Comparison of effects of quinapril and metoprolol on glycaemic control, serum lipids, blood pressure, albuminuria and quality of life in non-insulin-dependent diabetes mellitus patients with hypertension. Swedish Quinapril Group

First-line drugs inhibiting the renin angiotensin system versus other first-line antihypertensive drug classes for hypertension

BACKGROUND

This is the first update of a Cochrane Review first published in 2015. Renin angiotensin system (RAS) inhibitors include angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) and renin inhibitors. They are widely prescribed for treatment of hypertension, especially for people with diabetes because of postulated advantages for reducing diabetic nephropathy and cardiovascular morbidity and mortality. Despite widespread use for hypertension, the efficacy and safety of RAS inhibitors compared to other antihypertensive drug classes remains unclear.

OBJECTIVES

To evaluate the benefits and harms of first-line RAS inhibitors compared to other first-line antihypertensive drugs in people with hypertension.

SEARCH METHODS

The Cochrane Hypertension Group Information Specialist searched the following databases for randomized controlled trials up to November 2017: the Cochrane Hypertension Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1946), Embase (from 1974), the World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov. We also contacted authors of relevant papers regarding further published and unpublished work. The searches had no language restrictions.

SELECTION CRITERIA

We included randomized, active-controlled, double-blinded studies (RCTs) with at least six months follow-up in people with elevated blood pressure (≥ 130/85 mmHg), which compared first-line RAS inhibitors with other first-line antihypertensive drug classes and reported morbidity and mortality or blood pressure outcomes. We excluded people with proven secondary hypertension.

DATA COLLECTION AND ANALYSIS

Two authors independently selected the included trials, evaluated the risks of bias and entered the data for analysis.

MAIN RESULTS

This update includes three new RCTs, totaling 45 in all, involving 66,625 participants, with a mean age of 66 years. Much of the evidence for our key outcomes is dominated by a small number of large RCTs at low risk for most sources of bias. Imbalances in the added second-line antihypertensive drugs in some of the studies were important enough for us to downgrade the quality of the evidence.Primary outcomes were all-cause death, fatal and non-fatal stroke, fatal and non-fatal myocardial infarction (MI), fatal and non-fatal congestive heart failure (CHF) requiring hospitalizations, total cardiovascular (CV) events (fatal and non-fatal stroke, fatal and non-fatal MI and fatal and non-fatal CHF requiring hospitalization), and end-stage renal failure (ESRF). Secondary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR).Compared with first-line calcium channel blockers (CCBs), we found moderate-certainty evidence that first-line RAS inhibitors decreased heart failure (HF) (35,143 participants in 5 RCTs, risk ratio (RR) 0.83, 95% confidence interval (CI) 0.77 to 0.90, absolute risk reduction (ARR) 1.2%), and that they increased stroke (34,673 participants in 4 RCTs, RR 1.19, 95% CI 1.08 to 1.32, absolute risk increase (ARI) 0.7%). Moderate-certainty evidence showed that first-line RAS inhibitors and first-line CCBs did not differ for all-cause death (35,226 participants in 5 RCTs, RR 1.03, 95% CI 0.98 to 1.09); total CV events (35,223 participants in 6 RCTs, RR 0.98, 95% CI 0.93 to 1.02); and total MI (35,043 participants in 5 RCTs, RR 1.01, 95% CI 0.93 to 1.09). Low-certainty evidence suggests they did not differ for ESRF (19,551 participants in 4 RCTs, RR 0.88, 95% CI 0.74 to 1.05).Compared with first-line thiazides, we found moderate-certainty evidence that first-line RAS inhibitors increased HF (24,309 participants in 1 RCT, RR 1.19, 95% CI 1.07 to 1.31, ARI 1.0%), and increased stroke (24,309 participants in 1 RCT, RR 1.14, 95% CI 1.02 to 1.28, ARI 0.6%). Moderate-certainty evidence showed that first-line RAS inhibitors and first-line thiazides did not differ for all-cause death (24,309 participants in 1 RCT, RR 1.00, 95% CI 0.94 to 1.07); total CV events (24,379 participants in 2 RCTs, RR 1.05, 95% CI 1.00 to 1.11); and total MI (24,379 participants in 2 RCTs, RR 0.93, 95% CI 0.86 to 1.01). Low-certainty evidence suggests they did not differ for ESRF (24,309 participants in 1 RCT, RR 1.10, 95% CI 0.88 to 1.37).Compared with first-line beta-blockers, low-certainty evidence suggests that first-line RAS inhibitors decreased total CV events (9239 participants in 2 RCTs, RR 0.88, 95% CI 0.80 to 0.98, ARR 1.7%), and decreased stroke (9193 participants in 1 RCT, RR 0.75, 95% CI 0.63 to 0.88, ARR 1.7% ). Low-certainty evidence suggests that first-line RAS inhibitors and first-line beta-blockers did not differ for all-cause death (9193 participants in 1 RCT, RR 0.89, 95% CI 0.78 to 1.01); HF (9193 participants in 1 RCT, RR 0.95, 95% CI 0.76 to 1.18); and total MI (9239 participants in 2 RCTs, RR 1.05, 95% CI 0.86 to 1.27).Blood pressure comparisons between first-line RAS inhibitors and other first-line classes showed either no differences or small differences that did not necessarily correlate with the differences in the morbidity outcomes.There is no information about non-fatal serious adverse events, as none of the trials reported this outcome.

AUTHORS' CONCLUSIONS

All-cause death is similar for first-line RAS inhibitors and first-line CCBs, thiazides and beta-blockers. There are, however, differences for some morbidity outcomes. First-line thiazides caused less HF and stroke than first-line RAS inhibitors. First-line CCBs increased HF but decreased stroke compared to first-line RAS inhibitors. The magnitude of the increase in HF exceeded the decrease in stroke. Low-quality evidence suggests that first-line RAS inhibitors reduced stroke and total CV events compared to first-line beta-blockers. The small differences in effect on blood pressure between the different classes of drugs did not correlate with the differences in the morbidity outcomes.

Insulin and glucose-lowering agents for treating people with diabetes and chronic kidney disease

BACKGROUND

Diabetes is the commonest cause of chronic kidney disease (CKD). Both conditions commonly co-exist. Glucometabolic changes and concurrent dialysis in diabetes and CKD make glucose-lowering challenging, increasing the risk of hypoglycaemia. Glucose-lowering agents have been mainly studied in people with near-normal kidney function. It is important to characterise existing knowledge of glucose-lowering agents in CKD to guide treatment.

OBJECTIVES

To examine the efficacy and safety of insulin and other pharmacological interventions for lowering glucose levels in people with diabetes and CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 12 February 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs) and quasi-RCTs looking at head-to-head comparisons of active regimens of glucose-lowering therapy or active regimen compared with placebo/standard care in people with diabetes and CKD (estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2) were eligible.

DATA COLLECTION AND ANALYSIS

Four authors independently assessed study eligibility, risk of bias, and quality of data and performed data extraction. Continuous outcomes were expressed as post-treatment mean differences (MD). Adverse events were expressed as post-treatment absolute risk differences (RD). Dichotomous clinical outcomes were presented as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

Forty-four studies (128 records, 13,036 participants) were included. Nine studies compared sodium glucose co-transporter-2 (SGLT2) inhibitors to placebo; 13 studies compared dipeptidyl peptidase-4 (DPP-4) inhibitors to placebo; 2 studies compared glucagon-like peptide-1 (GLP-1) agonists to placebo; 8 studies compared glitazones to no glitazone treatment; 1 study compared glinide to no glinide treatment; and 4 studies compared different types, doses or modes of administration of insulin. In addition, 2 studies compared sitagliptin to glipizide; and 1 study compared each of sitagliptin to insulin, glitazars to pioglitazone, vildagliptin to sitagliptin, linagliptin to voglibose, and albiglutide to sitagliptin. Most studies had a high risk of bias due to funding and attrition bias, and an unclear risk of detection bias.Compared to placebo, SGLT2 inhibitors probably reduce HbA1c (7 studies, 1092 participants: MD -0.29%, -0.38 to -0.19 (-3.2 mmol/mol, -4.2 to -2.2); I2 = 0%), fasting blood glucose (FBG) (5 studies, 855 participants: MD -0.48 mmol/L, -0.78 to -0.19; I2 = 0%), systolic blood pressure (BP) (7 studies, 1198 participants: MD -4.68 mmHg, -6.69 to -2.68; I2 = 40%), diastolic BP (6 studies, 1142 participants: MD -1.72 mmHg, -2.77 to -0.66; I2 = 0%), heart failure (3 studies, 2519 participants: RR 0.59, 0.41 to 0.87; I2 = 0%), and hyperkalaemia (4 studies, 2788 participants: RR 0.58, 0.42 to 0.81; I2 = 0%); but probably increase genital infections (7 studies, 3086 participants: RR 2.50, 1.52 to 4.11; I2 = 0%), and creatinine (4 studies, 848 participants: MD 3.82 μmol/L, 1.45 to 6.19; I2 = 16%) (all effects of moderate certainty evidence). SGLT2 inhibitors may reduce weight (5 studies, 1029 participants: MD -1.41 kg, -1.8 to -1.02; I2 = 28%) and albuminuria (MD -8.14 mg/mmol creatinine, -14.51 to -1.77; I2 = 11%; low certainty evidence). SGLT2 inhibitors may have little or no effect on the risk of cardiovascular death, hypoglycaemia, acute kidney injury (AKI), and urinary tract infection (low certainty evidence). It is uncertain whether SGLT2 inhibitors have any effect on death, end-stage kidney disease (ESKD), hypovolaemia, fractures, diabetic ketoacidosis, or discontinuation due to adverse effects (very low certainty evidence).Compared to placebo, DPP-4 inhibitors may reduce HbA1c (7 studies, 867 participants: MD -0.62%, -0.85 to -0.39 (-6.8 mmol/mol, -9.3 to -4.3); I2 = 59%) but may have little or no effect on FBG (low certainty evidence). DPP-4 inhibitors probably have little or no effect on cardiovascular death (2 studies, 5897 participants: RR 0.93, 0.77 to 1.11; I2 = 0%) and weight (2 studies, 210 participants: MD 0.16 kg, -0.58 to 0.90; I2 = 29%; moderate certainty evidence). Compared to placebo, DPP-4 inhibitors may have little or no effect on heart failure, upper respiratory tract infections, and liver impairment (low certainty evidence). Compared to placebo, it is uncertain whether DPP-4 inhibitors have any effect on eGFR, hypoglycaemia, pancreatitis, pancreatic cancer, or discontinuation due to adverse effects (very low certainty evidence).Compared to placebo, GLP-1 agonists probably reduce HbA1c (7 studies, 867 participants: MD -0.53%, -1.01 to -0.06 (-5.8 mmol/mol, -11.0 to -0.7); I2 = 41%; moderate certainty evidence) and may reduce weight (low certainty evidence). GLP-1 agonists may have little or no effect on eGFR, hypoglycaemia, or discontinuation due to adverse effects (low certainty evidence). It is uncertain whether GLP-1 agonists reduce FBG, increase gastrointestinal symptoms, or affect the risk of pancreatitis (very low certainty evidence).Compared to placebo, it is uncertain whether glitazones have any effect on HbA1c, FBG, death, weight, and risk of hypoglycaemia (very low certainty evidence).Compared to glipizide, sitagliptin probably reduces hypoglycaemia (2 studies, 551 participants: RR 0.40, 0.23 to 0.69; I2 = 0%; moderate certainty evidence). Compared to glipizide, sitagliptin may have had little or no effect on HbA1c, FBG, weight, and eGFR (low certainty evidence). Compared to glipizide, it is uncertain if sitagliptin has any effect on death or discontinuation due to adverse effects (very low certainty).For types, dosages or modes of administration of insulin and other head-to-head comparisons only individual studies were available so no conclusions could be made.

AUTHORS' CONCLUSIONS

Evidence concerning the efficacy and safety of glucose-lowering agents in diabetes and CKD is limited. SGLT2 inhibitors and GLP-1 agonists are probably efficacious for glucose-lowering and DPP-4 inhibitors may be efficacious for glucose-lowering. Additionally, SGLT2 inhibitors probably reduce BP, heart failure, and hyperkalaemia but increase genital infections, and slightly increase creatinine. The safety profile for GLP-1 agonists is uncertain. No further conclusions could be made for the other classes of glucose-lowering agents including insulin. More high quality studies are required to help guide therapeutic choice for glucose-lowering in diabetes and CKD.

First-line drugs inhibiting the renin angiotensin system versus other first-line antihypertensive drug classes for hypertension

BACKGROUND

Renin-angiotensin system (RAS) inhibitors are widely prescribed for treatment of hypertension, especially for diabetic patients on the basis of postulated advantages for the reduction of diabetic nephropathy and cardiovascular morbidity and mortality. Despite widespread use of angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) for hypertension in both diabetic and non-diabetic patients, the efficacy and safety of RAS inhibitors compared to other antihypertensive drug classes remains unclear.

OBJECTIVES

To evaluate the benefits and harms of first-line RAS inhibitors compared to other first-line antihypertensive drugs in patients with hypertension.

SEARCH METHODS

We searched the Cochrane Hypertension Group's Specialised Register, MEDLINE, MEDLINE In-Process, EMBASE and ClinicalTrials.gov for randomized controlled trials up to November 19, 2014 and the Cochrane Central Register of Controlled Trials (CENTRAL) up to October 19, 2014. The WHO International Clinical Trials Registry Platform (ICTRP) is searched for inclusion in the Cochrane Hypertension Group's Specialised Register.

SELECTION CRITERIA

We included randomized, active-controlled, double-blinded studies with at least six months follow-up in people with primary elevated blood pressure (≥130/85 mmHg), which compared first-line RAS inhibitors with other first-line antihypertensive drug classes and reported morbidity and mortality or blood pressure outcomes. Patients with proven secondary hypertension were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently selected the included trials, evaluated the risk of bias and entered the data for analysis.

MAIN RESULTS

We included 42 studies, involving 65,733 participants, with a mean age of 66 years. Much of the evidence for our key outcomes is dominated by a small number of large studies at a low risk of bias for most sources of bias. Imbalances in the added second-line antihypertensive drugs in some of the studies were important enough for us to downgrade the quality of the evidence.Primary outcomes were all-cause death, fatal and non-fatal stroke, fatal and non-fatal myocardial infarction (MI), fatal and non-fatal congestive heart failure (CHF) requiring hospitalization, total cardiovascular (CV) events (consisted of fatal and non-fatal stroke, fatal and non-fatal MI and fatal and non-fatal CHF requiring hospitalizations), and ESRF. Secondary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR).Compared with first-line calcium channel blockers (CCBs), we found moderate quality evidence that first-line RAS inhibitors decreased heart failure (HF) (35,143 participants in 5 RCTs, RR 0.83, 95% CI 0.77 to 0.90, ARR 1.2%), and moderate quality evidence that they increased stroke (34,673 participants in 4 RCTs, RR 1.19, 95% CI 1.08 to 1.32, ARI 0.7%). They had similar effects on all-cause death (35,226 participants in 5 RCTs, RR 1.03, 95% CI 0.98 to 1.09; moderate quality evidence), total CV events (35,223 participants in 6 RCTs, RR 0.98, 95% CI 0.93 to 1.02; moderate quality evidence), total MI (35,043 participants in 5 RCTs, RR 1.01, 95% CI 0.93 to 1.09; moderate quality evidence). The results for ESRF do not exclude potentially important differences (19,551 participants in 4 RCTs, RR 0.88, 95% CI 0.74 to 1.05; low quality evidence).Compared with first-line thiazides, we found moderate quality evidence that first-line RAS inhibitors increased HF (24,309 participants in 1 RCT, RR 1.19, 95% CI 1.07 to 1.31, ARI 1.0%), and increased stroke (24,309 participants in 1 RCT, RR 1.14, 95% CI 1.02 to 1.28, ARI 0.6%). They had similar effects on all-cause death (24,309 participants in 1 RCT, RR 1.00, 95% CI 0.94 to 1.07; moderate quality evidence), total CV events (24,379 participants in 2 RCTs, RR 1.05, 95% CI 1.00 to 1.11; moderate quality evidence), and total MI (24,379 participants in 2 RCTs, RR 0.93, 95% CI 0.86 to 1.01; moderate quality evidence). Results for ESRF do not exclude potentially important differences (24,309 participants in 1 RCT, RR 1.10, 95% CI 0.88 to 1.37; low quality evidence).Compared with first-line beta-blockers, we found low quality evidence that first-line RAS inhibitors decreased total CV events (9239 participants in 2 RCTs, RR 0.88, 95% CI 0.80 to 0.98, ARR 1.7%), and low quality evidence that they decreased stroke (9193 participants in 1 RCT, RR 0.75, 95% CI 0.63 to 0.88, ARR 1.7% ). Our analyses do not exclude potentially important differences between first-line RAS inhibitors and beta-blockers on all-cause death (9193 participants in 1 RCT, RR 0.89, 95% CI 0.78 to 1.01; low quality evidence), HF (9193 participants in 1 RCT, RR 0.95, 95% CI 0.76 to 1.18; low quality evidence), and total MI (9239 participants in 2 RCTs, RR 1.05, 95% CI 0.86 to 1.27; low quality evidence).Blood pressure comparisons between RAS inhibitors and other classes showed either no differences or small differences that did not necessarily correlate with the differences in the morbidity outcomes.In the protocol, we identified non-fatal serious adverse events (SAE) as a primary outcome. However, when we extracted the data from included studies, none of them reported total SAE in a manner that could be used in the review. Therefore, there is no information about SAE in the review.

AUTHORS' CONCLUSIONS

We found predominantly moderate quality evidence that all-cause mortality is similar when first-line RAS inhibitors are compared to other first-line antihypertensive agents. First-line thiazides caused less HF and stroke than first-line RAS inhibitors. The quality of the evidence comparing first-line beta-blockers and first-line RAS inhibitors was low and the lower risk of total CV events and stroke seen with RAS inhibitors may change with the publication of additional trials. Compared with first-line CCBs, first-line RAS inhibitors reduced HF but increased stroke. The magnitude of the reduction in HF exceeded the increase in stroke. The small differences in effect on blood pressure between the different classes of drugs did not correlate with the differences in the primary outcomes.

Effects of antihypertensive treatments on incidence of diabetes: a case-control study

AIMS

Aim of this case-control study is the assessment of the relationship between antihypertensive treatment and incidence of diabetes in an unselected cohort of subjects participating in a screening program for diabetes.

METHODS

A case-control study nested within a cohort of nondiabetic subjects with a mean follow-up of 27.7 ± 11.3 months was performed, comparing 40 cases of incident diabetes and 160 controls matched for age, sex, body mass index, fasting plasma glucose, 2-h post-load glycemia, smoking and alcohol abuse.

RESULTS

When considering antihypertensive treatment at enrolment, a lower proportion of cases was exposed to ACE-inhibitors/angiotensin receptor blockers (ACE-i/ARB) in comparison with controls. A non-significant trend toward a higher exposure to diuretics, which were mainly represented by thiazide diuretics, was observed in cases. In a multivariate analysis, including both ACE-i/ARB and diuretics, a protective effect of ACEi/ARB, and an increased risk with diuretics were observed. Similar results were obtained in alternative models, after adjusting for systolic and diastolic blood pressure at enrolment, diagnosis of hypertension, concurrent treatment with β-blockers or calcium-channel blockers, and number of antihypertensive medications.

CONCLUSIONS

Diuretics seem to be associated with a higher incidence of diabetes, whereas treatment with ACEi/ARB could have a protective effect.

Health-related quality of life in hypertension, chronic kidney disease, and coexistent chronic health conditions

With the increasing prevalence of hypertension, there has been a growing interest in understanding the health-related quality of life (HRQOL) of patients with hypertension. Although hypertension is often perceived as asymptomatic, it is associated with impaired HRQOL because of complications or comorbidities, awareness of the diagnosis, and adverse effects from antihypertensive medications. This article focuses on the literature published since 2000, on HRQOL in elderly hypertensive individuals as well as hypertensives with co-existent diseases, including chronic kidney disease, cardiovascular disease, and diabetes mellitus. Most of the studies found that hypertensive individuals with co-existent co-morbidities tend to have lower HRQOL than those with hypertension alone, and identified the number of co-morbid illnesses as an independent determinant of HRQOL. The most pronounced effect was noted in the physical function domains of HRQOL. Studies have also examined the effects on HRQOL of specific classes of antihypertensive drugs without specific demonstration of superiority of one drug class over another in terms of HRQOL measures. Although there is evidence in favor of angiotensin-converting enzyme-inhibition for improving renal and cardiovascular outcomes in hypertensive patients, its role in ameliorating HRQOL outcomes remains to be established.

The effect of fat intake and antihypertensive drug therapy on serum lipid profile: a cross-sectional survey of serum lipids in male and female hypertensives

The present study aimed to investigate the effect of betablocker with diuretics therapy on serum cholesterol and high density lipoprotein (HDL-C) lipids in cross-sectional data (age, sex, weight, and body mass index (BMI), smoking/alcoholic consumption) and supplemented vegetarian low-fat diet with daily low fat energy intake, salt intake, duration of drug therapy, and serum protein as effective measures of lowering blood pressure among hypertensives in both males and females. Hypertensive patients on betablocker and/or thiazide therapy were compared in cross-section study with their age, blood pressure, fat intake, serum lipid profile, BMI, and serum albumin in males and females. Dietary fat intake and serum lipid profile were income related. Betablocker and diuretics therapy in combination with dietary fat intervention was beneficial for prolonged dyslipidemia control. Serum cholesterol level was main contributing factor dependent on BMI, duration of drug, and socio-economic factors. Fat intake contributed in hypertension and serum cholesterol levels. A cross-sectional data analysis showed beneficial effects of "low fat-salt-smoking-alcohol consumption and combined polyunsaturated fatty acid with antihypertensive therapy approach" to keep normal dyslipidemia and hypertension. Low fat intake, low salt, smoking, alcohol consumption, and combination of dietary oil supplements with lipid betablockers and diuretic modulators were associated with low hypertension and controlled dyslipidemia in Asian sedentary population.

Efficacy of ivabradine, a selective I(f) inhibitor, in patients with chronic stable angina pectoris and diabetes mellitus

Ivabradine is a specific heart rate-lowering antianginal agent that was evaluated in a clinical development program involving approximately 3,000 patients with stable coronary artery disease, most with angina pectoris. We analyzed the pharmacokinetics, efficacy (evaluated by exercise tolerance testing), safety, and effects on glucose metabolism of ivabradine in patients with diabetes mellitus (DM) in this program. Most analyses included data from 535 patients with DM, approximately 18% of the overall patient sample. Patients with DM were older, more likely to be women, and more likely to have more severe angina pectoris than patients without DM. The pharmacokinetics of ivabradine did not differ in patients with DM versus those without DM. A reduction in the heart rate at rest with ivabradine was similar in those with (15.2%) and without (15.7%) DM. At baseline, the exercise capacity tended to be lower in the patients with DM, but the improvements in most exercise tolerance measures with ivabradine treatment were similar in patients with and without DM. No special safety concerns were associated with ivabradine in those with DM. The rates of sinus bradycardia and visual disturbances, known to be related to the action of ivabradine, showed no relative increase in the patients with DM. Ivabradine treatment was not associated with adverse effects on glucose metabolism. In conclusion, ivabradine was effective in preventing angina in patients with DM and was not associated with particular safety concerns or adverse effects on glucose metabolism. Ivabradine represents an attractive alternative to beta blockers in patients with stable angina pectoris and DM.

Haemorheological disturbances in hypertensive type 2 diabetic patients ? influence of antihypertensive therapy

Haemorheological changes have been described in hypertension as well as in diabetes mellitus. Antihypertensive treatment improves rheology in hypertensive patients. The aim of this study was to describe the haemorheological profile and its impact on shear stress in hypertensive type 2 diabetes mellitus patients (HT + DM) and to investigate the effect of antihypertensive therapy on blood rheology using a double-blind randomized protocol, comparing the calcium antagonist amlodipine with the angiotensin-converting enzyme (ACE) inhibitor enalapril. A total of 144 patients with hypertension and type 2 diabetes (64 of transversal study and 80 of randomized clinical trial) were compared with 92 controls belonging to a transversal study. Secondarily, in a separate analysis, therapeutic effects of calcium antagonist amlodipine and ACE inhibitor enalapril were compared in a longitudinal, randomized trial in the patients. We assessed whole-blood viscosity, plasma viscosity, partial and total disaggregation times, haematocrit and fibrinogen. Radial artery systolic flow velocity was measured by pulsed Doppler. Shear stress was calculated as the product of flow velocity x whole-blood viscosity. Compared with controls, patients had significantly higher whole-blood viscosity for all shear rates (P < 0.001) as well as higher arterial diameter and systolic blood flow velocity (2.8 +/- 0.3 vs. 2.6 +/- 0.3 mm, P < 0.001; and 50.8 +/- 11.6 vs. 45.6 +/- 9.8 cm/s, P = 0.01, respectively). Whole-blood viscosity at shear rate gamma = 128/s tended to increase with amlodipine (+1.13%) and decrease with enalapril (-2.47%) (P = 0.028 for inter-group difference). In hypertensive diabetic patients, hyperviscosity contributes to increased shear stress. Haemorheological disturbances in these patients are not significantly influenced by blood pressure lowering with antihypertensive therapy by ACE inhibitor enalapril or calcium antagonist amlodipine. Other factors potentially contributing to rheology and arterial changes may be more critical in HT + DM patients and need further investigation.