Is screening and intervention for microalbuminuria worthwhile in patients with insulin dependent diabetes?

Screening, identifying, and treating chronic kidney disease: why, who, when, how, and what?

1 in 7 American adults have chronic kidney disease (CKD); a disease that increases risk for CKD progression, cardiovascular events, and mortality. Currently, the US Preventative Services Task Force does not have a screening recommendation, though evidence suggests that screening can prevent progression and is cost-effective. Populations at risk for CKD, such as those with hypertension, diabetes, and age greater than 50 years should be targeted for screening. CKD is diagnosed and risk stratified with estimated glomerular filtration rate utilizing serum creatinine and measuring urine albumin-to-creatinine ratio. Once identified, CKD is staged according to C-G-A classification, and managed with lifestyle modification, interdisciplinary care and the recently expanding repertoire of pharmacotherapy which includes angiotensin converting enzyme inhibitors or angiotensin-II receptor blockers, sodium-glucose-cotransporter-2 inhibitors, and mineralocorticorticoid receptor antagonists. In this paper, we present the why, who, when, how, and what of CKD screening.

Medical Costs Associated With Diabetes Complications in Medicare Beneficiaries Aged 65 Years or Older With Type 1 Diabetes

OBJECTIVE

To estimate medical costs associated with 17 diabetes complications and treatment procedures among Medicare beneficiaries aged ≥65 years with type 1 diabetes.

RESEARCH DESIGN AND METHODS

With use of the 2006-2017 100% Medicare claims database for beneficiaries enrolled in fee-for-service plans and Part D, we estimated the annual cost of 17 diabetes complications and treatment procedures. Type 1 diabetes and its complications and procedures were identified using ICD-9/ICD-10, procedure, and diagnosis-related group codes. Individuals with type 1 diabetes were followed from the year when their diabetes was initially identified in Medicare (2006-2015) until death, discontinuing plan coverage, or 31 December 2017. Fixed-effects regression was used to estimate costs in the complication occurrence year and subsequent years. The cost proportion of a complication was equal to the total cost of the complication, calculated by multiplying prevalence by the per-person cost divided by the total cost for all complications. All costs were standardized to 2017 U.S. dollars.

RESULTS

Our study included 114,879 people with type 1 diabetes with lengths of follow-up from 3 to 10 years. The costliest complications per person were kidney failure treated by transplant ($77,809 in the occurrence year and $13,556 in subsequent years), kidney failure treated by dialysis ($56,469 and $41,429), and neuropathy treated by lower-extremity amputation ($40,698 and $7,380). Sixteen percent of the total medical cost for diabetes complications was for treating congestive heart failure.

CONCLUSIONS

Costs of diabetes complications were large and varied by complications. Our results can assist in cost-effectiveness analysis of treatments and interventions for preventing or delaying diabetes complications in Medicare beneficiaries aged ≥65 years with type 1 diabetes.

Cost-effectiveness of Interventions to Manage Diabetes: Has the Evidence Changed Since 2008?

OBJECTIVE

To synthesize updated evidence on the cost-effectiveness (CE) of interventions to manage diabetes, its complications, and comorbidities.

RESEARCH DESIGN AND METHODS

We conducted a systematic literature review of studies from high-income countries evaluating the CE of diabetes management interventions recommended by the American Diabetes Association (ADA) and published in English between June 2008 and July 2017. We also incorporated studies from a previous CE review from the period 1985-2008. We classified the interventions based on their strength of evidence (strong, supportive, or uncertain) and levels of CE: cost-saving (more health benefit at a lower cost), very cost-effective (≤$25,000 per life year gained [LYG] or quality-adjusted life year [QALY]), cost-effective ($25,001-$50,000 per LYG or QALY), marginally cost-effective ($50,001-$100,000 per LYG or QALY), or not cost-effective (>$100,000 per LYG or QALY). Costs were measured in 2017 U.S. dollars.

RESULTS

Seventy-three new studies met our inclusion criteria. These were combined with 49 studies from the previous review to yield 122 studies over the period 1985-2017. A large majority of the ADA-recommended interventions remain cost-effective. Specifically, we found strong evidence that the following ADA-recommended interventions are cost-saving or very cost-effective: In the cost-saving category are 1) ACE inhibitor (ACEI)/angiotensin receptor blocker (ARB) therapy for intensive hypertension management compared with standard hypertension management, 2) ACEI/ARB therapy to prevent chronic kidney disease and/or end-stage renal disease in people with albuminuria compared with no ACEI/ARB therapy, 3) comprehensive foot care and patient education to prevent and treat foot ulcers among those at moderate/high risk of developing foot ulcers, 4) telemedicine for diabetic retinopathy screening compared with office screening, and 5) bariatric surgery compared with no surgery for individuals with type 2 diabetes (T2D) and obesity (BMI ≥30 kg/m²). In the very cost-effective category are 1) intensive glycemic management (targeting A1C <7%) compared with conventional glycemic management (targeting an A1C level of 8-10%) for individuals with newly diagnosed T2D, 2) multicomponent interventions (involving behavior change/education and pharmacological therapy targeting hyperglycemia, hypertension, dyslipidemia, microalbuminuria, nephropathy/retinopathy, secondary prevention of cardiovascular disease with aspirin) compared with usual care, 3) statin therapy compared with no statin therapy for individuals with T2D and history of cardiovascular disease, 4) diabetes self-management education and support compared with usual care, 5) T2D screening every 3 years starting at age 45 years compared with no screening, 6) integrated, patient-centered care compared with usual care, 7) smoking cessation compared with no smoking cessation, 8) daily aspirin use as primary prevention for cardiovascular complications compared with usual care, 9) self-monitoring of blood glucose three times per day compared with once per day among those using insulin, 10) intensive glycemic management compared with conventional insulin therapy for T2D among adults aged ≥50 years, and 11) collaborative care for depression compared with usual care.

CONCLUSIONS

Complementing professional treatment recommendations, our systematic review provides an updated understanding of the potential value of interventions to manage diabetes and its complications and can assist clinicians and payers in prioritizing interventions and health care resources.

Histological and biochemical effects of Cinnamomum cassia nanoparticles in kidneys of diabetic Sprague-Dawley rats

This study investigated the antidiabetic activity of Cinnamomum cassia (C. cassia, Cc) silver nanoparticles (CcAgNPS) and effects of C. cassia on the kidneys of rats with induced type 2 diabetes. Twenty-four Sprague-Dawley rats weighing 250 ± 20 g were induced with diabetes by intraperitoneal injection of streptozotocin (STZ, 60 mg/kg). Animals were randomly assigned to one of four groups (n = 6) and treated for eight weeks with normal saline (control, group A), 5 mg/kg of CcAgNPs (group B), 10 mg/kg of CcAgNPs (group C), or 200 mg/kg of Cc (group D). Body weight and fasting blood glucose (FBG) was measured weekly and fortnightly, respectively. At the end of experiments animals were euthanized, blood and kidney tissue samples were collected for biochemistry (oxidative stress markers and renal function parameters) and kidneys were harvested for histology (PAS and H.

Management of diabetic renal disease

Diabetic nephropathy is the leading cause of end stage renal failure (ESRF) worldwide, representing over 50% of patients on renal replacement therapy in some parts of the world. The condition is common in people with type 1 and type 2 diabetes, although the incidence appears to be declining, especially in type 1 diabetes. More than 1 in 3 people with type 2 diabetes have impaired kidney function. Advances in our understanding of the pathogenesis and natural history of the condition have enabled us to consider earlier therapy aimed at renal preservation and reduction in cardiovascular morbidity. Microalbuminuria is now established as the earliest risk marker for nephropathy in type 1 diabetes and cardiovascular disease in type 2 diabetes. This review examines the current concepts in the pathogenesis and management of diabetic nephropathy.

Novel Therapies of Diabetic Nephropathy

Diabetic nephropathy is currently the most common cause of end stage renal disease not only in the Western hemisphere but also in the developing nations. While the available therapeutic options remain not very effective, there is a strong ongoing effort to understand the pathogenesis better and develop more useful biomarkers. As the pathogenic mediators and signaling pathways get better defined, the scope of novel pharmaceutical agents to address such mediating factors as therapeutic targets is advancing. This review provides, in addition to a brief synopsis of currently used strategies, a comprehensive review of potential therapies that have been evolving in the past decade with a specific focus on the promising agents.

Cost-effectiveness of interventions to prevent and control diabetes mellitus: a systematic review

OBJECTIVE

To synthesize the cost-effectiveness (CE) of interventions to prevent and control diabetes, its complications, and comorbidities.

RESEARCH DESIGN AND METHODS

We conducted a systematic review of literature on the CE of diabetes interventions recommended by the American Diabetes Association (ADA) and published between January 1985 and May 2008. We categorized the strength of evidence about the CE of an intervention as strong, supportive, or uncertain. CEs were classified as cost saving (more health benefit at a lower cost), very cost-effective (<or=$25,000 per life year gained [LYG] or quality-adjusted life year [QALY]), cost-effective ($25,001 to $50,000 per LYG or QALY), marginally cost-effective ($50,001 to $100,000 per LYG or QALY), or not cost-effective (>$100,000 per LYG or QALY). The CE classification of an intervention was reported separately by country setting (U.S. or other developed countries) if CE varied by where the intervention was implemented. Costs were measured in 2007 U.S. dollars.

RESULTS

Fifty-six studies from 20 countries met the inclusion criteria. A large majority of the ADA recommended interventions are cost-effective. We found strong evidence to classify the following interventions as cost saving or very cost-effective: (I) Cost saving- 1) ACE inhibitor (ACEI) therapy for intensive hypertension control compared with standard hypertension control; 2) ACEI or angiotensin receptor blocker (ARB) therapy to prevent end-stage renal disease (ESRD) compared with no ACEI or ARB treatment; 3) early irbesartan therapy (at the microalbuminuria stage) to prevent ESRD compared with later treatment (at the macroalbuminuria stage); 4) comprehensive foot care to prevent ulcers compared with usual care; 5) multi-component interventions for diabetic risk factor control and early detection of complications compared with conventional insulin therapy for persons with type 1 diabetes; and 6) multi-component interventions for diabetic risk factor control and early detection of complications compared with standard glycemic control for persons with type 2 diabetes. (II) Very cost-effective- 1) intensive lifestyle interventions to prevent type 2 diabetes among persons with impaired glucose tolerance compared with standard lifestyle recommendations; 2) universal opportunistic screening for undiagnosed type 2 diabetes in African Americans between 45 and 54 years old; 3) intensive glycemic control as implemented in the UK Prospective Diabetes Study in persons with newly diagnosed type 2 diabetes compared with conventional glycemic control; 4) statin therapy for secondary prevention of cardiovascular disease compared with no statin therapy; 5) counseling and treatment for smoking cessation compared with no counseling and treatment; 6) annual screening for diabetic retinopathy and ensuing treatment in persons with type 1 diabetes compared with no screening; 7) annual screening for diabetic retinopathy and ensuing treatment in persons with type 2 diabetes compared with no screening; and 8) immediate vitrectomy to treat diabetic retinopathy compared with deferred vitrectomy.

CONCLUSIONS

Many interventions intended to prevent/control diabetes are cost saving or very cost-effective and supported by strong evidence. Policy makers should consider giving these interventions a higher priority.

N-terminal brain natriuretic peptide predicted cardiovascular events stronger than high-sensitivity C-reactive protein in hypertension: a LIFE substudy

BACKGROUND

N-terminal pro-brain natriuretic peptide (Nt-proBNP) and high-sensitivity C-reactive protein (hsCRP) are cardiovascular risk markers in various populations, but are not well examined in hypertension. Therefore, we wanted to investigate whether high Nt-proBNP or hsCRP predicted the composite endpoint of cardiovascular death, non-fatal stroke or non-fatal myocardial infarction independently of traditional cardiovascular risk factors and the urine albumin: creatinine ratio (UACR), which is a well established cardiovascular risk factor in hypertension.

METHODS

In 945 hypertensive patients from the LIFE study with electrocardiographic left ventricular (LV) hypertrophy, we measured traditional cardiovascular risk factors including electrocardiography, morning UACR, hsCRP by immunoturbidimetry assay and Nt-proBNP by immunoassay after 2 weeks of placebo treatment. During 55 months' follow-up 80 patients suffered a composite endpoint.

RESULTS

HsCRP as well as Nt-proBNP above the median values of 3.0 mg/l and 170 pg/ml, respectively, was associated with a higher incidence of composite endpoint (13.1 versus 3.8%, P < 0.01, and 11.5 versus 5.4%, P < 0.01). In Cox regression analyses, standardized log(hsCRP)/SD predicted a composite endpoint [hazard ratio (HR) 1.3 per SD = 0.47 log(mg/l), P < 0.05] after adjustment for traditional cardiovascular risk factors, but not after further adjustment for UACR. Standardized log(Nt-proBNP)/SD predicted a composite endpoint after adjustment for traditional cardiovascular risk factors [HR 1.9 per SD = 0.49 log(pg/ml), P < 0.05] as well as after further adjustment for UACR [HR 1.5 per SD = 0.49 log(pg/ml), P < 0.01]. Log(Nt-proBNP) added significantly to the Cox regression models using traditional cardiovascular risk factors with and without UACR (both P < 0.001).

CONCLUSION

Nt-proBNP predicted a composite endpoint after adjustment for traditional risk factors, UACR and a history of diabetes or cardiovascular disease and added significantly to the prediction of composite endpoint, whereas hsCRP did not.

Reductions in albuminuria and in electrocardiographic left ventricular hypertrophy independently improve prognosis in hypertension: the LIFE study

BACKGROUND

In the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study, reduced urine albumin/creatinine ratio (UACR) as well as regression of left ventricular hypertrophy have been associated with lower incidence of cardiovascular events. We wanted to investigate whether these prognostic improvements were independent.

METHODS

In 6679 hypertensive patients included in the LIFE study, we measured UACR, left ventricular hypertrophy by electrocardiography, serum cholesterol, plasma glucose and blood pressure after 2 weeks of placebo treatment and again after 1 year of anti-hypertensive treatment with either an atenolol- or a losartan-based regimen. During this first year of treatment, 77 patients encountered a non-fatal stroke or myocardial infarction and were excluded to avoid bias. During the next 3-4 years, 610 composite endpoints [cardiovascular death (n = 228), fatal or non-fatal myocardial infarction or stroke] were recorded.

RESULTS

In Cox regression analyses, the composite endpoint was after adjustment for treatment allocation predicted by baseline logUACR [hazard ratio (HR) = 1.16 per 10-fold increase, P < 0.05], 1-year logUACR (HR = 1.29 per 10-fold increase), baseline Sokolow-Lyon voltage (HR = 1.01 per mm, both P < 0.001) and 1-year Cornell product (HR = 1.01 per 100 mm x ms, P < 0.01). Cardiovascular death was predicted by 1-year logUACR (HR = 1.59, P < 0.001), baseline Sokolow-Lyon voltage (HR = 1.01, P = 0.06) and 1-year Cornell product (HR = 1.02, P < 0.001). Both were predicted independent of age, Framingham risk score, current smoking, history of cardiovascular disease and diabetes. Gender, serum cholesterol, plasma glucose and blood pressure did not enter the models.

CONCLUSIONS

Baseline UACR and Sokolow-Lyon voltage, as well as in-treatment UACR and Cornell product, added to the risk prediction independent of traditional risk factors, indicating that albuminuria and left ventricular hypertrophy reflect different aspects of cardiovascular damage and are modifiable cardiovascular risk factors.

Cost-consequence analysis in a French setting of screening and optimal treatment of nephropathy in hypertensive patients with type 2 diabetes

AIM

Forty percent of hypertensive type 2 diabetes patients develop nephropathy (microalbuminuria/overt nephropathy), indicating end organ damage, increased risk of cardiovascular disease (CVD), and death. In France, screening rates and nephropathy treatment are suboptimal. We assessed the health economic impact of nephropathy screening in hypertensive patients with type 2 diabetes followed by optimal antihypertensive/nephroprotective therapy in those who have nephropathy in France.

METHODS

A Markov/Monte Carlo model simulated lifetime impacts of screening for albuminuria (microalbuminuria/overt nephropathy) using semi-quantitative urine dipsticks in a primary care setting, and subsequent addition of irbesartan 300 mg to conventional therapy in hypertensive type 2 diabetes patients identified as having nephropathy. Progression from no renal disease to end-stage renal disease (ESRD) was simulated. Probabilities, utilities and costs of CVD events, medications and ESRD treatment came from published sources. Cumulative incidence of ESRD, life expectancy, quality-adjusted life years (QALYs) and direct costs were projected. Second-order Monte Carlo simulation accounted for uncertainty in multiple parameters. Costs and QALYs were discounted at 3% annually.

RESULTS

Screening and optimized treatment led to a 42% reduction in the cumulative incidence of ESRD from 10.1 +/- 9.9% without screening to 5.8 +/- 5.7%, improvements in life expectancy of 0.38 +/- 0.59 years, improvements of 0.29 +/- 0.32 QALYs, and decreased costs of Euro 4,812 +/- 7,882/patient over 25 years. Sensitivity analysis showed that the results were robust. Screening was most beneficial when performed in younger patients.

CONCLUSION

In hypertensive patients with type 2 diabetes, screening for albuminuria followed by optimal antihypertensive/nephroprotective treatment improves patient outcomes and leads to cost savings in France.

Antihypertensive agents for preventing diabetic kidney disease

BACKGROUND

Twenty to sixty percent of diabetic patients are affected by hypertension and antihypertensive agents are used to treat this condition. These agents are also used to prevent the onset of kidney disease both in normotensive and hypertensive diabetics.

OBJECTIVES

To evaluate the comparative effects of antihypertensive agents in patients with diabetes and normoalbuminuria.

SEARCH STRATEGY

MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, conference proceedings, and contact with investigators were used to identify relevant trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing any antihypertensive agent with placebo or another agent in hypertensive or normotensive patients with diabetes and no kidney disease (albumin excretion rate < 30 mg/d) were included.

DATA COLLECTION AND ANALYSIS

Two investigators independently extracted data on renal outcomes and other patient relevant outcomes (all-cause mortality, serious cardiovascular events), and assessed quality of trials. Analysis was by a random effects model and results expressed as relative risk (RR) and 95% confidence intervals (CI).

MAIN RESULTS

Sixteen trials (7603 patients) were identified, six of angiotensin converting enzyme inhibitors (ACEi) versus placebo, six of ACEi versus calcium channel blockers (CCBs), one of ACEi versus CCBs or combined ACEi and CCBs and three of ACEi versus other agents. Compared to placebo, ACEi significantly reduced the development of microalbuminuria (six trials, 3840 patients: RR 0.60, 95% CI 0.43 to 0.84) but not doubling of creatinine (three trials, 2683 patients: RR 0.81, 95% CI 0.24 to 2.71) or all-cause mortality (four trials, 3284 patients: RR 0.81, 95% CI 0.64 to 1.03). Compared to CCBs, ACEi significantly reduced progression to microalbuminuria (four trials, 1210 patients: RR 0.58, 95% CI 0.40 to 0.84).

AUTHORS' CONCLUSIONS

A significant reduction in the risk of developing microalbuminuria in normoalbuminuric patients with diabetes has been demonstrated for ACEi only. It appears that the effect of ACEi is independent of baseline blood pressure, renal function and type of diabetes, but data is too sparse to be confident that these are not important effect modifiers and an individual patient data meta-analysis is required.

N-Terminal Pro Brain Natriuretic Peptide Is Inversely Related to Metabolic Cardiovascular Risk Factors and the Metabolic Syndrome

We wanted to investigate the relationship of N-terminal pro brain natriuretic peptide (Nt-proBNP) to metabolic and hemodynamic cardiovascular (CV) risk factors in the general population. From a population-based sample of 2656 people 41, 51, 61, or 71 years of age, we selected 2070 patients without previous stroke or myocardial infarction who did not receive any CV, antidiabetic, or lipid-lowering treatment in 1993 to 1994. Traditional CV risk factors, 24-hour blood pressures, left ventricular (LV) mass, and ejection fraction by echocardiography, pulse wave velocity, urine albumin/creatinine ratio (UACR), and serum Nt-proBNP were measured in 1993 to 1994. The metabolic syndrome was defined in accordance with the definition of the European Group for the Study of Insulin Resistance (EGIR). Higher log(Nt-proBNP) was in multiple regression analysis related to female gender (beta=-0.37), older age (beta=0.32), higher clinic pulse pressure (beta=0.20), lower serum total cholesterol (beta=-0.15), lower LVEF (beta=-0.08, all P<0.001), lower log(serum insulin) (beta=-0.07), lower log(plasma glucose) (beta=-0.06, both P<0.01, lower log(serum triglyceride) (beta=-0.06), lower body mass index (beta=-0.05); lower heart rate (beta=-0.05), higher logUACR (beta=0.04, all P<0.05) and higher log(LV mass index) (beta=0.04, P=0.07), adjusted R2=0.35, P<0.001). The metabolic syndrome was associated with lower Nt-proBNP (35 pg/mL versus 48 pg/mL; P<0.001) and shifted the positive relationship between pulse pressure and Nt-proBNP to the right (ie, higher blood pressure for a given level of Nt-proBNP). The metabolic syndrome was associated with lower Nt-proBNP levels and shifted the positive relationship between Nt-proBNP and pulse pressure to the right, creating a possible link between the metabolic syndrome and hypertension.

Impairment of cardiac function in hypertensive patients with Type 2 diabetes: a LIFE study

AIMS

Type 2 diabetic patients with hypertension have an increased left ventricular (LV) mass and impaired cardiac function compared to hypertensive patients without diabetes. However, it is unknown if the impaired cardiac function can be explained solely by LV hypertrophy, or is independently related to diabetes. The aim of the present study was to compare LV function between diabetic and non-diabetic hypertensive patients with electrocardiographic LV hypertrophy.

METHODS

In 937 patients participating in the LIFE echocardiographic substudy, all echocardiograms were centrally evaluated by a core reading centre measuring LV mass, systolic and diastolic LV function. Known diabetes was present in 105 patients.

RESULTS

Left ventricular mass was similar in diabetic and non-diabetic patients. Endocardial systolic LV function, estimated by LV ejection fraction, was reduced and indices of midwall systolic LV function were impaired in the diabetic patients. Diastolic LV filling pattern was impaired and arterial stiffness, measured by pulse pressure/stroke index, was increased in diabetic patients.

CONCLUSIONS

Systolic and diastolic LV function in hypertensive patients with electrocardiographic LV hypertrophy and diabetes are impaired independent of LV mass, most likely reflecting the adverse effects of diabetes per se.

Hypertension-based clinical risk strategies for detecting microalbuminuria in diabetes

BACKGROUND

Microalbuminuria screening to identify patients at risk of diabetic nephropathy is widely accepted.

AIM

To investigate whether blood-pressure-based strategies can identify such patients without the need for microalbuminuria testing.

METHODS

Spot urine for albumin/creatinine ratios was performed in all patients over an 18-month period. The performance of four combinations of clinical models, based on existing triggers for anti-hypertensive intervention (prior use and/or existing systolic BP exceeding 140 or 160 mmHg and/or dipstick proteinuria exceeding 1+ or 2+) was evaluated at microalbuminuria thresholds of 3.5 and 10 mg/mmol. The models were ranked 1 to 4, based on their escalating relative strengths in predicting need for intervention.

RESULTS

Of 3748 patients, 1257 (34%) or 739 (20%) exceeded microalbuminuria thresholds of 3.5 or 10 mg/mmol. All four models predicted microalbuminuria risk (areas under ROC curves 0.60-0.77, all p < 0.001). The models (1-4) identified 2220, 2465, 2803 or 2937 for intervention, respectively, irrespective of microalbuminuria status, and missed 368, 232, 194 or 126 at 3.5 mg/mmol and 164, 87, 81 or 45 at 10 mg/mmol.

DISCUSSION

Clinical models using routinely measured parameters reduced the target population for microalbuminuria screening by 60-80%, missing 3-10% of patients with albumin/creatinine ratios exceeding 3.5 mg/mmol or 1-4% of those exceeding 10 mg/mmol.

The impact of serum uric acid on cardiovascular outcomes in the LIFE study

BACKGROUND

The Losartan Intervention For Endpoint reduction in hypertension (LIFE) study demonstrated the superiority of a losartan-based regimen over atenolol-based regimen for reduction of cardiovascular (CV) morbidity and mortality. It has been suggested that the LIFE study results may be related to the effects of losartan on serum uric acid (SUA). SUA has been proposed as an independent risk factor for CV morbidity and death.

METHODS

Cox regression analysis was used to assess relationship of SUA and treatment regimens with the LIFE primary composite outcome (CV death, fatal or nonfatal myocardial infarction, fatal or nonfatal stroke).

RESULTS

Baseline SUA was significantly associated with increased CV events [hazard ratio (HR) 1.024 (95% CI 1.017-1.032) per 10 micromol/L, P < 0.0001] in the entire study population. The association was significant in women [HR = 1.025 (1.013-1.037), P < 0.0001], but not in men [HR = 1.009 (0.998-1.019), P= 0.108]. After adjustment for Framingham risk score (FRS), SUA was no longer significant in the entire study population [HR = 1.006 (0.998-1.014), P= 0.122] or in men [HR = 1.006 (0.995-1.017), P= 0.291], but was significant in women [HR = 1.013 (1-1.025), P= 0.0457]. The baseline-to-end-of-study increase in SUA (standard deviation, SD) was greater (P < 0.0001) in atenolol-treated subjects (44.4 +/- 72.5 micromol/L) than in losartan-treated subjects (17.0 +/- 69.8 micromol/L). SUA as a time-varying covariate was strongly associated with events (P < 0.0001) in the entire population. The contribution of SUA to the treatment effect of losartan on the primary composite end point was 29% (14%-107%), P= 0.004. The association between time-varying SUA and increased CV risk tended to be stronger in women (P < 0.0001) than in men (P= 0.0658), although the gender-outcome interaction was not significant (P= 0.079).

CONCLUSION

The increase in SUA over 4.8 years in the LIFE study was attenuated by losartan compared with atenolol treatment, appearing to explain 29% of the treatment effect on the primary composite end point. The association between SUA and events was stronger in women than in men with or without adjustment of FRS.

Albuminuria predicts cardiovascular events independently of left ventricular mass in hypertension: a LIFE substudy

We wanted to investigate whether urine albumin/creatinine ratio (UACR) and left ventricular (LV) mass, both being associated with diabetes and increased blood pressure, predicted cardiovascular events in patients with hypertension independently. After 2 weeks of placebo treatment, clinical, laboratory and echocardiographic variables were assessed in 960 hypertensive patients from the LIFE Echo substudy with electrocardiographic LV hypertrophy. Morning urine albumin and creatinine were measured to calculate UACR. The patients were followed for 60+/-4 months and the composite end point (CEP) of cardiovascular (CV) death, nonfatal stroke or nonfatal myocardial infarction was recorded. The incidence of CEP increased with increasing LV mass (below the lower quartile of 194 g to above the upper quartile of 263 g) in patients with UACR below (6.7, 5.0, 9.1%) and above the median value of 1.406 mg/mmol (9.7, 17.0, 19.0%(***)). Also the incidence of CV death increased with LV mass in patients with UACR below (0, 1.4, 1.3%) and above 1.406 mg/mmol (2.2, 6.4, 8.0%(**)). The incidence of CEP was predicted by logUACR (hazard ratio (HR)=1.44(**) for every 10-fold increase in UACR) after adjustment for Framingham risk score (HR=1.05(***)), history of peripheral vascular disease (HR=2.3(*)) and cerebrovascular disease (HR=2.1(*)). LV mass did not enter the model. LogUACR predicted CV death (HR=2.4(**)) independently of LV mass (HR=1.01(*) per gram) after adjustment for Framingham risk score (HR=1.05(*)), history of diabetes mellitus (HR=2.4(*)) and cerebrovascular disease (HR=3.2(*)). (*)P<0.05, (**)P<0.01, (***)P<0.001. In conclusion, UACR predicted CEP and CV death independently of LV mass. CV death was predicted by UACR and LV mass in an additive manner after adjustment for Framingham risk score and history of CV disease.

Physical activity alters urinary albumin/ creatinine ratio in type 1 diabetic patient

While the best way to identify microalbuminuria is to determine albumin excretion rate (AER) in a 24 h urine sample. Published data have shown that calculation of an albumin/creatinine ratio (ACR) in a spot urine sample has reasonable rate of sensitivity and specificity. We aimed to evaluate the effect of daily exercise on ACR and estimate the best time for the examination of the ACR in a spot urine sample. Sixteen eligible patients with Type 1 diabetes mellitus were asked to perform varying degree of exercise periods. Urinary albumin and creatinine excretion rates during each period were determined. ACR and AER of timed urinary samples were compared with the 24 hour urinary AER. We found significant correlations between timed and 24 hour urinary AER. According to diagnostic performance tests, ACR and AER of timed urine samples were both found to be significantly more sensitive during resting period when compared with mild or moderate active periods. It is concluded that ACR and AER of a timed urine sample are sensitive and specific methods for determining microalbuminuria, while overnight resting samples give the impression of being more diagnostic. Key PointsTimed urine samples can predict microalbuminuria but because of the erroneous urine collections, microalbuminuria measurement should be calculated with creatiniuria measurement.With increasing physical activity during urine collection diagnostic performances of the cut-off values go downhill.For detecting microalbuminuria best results are reached with the early-morning urine samples.

A systematic review and meta-analysis of the efficacy and safety of a fixed, low-dose perindopril-indapamide combination as first-line treatment of hypertension

BACKGROUND

A low-dose combination of perindopril and indapamide may effectively reduce blood pressure (BP) in hypertensive patients, but some factors related to study design might have contributed to the between-group differences in the rate of reduction of BP observed in some trials.

OBJECTIVE

The aim of this study was to systematically assess the efficacy and safety profiles (through review of randomized, controlled trials) of the fixed, low-dose combination perindopril 2 mg and indapamide 0.625 mg given as 1 tablet daily as first-line antihypertensive therapy in patients with mild to moderate hypertension.

METHODS

We searched MEDLINE (1966-April 2003), EMBASE (1980-March 2003), BIOSIS (1999-December 2002), and the Cochrane Library, using the medical subject headings with the search terms perindopril, indapamide, hypertension, randomized controlled trials, randomly, random, randomization, perindopril-indapamide, essential hypertension, and primary hypertension. Additional articles were obtained from the reference lists of relevant reviews and papers.

RESULTS

We reviewed 11 trials (5936 individuals). In 5 studies of perindopril-indapamide versus placebo, the between-group weighted mean differences (WMDs) for both systolic and diastolic BP (SBP and DBP, respectively) favored perindopril-indapamide (SBP, -9.03 mm Hg [95% CI, -9.54 to -8.52]; DBP, -5.09 mm Hg [95% Cl, -5.42 to -4.77]; both P < 0.01 for z score for overall effect). In 6 studies of perindopril-indapamide versus routine antihypertensives, the between-group WMDs for SBP and DBP favored perindopril-indapamide (SBP, -3.72 mm Hg [95% CI, -7.11 to 0.33], P = 0.03 for z score for overall effect; DBP, -1.71 mm Hg [95% CI, -2.27 to -1.16], P < 0.01 for z score for overall effect). Five studies compared perindopril-indapamide and placebo; in the remaining 3 studies, which assessed perindopril-indapamide versus routine antihypertensives, the between-group WMDs for SBP and DBP favored perindopril-indapamide (SBP, -4.00 mm Hg [95% CI, -6.54 to -1.47], P < 0.01; DBP, -1.02 mm Hg [95% CI, -1.73 to -0.31], P < 0.01). Adverse events and withdrawals were not significantly different between perindopril-indapamide, placebo, or routine antihypertensive drugs.

CONCLUSION

The studies in our analysis consistently demonstrated that a fixed, low-dose perindopril-indapamide combination has a favorable safety profile and may be efficacious as first-line treatment for patients with mild to moderate essential hypertension.

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.

Effect of low-dose perindopril/indapamide on albuminuria in diabetes: preterax in albuminuria regression: PREMIER

Microalbuminuria in diabetes is a risk factor for early death and an indicator for aggressive blood pressure (BP) lowering. We compared a combination of 2 mg perindopril/0.625 mg indapamide with enalapril monotherapy on albumin excretion rate (AER) in patients with type 2 diabetes, albuminuria, and hypertension in a 12-month, randomized, double-blind, parallel-group international multicenter study. Four hundred eighty-one patients with type 2 diabetes and hypertension (systolic BP > or =140 mm Hg, <180 mm Hg, diastolic BP <110 mm Hg) were randomly assigned (age 59+/-9 years, 77% previously treated for hypertension). Results from 457 patients (intention-to-treat analysis) were available. After a 4-week placebo period, patients with albuminuria >20 and <500 microg/min were randomly assigned to a combination of 2 mg perindopril/0.625 mg indapamide or to 10 mg daily enalapril. After week 12, doses were adjusted on the basis of BP to a maximum of 8 mg perindopril/2.5 mg indapamide or 40 mg enalapril. The main outcome measures were overnight AER and supine BP. Both treatments reduced BP. Perindopril/indapamide treatment resulted in a statistically significant higher fall in both BP (-3.0 [95% CI -5.6, -0.4], P=0.012; systolic BP -1.5 [95% CI -3.0, -0.1] diastolic BP P=0.019) and AER -42% (95% CI -50%, -33%) versus -27% (95% CI -37%, -16%) with enalapril. The greater AER reduction remained significant after adjustment for mean BP. Adverse events were similar in the 2 groups. Thus, first-line treatment with low-dose combination perindopril/indapamide induces a greater decrease in albuminuria than enalapril, partially independent of BP reduction. A BP-independent effect of the combination may increase renal protection.

A blood pressure independent association between glomerular albumin leakage and electrocardiographic left ventricular hypertrophy. The LIFE Study. Losartan Intervention For Endpoint reduction

In the Losartan Intervention For Endpoint reduction (LIFE) study left ventricular (LV) hypertrophy was associated with increased urine albumin/creatinine ratio (UACR) at baseline. To evaluate whether this association was due only to parallel blood pressure (BP)-induced changes we re-examined the patients after 1 year of antihypertensive treatment to investigate whether changes in LV hypertrophy and UACR were related independently of changes in BP. In 7,142 hypertensive patients included in the LIFE study, we measured UACR, LV hypertrophy by electrocardiography, plasma glucose and BP after 2 weeks of placebo treatment and again after 1 year of antihypertensive treatment with either an atenolol or a losartan based regime. At baseline and still after 1 year of treatment logUACR (R = 0.28, P < 0.001) was still correlated to LV hypertrophy (beta = 0.05) assessed by ECG independently of systolic BP (beta = 0.16), plasma glucose (beta = 0.19) and age (beta = 0.08). Change in logUACR (R = 0.19, P < 0.001) during treatment was correlated to change in LV hypertrophy (beta = 0.10) independently of reduction in systolic BP (beta = 0.13) and change in plasma glucose (beta = 0.06). After 1 year of antihypertensive treatment UACR was still related to LV hypertrophy independently of systolic BP, and the reduction in UACR during that first year of treatment was related to regression of LV hypertrophy independently of reduction in systolic BP. This suggests that the relationship between LV hypertrophy and glomerular albumin leakage is not just due to parallel BP-induced changes. As glomerular albumin leakage may represent generalised vascular damage we hypothesise a vascular relationship between cardiac and glomerular damage.

Urine albumin/creatinine ratio and echocardiographic left ventricular structure and function in hypertensive patients with electrocardiographic left ventricular hypertrophy: the LIFE study. Losartan Intervention for Endpoint Reduction

BACKGROUND

Albuminuria, reflecting systemic microvascular damage, and left ventricular (LV) geometric abnormalities have both been shown to predict increased cardiovascular morbidity and mortality. However, the relationship between these markers of cardiovascular damage has not been evaluated in a large hypertensive population.

METHODS

The urine albumin/creatinine ratio (UACR) and echocardiographic measures of LV structure and function were obtained in 833 patients with stage I to III hypertension and LV hypertrophy determined by electrocardiogram (ECG) (Cornell voltage-duration or Sokolow-Lyon voltage criteria) after 14 days of placebo treatment.

RESULTS

Patients' mean ages were 66 years, 42% were women, 23% had microalbuminuria, and 5% had macroalbuminuria. Patients with eccentric or concentric LV hypertrophy had higher prevalences of microalbuminuria (average 26%-30% vs 9%, P <.001) and macroalbuminuria (6%-7% vs <1%, P <.001). Furthermore, patients with microalbuminuria and macroalbuminuria had a significantly higher LV mass and lower endocardial and midwall fractional shortening. Patients with abnormal diastolic LV filling parameters had a significantly increased prevalence of microalbuminuria. In univariate analyses, UACR correlated positively to LV mass, systolic blood pressure, age (all P <.001) and pulse pressure/stroke volume and negatively to relative wall thickness (both P <.01) and endocardial (P <.05) and midwall shortening (P <.001) but not to diastolic filling parameters. In multiple regression analysis higher UACR was associated with higher LV mass (beta=.169, P <.001) independently of older age (beta =.095, P <.01), higher systolic pressure (beta=.163), black race (beta=.186), and diabetes (beta=.241, all P <.001).

CONCLUSIONS

In hypertensive patients with ECG LV hypertrophy, abnormal LV geometry and high LV mass are associated with high UACR independent of age, systolic blood pressure, diabetes, and race, suggesting parallel cardiac and microvascular damage.

The role of cost-effectiveness analysis and health insurance in diabetes care

The theme of World Diabetes Day for 1999 is 'The Costs of Diabetes'. This theme was chosen quite purposely to reflect the broad nature in which diabetes affects individuals, families, and society. For the theme can highlight the importance of diabetes from a medical, social, or economic perspective. This presentation addresses two issues, cost-effectiveness analysis and financial barriers to care, that pertain to the economic viewpoint. Economically, the costs of diabetes are varied. They include items that one can easily recognize, such as the expenditures related to medical treatment for diabetes (direct costs) or the earnings lost to individuals prematurely disabled or dying young (indirect costs). Other less well known costs exists as well. These include the opportunity costs to individuals with diabetes who forego other 'opportunities in life' because they made a decision to devote their financial or time resources to diabetes care. They also include costs to society, such as the impact of using existing resources in diabetes care unwisely, or having inappropriate priorities. Cost-effectiveness analyses in diabetes care address this last point. Health insurance issues highlight one aspect of opportunity costs in diabetes care.

Projected number of diabetic renal disease patients among insulin-dependent diabetes mellitus children in Japan using a Markov model with probabilistic sensitivity analysis

BACKGROUND

To plan prevention programmes for the diabetic renal disease among insulin-dependent diabetes mellitus (IDDM) children, projections of future trends for the disease is crucial. We projected future trends in the number of diabetic renal disease patients among IDDM children and assessed an impact of treatment dissemination in Japan.

METHODS

We used a Markov model to describe the clinical courses of diabetic renal disease. Future trends in the number of patients with diabetic nephropathy (DN) and end-stage renal disease (ESRD) were projected from the year 1995 to 2015. We made three scenarios for assessing an impact of the dissemination of new treatment. We performed a probabilistic sensitivity analysis for the uncertainty of transition probabilities.

RESULTS

The results showed that the number of patients with DN was 790.5 (5th to 95th percentile: 652.5-955.1), ESRD was 253.3 (5th to 95th percentile: 207.3-310.0) in year 2015 on basic scenario. Considering the dissemination of intensive insulin therapy, under the scenario of the gradual increase of the treatment, the result showed that the number of patients with DN was 713.1 (5th to 95th percentile: 546.2-930.6), ESRD was 231.0 (5th to 95th percentile: 176.6-296.2). Under the scenario of the immediate change of the treatment, the results showed that the number of patients with DN in 2015 was 418.9 (5th percentile; 345.4; 95th percentile; 506.1) and with ESRD was 133.4 (5th percentile; 109.0; 95th percentile; 163.8).

CONCLUSIONS

The results of the projection showed a gradual increase in the number of patients with DMN and ESRD. Examination of three possible scenarios showed that the programme of dissemination of intensive insulin therapy prevented the progression of diabetic renal disease.

Reference intervals for the markers of proteinuria with a standardised bed-rest collection of urine

Reference intervals for markers of proteinuria or glomerular charge selectivity were measured in 61 healthy female and 61 healthy male individuals. Timed bed-rest and daytime collections were used to assess significance of preanalytical variability of results. Bed-rest collections are advisable for research on renal damage, whereas in routine care, robust protein/creatinine ratios work as practical estimates of protein excretion rates, the correlations to excretion rates improving with increasing proteinuria. For glomerular charge selectivity, pancreatic/salivary isoamylase clearance ratio showed lower within-subject biological variation than IgG/IgG4 clearance ratio, allowing more accurate classification into normal and reduced charge selectivity. With our method, the lower 2.5% reference intervals for isoamylase clearance ratio were 1.1 in men and 1.9 in women.

Outline of a diabetes disease management model: principles and applications

A complex interactive computer model was developed to determine the health outcomes and economic consequences of different diabetes interventions for user-defined observation periods. The interventions include intensive or conventional insulin therapy, different oral hypoglycaemic medications, different screening and treatment strategies for micro-vascular complications, different treatment strategies for end-stage complications, or multi-factorial interventions. The analyses can be performed on different sub-groups of type 1 and 2 diabetic patients, defined in terms of age, gender, baseline risk factors and pre-existing complications. The model performs real-time simulations. Full on-screen documentation of the model structure, logic, calculations and data sources is available to maximize the model's transparency. Economic and clinical data used in the disease management model are editable by the user, allowing the input of new data as they become available, the creation of country-specific, HMO-specific, or provider-specific versions of the model, and the exploration of new hypotheses ('what-if' analyses). The approach used allows maximum flexibility, adaptability, and transparency within the model structure. For the user-defined patient cohorts and intervention strategies the diabetes disease management model compares life expectancy, expected incidence and prevalence of complications as well as expected life-time (or shorter) treatment cost. Diabetes and complication management strategies can be compared in different patient populations in a variety of realistic clinical settings. The model allows extrapolation of results obtained from relatively short-term clinical trials to longer-term medical outcomes, and from trial populations to real-life populations providing a tangible yardstick to judge the quality of diabetes care. The model was used to evaluate diabetes care options in Germany, France, Switzerland, UK and US.

Higher incidence of diabetic nephropathy in type 2 than in type 1 diabetes in early-onset diabetes in Japan

BACKGROUND

Whether the type of diabetes, race, and year and age of diagnosis affect the incidence of diabetic vascular complications is unknown. That both type 1 and type 2 diabetes occur in the young Japanese population prompted us to investigate whether the type of diabetes and the year of diagnosis are related to the incidence of nephropathy.

METHODS

Of the 17,256 diabetic patients who visited the outpatient clinic at our diabetes center between 1965 and 1990, 1578 (9.1%) had early-onset diabetes (diagnosed before the age of 30); of these, 620 (39%) had type 1, and 958 (61%) had type 2 diabetes. The incidence of nephropathy was analyzed in the patients according to postpubertal duration and year of diagnosis.

RESULTS

The cumulative incidence of nephropathy after 30 years of postpubertal diabetes was significantly higher (P < 0.0001) in type 2 diabetic patients (44.4%, 95% CI, 37.0 to 51.8%) than in type 1 diabetic patients (20.2%, 95% CI, 14.9 to 25.8%). The incidence of nephropathy among type 1 diabetic patients has declined during the past two decades, whereas it has not among type 2 diabetic patients. The rate ratio for type 2 diabetic patients diagnosed between 1980 and 1984 relative to type 1 diabetic patients diagnosed in the same period was 2.74 (95% CI, 1. 17 to 6.41).

CONCLUSIONS

The incidence of nephropathy has declined in Japanese patients with type 1 but not in those with type 2 diabetes. In young Japanese patients, because of the higher incidence of nephropathy in type 2 diabetes and the higher prevalence of type 2 than type 1 diabetes, type 2 diabetes is likely the major cause of diabetic nephropathy.

Pancreas transplantation for the prevention of diabetic nephropathy

Diabetic nephropathy is the leading cause of kidney failure in the United States. Poor glycemic control, hypertension, and smoking have been implicated as risk factors for the development and progression of diabetic nephropathy in patients with type 1 diabetes mellitus. Improved medical therapy including angiotensin-converting enzyme inhibitors and tight glycemic control with use of intensive insulin therapy have been shown to reduce the progression of diabetic nephropathy substantially based on albumin excretion rates. Despite these improvements in medical management, many patients still experience progression from early diabetic nephropathy to end-stage renal disease. Successful pancreas transplantation leads to normal glycemic control in patients with type 1 diabetes, but historically it has generally been limited to patients with both kidney failure and diabetes. In this review of the current treatment of diabetic nephropathy, we examine the potential role of preemptive pancreas transplantation in patients with diabetic nephropathy.

Systolic hypertension and duration of diabetes mellitus are important determinants of retinopathy and microalbuminuria in young diabetics

This cross-sectional study looked at the prevalence of microalbuminuria and retinopathy in a cohort of 926 young, Type 1 and Type 2 diabetes mellitus (DM) patients, and determined the factors which were associated with these microvascular complications. The prevalence of microalbuminuria, defined as the albumin:creatinine ratio > or = 2.5 (for males) or > or = 3.5 mg/mmol (for females), was 13.4% in Type 1 DM, 69.5% in insulin-requiring Type 2 DM and 16% in Type 2 DM treated only with oral hypoglycemic agents. Compared to those with normal renal functions, these patients were older (P < or = 0.01), had significantly elevated blood pressures (P < 0.01 or P = 0.0001), and in the case of Type 1 DM, with a higher body mass index (P = 0.0001) and waist-hip ratio (P < 0.01). The prevalence of diabetic retinopathy in Type 1 DM was found to increase with the duration of diabetes, from 1.4% in the newly-onset (< 5 years), to 9.9% in those with 5-10 years disease, to 35% among patients with more than 10 years of diabetes (P < 0.0001). In this study, it was also observed that 10% of the Type 2 DM patients already had retinopathy within 5 years of diagnosis, and the prevalence increased significantly to 42.9% (P < 0.0001) among patients who had been diabetics for more than 10 years. Stepwise multiple regression analysis showed that besides the disease duration, systolic blood pressure was the most common and significant determinant for both microalbuminuria and retinopathy in both types of DM, thus implying that in order to reduce the risk of microvascular complications in diabetes mellitus, systolic and not just the diastolic blood pressure, should be effectively controlled.

Costs of diabetes. A methodological analysis of the literature

OBJECTIVE

To review studies on the costs of diabetes and its complications through a scheme designed specifically for assessing the quality of cost-of-illness (COI) studies.

DESIGN AND SETTING

The methodology of COI studies in diabetes was analysed in order to assess the significance of quantitative results. The scheme adopted 7 items identified as the main points for discussing the methodological choices governing the results. We also used a checklist based on questions related to the 7 items.

MAIN OUTCOME MEASURES AND RESULTS

The answers showed that many studies appear not to give technical details, so it is hard to understand the method. Methodological choices varied widely between the studies. This is probably due to the lack of consensus on the methodology of COI studies. Based on the findings of this review, we suggest also some specific points that could help produce more reliable results on the costs of diabetes.

CONCLUSIONS

Clearly, a general consensus on COI studies is still remote, making the value of any comparison of results questionable.

Blood pressure control, microalbuminuria and cardiovascular risk in Type 2 diabetes mellitus

Type 2 (noninsulin-dependent) diabetes mellitus (DM) affects about 3% of the UK population. Diabetes often coexists with a cluster of other potent cardiovascular risk factors, including hypertension, dyslipidaemia and increased tendency for thrombosis, and increases the risk of early death from cardiovascular causes by about threefold. Microalbuminuria or proteinuria also may be present, further increasing the risk of cardiovascular mortality. Cardiovascular risk factors must be treated aggressively in patients with Type 2 diabetes and control of blood pressure at 140/85 mm Hg or lower is a priority. The management of hypertension in patients from some ethnic groups demands special consideration because they have a high incidence of diabetes and hypertensive complications. Patients must be urged to adopt appropriate lifestyle changes in the first instance but additional drug treatment for hypertension is usually required. All the major classes of antihypertensive agents lower blood pressure in Type 2 diabetic patients but have different effects on metabolic risk factors in different ways. Low-dose thiazide diuretics, beta-blockers, calcium channel blockers and angiotensin converting enzyme (ACE) inhibitors have been shown to reduce cardiovascular risk. Individually, the effects of low-dose thiazide diuretics and beta-blockers on glucose and lipid metabolism is clinically insignificant, though in combination much larger metabolic effects are seen. ACE inhibitors and calcium channel blockers have no, or small, beneficial effects on glucose and lipid metabolism, while the greater beneficial effects of alpha1-blockers on lipid profiles may render them especially useful in the Type 2 diabetic patient. Long-acting calcium-channel blockers and ACE inhibitors protect renal function and are suitable as first line therapy in patients with microalbuminuria or proteinuria. Until results from the current batch of randomized, placebo-controlled trials comparing different classes of antihypertensive agents are available, the choice of antihypertensive agent is difficult. Addressing overall cardiovascular risk factors, rather than hypertension alone, is essential in the management of the hypertensive Type 2 diabetic patient.

Microalbuminuria in diabetes

Microalbuminuria is still the only early abnormality of the diabetic kidney that has an established prognostic value. Microalbuminuria evolves into clinical nephropathy and renal failure in a majority of cases of insulin-dependent diabetic patients, and is defined by the detection of urinary albumin excretion rates of 20-200 microg/min in timed urine collections. The occurrence of microalbuminuria at rates of 5-27 % of non-proteinuric patients and cost-benefit considerations justify the screening for microalbuminuria in diabetic outpatient clinics. Both near-normalisation of glycaemic control and treatment with ACE-inhibitors are indicated in patients with insulin-dependent diabetes to correct the progression of micro- to macroalbuminuria. Other therapeutic perspectives are being considered, but the current notion that the available therapies may not arrest the course of nephropathy at this stage suggests that earlier interventions may be required. Prevention of microalbuminuria and overt nephropathy may require a primary approach to the subset of patients with a genetic predisposition to this complication, and several studies (candidate gene or genomic scan with microsatellite probes) now address the chromosomal loci and the nature of the genes that may be involved.

Design of cost-effective packages of care for non-insulin-dependent diabetes mellitus. Defining the information needs

This review concludes that: a) the global burden of disease from non-insulin-dependent diabetes mellitus (NIDDM) cannot be completely estimated at present; b) evidence for the efficacy of key elements of a package of care is still needed; c) generalizing the results of evaluations of costs or effectiveness across different populations is not straightforward; and d) for this complex intervention, the costs and effectiveness of intervention may be highly dependent on methods of organizing care. Addressing this information deficit represents an important task for researchers and health decision makers.

The importance of microalbuminuria as an indicator of incipient diabetic nephropathy: therapeutic implications

Nephropathy is the major life-threatening complication of insulin-dependent diabetes mellitus (IDDM). The clinical syndrome is characterized by persistent albuminuria (greater than 300 mg day), a rise in arterial blood pressure, and a relentless decline in glomerular filtration rate leading to end-stage renal failure. The availability of a radioimmunoassay for detecting albumin in low concentrations in urine has allowed the study of urinary albumin excretion rates in diabetics well before clinically persistent proteinuria develops. An albumin excretion rate greater than that in normal subjects and lower than that in macroalbuminuric subjects is called microalbuminuria (range 20-200 microg/min or 30-300 mg/24 h). Although recent studies have challenged the predictive value of microalbuminuria for later development of overt diabetic nephropathy, albumin excretion rate in the microalbuminuric range and its tracking (i.e. annual increase) are still considered reliable markers for prediction of later overt diabetic kidney disease. Overnight urinary collection is preferred for calculation of the rate of albumin excretion, but may be difficult to perform precisely. The albumin:creatinine ratio of the first morning urine sample is a reliable screening method: the microalbuminuric range is considered to be 2.5-25 mg/mmol or 30-300 mg/g (3.5 mg/mol has been proposed as lower limit in females because of their lower creatinine excretion). Irrespective of the procedure used, at least two samples over a 3-6-month period should test positive before microalbuminuria is confirmed and 'persistent microalbuminuria' defined. If the albumin excretion rate is persistently in the microalbuminuric range it is of crucial importance to define strategies and carry out interventions for prevention of decline in kidney function. The goal of achieving the best glycaemic control as early as possible in as many IDDM patients as is safely possible is particularly important in microalbuminuric patients. Although it is unsafe to reduce dietary protein intake drastically, particularly in children and adolescents, moderate decrease of protein intake (i.e. 0.9-1.1/g/kg day) is advisable in diabetic patients from the very beginning of the disease. Timely treatment with an angiotensin-converting enzyme inhibitor, independently of rise in arterial blood pressure, should be considered if improvement of glycaemic control and moderate decrease of dietary protein intake for 6-12 months have failed to reduce the albumin excretion rate. Screening programmes for microalbuminuria and early intervention can substantially modify the natural history of diabetic renal involvement and disease and possibly reduce the incidence of end-stage renal failure.

Cost-benefit analyses in the health-care literature: don't judge a study by its label

OBJECTIVES

To assess whether health-care related economic evaluations labeled as "cost benefit analyses" (CBA) meet a contemporary definition of CBA methodology and to assess the prevalence of methods used for assigning monetary units to health outcomes.

DATA SOURCES

Medline, Current Contents, and HSTAR databases and reference lists of review articles, 1991-1995.

STUDY SELECTION

Economic analyses labeled as CBAs were included. Agreement on study selection was assessed. STUDY EVALUATION: CBA studies were classified according to standard definitions of economic analytical techniques. For those valuing health outcomes in monetary units (bona fide CBAs), the method of valuation was classified.

RESULTS

53% of 95 studies were reclassified as cost comparisons because health outcomes were not appraised. Among the 32% considered bona fide CBAs, the human capital approach was employed to value health states in monetary units in 70%. Contingent valuation methods were employed infrequently (13%).

CONCLUSIONS

Studies labeled as CBAs in the health-care literature often offer only partial program evaluation. Decisions based only on resource costs are unlikely to improve efficiency in resource allocation. Among bona fide CBAs, the human capital approach was most commonly used to valuing health, despite its limitations. The results of health-care related CBAs should be interpreted with extreme caution.

Economic evaluation of ACE inhibitor treatment of nephropathy in patients with insulin-dependent diabetes mellitus in Italy

Diabetic nephropathy is one of the major complications of insulin-dependent diabetes mellitus (IDDM), with proteinuria being the main clinical manifestation of diabetic nephropathy. Most patients who develop overt proteinuria progress to end-stage renal disease (ESRD), usually within 5 to 7 years; ESRD necessitates dialysis or renal transplantation. Although a relationship between blood pressure reduction and delaying of ESRD has been assumed for a long time, only recently has a controlled randomised clinical trial shown that the treatment of diabetic nephropathy with an ACE inhibitor can significantly delay the loss of renal function and, therefore, ESRD. Consistent with the clinical trial on which this economic evaluation was based, the costs and consequences of 2 alternatives were considered: (i) patients subject to blood pressure control with only antihypertensive medication, but without an ACE inhibitor (placebo group) and (ii) patients given ACE inhibitor therapy (captopril group) with similar blood pressure control to the placebo group. This cost-effectiveness analysis was performed from the perspective of the Italian National Health Service [Servizio Sanitario Nazionale (SSN)]. Accordingly, only direct costs related to publicly funded healthcare services were included. The number of dialysis-years avoided (DYA) was the clinical end-point. A 10-year time horizon was considered for the economic evaluation. Captopril therapy was dominant, being at the same time more effective and less costly. The total cost for the captopril alternative during the 10-year period was 21,901,625 Italian lire (L; 1993 values) per patient, while total cost for the placebo alternative was L30,352,590 per patient. Compared with placebo, 20.01 DYA per 100 patients treated were estimated with captopril therapy during the trial period, equivalent to 2.4 months per patient. The robustness of this result was confirmed by sensitivity analysis: for both extremes, captopril remained dominant. This economic evaluation, requested by the Italian Ministry of Health, demonstrated savings in healthcare expenditure with the use of an ACE inhibitor in patients with proteinuria.