The effect of metabolic control on rate of decline in renal function in insulin-dependent diabetes mellitus with overt diabetic nephropathy

Emerging drugs for the treatment of diabetic nephropathy

INTRODUCTION

Diabetic nephropathy remains a significant economic and social burden on both the individual patient and health-care systems as the prevalence of diabetes increases in the general population. The complex pathophysiology of diabetic kidney disease poses a challenge in the development of effective medical treatments for the disease. However, the multiple facets of diabetic nephropathy also offer a variety of potential strategies to manage this condition.

AREAS COVERED

We retrieved PubMed, Cochrane Library, Scopus, Google Scholar, and ClinicalTrials.gov records to identify studies and articles focused on new pharmacologic advances to treat diabetic nephropathy.

EXPERT OPINION

RAAS blockers have remained the mainstay of therapy for DM nephropathy for many years, with only recent advancements with SGLT2 inhibitors and nonsteroidal MRAs. Better understanding of the long-term renal effects of ambient hyperglycemia, ranging from hemodynamic changes to increased production of oxidative and pro-inflammatory substances, has evolved our approach to the treatment of diabetic nephropathy. With continuing research for new therapeutics as well as combination therapy, the medical community may be able to better ease the burden of diabetic kidney disease.

Adjusting the 17β-Estradiol-to-Androgen Ratio Ameliorates Diabetic Nephropathy

Diabetes is manifested predominantly in males in experimental models, and compelling evidence suggests that 17β-estradiol (E2) supplementation improves hyperglycemia in humans. We previously generated a severely diabetic transgenic (Tg) mouse model by β-cell–specific overexpression of inducible cAMP early repressor (ICER) and found that male but not female ICER-Tg mice exhibit sustained hyperglycemia and develop major clinical and pathologic features of human diabetic nephropathy (DN). Thus, we hypothesized that differences in circulating hormone levels have a key role in determining susceptibility to diabetes. Here, we examined whether DN in male ICER-Tg mice is rescued by adjusting the androgen-to-E2 ratio to approximate that in normoglycemic female ICER-Tg mice. We treated hyperglycemic male ICER-Tg mice with orchiectomy (ORX), E2 pellet implantation, or both. E2 pellet implantation at an early stage of DN with or without ORX caused a rapid drop in blood glucose and a dramatic increase in β-cell number, and it markedly inhibited DN progression [namely, E2 reduced glomerulosclerosis, collagen 4 deposition and albuminuria, and prevented hyperfiltration]. Furthermore, E2 pellet implantation was more effective than ORX alone and induced a remarkable improvement, even when initiated at advanced-stage DN. In contrast, induction of normoglycemia by islet transplant in ICER-Tg mice eliminated albuminuria but was less effective than E2 + ORX in reducing glomerulosclerosis, collagen 4 deposition, and hyperfiltration. These findings indicate that E2 treatment is effective, even after establishment of DN, whereas glucose normalization alone does not improve sclerotic lesions. We propose that E2 intervention is a potential therapeutic option for DN.

Maintenance Dialysis throughout the World in Years 1990 and 2010

Rapidly rising global rates of chronic diseases portend a consequent rise in ESRD. Despite this, kidney disease is not included in the list of noncommunicable diseases (NCDs) targeted by the United Nations for 25% reduction by year 2025. In an effort to accurately report the trajectory and pattern of global growth of maintenance dialysis, we present the change in prevalence and incidence from 1990 to 2010. Data were extracted from the Global Burden of Disease 2010 epidemiologic database. The results are on the basis of an analysis of data from worldwide national and regional renal disease registries and detailed systematic literature review for years 1980-2010. Incidence and prevalence estimates of provision of maintenance dialysis from this database were updated using a negative binomial Bayesian meta-regression tool for 187 countries. Results indicate substantial growth in utilization of maintenance dialysis in almost all world regions. Changes in population structure, changes in aging, and the worldwide increase in diabetes mellitus and hypertension explain a significant portion, but not all, of the increase because increased dialysis provision also accounts for a portion of the rise. These findings argue for the importance of inclusion of kidney disease among NCD targets for reducing premature death throughout the world.

Prevalence and Management of Diabetic Nephropathy in Western Countries

BACKGROUND

Diabetic nephropathy (DN) often results in end-stage renal disease, and this is the most common reason for initiation of dialysis in the United States. Complications of diabetes, particularly renal disease, substantially increase the risk of subsequent severe illness and death. The prevalence of DN is still rising dramatically, with concomitant increases in associated mortality and cardiovascular complications.

SUMMARY

Renal involvement in type 1 and type 2 diabetes reflects a complex pathogenesis. Various genetic and environmental factors determine the susceptibility and progression to advanced stages of the disease. DN should be considered in patients who have had type 1 diabetes for at least 10 years with microalbuminuria and diabetic retinopathy, as well as in patients with type 1 or type 2 diabetes with macroalbuminuria in whom other causes for proteinuria are absent. The glomerular characteristic features include mesangial expansion, thickened glomerular basement membrane, and hyalinosis of arterioles. The optimal therapy of DN continues to evolve. For all diabetic patients, practical management including blood glucose and blood pressure control with renin-angiotensin-aldosterone blockade combined with lipid control, dietary salt restriction, lowering the dietary protein intake, increased physical activity, weight reduction, and smoking cessation can reduce the rate of progression of nephropathy and cardiovascular disease.

KEY MESSAGE

DN is a complex disease linking hemodynamic and metabolic pathways with oxidative stress, and systemic inflammation. We summarize the current evidence of epidemiology, clinical diagnosis, and the current management of DN in Western countries.

FACTS FROM EAST AND WEST

The prevalence of DN is increasing in Asia and Western countries alike. The deletion (D) allele of the angiotensin-converting enzyme gene is associated with progression to end-stage renal disease in Asian patients with DN, but this association is uncertain in Europeans. An association between DN and polymorphism of the gene coding for acetyl coenzyme A carboxylase β has been reported in Asian and Western populations. Both in Japan and the US, criteria for diagnosis are a 5-year history of diabetes and persistent albuminuria. Renal biopsy should be done in patients with severe hematuria, cellular casts and - in the US - hepatitis and HIV to rule out other pathologies. Diabetic retinopathy is considered a key criterion in Japan, but the absence of it does not rule out DN in the US. Enlargement of the kidney is observed as a diagnostic criterion in Japan. The differential use of renal biopsy as diagnostic tool might account for a different prevalence between Asian countries. Some Japanese diabetic patients show typical histological alterations for DN with a normal ACR and GFR. The clinical classification is similar between Japan and the US including five stages based on ACR and GFR. The Japanese guidelines do not include blood pressure values for the classification of DN. Guidelines for DN treatment are evolving quickly both in Asia and Western countries based on the numerous clinical trials performed worldwide. Targeting the angiotensin system for its hemodynamic and nonhemodynamic effects is a common approach. DPP-4 inhibitors are widely used in Japan and might have a higher glucose-lowering effect in Asian patients due to their specific diet. A randomized, double-blind placebo-controlled study has been launched to assess the efficacy of the Chinese herbal tea extract Shenyan Kangfu in DN.

Diabetic kidney disease: a clinical update from Kidney Disease: Improving Global Outcomes

The incidence and prevalence of diabetes mellitus (DM) continue to grow markedly throughout the world, due primarily to the increase in type 2 DM (T2DM). Although improvements in DM and hypertension management have reduced the proportion of diabetic individuals who develop chronic kidney disease (CKD) and progress to end-stage renal disease (ESRD), the sheer increase in people developing DM will have a major impact on dialysis and transplant needs. This KDIGO conference addressed a number of controversial areas in the management of DM patients with CKD, including aspects of screening for CKD with measurements of albuminuria and estimated glomerular filtration rate (eGFR); defining treatment outcomes; glycemic management in both those developing CKD and those with ESRD; hypertension goals and management, including blockers of the renin-angiotensin-aldosterone system; and lipid management.

Comprehensive approach to diabetic nephropathy

Diabetic nephropathy (DN) is a leading cause of mortality and morbidity in patients with diabetes. This complication reflects a complex pathophysiology, whereby various genetic and environmental factors determine susceptibility and progression to end-stage renal disease. DN should be considered in patients with type 1 diabetes for at least 10 years who have microalbuminuria and diabetic retinopathy, as well as in patients with type 1 or type 2 diabetes with macroalbuminuria in whom other causes for proteinuria are absent. DN may also present as a falling estimated glomerular filtration rate with albuminuria as a minor presenting feature, especially in patients taking renin-angiotensin-aldosterone system inhibitors (RAASi). The pathological characteristic features of disease are three major lesions: diffuse mesangial expansion, diffuse thickened glomerular basement membrane, and hyalinosis of arterioles. Functionally, however, the pathophysiology is reflected in dysfunction of the mesangium, the glomerular capillary wall, the tubulointerstitium, and the vasculature. For all diabetic patients, a comprehensive approach to management including glycemic and hypertensive control with RAASi combined with lipid control, dietary salt restriction, lowering of protein intake, increased physical activity, weight reduction, and smoking cessation can reduce the rate of progression of nephropathy and minimize the risk for cardiovascular events. This review focuses on the latest published data dealing with the mechanisms, diagnosis, and current treatment of DN.

Renal outcomes in patients with type 1 diabetes and macroalbuminuria

Macroalbuminuria, defined as urine albumin excretion rate (AER)≥300 mg/d, has long been considered a stage of irreversible kidney damage that leads reliably to GFR loss. We examined the long-term renal outcomes of persons with type 1 diabetes who developed incident macroalbuminuria during the Diabetes Control and Complications Trial (DCCT)/Epidemiology of Diabetes Interventions and Complications (EDIC) study. One hundred fifty-nine participants developed incident macroalbuminuria and were subsequently followed for a median duration of 9 years (maximum of 25 years). At the time of macroalbuminuria diagnosis, mean (SD) age was 37 (9) years, mean (SD) duration of diabetes was 17 (5) years, median AER was 524 mg/d, and mean (SD) eGFR was 108 (20) ml/min per 1.73 m(2). Ten years after macroalbuminuria diagnosis, the cumulative incidence of a sustained reduction in AER to <300 mg/d was 52%, mostly but not entirely under treatment with renin-angiotensin system inhibitors. The cumulative incidence of impaired GFR (sustained eGFR<60 ml/min per 1.73 m(2)) 10 years after macroalbuminuria diagnosis was 32%, including 16% who developed ESRD. Lower hemoglobin A1c and BP and regression to AER<300 mg/d were associated with reduced risk of developing impaired GFR. In conclusion, people with type 1 diabetes who develop macroalbuminuria are at high risk of progressive kidney disease. However, through at least 10 years of follow-up, AER could often be controlled, and GFR frequently remained in the normal range.

Improved glycemic control and risk of ESRD in patients with type 1 diabetes and proteinuria

Most patients with type 1 diabetes (T1D) and proteinuria have poor glycemic control and a high risk of ESRD. We investigated whether long-term improvement of glycemic control reduces risk of ESRD in a prospective 7- to 15-year follow-up observation of 349 patients with CKD stages 1-3 enrolled in the Joslin Proteinuria Cohort of adults with T1D. All patients developed proteinuria between 1990 and 2004 and were followed until 2011 to ascertain onset of ESRD and deaths unrelated to ESRD. Furthermore, we analyzed data from 279 patients with ≥3 years of clinic follow-up available to assess the level of glycemic control after enrollment. Average HbA1c during the 5 years before study enrollment (prebaseline) was compared with HbA1c (postbaseline) averaged during the first half of follow-up (median, 5.1 years). Median prebaseline HbA1c was 9.3%, decreasing to 8.7% postbaseline. Cumulative risk of ESRD after 15 years was significantly lower for patients whose HbA1c decreased than for those whose HbA1c increased or remained poor (29% versus 42%; P<0.001). The difference between these groups was not visible at 5 years of follow-up but became visible at 10 and 15 years of follow-up. In multivariate Cox regression analysis of ESRD risk, the hazard ratio corresponding to a 1-percentage point improvement in postbaseline HbA1c was 0.76 (95% confidence interval, 0.63 to 0.91; P=0.003). In conclusion, results of this study suggest that long-term sustained improvement in HbA1c decelerates eGFR loss and delays the onset of ESRD in patients with T1D and proteinuria.

Estimated glomerular filtration rate decline is a better risk factor for outcomes of systemic disease-related nephropathy than for outcomes of primary renal diseases

BACKGROUND

Currently, the contribution of kidney function decline in renal and patient outcomes is unclear. There are few data on the associations of different etiologies of estimated glomerular filtration rate (eGFR) decline with outcomes in multidisciplinary care. The purpose of this investigation was to establish whether eGFR decline in patients with disease is an important risk factor for developing end-stage renal disease (ESRD) and death.

METHODS

From December 1, 2001 to December 31, 2011, 5097 adults with chronic kidney disease (CKD) received biochemical tests, physical examinations, a pathological examination, and a comprehensive questionnaire. We used linear regression models and multivariate Cox proportional hazards model to examine the outcome of eGFR decline in renal diseases with different etiologies.

RESULTS

Mean age was 68.1±16.1 (standard deviation, SD) years, and 63.3% patients were male. In the studied cohort, 58.2% of the patients had systemic disease-related nephropathy (SDRN), 29.4% had primary renal diseases (PRDs), and 12.4% had other etiologies. The eGFR decline in SDRN had a significant association with dialysis in the Cox proportional hazards model [crude hazard ratio (HR) = 1.07, 95% confidence interval (CI), 1.04 to 1.10; adjusted HR 1.05, 95% CI, 1.02 to 1.08]. Diabetic nephropathy (DN) had the most severe eGFR decline in CKD stages 3, 4, and 5, and all contributed to the initiation of dialysis and death regardless of whether DN with or without eGFR decline was considered to be the cause. Although hypertensive nephropathy (HN) was related to significant acceleration of eGFR decline, it did not lead to poor outcome. There were still discrepancies between eGFR decline and outcomes in PRDs, hypertensive nephropathy, and lupus nephritis.

CONCLUSIONS

eGFR decline and CKD staging provide an informative guide for physicians to make proper clinical judgments in the treatment of CKD, especially SDRN. Poor control of the underlying systemic disease will thus lead to more rapid progression of SDRN.

Renal function is ameliorated in a diabetic nephropathy rat model through a duodenal-jejunal bypass

AIMS

Diabetes surgery is growing in popularity and has been shown to have marked effects on diabetes. However, several studies have shown it may induce some renal injury, and, currently, the impact of diabetes surgery on renal function is unclear. In this study, we examined renal function and histological changes in rats with diabetic nephropathy (DN) following a duodeno-jejunal bypass (DJB) operation.

METHODS

Rats with streptozotocin (STZ)-induced diabetes were randomly assigned to 3 groups: DJB group (DJB), Sham-DJB group (S-DJB) and diabetes group (DM). Six age-matched normal rats were assigned as the control group. DJB and sham surgery were performed. Body weight, food intake, glucose levels, lipid parameters, cystatin C (Cys_C) levels, serum and urinary creatinine, 24h urine albumin excretion rate (UAER) and glomerular filtration rate (GFR) were measured. Histological analysis and immunohistochemical studies of renal sections were also performed.

RESULTS

DJB ameliorated renal function by improving UAER, GFR and Cys_C levels 4 and 8 weeks after surgery. It also improved lipid metabolism by decreasing fasting total serum cholesterol (TC) and triglyceride (TG) levels. Immuno-staining of synaptopodin showed podocyte injury was also improved in DJB glomeruli compared with sham and DM groups. Histological analysis showed that the mesangial expansion was not significantly prevented 8 weeks after DJB surgery.

CONCLUSION

DJB ameliorated renal function in UAER and GFR but not mesangial expansion in a DN rat model. The improvement of renal function may be attributed to reversing the injury or loss of podocytes after DJB surgery.

Nephropathy in diabetes

The most common cause of end stage renal disease (ESRD) requiring dialysis is diabetes. Both environmental and genetic factors have been postulated as the risk factors of Diabetic Nephropathy (DN). Hyperglycemia-induced metabolic and hemodynamic pathways are recognized to be mediators of kidney injury. Multiple biochemical pathways have been postulated that explain how hyperglycemia causes tissue damage: Non-enzymatic glycation that generates advanced glycation end products, activation of protein kinase C, acceleration of the polyol pathway and oxidative stress. Three major histologic pathological changes occur in DN: Mesangial expansion, GBM thickening, and glomerular sclerosis. It now seems clear in targeting a therapeutic regimen to achieve blood glucose, blood pressure and proteunuric goals, dietary protein and salt restriction, weight reduction, aggressive lipid lowering, smoking cessation and exercise. Multiple intensive interventions reduce cardiovascular events as well as nephropathy by about half when compared with conventional multifactorial treatment.

KDOQI Clinical Practice Guideline for Diabetes and CKD: 2012 Update

The 2012 update of the Kidney Disease Outcomes Quality Initiative (KDOQI) Clinical Practice Guideline for Diabetes and Chronic Kidney Disease (CKD) is intended to assist the practitioner caring for patients with diabetes and CKD. Substantial high-quality new evidence has emerged since the original 2007 KDOQI guideline that could significantly change recommendations for clinical practice. As such, revisions of prior guidelines are offered that specifically address hemoglobin A(1c) (HbA(1c)) targets, treatments to lower low-density lipoprotein cholesterol (LDL-C) levels, and use of angiotensin-converting enzyme inhibitor (ACE-I) and angiotensin receptor blocker (ARB) treatment in diabetic patients with and without albuminuria. Treatment approaches are addressed in each section and the stated guideline recommendations are based on systematic reviews of relevant trials. Appraisal of the quality of the evidence and the strength of recommendations followed the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Limitations of the evidence are discussed and specific suggestions are provided for future research.

Pregnancy management of women with pregestational diabetes

Optimal glycemic control is pivotal to the successful outcome of diabetic pregnancy. The goals for glycemic control include levels for preprandial and postprandial glucose and HbA1c as well as avoidance of severe hypoglycemia. These goals are best obtained with diet, exercise, and insulin treatment, often a multiple-dose insulin regimen or insulin pump. A focus on blood pressure, microalbuminuria, diabetic nephropathy, and diabetic retinopathy is needed.

Glycemic control and burnt-out diabetes in ESRD

Treatment of early diabetes mellitus, the most common cause of chronic kidney disease (CKD), may prevent or slow the progression of diabetic nephropathy and lower mortality and the incidence of cardiovascular disease in the general diabetic population and in patients with early stages of CKD. It is unclear whether glycemic control in patients with advanced CKD, including those with end-stage renal disease (ESRD) who undergo maintenance dialysis treatment is beneficial. Aside from the uncertain benefits of treatment in ESRD, hypoglycemic interventions in this population are also complicated by the complex changes in glucose homeostasis related to decreased kidney function and to dialytic therapies, occasionally leading to spontaneous resolution of hyperglycemia and normalization of hemoglobin A1c levels, a condition which might be termed "burnt-out diabetes." Further difficulties in ESRD are posed by the complicated pharmacokinetics of antidiabetic medications and the serious flaws in our available diagnostic tools used for monitoring long-term glycemic control. We review the physiology and pathophysiology of glucose homeostasis in advanced CKD and ESRD, the available antidiabetic medications and their specifics related to kidney function, and the diagnostic tools used to monitor the severity of hyperglycemia and the therapeutic effects of available treatments, along with their deficiencies in ESRD. We also review the concept of burnt-out diabetes and summarize the findings of studies that examined outcomes related to glycemic control in diabetic ESRD patients, and emphasize areas in need of further research.

Large kidneys predict poor renal outcome in subjects with diabetes and chronic kidney disease

Background

Renal hypertrophy occurs early in diabetic nephropathy, its later value is unknown. Do large kidneys still predict poor outcome in patients with diabetes and Chronic Kidney Disease (CKD)?

Methods

Seventy-five patients with diabetes and CKD according to a Glomerular Filtration Rate (GFR, by 51Cr-EDTA clearance) below 60 mL/min/1.73 m² or an Albumin Excretion Rate above 30 mg/24 H, had an ultrasound imaging of the kidneys and were cooperatively followed during five years by the Diabetology and Nephrology departments of the Centre Hospitalier Universitaire de Bordeaux.

Results

The patients were mainly men (44/75), aged 62 ± 13 yrs, with long-standing diabetes (duration:17 ± 9 yrs, 55/75 type 2), and CKD: initial GFR: 56.5 (8.5-209) mL/min/1.73 m², AER: 196 (20-2358) mg/24 H. Their mean kidney lenght (108 ± 13 mm, 67-147) was correlated to the GFR (r = 0.23, p < 0.05). During the follow-up, 9/11 of the patients who had to start dialysis came from the half with the largest kidneys (LogRank: p < 0.05), despite a 40% higher initial isotopic GFR. Serum creatinine were initially lower (Small kidneys: 125 (79-320) μmol/L, Large: 103 (50-371), p < 0.05), but significantly increased in the "large kidneys" group at the end of the follow-up (Small kidneys: 129 (69-283) μmol/L, Large: 140 (50-952), p < 0.005 vs initial). The difference persisted in the patients with severe renal failure (KDOQI stages 4,5).

Conclusions

Large kidneys still predict progression in advanced CKD complicating diabetes. In these patients, ultrasound imaging not only excludes obstructive renal disease, but also provides information on the progression of the renal disease.

The epidemic challenge of chronic kidney disease in older patients

Since the introduction of estimated glomerular filtration rate (GFR), the number of patients with chronic kidney disease (CKD) has considerably increased. This is particularly true for elderly patients as the majority have a low GFR. Chronic kidney disease has a significant impact on a patient's outcome. We have reviewed important aspects of CKD in older patients, with emphasis on diagnosis and management, as well as explored decision-making regarding specialist-care referral and renal replacement therapy.

How reliable is estimation of glomerular filtration rate at diagnosis of type 2 diabetes?

OBJECTIVE

The Cockcroft-Gault (CG) and Modification of Diet in Renal Disease (MDRD) equations previously have been recommended to estimate glomerular filtration rate (GFR). We compared both estimates with true GFR, measured by the isotopic (51)Cr-EDTA method, in newly diagnosed, treatment-naïve subjects with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 292 mainly normoalbuminuric (241 of 292) subjects were recruited. Subjects were classified as having mild renal impairment (group 1, GFR <90 ml/min per 1.73 m(2)) or normal renal function (group 2, GFR >/=90 ml/min per 1.73 m(2)). Estimated GFR (eGFR) was calculated by the CG and MDRD equations. Blood samples drawn at 44, 120, 180, and 240 min after administration of 1 MBq of (51)Cr-EDTA were used to measure isotopic GFR (iGFR).

RESULTS

For subjects in group 1, mean (+/-SD) iGFR was 83.8 +/- 4.3 ml/min per 1.73 m(2). eGFR was 78.0 +/- 16.5 or 73.7 +/- 12.0 ml/min per 1.73 m(2) using CG and MDRD equations, respectively. Ninety-five percent CIs for method bias were -11.1 to -0.6 using CG and -14.4 to -7.0 using MDRD. Ninety-five percent limits of agreement (mean bias +/- 2 SD) were -37.2 to 25.6 and -33.1 to 11.7, respectively. In group 2, iGFR was 119.4 +/- 20.3 ml/min per 1.73 m(2). eGFR was 104.4 +/- 26.3 or 92.3 +/- 18.7 ml/min per 1.73 m(2) using CG and MDRD equations, respectively. Ninety-five percent CIs for method bias were -17.4 to -12.5 using CG and -29.1 to -25.1 using MDRD. Ninety-five percent limits of agreement were -54.4 to 24.4 and -59.5 to 5.3, respectively.

CONCLUSIONS

In newly diagnosed type 2 diabetic patients, particularly those with a GFR >/=90 ml/min per 1.73 m(2), both CG and MDRD equations significantly underestimate iGFR. This highlights a limitation in the use of eGFR in the majority of diabetic subjects outside the setting of chronic kidney disease.

Nutritional status in patients with diabetes and chronic kidney disease: a prospective study

BACKGROUND

A poor nutritional status reduces the life expectancy of diabetes patients undergoing hemodialysis.

OBJECTIVE

The study objective was to specify the nutritional outcome in patients with chronic kidney disease (CKD) and well-controlled diabetes.

DESIGN

Forty-five diabetes patients with CKD were enrolled in a cooperative-care program designed to control glucose, blood pressure, LDL cholesterol, and the albumin excretion rate (AER). Their glomerular filtration rate (GFR), body composition, serum albumin (SA), and resting energy expenditure were assessed and compared at baseline and 2 y later.

RESULTS

Thirty-five patients did not start dialysis. Their glycated hemoglobin, blood pressure, LDL cholesterol, and AER improved; their GFR declined slowly (-3.3 mL x min(-1) x 1.73 m(-2) x y(-1)). Their body mass index (BMI), lean body mass, and SA increased. The GFR decline was correlated negatively with the initial BMI (r = -0.37, P < 0.05) and positively with the initial GFR (r = 0.34, P < 0.05). Ten patients started hemodialysis: except for higher total body water (P < 0.05) and extracellular volume (P < 0.01), their initial nutritional status did not differ significantly from that of 10 patients with comparable baseline severe CKD but without dialysis. At the second evaluation, patients on hemodialysis lost lean body mass, and their SA was lower than that of the patients with severe CKD (P = 0.05); lean body mass was unchanged and SA was higher (P = 0.01) in the patients with severe CKD. No significant difference was detected for resting energy expenditure.

CONCLUSIONS

Nutritional status improved in CKD patients with well-controlled diabetes without dialysis, and it deteriorated in patients who started dialysis. A high initial BMI was associated with a slower decline in GFR.

Glucose control influences glomerular filtration rate and its prediction in diabetic subjects

OBJECTIVE

Hyperglycemia increases glomerular filtration rate (GFR), but the influence of HbA(1c) (A1C) on GFR and GFR's prediction by recommended equations remains to be determined.

RESEARCH DESIGN AND METHODS

In 193 diabetic patients, we searched for an association between A1C and isotopically measured GFR (51Cr-EDTA) and their predictions by the Cockcroft and Gault formula (CG) and the modification of diet in renal disease (MDRD) equation. Their accuracy for the diagnosis of moderate (GFR <60 ml/min per 1.73 m(2)) or severe (GFR <30 ml/min per 1.73 m(2)) renal failure was compared from receiver operating characteristic (ROC) curves, before and after categorizing the patients as well (A1C <or=8%) or poorly controlled.

RESULTS

The mean GFR was 57.0 +/- 34.8 ml/min per 1.73 m(2) and was well correlated with both estimations (CG r = 0.75, MDRD r = 0.83; P < 0.05). The areas under the ROC curves were higher with the MDRD (P < 0.05). A1C was correlated (P < 0.001) with the GFR (r = 0.29), MDRD (r = 0.38), CG (r = 0.26), and the absolute differences between the GFR and their CG but not MDRD estimations (r = 0.17, P < 0.05). Each +1% A1C was associated with +6.0 ml/min per 1.73 m(2) GFR (CG +5.6, MDRD +5.3). After separating well-controlled (n = 88, A1C 7.0 +/- 0.7%) and poorly controlled (n = 105, 9.6 +/- 1.3%) patients, the diagnostic accuracies were better (P < 0.05) for the MDRD, except for the diagnosis of moderate renal failure in well-controlled patients (NS).

CONCLUSIONS

GFR and its estimations correlate with A1C. Although the relations between GFR and its estimations were not affected by the degree of glucose control, the precision and diagnostic accuracy of the CG formula were diminished for A1C >8%. The MDRD equation was more accurate and robust in diabetic patients with impaired renal function.

[Effect of glycemic control on microalbuminuria and arterial blood pressure in patients with type 1 diabetes]

INTRODUCTION

Diabetic nephropathy is the leading cause of hypertension in type 1 diabetes. Microalbuminuria is usually the first manifestation of renal disease and antedate hypertension. The aim of this study was to investigate relationships between glycemic control, hypertension and microalbuminuria in type 1 diabetics.

MATERIAL AND METHODS

We studied 27 type 1 diabetics, 18 male and 9 female, aged 18-50 years, with a duration of diabetes <20 years. Glycemic control was assessed using glycosylated hemoglobin (HbA1c) measurements, fructosamine and lipid analysis. 24-h urinary albumin excretion rate was evaluated by radioimmunoassay. Patients with persistent urinary albumin excretion rate 30-300 mg/24 h were defined as microalbuminuric (Group A--41% patients) and lower than that, as normoalbuminuric (Group B--59%). We examined them twice: first in poor glycemic control and then in good glycemic control.

RESULTS

We found significant differences (Student's t-test) between groups in regard to microalbuminuria (p <0.01), diabetes duration (p=0.05), systolic blood pressure (BP) and diastolic BP (p<0.05). Systolic BP (p<0.01), diastolic BP (p<0.01) and microalbuminuria (p=0.05) positively correlated (Spearman's rho) with poor glycemic control in Group A. In both groups there was a significant improvement in glycemic control and regression in systolic and diastolic BP (p<0.01), but only Group B showed significant reduction in urinary albumnin excretion rate (p<0.01).

DISCUSSION AND CONCLUSION

In this study, type 1 diabetics showed regression in systolic and diastolic hypertension with improvements of glycemic control regardless of presence of microalbuminuria, but only normoalbuminuric showed significant reduction in urinary albumin excretion rate.

[Relationship between low glomerular filtration rate, hypertension, and microalbuminuria in type 1 diabetes mellitus]

AIM

To investigate the influence of low glomerular filtration rate, as well as of systolic and diastolic hypertension, on microalbuminuria in patients with type 1 diabetes mellitus.

METHODS

Twenty seven patients with type 1 diabetes mellitus (18 males, 9 females) were studied. All of the patients were below 50 years of age. In 93% of the cases, the duration of diabetes was less than 15 years. GFR was determined, after intravenous injection in the lying position, by using a 99m-Tc-DTPA, while microalbuminuria was calculated for the 24-hour urine using the nephelometric immunoassay (30-300 mg/24 h). The patients were divided into 3 groups according to the value of GFR. The values ranged from 90 to 125 ml/min/1.73 m2 were considered normal (in 63% of the patients in group 1), those above that range were considered as hyperfiltration (in 22.2% of the patients in group 2), while those below that range were considered as hypofiltration (in 13.8% of the patient in group 3).

RESULTS

Data analyzed with the one-way ANOVA, indicated a significant statistical difference between the 3 groups in the duration of diabetes (p < 0.05), micro-albuminuria (p < 0.01), systolic BP (p < 0.01), diastolic BP (p < 0.05), fructosamine (p = 0.50), urea (p < 0.05), creatinine (p = 0.05), and uric acid (p < 0.05). Microalbuminuria correlated with the age of patients (p <0.05) (Spearman's rho), diabetes mellitus duration (p < 0.01), systolic BP (p < 0.05), diastolic BP (p < 0.05), LDL-cholesterol (p < 0.05). There was no statistically significant correlation between GFR and the other parameters. Hypertension, microalbuminuria, and the duration of diabetes correlated positively with the reduction of GFR, revealing the most frequent reduction of GFR in the patients with more than 15-year duration of diabetes.

CONCLUSIONS

Hypertension and low GFR were associated with microalbuminuria in type 1 diabetes, while the duration of diabetes was shown to be the independent risk factor for the development of microalbuminuria.

Long-term exposure of proximal tubular epithelial cells to glucose induces transforming growth factor-beta 1 synthesis via an autocrine PDGF loop

We have recently reported increased transforming growth factor (TGF)-beta1 gene transcription in proximal tubular cells within 12 hours of exposure to 25 mmol/L D-glucose, with a requirement for a second stimulus such as platelet-derived growth factor (PDGF) to increase its translation in short-term experiments. In the current study we investigated the effect on TGF-beta 1 production of prolonged exposure of proximal tubular cells to high glucose concentrations. Enzyme-linked immunosorbent assay of cell culture supernatant showed significant increase in latent TGF-beta 1 only after 7 days exposure to high glucose. Radiolabeling of glucose-stimulated cells with (3)H amino acids and subsequent immunoprecipitation of TGF-beta 1 demonstrated de novo synthesis from day 5 of high glucose exposure onwards. Similarly, polysome analysis showed enhanced translation of TGF-beta mRNA after 4 or more days of high glucose exposure. TGF-beta 1 synthesis, following addition of glucose, was inhibited by blockade of the PDGF-alpha receptor subunit. Glucose did not alter PDGF expression, nor expression of PDGF alpha-receptors. Activation of the receptor following addition of 25 mm D-glucose could be demonstrated suggesting increased sensitivity to endogenous PDGF. Exposure to glucose activated p38MAP kinase, and inhibition of this activation abrogated both glucose induced TGF-beta 1 transcriptional activation and TGF-beta 1 synthesis. Inhibition of p38MAP kinase did not influence the effect of exogenous PDGF when cells were stimulated sequentially by glucose and PDGF. We postulate that glucose induces an early increase in TGF-beta 1 transcription via activation of p38MAP kinase. In addition, glucose causes a late increase in PDGF-dependent TGF-beta 1 translation by enhancing cellular sensitivity to PDGF. This provides a potential explanation for the clinical observation that prolonged poor glycemic control may contribute to progression of diabetic nephropathy.

Cost-effective strategies in the prevention of diabetic nephropathy

A significant subgroup of patients with diabetes mellitus are predisposed to developing diabetic nephropathy and it is in this subgroup that other diabetes- related complications, and in particular greatly increased cardiovascular disease risk, are concentrated. The high personal, social and financial costs of managing end-stage renal failure and the other complications associated with diabetic nephropathy make a powerful case for screening and effective intervention programmes to prevent the condition or retard its progression. As major breakthroughs in finding genetic susceptibility factors remain elusive, screening efforts continue to be based on microalbuminuria testing, despite increasing recognition of its limitations as a positive predictor of nephropathy. Interventions have been extensively studied, but results remain conflicting. Economic evaluations of such screening and intervention programmes are essential for health planners, yet models of the cost/benefit ratio of such interventions often rely on a rather slim evidence base. Where economic models are developed, they are frequently based on those papers that propound the greatest clinical benefits of a given intervention, leading to a possible over-estimation of the advantages of the chosen approach. Furthermore, the benefits of even such generally accepted interventions as ACE inhibitor treatment are less firmly established than generally appreciated. Lifestyle interventions are instinctively attractive, but are by no means a low-cost option (as is often assumed by both medical professionals and politicians). This review critically assesses the evidence for clinical efficacy and economic benefit of microalbuminuria screening and interventions such as intensive glycaemic control, antihypertensive treatment, ACE inhibition and angiotensin receptor blockade, dietary protein restriction and lipid-modifying therapy. The various costs associated with diabetic nephropathy are so great that even expensive interventions may have a favourable cost/benefit ratio, provided they are truly effective.

The role of renal proximal tubular cells in diabetic nephropathy

We now know that the rate of progression of diabetic nephropathy, like all progressive renal disease, correlates with the degree of corticointerstitial fibrosis. Therefore, much interest has focused on the contribution of the resident cells in the renal cortex to this process. This article reviews the evidence that the epithelial cells of the proximal tubule are major players in orchestrating events in the corticointerstitium in diabetic nephropathy. More specifically, it addresses their role in extracellular matrix turnover, generation of cytokines, and recruitment of inflammatory cells, as well as examining the concept that they are the source of the interstitial myofibroblasts, which are the principal mediators of the fibrotic process.

A novel potential therapy for diabetic nephropathy and vascular complications: protein kinase C beta inhibition

Diabetic nephropathy is one of the most common microvascular complications of diabetes mellitus and the leading cause of end-stage renal disease in developed countries. Current treatment includes glycemic control, blood pressure control (with special emphasis on agents targeting the renin-angiotensin system), a low-protein (0.6 to 0.8 g/kg) diet, and the use of hypolipidemic agents. Although these therapeutic options may slow progression, the burden of disease remains large, and additional therapeutic agents are urgently needed. Ruboxistaurin (LY333531) mesylate is a bisindolylmaleimide that shows a high degree of specificity within the protein kinase C (PKC) gene family for inhibiting PKC beta isoforms. In animal models of diabetes, including the streptozotocin (STZ) rat, Lepr(db)/Lepr(db) mouse, and STZ-Ren 2 rat models, ruboxistaurin normalized glomerular hyperfiltration, decreased urinary albumin excretion, and reduced glomerular transforming growth factor-beta1 and extracellular matrix protein production. As a result, improvements were noted in mesangial expansion, glomerulosclerosis, tubulointerstitial fibrosis, and renal function. Other studies using less specific probes of PKC activity also have shown an important role for PKC in the development of diabetic nephropathy and a close relationship to pathways believed to be important in its pathogenesis. Inhibition of PKC beta, a common signaling molecule in diabetes-related renal and vascular injury, holds promise as a novel strategy to improve microvascular and macrovascular outcomes in diabetes. Such therapies are needed to reduce the occurrence of devastating diabetic complications.

Nephrin expression is reduced in human diabetic nephropathy: evidence for a distinct role for glycated albumin and angiotensin II

We studied the distribution of nephrin in renal biopsies from 17 patients with diabetes and nephrotic syndrome (7 type 1 and 10 type 2 diabetes), 6 patients with diabetes and microalbuminuria (1 type 1 and 5 type 2 diabetes), and 10 normal subjects. Nephrin expression was semiquantitatively evaluated by measuring immunofluorescence intensity by digital image analysis. We found an extensive reduction of nephrin staining in both type 1 (67 +/- 9%; P < 0.001) and type 2 (65 +/- 10%; P < 0.001) diabetic patients with diabetes and nephrotic syndrome when compared with control subjects. The pattern of staining shifted from punctate/linear distribution to granular. In patients with microalbuminuria, the staining pattern of nephrin also showed granular distribution and reduction intensity of 69% in the patient with type 1 diabetes and of 62 +/- 4% (P < 0.001) in the patients with type 2 diabetes. In vitro studies on human cultured podocytes demonstrated that glycated albumin and angiotensin II reduced nephrin expression. Glycated albumin inhibited nephrin synthesis through the engagement of receptor for advanced glycation end products, whereas angiotensin II acted on cytoskeleton redistribution, inducing the shedding of nephrin. This study indicates that the alteration in nephrin expression is an early event in proteinuric patients with diabetes and suggests that glycated albumin and angiotensin II contribute to nephrin downregulation.

Treatment of diabetic nephropathy in its early stages

Diabetic nephropathy is one of the most frequent causes of end-stage renal disease (ESRD), and, in recent years, the number of diabetic patients entering renal replacement therapy has dramatically increased. The magnitude of the problem has led to numerous efforts to identify preventive and therapeutic strategies. In normoalbuminuric patients, optimal glycemic control (HbA(1c) lower than 7.5%) plays a fundamental role in the primary prevention of ESRD [weighted mean relative risk reduction (RRR) approximately 37% for metabolic control versus trivial renoprotection for intensive anti-hypertensive therapy or ACE-inhibitors (ACE-I)]. In the microalbuminuric stage, strict glycemic control probably reduces the incidence of overt nephropathy (weighted mean RRR approximately 50%), while blood pressure levels below 130/80 mmHg are recommended according to the average blood pressure levels obtained in various studies. In normotensive patients, ACE-I markedly reduce the development of overt nephropathy almost regardless of blood pressure levels; in hypertensive patients, ACE-I are less clearly active (weighted mean RRR approximately 23% versus other drugs), whereas angiotensin-receptor blockers (ARB) appear strikingly renoprotective. Once overt proteinuria appears, it is uncertain whether glycemic control affects the progression of nephropathy. In type 1 diabetes, various anti-hypertensive treatments, mainly ACE-I, are effective in slowing down the progression of nephropathy; in type 2 diabetes, two recent studies demonstrate that ARB are superior to conventional therapy or calcium channel blockers (CCB). In clinical practice, pharmacological tools are not always used to the best benefit of the patients. Therefore, clinicians and patients need to be educated regarding the renoprotection of drugs inhibiting the renin-angiotensin system (RAS) and the overwhelming importance of achieving target blood pressure.

The relationship between glucose control and the development and progression of diabetic nephropathy

Diabetic nephropathy is a major cause of morbidity and mortality in patients with diabetes; it occurs in about one third of such patients. The course of nephropathy is better defined and similar for both type 1 and type 2 diabetes. Patients initially develop microalbuminuria (albumin excretion rates [AERs] between 20 and 200 micrograms/min), then overt nephropathy (AER > or = 200 micrograms/min), and finally a decline in glomerular filtration rate (GFR) eventuating in end-stage renal disease. Although metabolic control has long been hypothesized as a contributor to the development of nephropathy, it is only in recent years that this hypothesis has been proven. A number of observational studies have shown correlations between glycemic control and the development of various levels of albuminuria and also declines in GFR. However, large long-term prospective, randomized, interventional studies have now definitely proven that improved metabolic control that achieves near-normoglycemia can significantly decrease the development and progression of diabetic nephropathy as well as other long-term complications of diabetes, including retinopathy and neuropathy. It is now conceivable that the achievement of near-normoglycemia, plus medications that inhibit the renin-angiotensin system if microalbuminuria develops, may greatly decrease the numbers of patients eventually requiring renal replacement therapy.

Blood pressure control--effects on diabetic nephropathy progression: how low does blood pressure have to be?

Hypertension and diabetes are independent risk factors for both cardiovascular disease and renal complications. Coexistence of these comorbid conditions predisposes the patient to a much greater risk of progression to end-stage renal disease. Combined with the increased cardiovascular mortality, this has led to recent Joint National Committee-VI recommendations for the initiation of antihypertensive therapy for people with diabetes at a blood pressure of 130/85 mm Hg, a level lower than that recommended for the nondiabetic population. Results of a review of recently published investigations on the effects of blood pressure on diabetic nephropathy progression are presented in this article. This review finds evidence to support reducing the mean arterial blood pressure to levels below 95 mm Hg, a level that is even lower than the blood pressure of 130/80 mm Hg (mean arterial pressure of 97 mm Hg) recommended by the American Diabetes Association and National Kidney Foundation. The effect of blood pressure on renal disease progression is linear and appears to have no lower threshold for the benefits of blood pressure reduction on limiting nephropathy progression. The answer to the question of how low does blood pressure have to be to minimize the effects of blood pressure on diabetic nephropathy progression might be "the lower, the better."

Remission of nephrotic-range albuminuria in type 1 diabetic patients

OBJECTIVE

To evaluate the cumulative incidence of nephrotic-range albuminuria (NRA), the frequency of remission, and the impact on progression, we analyzed data from a prospective cohort study of type 1 diabetic patients with diabetic nephropathy.

RESEARCH DESIGN AND METHODS

All of the albuminuric type 1 diabetic patients (n = 321, 121 women), who had at least yearly measurements of glomerular filtration rate (GFR) with a (51)Cr-EDTA plasma clearance technique and were followed for at least 3 years, were evaluated. NRA, defined as persistent albuminuria >2,500 mg/24 h, occurred in 126 patients (35 women) aged (mean +/- SD) 34 +/- 8 years, with duration of diabetes 22 +/- 8 years and follow-up time from onset of NRA (median [range]) 8.7 (3.0-20.9) years. Remission of NRA was defined as sustained albuminuria <600 mg/24 h for at least 1 year.

RESULTS

The cumulative incidence of NRA was 39%. Remission was induced in 28 of 126 (22%) patients; 21 were predominantly treated with ACE inhibitors, 7 with non-ACE inhibitor medications. Remission lasted 3.6 (1.0-18.1) years. More women (37%) than men (16%) obtained remission (P = 0.01). In the remission group compared with the no-remission group, mean arterial blood pressure (mean +/- SEM) was reduced (102 +/- 1 vs. 106 +/- 1 mmHg, P < 0.01), the rate of decline in GFR was diminished (3.8 +/- 0.6 vs. 7.5 +/- 0.5 ml x min(-1) x year(-1), P < 0.001), and serum cholesterol was lower (5.3 +/- 0.2 vs. 6.1 +/- 0.1 mmol/l, P < 0.01) during the whole follow-up period. No difference in glycemic control was found between groups (HbA(1c) 9.2 vs. 9.4%, NS).

CONCLUSIONS

In contrast to observations made before the use of antihypertensive treatment, our prospective observational study suggests that aggressive antihypertensive treatment with and without ACE inhibitors can induce long-lasting remission in a sizeable fraction of type 1 diabetic patients with NRA. The group of patients obtaining remission is characterized by slow progression of diabetic nephropathy and improved cardiovascular risk profile.

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.

Risk of advanced diabetic nephropathy in type 1 diabetes is associated with endothelial nitric oxide synthase gene polymorphism

Risk of advanced diabetic nephropathy in type 1 diabetes is associated with endothelial nitric oxide synthase gene polymorphism.

BACKGROUND

Polymorphisms in the endothelial nitric oxide synthase gene (eNOS) may be implicated in the development of nephropathy in patients with type 1 or insulin-dependent diabetes mellitus (IDDM).

METHODS

Three groups of IDDM patients were selected to study this hypothesis: cases with advanced diabetic nephropathy (N = 78), cases with overt proteinuria but normal serum creatinine (N = 74), and controls with normoalbuminuria despite 15 years of diabetes (N = 195). Parents of 132 cases and 53 controls were also examined and were used for the transmission disequilibrium test, a family-based study design to test association.

RESULTS

We examined four eNOS polymorphisms, and two were associated with diabetic nephropathy in the case-control comparisons: a T to C substitution in the promoter at position -786 and the a-deletion/b-insertion in intron 4. For the former, the risk of developing advanced nephropathy was higher for C allele homozygotes than for the other two genotypes (odds ratio 2.8, 95% CI, 1.4 to 5.6). For the latter polymorphism, it was the a-deletion carriers that had the higher risk (odds ratio 2.3, 95% CI, 1.3 to 4.0) in comparison with noncarriers. Both polymorphisms were analyzed together as haplotypes in a family-based study using the transmission disequilibrium test. The C/a-deletion haplotype was transmitted from heterozygous parents to cases with advanced diabetic nephropathy with a significantly higher frequency than expected (P = 0.004).

CONCLUSION

The findings of the case-control and family-based studies demonstrate clearly that DNA sequence differences in eNOS influence the risk of advanced nephropathy in type 1 diabetes.

Effect of medical therapy on progressive nephropathy: influence of pregnancy, diabetes and hypertension

Nephropathy is a complication of diabetes mellitus that can affect women in their reproductive years. This article reviews the effects on treatment on the main factors associated with short- and long-term complications in pregnant women with diabetic nephropathy. Tight glycemic control, adequate treatment of elevated blood pressure, and renal function in early pregnancy are the most significant predictors of maternal and perinatal outcomes. Contemporary methods of perinatal care and adequate treatment of blood pressure allow fetal survival rates of 95%. Furthermore, pregnancy per se does not appear to worsen the natural progression to end-stage renal disease for most women with renal insufficiency. However, patients with moderate to severe renal impairment may experience acceleration of renal disease.

Prospective comparison of therapeutical attitudes in hypertensive type 2 diabetic patients uncontrolled on monotherapy. A randomized trial: the EDICTA study

OBJECTIVE

To compare the anti-hypertensive effect of combination therapy versus a single drug regimen schedule (dose-titration or switching to a different drug class) in type 2 diabetic hypertensive patients with inadequate blood pressure (BP) control on monotherapy.

DESIGN

Prospective, randomized, open-fashion, parallel study of two therapeutic strategies during an 8-week period.

SETTING

Primary care centers in Spain.

PARTICIPANTS

A total of 898 men and women with type 2 diabetes mellitus and hypertension, receiving antihypertensive treatment with one single drug and whose BP was > 140 and/or 90 mmHg.

INTERVENTION

Patients were randomized to a fixed combination therapy (verapamil 180 mg plus trandolapril 2 mg; Knoll AG, Ludwigshafen, Germany) or continued on a single drug regimen, either increasing the dose of the current drug or switching to a different drug class.

MAIN OUTCOME MEASURE

Absolute BP reduction in the two groups of treatment, and the percentage of normalized patients (< 140/90 mmHg) in each group.

RESULTS

The diastolic BP (DBP) decrease (5.6 mmHg) was significantly greater in patients treated with combination therapy, compared to patients on monotherapy (2.9 mmHg). The decrease in systolic BP (SBP) was not significantly different (11.1 versus 10.0 mmHg). In addition, a significantly higher number of patients treated with combination therapy (82% versus 74%) reached diastolic BP normalization (< 90 mmHg).

CONCLUSIONS

In type 2 hypertensive patients with uncontrolled BP despite anti-hypertensive monotherapy, the change to combination therapy was more effective in attaining DBP control than any monotherapy schedule (either increasing the dose or switching to another different drug class).