients with decreased heart rate variability had an excess overall mortality that diminished after adjusting for conventional cardiovascular risk factors; hazard ratio 2.5 (0.9-6.8; p = 0.071) compared to patients with normal heart rate variability. Likewise, prolonged QTc interval was associated with premature death with an adjusted hazard ratio of 2.3 (1.3-4.0; p = 0.005). In a combined analysis, patients with abnormal values for heart rate variability and QTc had a poorer prognosis compared to patients with normal test values for both parameters (adjusted hazard ratio 6.7 (1.8-25; p = 0.005)). Of the 34 patients with both test values abnormal, 15 died and 14 of these from cardiovascular causes.

CONCLUSIONS

We conclude that combined abnormality in heart rate variability and QTc is a strong predictor of mortality in type 1 diabetes independently of conventional risk factors. These results have implications for future screening and treatment programmes for cardiovascular disease in type 1 diabetes.

Kidney function in acromegaly

Creatinine clearance and daily urinary albumin and beta2-microglobulin excretion rates (radio-immunoassays) were measured several times in 14 patients with acromegaly. Eleven patients were treated with bromocriptine, 5 to 55 mg/day. The activity of the disease was assessed by measuring urinary growth hormone excretion (radio-immunoassay). In agreement with previous investigations we found the creatinine clearance elevated. However, no correlation was found between this variable and urinary growth hormone excretion. Urinary albumin and beta 2-microglobulin excretion rates were not significantly different from our previous results in 27 adults control subjects. There was no correlation between urinary growth hormone excretion and urinary albumin or beta 2-microglobulin excretion rates. Bromocriptine treatment reduced urinary growth hormone excretion from 220 to 91 ng/24 hours, p less than 0.01, but no significant alterations were induced in the above mentioned kidney function variables.

Prevalence of hyperglycaemia and undiagnosed diabetes mellitus in patients with acute myocardial infarction

The prevalence of hyperglycaemia and undiagnosed diabetes mellitus was assessed in 214 consecutive patients admitted to the coronary care units with acute myocardial infarction (AMI). On admission, 16 patients (7.5%) had known diabetes, and 19 patients, not previously known to be diabetic, had blood glucose concentrations of greater than or equal to 9 mmol/l. Fifteen patients survived for 2 months at which time a 75 g oral glucose tolerance test showed diabetes in 9 (60%) and impaired glucose tolerance in 4 (27%). Ten of these 13 patients (77%) with abnormal glucose tolerance had elevated glycosylated haemoglobin (HbA1c) on admission, indicating pre-existing glucose intolerance or diabetes. The prevalence of undiagnosed diabetes was 4.5% (9/198). However, we may have overlooked undiagnosed diabetes in a small number of patients on admission, since only a random blood glucose less than 8 mmol/l rules out diabetes, WHO criteria. Elevated blood glucose in patients with AMI is more likely to reflect a stationary pre-existing abnormal glucose tolerance than a temporary stress-induced phenomenon.

Optimal dose of lisinopril for renoprotection in type 1 diabetic patients with diabetic nephropathy: a randomised crossover trial

AIMS/HYPOTHESIS

The purpose of this study was to evaluate the optimal renoprotective effect of ultrahigh doses of lisinopril, as reflected by short-term changes in urinary albumin excretion rate (UAER), in type 1 diabetic patients with diabetic nephropathy.

METHODS

At the Steno Diabetes Center, 49 type 1 diabetic patients with diabetic nephropathy completed this double-masked randomised crossover trial consisting of an initial washout period followed by three treatment periods each lasting 2 months, where all patients received lisinopril 20, 40 and 60 mg once daily in randomised order in addition to slow-release furosemide. Allocation was concealed by sequentially numbered opaque sealed envelopes. UAER, 24 h ambulatory blood pressure (ABP) and estimated GFR were determined at baseline and after each treatment period.

RESULTS

All 49 patients completed all three treatment periods. Baseline values were: UAER (geometric mean [95% CI]) 362 (240-545) mg/24 h, 24 h ABP (mean [SD]) 142 (14)/74 (8) mmHg and estimated GFR 75 (29) ml min(-1) 1.73 m(-2). Reductions in UAER from baseline were 63%, 71% and 70%, respectively, with the increasing doses of lisinopril (p < 0.001). Compared with lisinopril 20 mg there was a further reduction in UAER of 23% with lisinopril 40 mg and 19% with 60 mg, p < 0.05. ABP was reduced from baseline by 10/5, 13/7 and 12/7 mmHg (p < 0.001 vs baseline, p < 0.05 for diastolic ABP 20 vs 40 mg, otherwise NS between doses). The difference in UAER between 20 and 40 mg lisinopril was significant after adjustment for changes in ABP (p < 0.01). Two patients were excluded from the study because of an increase in plasma creatinine and one because of high BP; otherwise the study medication was well tolerated with few, mild, dose-independent adverse effects.

CONCLUSIONS/INTERPRETATION

Lisinopril 40 mg once daily is generally safe and offers additional reductions in BP and UAER in comparison with the currently recommended dose of 20 mg. Lisinopril 60 mg offers no further beneficial effect.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00118976.

The selective vitamin D receptor activator for albuminuria lowering (VITAL) study: study design and baseline characteristics

BACKGROUND

Patients with diabetic nephropathy are at high risk for further progressive renal function loss. Treatments that decrease albuminuria have been linked with renal and cardiovascular protection. However, even when taking optimal treatment, residual renal and cardiovascular risk remains high which correlates with the magnitude of residual albuminuria. Use of vitamin D receptor activators, such as calcitriol and paricalcitol, is associated with improved sur- vival. A small study with paricalcitol showed reductions in albuminuria. The VITAL study tests the hypothesis whether paricalcitol persistently reduces albuminuria in diabetic subjects already receiving angiotensin-converting enzyme inhibitor (ACEI) and/or angiotensin receptor blocker (ARB) therapy.

METHODS

Randomization in this double-blind trial is equal allocation to paricalcitol 1 micro/day, 2 microg/day, or placebo. Inclusion criteria include: a diagnosis of type 2 diabetes, urinary albumin/creatinine ratio (UACR) between 100-3,000 mg/g, estimated glomerular filtration rate (eGFR) between 15-90 ml/min/1.73 m(2), serum calcium <9.8 mg/dl, and parathyroid hormone (PTH) between 35-500 pg/ml.

RESULTS

Baseline characteristics of the 281 subjects are: 69% men, mean age 64.9 +/- 10.4 years, eGFR 40.7 +/- 16.7 ml/min, median UACR (interquartile range) 612.3 mg/g (281-1,181 mg/g) and PTH 98.4 +/- 63.8 pg/ml.

CONCLUSION

This trial will be the first clinical test of the hypothesis that paricalcitol possesses pleiotropic effects and can modulate albuminuria in the setting of ACEI and/or ARB therapy. Results will have important clinical implications and are expected in November 2009.

Plasma osteoprotegerin levels predict cardiovascular and all-cause mortality and deterioration of kidney function in type 1 diabetic patients with nephropathy

AIMS/HYPOTHESIS

The bone-related peptide osteoprotegerin is produced by vascular cells and is involved in the process of vascular calcification. The aim of this study was to investigate the predictive value of plasma levels of osteoprotegerin in relation to mortality, cardiovascular events and deterioration in kidney function in patients with type 1 diabetes.

METHODS

This prospective observational follow-up study included 397 type 1 diabetic patients with overt diabetic nephropathy (243 men; age [mean+/-SD] 42.1 +/- 10.6 years, duration of diabetes 28.3 +/- 9.9 years, GFR 67 +/- 28 ml min(-1) 1.73 m(2)) and a group of 176 patients with longstanding type 1 diabetes and persistent normoalbuminuria (105 men; age 42.6 +/- 9.7 years, duration of diabetes 27.6 +/- 8.3 years).

RESULTS

The median (range) follow-up period was 11.3 (0.0-12.9) years. Among patients with diabetic nephropathy, individuals with high osteoprotegerin levels (fourth quartile) had significantly higher all-cause mortality than patients with low levels (first quartile) (covariate-adjusted hazard ratio [HR] 3.00 [1.24-7.27]). High osteoprotegerin levels also predicted cardiovascular mortality (covariate-adjusted HR 4.88 [1.57-15.14]). Furthermore, patients with high osteoprotegerin levels had significantly higher risk of progression to end-stage renal disease than patients with low levels (covariate-adjusted HR 4.32 [1.45-12.87]). In addition, patients with high levels of plasma osteoprotegerin had an elevated rate of decline in GFR.

CONCLUSIONS/INTERPRETATION

High levels of osteoprotegerin predict all-cause and cardiovascular mortality in patients with diabetic nephropathy. Furthermore, high levels of osteoprotegerin predict deterioration of kidney function towards end-stage renal disease.

The PPAR gamma 2 Pro12Ala variant predicts ESRD and mortality in patients with type 1 diabetes and diabetic nephropathy

The Pro12Ala polymorphism in the peroxisome proliferator-activated receptor-gamma 2 gene is suggested to associate with diabetic nephropathy and cardiovascular disease in type 2 diabetes. The aim of this study was to investigate the polymorphism in relation to diabetic nephropathy, end-stage renal disease (ESRD), mortality and cardiovascular (CVD) events in type 1 diabetic patients. This prospective observational follow-up study included 415 type 1 diabetic patients with overt diabetic nephropathy (252 men; age 42.2+/-10.4 years [mean+/-SD], duration of diabetes 28.3+/-8.8 years, GFR 66+/-8.8 ml/min) and 428 patients with longstanding type 1 diabetes and persistent normoalbuminuria (230 men; age 45.4+/-11.6 years, duration of diabetes 27.8+/-10.1 years).

FOLLOW-UP

8.1 (0.0-12.8) years (median [range]). There where no significant differences between cases and controls in genotype (p=0.51) or allele frequencies (p=0.25). Cox regression analysis revealed a covariate-adjusted hazard ratio (HR) for all-cause mortality in patients with the Ala/Ala genotype of 2.44 (1.23-4.84). The Pro12Ala polymorphism did not predict CVD events. However, the Ala/Ala genotype predicts ESRD (covariate-adjusted HR 2.60 (1.11-6.07)). Furthermore, Carriers of the Ala-allele had a higher rate of decline in GFR (p=0.040). In conclusion, the Pro12Ala polymorphism is not associated with type 1 diabetic nephropathy. The Ala-allele is associated with enhanced decline in GFR and predicts ESRD and all-cause mortality in patients with nephropathy.

Long-term prevention of diabetic nephropathy: an audit

AIMS/HYPOTHESIS

In type 1 diabetic patients with microalbuminuria not receiving antihypertensive treatment, an increase in urinary AER (UAER) of 6-14%/year and a risk of developing diabetic nephropathy (DN) of 3-30%/year have been reported. We audited the long-term effect of blocking the renin-angiotensin-aldosterone system (RAAS) with an ACE inhibitor (ACEI) or angiotensin II receptor blocker (ARB) in microalbuminuric type 1 diabetic patients on progression of microalbuminuria and development of DN.

METHODS

All patients with type 1 diabetes and persistent microalbuminuria (30-300 mg/24 h) were identified (n=227) in 1995 at Steno Diabetes Center and followed for 11 years. Development of DN was defined as a UAER of >300 mg/24 h in two of three consecutive urine samples.

RESULTS

Age and duration of diabetes at baseline (mean+/-SD) were 46+/-15 and 28+/-13 years, respectively. During follow-up 14 patients emigrated and 58 (26%) died. Over the same period 79% were treated with an ACEI or ARB. There was a mean decline in UAER of 4%/year. Sixty-five patients (29%) progressed to overt DN, corresponding to 3.1%/year. However, 29 of them regressed to normo- or microalbuminuria on intensified antihypertensive treatment. Glycaemic control and blood pressure remained nearly unchanged.

CONCLUSIONS/INTERPRETATION

In our outpatient clinic, the implementation of RAAS-blocking treatment in type 1 diabetic patients with microalbuminuria successfully reduced long-term progression to overt DN to a rate similar to those previously reported in randomised, double-blind intervention trials of shorter duration using RAAS blockade.

Increased renal gene transcription of protein kinase C-beta in human diabetic nephropathy: relationship to long-term glycaemic control

AIMS/HYPOTHESIS

Activation of protein kinase C (PKC) isoforms has been implicated as a central mediator in the pathogenesis of diabetic nephropathy. Although high glucose levels stimulate catalytic activity of PKC, the effects of high glucose levels on the expression of genes encoding PKC isoforms are unknown. We sought to determine whether in addition to activation, diabetes may lead to increased transcription of two PKC isoforms that have been implicated in the pathogenesis of diabetic nephropathy, PKC-alpha and PKC-beta.

METHODS

Recent advances in molecular biological techniques now permit quantitative analysis of mRNA from archival, formalin-fixed, paraffin-embedded tissue sections. RNA was extracted from scraped 6 microm sections of biopsy tissue, and PRKC-alpha and PRKC-beta (also known as PRKCA and PRKCB) mRNA measured using real-time PCR. Expression of genes encoding PKC isoforms was examined in renal biopsies (n=25) with classical histological features of diabetic nephropathy and compared with that in normal control tissue (n=6). Peptide localisation of PKC-alpha, PKC-beta and the activated forms phosphorylated PKC-alpha and -beta was also performed on matched paraffin-embedded sections of renal biopsies using immunohistochemistry. The effects of high glucose on PRKC-beta expression and peptide production in cultured human proximal tubular epithelial cells were assessed.

RESULTS

Quantitative real-time PCR demonstrated a 9.9-fold increase in PRKC-beta mRNA in kidney biopsies of diabetic patients relative to control (p<0.001). No increase in PRKC-alpha expression was seen. In addition, a correlation between renal PRKC-beta mRNA and HbA(1c) was observed in diabetic patients (r=0.63, p<0.05). There was co-localisation of PKC-beta and phospho-PKC-beta predominantly to proximal tubules. A 60% increase in PRKC-beta mRNA and peptide in cultured human proximal tubular epithelial cells exposed to high glucose (p<0.05) was seen in vitro.

CONCLUSIONS/INTERPRETATION

PKC-beta is upregulated at the gene expression level in human diabetic nephropathy. PRKC-beta mRNA correlates closely with serum HbA(1c), possibly partially explaining the relationship between glycaemic control and progression of diabetic nephropathy. Archival human tissue provides a valuable resource for molecular analyses.

Time course of the antiproteinuric and antihypertensive effects of direct renin inhibition in type 2 diabetes

Inhibition of renin with an active site inhibitor, aliskiren, lowers blood pressure (BP) in diabetic patients. Here, we studied the time course of the antihypertensive and antiproteinuric effect of renin inhibition in 15 patients with type 2 diabetes and elevated urinary albumin/creatinine ratios (UACRs) to check whether aliskiren can decrease proteinuria. After a 4-week washout of previous medications, patients received aliskiren and furosemide daily for 28 days followed by a 4-week withdrawal period. Twenty-four-hour BPs were measured at baseline throughout treatment and withdrawal periods. The UACR was significantly reduced after 2-4 days of treatment with another significant reduction after 28 days. Systolic blood pressure (SBP) was significantly lower after 7 days with no further reduction after 28 days. The BP returned toward baseline 3 days after withdrawal, whereas the UACR was still significantly reduced compared with baseline 12 days after withdrawal. Our study shows that aliskiren reduced 24 h SBP, and this was associated with a reduction in albuminuria in type 2 diabetic patients.

Pregnancy-associated plasma protein A in a large cohort of Type 1 diabetic patients with and without diabetic nephropathy-a prospective follow--up study

AIM

Pregnancy-associated plasma protein A (PAPP-A) has been implicated in the aetiology of acute coronary syndromes and carotid and peripheral artherosclerosis. Diabetic nephropathy is characterized by increased cardiovascular risk. We investigated the prognostic value of PAPP-A in a large cohort of Type 1 diabetic patients.

METHODS

In a prospective observational follow-up study, 197 Type 1 diabetic patients with diabetic nephropathy and a matched group of 178 patients with normoalbuminuria were followed for 10.1 (0-10.3) years. PAPP-A was determined at baseline.

RESULTS

In patients with diabetic nephropathy, plasma PAPP-A was elevated 3.6 (0.4-51.1) mIU/l [median (range)] vs. 2.1 (0.4-46.6) mIU/l in normoalbuminuric patients, P < 0.0001. For acute coronary syndromes, a PAPP-A threshold of 10 mIU/l has been suggested. Thirty-seven patients were above the threshold and of these 13 patients (35%) died, compared with 60 of 338 patients (18%) below the threshold; log rank test P = 0.007. PAPP-A significantly predicted mortality after adjustment for presence of nephropathy; hazard ratio for dying when PAPP-A was above the threshold 2.1 (95% CI 1.13-3.9); P = 0.019. After adjusting for traditional risk factors, the results were attenuated. When only patients with nephropathy were analysed, PAPP-A was significantly predictive of all-cause mortality [P = 0.008; 2.43 (1.26-4.67)] in unadjusted analysis. After adjustment, the predictive value of PAPP-A for all-cause mortality was attenuated (P = 0.064).

CONCLUSION

We find PAPP-A to be associated with increased mortality in Type 1 diabetic patients with nephropathy in unadjusted analysis. After adjustment for traditional risk factors, the prognostic value of PAPP-A was no longer significant.

The association between metabolic syndrome, microalbuminuria and impaired renal function in the general population: impact on cardiovascular disease and mortality

OBJECTIVE

Microalbuminuria and metabolic syndrome are both associated with cardiovascular disease (CVD). The aim of this study was to determine the potential association between numbers of components in the metabolic syndrome, different levels of microalbuminuria and renal function. We also aimed to determine the risk of death and CVD at different levels of microalbuminuria and renal function and numbers of components in the metabolic syndrome.

DESIGN

Population-based observational follow-up study.

SETTING

Epidemiological research unit (Copenhagen City Heart Study).

SUBJECTS

A total of 2,696 men and women, 30-70 years of age. BASELINE MEASURES: Urinary albumin excretion (UAE), creatinine clearance and metabolic risk factors were measured in 1992-1994.

MAIN OUTCOME MEASUREMENTS

The participants were followed prospectively by registers until 1999-2000 with respect to CVD, and until 2004 with respect to death.

RESULTS

We found a strong association between microalbuminuria and the metabolic syndrome: 2% with none and 18% with five metabolic risk factors had microalbuminuria (P < 0.001). No association between impaired renal function defined as creatinine clearance <60 mL min(-1) and the metabolic syndrome was found. Microalbuminuria was associated with increased risk of death and CVD to a similar extend as the metabolic syndrome, irrespective of concomitant presence of metabolic syndrome (RR approximately 2; P < 0.001). Impaired renal function was not associated with increased risk of death and CVD in subjects with the metabolic syndrome.

CONCLUSIONS

Microalbuminuria (UAE >5 microg min(-1)) confers increased risk of death and CVD to a similar extent as the metabolic syndrome.

Endothelial dysfunction and low-grade inflammation and the progression of retinopathy in Type 2 diabetes

AIMS

To study whether microalbuminuria, endothelial dysfunction and low-grade inflammation are associated with the presence and progression of diabetic retinopathy.

METHODS

Patients with Type 2 diabetes (n = 328) attending a diabetes clinic were followed for 10 years and examined annually during the last 7 years. Retinopathy was assessed after pupillary dilatation by direct ophthalmoscopy (baseline) and two-field 60 degrees fundus photography (follow-up). Urinary albumin excretion, and markers of endothelial function (von Willebrand factor, tissue-type plasminogen activator, soluble E-selectin (sE-selectin), and soluble vascular cell adhesion molecule 1) and inflammatory activity (C-reactive protein and fibrinogen) were determined.

RESULTS

The prevalence of retinopathy was 33.8%. The median diabetes duration at baseline was 7 years (interquartile range 2-12 years). The highest tertiles of baseline urinary albumin excretion and glycated haemoglobin (HbA(1c)) were associated with prevalent retinopathy: odds ratio (OR) 95% confidence interval (CI) 2.80 (1.44-5.46) and 2.19 (1.11-4.32), respectively. Progression of retinopathy occurred in 188 patients. The second and third tertiles of baseline sE-selectin were associated with progression of retinopathy [1.44 (1.04-2.01) and 1.61 (1.19-2.18)] but not independently of HbA(1c). None of the other markers was significantly associated with the presence or progression of retinopathy. High baseline HbA(1c) was significantly associated with progression of retinopathy: 1.65 (1.21-2.25).

CONCLUSIONS

In this population of patients with Type 2 diabetes who attended a diabetes clinic, there was some evidence for a role of endothelial dysfunction in the progression of retinopathy. We could not demonstrate a role for low-grade inflammation. Our study emphasizes the importance of glycaemic control in the development and progression of retinopathy.

Targeting hyperglycaemia with either metformin or repaglinide in non-obese patients with type 2 diabetes: results from a randomized crossover trial

AIM

Metformin is the 'drug-of-first-choice' in obese patients with type 2 diabetes mellitus (T2DM) due to its antihyperglycaemic and cardiovascular protective potentials. In non-obese patients with T2DM, insulin secretagogues are empirically used as first choice. In this investigator-initiated trial, we evaluated the effect of metformin vs. an insulin secretagogue, repaglinide on glycaemic regulation and markers of inflammation and insulin sensitivity in non-obese patients with T2DM.

METHODS

A single-centre, double-masked, double-dummy, crossover study during 2 x 4 months involved 96 non-obese (body mass index < or = 27 kg/m(2)) insulin-naïve patients with T2DM. At enrolment, previous oral hypoglycaemic agents (OHA) were stopped and patients entered a 1-month run-in on diet-only treatment. Hereafter, patients were randomized to either repaglinide 2 mg thrice daily followed by metformin 1 g twice daily or vice versa each during 4 months with 1-month washout between interventions.

RESULTS

End-of-treatment levels of haemoglobin A(1c) (HbA(1c)), fasting plasma glucose, mean of seven-point home-monitored plasma glucose and fasting levels of high-sensitivity C-reactive protein and adiponectin were not significantly different between treatments. However, body weight, waist circumference, fasting serum levels of insulin and C-peptide were lower and less number of patients experienced hypoglycaemia during treatment with metformin vs. repaglinide. Both drugs were well tolerated.

CONCLUSIONS

In non-obese patients with T2DM, overall glycaemic regulation was equivalent with less hypoglycaemia during metformin vs. repaglinide treatment for 2 x 4 months. Metformin was more effective targeting non-glycaemic cardiovascular risk markers related to total and abdominal body fat stores as well as fasting insulinaemia. These findings may suggest the use of metformin as the preferred OHA also in non-obese patients with T2DM.

Prevalence and risk factors for microalbuminuria in a referred cohort of type II diabetic patients: a global perspective

We described the characteristics in a referred cohort of type II diabetic patients in the Developing Education on Microalbuminuria for Awareness of renal and cardiovascular risk in Diabetes study evaluating the global prevalence and determinants of microalbuminuria (MA). A cross-sectional study evaluating 32,208 type II diabetic patients without known albuminuria from 33 countries was performed. Overall, 8057 patients were excluded, either because of prior known proteinuria or non-diabetic nephropathy (3670), or because of invalid urine collections (4387). One single random urinary albumin/creatinine ratio was obtained in 24,151 patients (75%). The overall global prevalence of normo-, micro-, and macroalbuminuria was 51, 39, and 10%, respectively. The Asian and Hispanic patients had the highest prevalence of a raised urinary albumin/creatinine ratio (55%) and Caucasians the lowest (40.6), P<0.0001. HbA1c, systolic blood pressure (BP), ethnicity, retinopathy, duration of diabetes, kidney function, body height, and smoking were all independent risk factors of MA, P<0.0001. Estimated glomerular filtration rate was below 60 ml/min/1.73 m(2) in 22% of the 11,573 patients with available data. Systolic BP below 130 mmHg was found in 33 and 43% had an HbA1c below 7%. The frequency of patients receiving aspirin was 32%, statins 29%, and BP-lowering therapy 63%. A high prevalence globally of MA and reduced kidney function, both conditions associated with enhanced renal and cardiovascular risk, was detected in type II diabetic patients without prior known nephropathy. Early detection, monitoring of vascular complications, and more aggressive multifactorial treatment aiming at renal and vascular protection are urgently needed.

Plasma N-terminal pro-B-type natriuretic peptide and mortality in type 2 diabetes

AIMS/HYPOTHESIS

Raised N-terminal pro-B-type natriuretic peptide (NT-proBNP) is associated with a poor cardiac outcome in non-diabetic populations. Elevated NT-proBNP predicts excess morbidity and mortality in diabetic patients with an elevated urinary albumin excretion rate. This study investigated the prognostic value of NT-proBNP in a cohort of type 2 diabetic patients.

SUBJECTS, MATERIALS AND METHODS

In a prospective observational follow-up study, 315 type 2 diabetic patients with normoalbuminuria (n=188), microalbuminuria (n=80) and macroalbuminuria (n=47) at baseline were followed for a median (range) of 15.5 (0.2-17.0) years. Plasma NT-proBNP concentrations were determined by immunoassay at baseline. Endpoints were overall and cardiovascular mortality.

RESULTS

Of the patients, 162 died (51%), 119 of them (74%) due to cardiovascular causes. All-cause mortality was increased in patients with NT-proBNP in the second and third tertiles (hazard ratios [95% CI] compared with the first tertile, 1.70 [1.08-2.67] and 5.19 [3.43-7.88], p<0.001). These associations persisted after adjustment for urinary albumin excretion rate, glomerular filtration rate and conventional cardiovascular risk factors (covariate adjusted hazard ratios 1.46 [0.91-2.33] and 2.54 [1.56-4.14], p<0.001). This increased mortality was attributable to more cardiovascular deaths in the second and third NT-proBNP tertile (unadjusted hazard ratios 1.63 [0.96-2.77] and 4.88 [3.01-7.91], p<0.001; covariate adjusted 1.37 [0.79-2.37] and 2.26 [1.27-4.02], p=0.01). When patients with normo-, micro- and macroalbuminuria were analysed separately, NT-proBNP levels above the median (62 ng/l) were consistently associated with increased overall and cardiovascular mortality in all three groups (p<0.001).

CONCLUSIONS/INTERPRETATION

In patients with type 2 diabetes, elevated circulating NT-proBNP is a strong predictor of the excess overall and cardiovascular mortality, this predictor status being independent of urinary albumin excretion rate and conventional cardiovascular risk factors.