Progression of diabetic nephropathy

BACKGROUND

Diabetic nephropathy is a major cause of renal failure. The decline in glomerular filtration rate (GFR) is highly variable, ranging from 2 to 20, with a median of 12 mL/min/year. The risk factors of losing filtration power (progression promoters) have not been clearly identified. Furthermore, information on optimal arterial blood pressure, glycemic control, and cholesterol levels are lacking.

METHODS

We measured GFR with (51)Cr-EDTA plasma clearance technique, blood pressure, albuminuria, glycosylated hemoglobin A1c, and serum cholesterol every year for seven years (range 3 to 14 years) in 301 consecutive type 1 diabetic patients with diabetic nephropathy recruited consecutively during 1983 through 1997. Diabetic nephropathy was diagnosed clinically if the following criteria were fulfilled: persistent albuminuria> 200 microg/min, presence of diabetic retinopathy, and no evidence of other kidney or renal tract disease. In total, 271 patients received antihypertensive treatment at the end of the observation period.

RESULTS

Mean arterial blood pressure was 102 +/- 0.4 (SE) mm Hg. The average decline in GFR was 4.0 +/- 0.2 mL/min/year and even lower (1.9 +/- 0.5 mL/min/year) in the 30 persistently normotensive patients, none of whom had ever received antihypertensive treatment (P < 0.01). A multiple linear regression analysis revealed a significant positive correlation between the decline in GFR and mean arterial blood pressure, albuminuria, glycosylated hemoglobin A(1c), and serum cholesterol during follow-up (R(adj)(2) = 0.29, P < or = 0.001). No threshold level for blood pressure, glycosylated hemoglobin A(1c), or serum cholesterol was demonstrated. A two-hit model with mean arterial blood pressure and glycosylated hemoglobin A(1c) below and above the median values (102 mm Hg and 9.2%, respectively) revealed a rate of decline in GFR of only 1.5 mL/min/year in the lowest stratum compared with 6.1 mL/min/year in the highest stratum (P < 0.001).

CONCLUSIONS

The prognosis of diabetic nephropathy has improved during the past decades, predominantly because of effective antihypertensive treatment. Genuine normotensive patients have a slow progression of nephropathy. Several modifiable variables have been identified as progression promoters.

Renoprotective effects of angiotensin II receptor blockade in type 1 diabetic patients with diabetic nephropathy

BACKGROUND

Angiotensin I-converting enzyme (ACE) inhibitors reduce angiotensin II formation and induce bradykinin accumulation. Animal studies suggest that bradykinin may play a role for the effects of ACE inhibition on blood pressure and kidney function. Therefore, we compared the renal and hemodynamic effects of specific intervention in the renin-angiotensin system by blockade of the angiotensin II subtype-1 receptor to the effect of ACE inhibition.

METHODS

A randomized, double-blind, cross-over trial was performed in 16 type 1 diabetic patients (10 men), age 42 +/- 2 years (mean +/- SEM). The study consisted of five periods, each lasting two months. The patients received losartan 50 mg, losartan 100 mg, enalapril 10 mg, enalapril 20 mg, and placebo in random order. At the end of each period, albuminuria, 24-hour blood pressure, and glomerular filtration rate (GFR) were determined.

RESULTS

Both doses of losartan and enalapril reduced albuminuria (P < 0.05) and mean arterial blood pressure (MABP; P < 0.05), whereas GFR remained stable. Albuminuria was reduced by 33% (95% CI, 12 to 51) on losartan 50 mg, 44% (95% CI, 26 to 57) on losartan 100 mg, 45% (95% CI, 23 to 61) on enalapril 10 mg, and 59% (95% CI, 39 to 72) on enalapril 20 mg, and MABP fell by 9 +/- 2, 8 +/- 2, 6 +/- 3, and 11 +/- 3 mm Hg (mean +/- SEM), respectively. No significant differences were found between the effects of losartan 100 mg and enalapril 20 mg. HbA1C and sodium intake remained unchanged throughout the study, whereas a significant rise in serum potassium occurred during ACE inhibition.

CONCLUSION

The angiotensin II subtype 1 receptor antagonist, losartan, reduces albuminuria and MABP similar to the effect of ACE inhibition. These results indicate that the reduction in albuminuria and blood pressure during ACE inhibition is primarily caused by interference in the renin-angiotensin system. Our study suggest that losartan represents a valuable new drug in the treatment of hypertension and proteinuria in type 1 diabetic patients with diabetic nephropathy.

Increased serum adiponectin levels in type 1 diabetic patients with microvascular complications

AIMS/HYPOTHESIS

Low serum adiponectin (ADPN) has been associated with increased risk of cardiovascular disease (CVD) and retinopathy in patients with type 2 diabetes mellitus. In type 1 diabetic patients, the relationship between ADPN and the presence of vascular complications is largely unknown.

METHODS

We investigated the relationship between serum ADPN and the presence of retinopathy, nephropathy and CVD in patients with type 1 diabetes, divided into matched groups with normoalbuminuria and no retinopathy (n=67), simplex retinopathy (n=106) or proliferative retinopathy (n=19), and nephropathy with simplex (n=62) or proliferative retinopathy (n=137). Healthy control subjects (n=25) were included.

RESULTS

Serum ADPN was increased in subjects with type 1 diabetes compared with control subjects (p<0.0001). Further, serum ADPN was higher in patients with than in those without nephropathy (p<0.0001). It was also higher in normoalbuminuric patients with than in those without proliferative retinopathy (p<0.0001). These differences remained significant after adjustment for known risk factors (p<0.03). CVD was also associated with elevated ADPN levels (p<0.05), but this difference became insignificant after risk factor adjustment. The most important predictor of serum ADPN was sex (r2=19%) in normoalbuminuric patients and GFR in patients with nephropathy (r2=18%).

CONCLUSION/INTERPRETATION

Patients with type 1 diabetes and microvascular complications have higher serum levels of ADPN than patients without complications. It remains to be clarified whether elevated levels of ADPN are pathogenically related to the development of microvascular complications or represent a beneficial counter-regulatory response.

Aldosterone escape during blockade of the renin-angiotensin-aldosterone system in diabetic nephropathy is associated with enhanced decline in glomerular filtration rate

AIMS/HYPOTHESIS

It has been suggested that aldosterone plays a role in the initiation and progression of renal disease independently of arterial blood pressure and plasma angiotensin II levels. We evaluated the influence of plasma aldosterone levels on progression of diabetic nephropathy during long-term blockade of the renin-angiotensin-aldosterone system.

METHODS

A total of 63 hypertensive patients with type 1 diabetes and diabetic nephropathy were treated with losartan, 100 mg once daily, for a mean follow-up period of 35 months. Plasma aldosterone, GFR, albuminuria and 24-h blood pressure were determined at baseline and at regular intervals during the study.

RESULTS

Patients were divided according to their increasing or decreasing levels of plasma aldosterone during long-term losartan treatment in an escape group (n=26) and a non-escape group (n=37). In the escape group, aldosterone levels increased from (geometric mean [95% CI]) 57 pg/ml (43-76 pg/ml) at 2 months, to 102 pg/ml (78-134 pg/ml) at the end of the study (p<0.01). The corresponding levels in the non-escape group were 83 pg/ml (69-102 pg/ml) and 49 pg/ml (40-60 pg/ml; p<0.01). The median rate of decline in GFR was 5.0 ml.min(-1).year(-1) (range 0.4-15.9 ml.min(-1).year(-1)) in the escape group, compared with 2.4 ml.min(-1).year(-1) (-1.6 to 11.0 ml.min(-1).year(-1)) in the non-escape group (p<0.005). The increase in plasma aldosterone correlated with the rate of decline in GFR (r(2)=0.19, p<0.001), corresponding to a decline in GFR of 1.5 ml.min(-1).year(-1) for every two-fold increase in plasma aldosterone. Pre-treatment and treatment values of plasma aldosterone were not related to albuminuria or to changes in albuminuria during the study.

CONCLUSIONS/INTERPRETATION

Our data suggest that aldosterone escape during long-term blockade of the renin-angiotensin-aldosterone system is associated with an enhanced decline in GFR in patients with type 1 diabetes and diabetic nephropathy.

Beneficial impact of spironolactone on nephrotic range albuminuria in diabetic nephropathy

Reduction of nephrotic range albuminuria is associated with markedly improved renal and cardiovascular outcome in patients with diabetic nephropathy. Aldosterone has been suggested to play a role in the progression of diabetic nephropathy. We therefore aimed to evaluate the short-term effect of aldosterone antagonism with spironolactone on nephrotic range albuminuria and blood pressure in diabetic nephropathy. Twenty Caucasian patients with diabetic nephropathy and nephrotic range albuminuria (>2500 mg/24 h) despite recommended antihypertensive treatment completed this double-masked, randomized crossover trial. Patients were treated in random order with spironolactone 25 mg once daily and matched placebo for 2 months, on top of ongoing antihypertensive treatment, including an angiotensin-converting enzyme inhibitor or an angiotensin II receptor blocker in maximally recommended doses. Median (range) number of antihypertensive drugs was 3 (2-5). After each treatment period, albuminuria, 24-h ambulatory blood pressure, and glomerular filtration rate (GFR) were determined. Spironolactone on top of recommended renoprotective treatment induced a 32% (95% confidence interval (CI): 21-42%) reduction in albuminuria from (geometric mean (95% CI)) 3718 (2910-4749) mg/24 h on placebo treatment (P<0.001). There was a significant reduction in 24-h blood pressure of 6 (2-10)/4 (2-6) mm Hg and day blood pressure of 7 (3-12)/5 (3-7) mm Hg (P<0.01), whereas night blood pressure remained unchanged. Spironolactone induced an insignificant reversible reduction in GFR of 3 ml/min/1.73 m2 from 64 (27) ml/min/1.73 m2. No patients were excluded due to adverse events. Our results suggest that spironolactone treatment on top of recommended renoprotective treatment including maximal renin-angiotensin system blockade may offer additional renoprotection in patients with diabetic nephropathy and nephrotic range albuminuria.

Effect of deletion polymorphism of angiotensin converting enzyme gene on progression of diabetic nephropathy during inhibition of angiotensin converting enzyme: observational follow up study

OBJECTIVE

To evaluate the concept that an insertion/deletion polymorphism of the angiotensin converting enzyme gene predicts the therapeutic efficacy of inhibition of angiotensin converting enzyme on progression of diabetic nephropathy.

DESIGN

Observational follow up study of patients with insulin dependent diabetes and nephropathy who had been treated with captopril for a median of 7 years (range 3-9 years).

SETTING

Outpatient diabetic clinic in a tertiary referral centre.

PATIENTS

35 patients with insulin dependent diabetes and nephropathy were investigated during captopril treatment (median 75 mg/day (range 12.5 to 150 mg/day)) that was in many cases combined with a loop diuretic, 11 patients were homozygous for the deletion allele and 24 were heterozygous or homozygous for the insertion allele of the angiotensin converting enzyme gene.

MAIN OUTCOME MEASURES

Albuminuria, arterial blood pressure, and glomerular filtration rate according to insertion/deletion polymorphism.

RESULTS

The two groups had comparable glomerular filtration rate, albuminuria, blood pressure, and haemoglobin A1c concentration at baseline. Captopril induced nearly the same reduction in mean blood pressure in the two groups-to 103 (SD 5) mm Hg in the group with the deletion and 102 (8) mm Hg in the group with the insertion-and in geometric mean albumin excretion-573 (antilog SE 1.3) micrograms/min and 470 (1.2) micrograms/min, respectively. The rate of decline in glomerular filtration rate (linear regression of all glomerular filtration rate measurements during antihypertensive treatment) was significantly steeper in the group homozygous for the double deletion allele than in the other group (mean 5.7 (3.7) ml/min/year and 2.6 (2.8) ml/min/year, respectively; P = 0.01). Multiple linear regression analysis showed that haemoglobin A1c concentration, albuminuria, and the double deletion genotype independently influenced the sustained rate of decline in glomerular filtration rate (R1 (adjusted) = 0.51).

CONCLUSION

The deletion polymorphism in the angiotensin converting enzyme gene reduces the long term beneficial effect of angiotensin converting enzyme inhibition on the progression of diabetic nephropathy in patients with insulin dependent diabetes.

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.

Amadori albumin in type 1 diabetic patients: correlation with markers of endothelial function, association with diabetic nephropathy, and localization in retinal capillaries

Nonenzymatic glycation is increased in diabetes. Most studies so far have focused on the role of advanced glycation end products (AGEs) in vascular complications, whereas the role of early glycation Amadori-modified proteins, which is the predominant form of glycated proteins, has not been systemically investigated in humans. We developed an antiserum against glycated human serum albumin (HSA) and used this to study the role of early glycation products in vascular complications in type 1 diabetic patients. Amadori albumin was determined to be the recognition epitope of the antiserum. The antibody recognized a specific glucose adduct and a conformational component specific for human albumin in Amadori albumin, with no recognition of AGEs. Plasma Amadori albumin levels were significantly higher in type 1 diabetic patients (n = 55) than in healthy control subjects (n = 60) (39.2+/-9.9 vs. 20.9+/-4.0 U/ml, P < 0.0005). Amadori albumin correlated with levels of plasma markers of endothelial function von Willebrand factor (r = 0.29, P < 0.05) and vascular cell adhesion molecule-1 (r = 0.41, P < 0.005), but not soluble E-selectin. In addition, Amadori albumin immunoreactivity was detected in the capillaries of retinas of diabetic patients. Plasma levels of Amadori albumin were determined in a second group of type 1 diabetic patients with long-standing diabetes with (n = 199) or without (n = 192) diabetic nephropathy. Patients with nephropathy had higher Amadori albumin levels than did those without it (50.9+/-9.5 vs. 45.1+/-6.3 U/ml, P < 0.0005). Age-, sex-, and diabetes duration-adjusted analyses showed that nephropathy was significantly associated with Amadori albumin with an odds ratio (OR [95% CI]) of 1.11 [1.08-1.15] per U/ml increase. After additional adjustment for levels of creatinine, glycated hemoglobin, cholesterol, triglycerides, blood pressure, preexistent retinopathy, and cardiovascular disease, Amadori albumin continued to be significantly associated with nephropathy (OR 1.06 [1.01-1.11]) per U/ml increase. Our results are consistent with a proposed pathophysiological role of Amadori albumin in microvascular complications of type 1 diabetic patients.

Lack of relationship between an insertion/deletion polymorphism in the angiotensin I-converting enzyme gene and diabetic nephropathy and proliferative retinopathy in IDDM patients

Genotypic abnormalities of the renin-angiotensin system have been suggested as a risk factor for the development of diabetic nephropathy and proliferative retinopathy. We studied the relationship between an insertion(I)/deletion (D) polymorphism in the angiotensin-converting enzyme (ACE) gene in insulin-dependent diabetes mellitus (IDDM) patients with diabetic nephropathy (121 men and 77 women, age 40.9 +/- 10 years, diabetes duration 27 +/- 8 years) and in IDDM patients with normoalbuminuria (118 men and 74 women, age 42.7 +/- 10 years, diabetes duration 26 +/- 8 years). A total of 155 patients (40%) had proliferative retinopathy, and 67 patients (17%) had no diabetic retinopathy. There was no difference in genotype distribution between IDDM patients with diabetic nephropathy and those with normalbuminuria: 63 (32%)/95 (48%)/40 (20%) vs. 67 (35%)/77 (41%)/46 (24%) had DD/ID/II genotypes, respectively. Patients with nephropathy had higher plasma ACE levels (609 [151-1,504] micrograms/l) compared with patients with normoalbuminuria (428 [55-1,630] micrograms/l) (P < 0.001). Multiple linear regression analysis revealed that the plasma ACE level in patients with nephropathy is partially determined by ACE/ID polymorphism, mean arterial blood pressure, and glomerular filtration rate (r2 = 0.30, P < 0.001). There was no difference in genotype distribution between IDDM patients with proliferative retinopathy and those without diabetic retinopathy: 52 (34%)/74 (48%)/29 (19%) vs. 26 (39%)/25 (37%)/16 (24%) had DD/ID/II genotypes, respectively. There was also no difference in plasma ACE concentration detected among patients with no, simplex, or proliferative retinopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Prevalence of arterial hypertension in diabetic patients before and after the JNC-V

OBJECTIVE

To compare the prevalence of arterial hypertension in patients with insulin-dependent diabetes mellitus (IDDM) and non-insulin-dependent diabetes mellitus (NIDDM) according to blood pressure (BP) criteria from the World Health Organization (WHO) and The Fifth Report of the Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure (JNC-V).

RESEARCH DESIGN AND METHODS

Two cohorts of Caucasian patients attending the outpatient clinic at Hvidöre Hospital were identified: 1) 957 patients with IDDM; 53% men, 40 (18-75) years of age (mean [range]); and 2) 549 patients with NIDDM; 53% men, 60 (20-76) years of age. BP was measured at least yearly, while patients rested in a sitting position, with a standard clinical sphygmomanometer. Patients were classified as hyper- or normotensive based on average BP during a 3-year follow-up period. Patients receiving antihypertensive treatment were classified as hypertensives.

RESULTS

In IDDM patients, the prevalence of arterial hypertension rose from 15 to 42% in the normoalbuminuric group, from 26 to 52% in the microalbuminuric group, and from 61 to 79% in the macroalbuminuric group when WHO and JNC-V criteria were compared. The corresponding rises in NIDDM patients were from 51 to 71% (normo-), from 73 to 90% (micro-), and from 82 to 93% (macroalbuminuria). Of the untreated hypertensive patients, 78% of IDDM patients and 50% of NIDDM patients had stage 1 (140-159/90-99 mmHg) hypertension; 20% of IDDM patients and 37% of NIDDM patients had stage 2 (160-179/100-109 mmHg) hypertension. Two out of three untreated hypertensive patients had isolated systolic hypertension.

CONCLUSIONS

The new JNC-V criteria approved by the American Diabetes Association leads to a considerable increase in the prevalence of arterial hypertension in a population of IDDM and NIDDM patients. Isolated systolic hypertension contributes importantly.

Exome sequencing-driven discovery of coding polymorphisms associated with common metabolic phenotypes

AIMS/HYPOTHESIS

Human complex metabolic traits are in part regulated by genetic determinants. Here we applied exome sequencing to identify novel associations of coding polymorphisms at minor allele frequencies (MAFs) >1% with common metabolic phenotypes.

METHODS

The study comprised three stages. We performed medium-depth (8×) whole exome sequencing in 1,000 cases with type 2 diabetes, BMI >27.5 kg/m(2) and hypertension and in 1,000 controls (stage 1). We selected 16,192 polymorphisms nominally associated (p < 0.05) with case-control status, from four selected annotation categories or from loci reported to associate with metabolic traits. These variants were genotyped in 15,989 Danes to search for association with 12 metabolic phenotypes (stage 2). In stage 3, polymorphisms showing potential associations were genotyped in a further 63,896 Europeans.

RESULTS

Exome sequencing identified 70,182 polymorphisms with MAF >1%. In stage 2 we identified 51 potential associations with one or more of eight metabolic phenotypes covered by 45 unique polymorphisms. In meta-analyses of stage 2 and stage 3 results, we demonstrated robust associations for coding polymorphisms in CD300LG (fasting HDL-cholesterol: MAF 3.5%, p = 8.5 × 10(-14)), COBLL1 (type 2 diabetes: MAF 12.5%, OR 0.88, p = 1.2 × 10(-11)) and MACF1 (type 2 diabetes: MAF 23.4%, OR 1.10, p = 8.2 × 10(-10)).

CONCLUSIONS/INTERPRETATION

We applied exome sequencing as a basis for finding genetic determinants of metabolic traits and show the existence of low-frequency and common coding polymorphisms with impact on common metabolic traits. Based on our study, coding polymorphisms with MAF above 1% do not seem to have particularly high effect sizes on the measured metabolic traits.

Elevated vascular endothelial growth factor in type 1 diabetic patients with diabetic nephropathy

BACKGROUND

Growth factors have been suggested to play a role in the development and progression of diabetic nephropathy. Vascular endothelial growth factor (VEGF) is a potent cytokine family that induces angiogenesis and markedly increases endothelial permeability. The aim of the present study was to investigate plasma levels of VEGF in a large cohort of type 1 diabetic patients with diabetic nephropathy and in long-standing type 1 diabetic patients with persistent normoalbuminuria, and to evaluate VEGF as a predictor of nephropathy progression.

METHODS

We measured VEGF with an enzyme-linked immunosorbent assay (ELISA) technique in 199 type 1 diabetic patients with diabetic nephropathy (122 males, age 41 +/- 10 years, diabetes duration 28 +/- 8 years), glomerular filtration rate (GFR) (median [range]) 75 [10-143] mL/min/1.73 m2, and in 188 long-standing type 1 diabetic patients with persistent normoalbuminuria (115 males, age 43 +/- 10 years, diabetes duration 27 +/- 9 years). One hundred fifty-five of the proteinuric patients were followed for at least 3 years after baseline examination with yearly GFR measurements.

RESULTS

Plasma levels of VEGF were significantly increased in patients with nephropathy as compared to the normoalbuminuric group; (median [range]): 45.7 [22.0-410] versus 27.1 [22.0-355] ng/L, respectively, P < 0.001. This difference was ascribed to elevated VEGF levels in nephropathic men: 51.8 [22.0-410] versus 22.0 [22.0-308] ng/L, P < 0. 001. No differences were found between women with and without nephropathy: 37.8 [22.0-325] versus 36.6 [22.0-335] ng/L, NS. In proteinuric patients with GFR above and below the median value, there was no difference in the level of VEGF, NS. Plasma VEGF was below the detection limit (22.0 ng/L) in 60 patients with nephropathy and 93 patients with normoalbuminuria, P < 0.001. The mean rate of GFR decline was 3.5 (SE: 0.4) mL/min/year, and the following baseline variables acted as predictors of progression: albuminuria, mean arterial blood pressure and male gender. Hemoglobin A1c and plasma VEGF did not act as predictors. No significant differences between patients with and without proliferative retinopathy were detected.

CONCLUSIONS

Our data suggest that VEGF is elevated early in the course of diabetic nephropathy in men with type 1 diabetes mellitus. Baseline albuminuria, arterial blood pressure and male gender was predictors of diabetic nephropathy progression, while plasma VEGF and Hemoglobin A1c did not contribute. The importance of VEGF in the initiation of diabetic nephropathy remains to be established.

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.

Increased levels of mannan-binding lectin in type 1 diabetic patients with incipient and overt nephropathy

AIMS/HYPOTHESIS

Diabetic nephropathy is associated with insulin resistance, and low-grade inflammation and activation of the complement system may contribute to this cascade. Mannan-binding lectin (MBL) activates the complement system, and elevated MBL concentrations have been observed in normoalbuminuric type 1 diabetic patients. The aim of this study was to assess whether MBL is associated with diabetic nephropathy in type 1 diabetes, and whether there is an association between MBL and low-grade inflammatory markers or insulin resistance.

METHODS

A total of 191 type 1 diabetic patients from the Finnish Diabetic Nephropathy Study were divided into three groups based upon their AER. Patients with normal AER (n=67) did not take antihypertensive medication, while patients with microalbuminuria (n=62) or macroalbuminuria (n=62) were all treated with an ACE inhibitor. As a measure of insulin sensitivity we used estimated glucose disposal rate. MBL was measured by an immunofluorometric assay, C-reactive protein by a radioimmunoassay and IL-6 by high-sensitivity enzyme immunoassay.

RESULTS

Patients with normal AER (median [interquartile range]: 1,154 microg/l [180-2,202 microg/l]) had lower levels of MBL than patients with microalbuminuria (1,713 microg/l [724-2,760 microg/l]; p=0.029) or macroalbuminuria (1,648 microg/l [568-3,394 microg/l]; p=0.019). There was a significant correlation between MBL and estimated glucose disposal rate, but not between MBL and C-reactive protein or IL-6 levels in univariate analysis. However, in a multiple regression analysis, HbA1c was the single variable independently associated with MBL (beta+/-SEM: 0.26+/-0.08; p=0.003).

CONCLUSIONS/INTERPRETATION

MBL concentrations are increased in type 1 diabetic patients with diabetic nephropathy. MBL was not associated with low-grade inflammatory markers.

Angiotensin converting enzyme gene polymorphism and ACE inhibition in diabetic nephropathy

The antiproteinuric effect of angiotensin converting enzyme (ACE) inhibition in insulin-dependent diabetes mellitus (IDDM) patients with diabetic nephropathy varies considerably. Therefore, we tested the potential role of an insertion (I)/deletion (D) polymorphism of the ACE gene on this early antiproteinuric responsiveness in an observational follow-up study. Sixty (II, N = 13; ID, N = 26 and DD, N = 21) young hypertensive IDDM patients suffering from diabetic nephropathy were investigated during three months before and for the initial six month period during ACE inhibition [captopril 44 (SD 22) mg/24 hr, no differences in drug dose between groups]. Blood pressure (MABP) and albuminuria (ELISA) were measured three (1 to 6) times before and three (1 to 13) times during ACE inhibition. At baseline the groups (II/ID/DD) had comparable (1) mean arterial blood pressure (MABP mm Hg) of 113 +/- 10/108 +/- 9/114 +/- 8, (2) albuminuria (geometric mean with 95% CI) 1394 (747 to 2608)/1176 (844 to 1797) and 1261 (827 to 2017) mg/24 hr, and (3) serum creatinine (geometric mean with 95% CI), 80 (68 to 93)/85 (76 to 97)/103 (85 to 119) mumol/liter, respectively. Angiotensin converting enzyme inhibition induced a significant reduction in MABP, albuminuria and kidney function in all three groups (II/ID/DD; P < 0.05): (1) MABP (mean +/- SD) 12 +/- 7/5 +/- 7/8 +/- 9 mm Hg (ANOVA, P = 0.02); (2) albuminuria [mean (95% CI)] 61 (34 to 77)/22 (3 to 37)/31 (13 to 46) %, (ANOVA, P < 0.01); and (3) increasing serum creatinine [mean (95% CI)] 8 (4 to 12)/9 (3 to 16)/8 (0 to 16) % (ANOVA, NS), respectively. Adjusting for differences in reduction in MABP did not change the association between decrease in albuminuria and ACE/ID genotypes (P < 0.01). A multiple linear regression analysis revealed that the ACE/ID polymorphism, albuminuria and MABP at baseline independently influenced the decline in albuminuria after initiation of ACE inhibition (R2 = 0.21, P < 0.01). A significant association between changes in MABP and albuminuria was demonstrated (R2 = 0.16, P < 0.01). Our data show that hypertensive albuminuric IDDM patients with the II genotype are particularly susceptible to commonly advocated renoprotective treatment.

Remission and regression in the nephropathy of type 1 diabetes when blood pressure is controlled aggressively

BACKGROUND

Diabetic nephropathy is a chronic, progressive kidney disease with a mean rate of decline of in glomerular filtration rate (GFR) of 10 to 12 mL/min/year (natural history). The introduction of aggressive antihypertensive treatment has improved the renal prognosis during the last decades. To examine whether remission and regression of diabetic nephropathy are possible in type 1 diabetic patients, we analyzed data from a prospective observational cohort study that was started in 1983.

METHODS

We measured GFR with a 51Cr-EDTA plasma clearance technique every year for seven years (range 3 to 14 years) in 301 consecutive type 1 diabetic patients with diabetic nephropathy. Diabetic nephropathy was diagnosed clinically if the following criteria were fulfilled: persistent albuminuria> 200 microg/min, presence of diabetic retinopathy, and no evidence of other kidney or renal tract disease. Blood pressure, albuminuria, glycosylated hemoglobin A1c, and serum cholesterol were measured every three to four months during the study. In total, 271 patients received antihypertensive treatment, 179 patients predominantly with angiotensin-converting enzyme inhibitors. Remission was defined as albuminuria <200 microg/min sustained for at least one year and a decrease of at least 30% from preremission levels (surrogate endpoint), and regression as a rate of decline in GFR (DeltaGFR) equal to the natural aging process: < or =1 mL/min/year during the entire observation period (principal end point).

RESULTS

The total number of patients who obtained remission was 92 (31%), with a duration of remission of [median (range)] 3.4 (1.0 to 14.1) years, and regression 67 (22%). The patients were stratified in quintiles by the average value of office mean arterial blood pressure (mean +/- SE): 93 +/- 0.5, 99 +/- 0.2, 103 +/- 0.1, 107 +/- 0.2, and 113 +/- 0.4 mm Hg. The prevalence of patients obtaining remission/regression was 58/42, 33/32, 25/11, 20/20, and 17/7% in each quintile, respectively. Spontaneous remission and regression occurred in 10 and 14 patients from the persistent normotensive group (N = 30), none of whom had ever received antihypertensive treatment. In all 301 consecutive patients, the (mean +/- SE) DeltaGFR was 4.0 +/- 0.2 mL/min/year during the investigation period.

CONCLUSIONS

Our study suggests that aggressive antihypertensive treatment in type 1 diabetic patients can induce remission and regression in a sizable fraction of patients with diabetic nephropathy. Lower arterial blood pressure, reduced albuminuria, and better glycemic control were predictors of regression of diabetic nephropathy.

Progression of diabetic nephropathy in normotensive type 1 diabetic patients

BACKGROUND

The first aim of our long-term study was to describe the natural history of diabetic nephropathy in 59 normotensive type 1 diabetic patients. Secondly, we evaluated genetic and nongenetic progression promoters.

METHODS

The following progression promoters were determined: the insertion/deletion polymorphism in the angiotensin converting enzyme (ACE) gene, blood pressure, albuminuria, hemoglobin A1c, cholesterol, smoking, height, and gender. We studied the natural history by measuring 51Cr-EDTA plasma clearance at yearly intervals at least three times during [median (range)] 5.5 (2.2 to 18.3) years.

RESULTS

At baseline the three groups (II, N = 11; ID, N = 25, and DD, N = 23) had comparable GFR (103 +/- 16; 99 +/- 19; 113 +/- 22 ml/min/1.73 m2, respectively; mean +/- SD), arterial blood pressure, albuminuria, and hemoglobin A1c. During the follow-up there was a median rate of decline in GFR in all 59 patients of 1.2 (range 12.9 to -4.4) ml/min/year. During the study period no significant differences were observed in: the rate of decline in glomerular filtration rate [median (range) 0.9 (10.6 to -1.9); 2.5 (12.9 to -4.4); 1.4 (10.8 to -1.9 ml/min/year)], arterial blood pressure, albuminuria, hemoglobin A1c or cholesterol between the three groups (II, ID and DD), respectively. At baseline, multiple linear regression analysis including the above-mentioned putative risk factors revealed that albuminuria, short stature, and male gender independently predict an enhanced decline in GFR [R2 (adjusted) = 0.33; P < 0.002]. During the follow-up period, only albuminuria acted as an independent progression promoter [R2 (adjusted) = 0.37; P < 0.0001].

CONCLUSIONS

Our study revealed a rather slow progression of kidney disease in normotensive type 1 diabetic patients with diabetic nephropathy. Albuminuria, short stature, and male gender act as progression promoters in such patients.

A phase 2a, randomized, double-blind 28-day study of TZP-102 a ghrelin receptor agonist for diabetic gastroparesis

BACKGROUND

Gastroparesis causes significant morbidity and treatment options are limited. TZP-102 a novel, macrocyclic, selective, oral ghrelin receptor agonist, was evaluated in a randomized, double-blind, placebo-controlled trial in patients with diabetic gastroparesis.

METHODS

A total of 92 outpatients were randomized to once-daily administrations of 10-mg (n = 22), 20-mg (n = 21), 40-mg (n = 23) TZP-102 or placebo (n = 26). The primary endpoint was the change from baseline in gastric half-emptying time (T(½)) utilizing (13)C-breath test methodology and secondary endpoints included symptom improvement using patient-reported gastroparesis symptom scores (PAGI-SYM questionnaire) and patient and physician overall treatment evaluations (OTE).

KEY RESULTS

Gastric T½ changes were not statistically significant between TZP-102 and placebo after 28 days of treatment at any dose. Clinical improvements (-1.0 to -1.4 point mean decrease in symptom severity) occurred in the Gastroparesis Cardinal Symptom Index (GCSI) component of the PAGI-SYM, which was significant vs placebo for all TZP-102 doses combined. Improvements became evident after 1 week of treatment. Significantly, more patients given TZP-102 (any dose) had a 50% reduction in baseline GCSI score (28.8%vs 7.7% placebo). Safety profiles were similar across groups. All TZP-102 doses were well-tolerated with no adverse cardiac, weight, or glucose control outcomes.

CONCLUSIONS & INFERENCES

TZP-102 for 28 days, at doses of 10-40 mg once daily, was well-tolerated and resulted in a reduction in symptoms of gastroparesis. The lack of correlation between symptom improvement and gastric emptying change is consistent with previous studies in diabetic gastroparesis, and emphasizes the value of patient-defined outcomes in determining therapeutic benefit.

Genetics of diabetic nephropathy

Diabetic nephropathy is a clinical syndrome characterized by persistent albuminuria, a relentless decline in GFR, raised arterial blood pressure, and increased relative mortality for cardiovascular diseases. Diabetic nephropathy is a leading cause of end-stage renal failure. The pathogenesis of diabetic nephropathy is multifactorial, with contributions from metabolic abnormalities, hemodynamic alterations, and various growth factors and genetic factors. Epidemiologic and family studies have demonstrated that only a subset of the patients develop this complication that family clustering of nephropathy is present, and that ethnicity plays an important role in the risk of developing this kidney disease. Short stature and low birth weight are both associated with increased risk of developing diabetic nephropathy, supporting the hypothesis that genetic predisposition or factors operating in utero, in early childhood, or both contribute to the development of diabetic nephropathy. Studies elucidating phenotypic markers such as parenteral hypertension and systemic blood pressure elevation have yielded conflicting results. The contribution from elevated blood pressure only plays a minor role in the majority of the patients developing diabetic nephropathy. The majority of the studies have demonstrated increased sodium/lithium countertransport activity in insulin-dependent diabetes mellitus patients with nephropathy, whereas studies of this phenotypic marker in parents of patients with and without nephropathy have yielded conflicting results. Recently, studies of genetic markers involved in the regulation of blood pressure and levels of cardiovascular risk factors have been conducted. Several studies have demonstrated that the deletion polymorphism in the angiotensin-I-converting enzyme acts as a risk factor for cardiovascular disease in diabetic patients. However, a meta-analysis does not support the suggestion that this factor plays any role for the initiation of diabetic nephropathy. Similar negative results have been obtained in relation to polymorphisms of the genes encoding for angiotensinogen and the angiotensin II Type 1 receptor. However, studies in diabetic and non-diabetic glomerulopathies have clearly demonstrated a deleterious effect of the deletion polymorphism in the angiotensin-converting enzyme on the progression of kidney function.

Increased glomerular filtration rate after withdrawal of long-term antihypertensive treatment in diabetic nephropathy

Initiation of antihypertensive treatment (AHT) in hypertensive insulin-dependent diabetic (IDDM) patients with diabetic nephropathy (DN) induces a faster initial (0 to 6 months) and a slower subsequent (6 months to end of observation) decline in GFR [delta GFR (ml/min/month) approximately 1.5 vs. 0.35]. Whether this initial phenomenon is reversible (hemodynamic) or irreversible (structural damage) after prolonged AHT is not known. To elucidate these mechanisms we investigated 42 hypertensive IDDM patients (16F/26M, age 40 +/- 7 years, mean +/- SD) with DN receiving AHT (angiotensin converting enzyme inhibition, N = 30) for 6 (2 to 15) years [median (range)]. GFR (ml/min/1.73 m2), arterial blood pressure (BP, mm Hg) and albuminuria (mg/24 hr) were measured the last day on AHT and one month after withdrawal of AHT. The measured variables were all significantly elevated after withdrawal of AHT: GFR [mean(SEM)] from 76(4) to 81(4) (P < 0.0001), BP [mean(SEM)] from 140/82 (2/1) to 151/89 (2/1) (P < 0.0005) and albuminuria [geometric mean (antilog SEM)] from 704 (1.2) to 1122 (1.2) (P < 0.0001). A correlation between relative rise in systolic blood pressure (delta Sys%) and relative change in GFR (delta GFR%) was found (r = 0.44, P < 0.005). Our results render some support of the hypothesis that the faster initial decline in GFR is due to a functional (hemodynamic) effect of AHT, which does not attenuate over time, while the subsequent slower decline reflects the beneficial effect on progression of diabetic nephropathy.

Long-term renoprotective effect of nisoldipine and lisinopril in type 1 diabetic patients with diabetic nephropathy

OBJECTIVE

To compare the long-term effect on kidney function of a long-acting calcium antagonist (nisoldipine) versus a long-acting ACE inhibitor (lisinopril) in hypertensive type 1 diabetic patients with diabetic nephropathy.

RESEARCH DESIGN AND METHODS

We performed a 4-year prospective, randomized, double-dummy controlled study comparing nisoldipine (20-40 mg once a day) with lisinopril (10-20 mg once a day). The study was double-blinded for the first year and single-blinded thereafter. The study included 51 hypertensive type 1 diabetic patients with diabetic nephropathy. Three patients dropped out during the first month; results for the remaining 48 patients are presented.

RESULTS

At baseline, the two groups were comparable: glomerular filtration rate (GFR) was 85 +/- 5 and 85 +/- 6 ml x min(-1) x [1.73 m](-2); mean 24-h ambulatory blood pressure was 108 +/- 3 and 105 +/- 2 mmHg, and albuminuria was 1,554 mg/24 h (95% CI 980-2,465) and 1,033 mg/24 h (760-1,406) in the lisinopril and nisoldipine groups, respectively. Mean 24-h arterial blood pressure during the study did not differ between the lisinopril and nisoldipine groups (100 +/- 2 and 103 +/- 1 mmHg, respectively). The time-course of albuminuria differed between groups (P < 0.001). Whereas initiation of treatment with lisinopril resulted in a reduction from baseline albuminuria by 52% (95% CI 14-73), albuminuria in the nisoldipine group did not change throughout the study GFR declined in a biphasic manner with an initial (0-6 months) reduction of 1.3 +/- 0.3 ml x min(-1) x month(-1) in the lisinopril group compared with 0.2 +/- 0.4 ml x min(-1) x month(-1) in the nisoldipine group (P < 0.01). The subsequent sustained decline (6 to 48 months or the end of treatment) was identical in the two groups: 0.5 +/- 0.1 ml min(-1) x month(-1) (NS). Two patients in the lisinopril group and three patients in the nisoldipine group entered therapy for end-stage renal failure.

CONCLUSIONS

Long-term treatment with lisinopril or nisoldipine has similar beneficial effects on progression of diabetic nephropathy in hypertensive type 1 diabetic patients.

Development of enzyme-linked immunoassays for human angiotensin I converting enzyme suitable for large-scale studies

OBJECTIVE

To develop and validate a simple immunological assay for human angiotensin converting enzyme (ACE) based on monoclonal antibodies.

METHODS

Microtitre plates were coated with mouse monoclonal antibody (MoAb) to human ACE (9B9) and incubated with diluted samples of human plasma. In the sandwich enzyme-linked immunosorbent assay (ELISA), the plasma ACE, bound to MoAb 9B9, was revealed using polyclonal anti-ACE antibodies and alkaline phosphatase conjugated to goat anti-rabbit immunoglobulin G. In the plate precipitation assay the ACE activity, quantitatively precipitated from human plasma by MoAb 9B9, was measured by enzymatic fluorimetric assay with p-benzyloxycarboxyl-glycyl-L-histidyl-L-leucine or p-benzyloxycarboxyl-L-phenylalanyl-L-histidyl-L-leucine as substrate, directly in the wells.

RESULTS

These assays are specific for the amino-terminal domain of ACE and recognize differences in the conformations of native and recombinant ACE. The sensitivity of the sandwich ELISA was 200 pg/ml assay medium; it quantifies the ACE in 10 microliters human plasma or less. Intra- and inter-assay variability coefficients were 6.2 and 13.6%, respectively. Both variants of the assay determined the plasma ACE concentration in the presence of ACE inhibitors or EDTA. The ACE concentrations were determined by sandwich ELISA in a population of 138 middle-aged healthy Caucasian subjects. They were strongly correlated with the ACE gene insertion/deletion (I/D) polymorphism, which accounted for 20% of the variance of plasma ACE concentration in this population and 16-24% of the variance in plasma ACE activity as measured with three different enzymatic assays.

CONCLUSION

The ACE concentration (but not inhibition) can be determined by this ELISA which is suitable for large-scale studies of plasma ACE levels.

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.

Cyclosporine nephrotoxicity in type 1 diabetic patients. A 7-year follow-up study

OBJECTIVE

To evaluate kidney function 7 years after the end of treatment with cyclosporine A (CsA) (initial dosage of 9.3 tapered off to 7.0 mg.kg-1.day-1) in young patients (mean age 20 years) with newly diagnosed type 1 diabetes participating in a randomized, double-blind, placebo-controlled CsA trial.

RESEARCH DESIGN AND METHODS

In this study, 21 patients received CsA for 12.5 +/- 4.0 months (mean +/- SD) and 19 patients received placebo for 14.4 +/- 3.8 months. The two groups were similar with regard to mean arterial blood pressure (BP), urinary albumin excretion rate (UAER), serum creatinine, and estimated glomerular filtration rate (GFR [Cockcroft and Gault]) at initiation of CsA treatment (baseline). HbA1c (mean +/- SEM) during 7 years of follow-up was also the same: 8.7 +/- 0.4 vs. 8.3 +/- 0.4% in the CsA and placebo groups, respectively.

RESULTS

During the 7 years after cessation of study medication, two CsA group patients and one control patient were lost to follow-up. One placebo-treated patient developed IgA nephropathy (biopsy proven) and was excluded. Four CsA-treated patients developed persistently elevated UAER > 30 mg/24 h (n = 3 with microalbuminuria), whereas all the 17 placebo-treated patients had normal UAER (< 30 mg/24 h) after 7 years of follow-up. At the end of follow-up, the CsA group had a more pronounced rise in UAER: 2.5-fold (95% CI 1.4-4.5) higher than baseline value vs. 1.1-fold (0.7-1.7) in the placebo-treated group (P < 0.05). Estimated GFR (ml.min-1.1.73 m-2) declined from baseline to end of follow-up (1994) by 6.3 +/- 6.0 in the former CsA group, whereas it rose by 7.4 +/- 5.0 in the placebo group (P = 0.05). In 1994, 24-h blood pressure was nearly the same: 131/77 +/- 4/2 vs. 127/75 +/- 2/2 mmHg (NS) in the CsA and placebo groups, respectively. Five randomly selected CsA-treated patients had a kidney biopsy performed shortly after the CsA treatment was stopped. Interstitial fibrosis/tubular atrophy and/or arteriolopathy were present in two subjects who both subsequently developed persistent microalbuminuria.

CONCLUSIONS

The results of our 7-year follow-up study suggested that short-lasting CsA treatment in young, newly diagnosed type 1 diabetic patients accelerated the rate of progression in UAER and tended to induce a loss in kidney function. Longer term follow-up is mandatory to clarify whether CsA-treated patients are at increased risk of developing clinical nephropathy.