Natural history of cardiovascular and renal disease in patients with type 2 diabetes: effect of therapeutic interventions and risk modification

Hypertension in diabetes: treatment considerations

Treatment of blood pressure in the patient with diabetes remains a challenge. While data extrapolated from many trials seemed to imply that lower blood pressures leads to more favorable cardiovascular outcomes, this paper reviews newer trials designed to treat to blood pressure targets below 130/80 mmHg in patients with long term established diabetes, which showed that this goal may prove more harmful than helpful. In clinical practice this may be less relevant due to the fact that less than half of patients are even at the goal of 130/80. The interaction between glucose control and blood pressure control are also discussed, emphasizing the importance of multifactorial treatment.

Use of Antiplatelet Agents for Primary and Secondary Prevention of Cardiovascular Disease Amongst Type 2 Diabetic Patients

Background. A retrospective observational study was conducted to study the use of antiplatelet agents for primary and secondary prevention of cardiovascular disease among hospitalized type 2 diabetes mellitus patients.

Method. A total of 355 patients were included in the study. The compliance with the American Diabetes Association recommendation on the use of antiplatelet therapy for prevention of cardiovascular disease was studied.

Results. For the primary prevention group, type 2 diabetes mellitus, patients with known dyslipidemia were more likely to receive antiplatelet therapy than those without dyslipidemia (P = 0.023). The rate of adherence to the American Diabetes Association recommendations on the use of antiplatelet therapy for secondary prevention of cardiovascular disease was higher than for primary prevention of cardiovascular disease (P = 0.001).

Conclusion. In conclusion, many of the eligible patients still do not receive antiplatelet therapy, particularly in primary prevention of cardiovascular disease. Measures should be taken to ensure that type 2 diabetes mellitus patients receive the antiplatelet therapy and hence prevent macrovascular complications.

Antihypertensive Therapy in the Presence of Proteinuria

The presence of proteinuria is a well-known risk factor for both the progression of renal disease and cardiovascular morbidity and mortality, and decreases in urine protein excretion level were associated with a slower decrease in renal function and decrease in risk of cardiovascular events. Increased blood pressure has a major role in the development of proteinuria in patients with either diabetic or nondiabetic kidney disease, and all recent guidelines recommend a blood pressure goal less than 130/80 mm Hg in patients with proteinuria to achieve maximal renal and cardiovascular protection. Drugs interfering with the renin-angiotensin system, ie, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, should be used as first-line antihypertensive therapy in patients with proteinuria because they seem to have a blood pressure-independent antiproteinuric effect, and if blood pressure levels are still out of goal, a diuretic should be added to this regimen. A combination of an angiotensin-converting enzyme inhibitor with an angiotensin receptor blocker or other classes of medications shown to decrease protein excretion, such as nondihydropyridine calcium antagonists or aldosterone receptor blockers, should be considered to decrease proteinuria further. This review provides an extended summary of current evidence regarding the associations of blood pressure with proteinuria, the rationale for currently recommended blood pressure goals, and the use of various classes of antihypertensive agents in proteinuric patients.

The role of lipids in the development of diabetic microvascular complications: implications for therapy

Dyslipidemia is a major factor responsible for coronary heart disease and its reduction decreases coronary risk in patients with diabetes mellitus. However, the association of dyslipidemia with microvascular complications and the effect of intervention with lipid-lowering therapy in diabetes have been less investigated. We present the systematic review of association and intervention studies pertaining to dyslipidemia and microvascular disease in diabetes and also review possible mechanisms. Dyslipidemia may cause or exacerbate diabetic retinopathy and nephropathy by alterations in the coagulation-fibrinolytic system, changes in membrane permeability, damage to endothelial cells and increased atherosclerosis. Hyperlipidemia is associated with faster decline in glomerular filtration rate and progression of albuminuria and nephropathy. Recent evidence also suggests a role of lipoprotein(a) in progression of retinopathy and nephropathy in patients with diabetes mellitus. Lipid-lowering therapy, using single agents or a combination of drugs may significantly benefit diabetic retinopathy and diabetic nephropathy. In particular, hydroxymethyl glutaryl coenzyme A reductase inhibitors may be effective in preventing or retarding the progression of microvascular complications because of their powerful lipid-lowering effects and other additional mechanisms. However, most of the data are based on short-term studies, and need to be ascertained in long-term studies. Until more specific guidelines are available, aggressive management of diabetic dyslipidemia, according to currently accepted guidelines, should be continued for the prevention of macrovascular disease which would also benefit microvascular complications.

Selection of the dose of angiotensin converting enzyme inhibitor for patients with diabetic nephropathy depends on the presence or absence of left ventricular hypertrophy

The coexistence of hypertension increases cardiovascular risks and the rate of deterioration of renal function for diabetic patients. For patients with left ventricular hypertrophy (LVH), the use of an angiotensin converting enzyme (ACE) inhibitor is known to be effective and well tolerated and to be protective against chronic renal insufficiency (CRI). However, serious adverse reactions to ACE inhibitors, such as the rapid deterioration of renal function, have been reported, making physicians hesitant to use these agents. To resolve this dilemma, we compared changes in renal function and left ventricular function and the safety and effectiveness of benazepril, an ACE inhibitor, in patients with diabetic nephropathy, with or without LVH. The age, sex, duration of diabetes, levels of blood pressure and blood glucose and rates of creatinine clearance (CrCl) were compared between 36 diabetic patients with LVH and 36 matched diabetic patients without LVH. The rates of CrCl in all patients were between 14 and 35 ml/min, and all patients received an ACE inhibitor before enrollment. The group comprised 43 men and 29 women, with a mean age of 56 +/- 4 years. These patients were divided into three groups, each of which was subdivided into a group with and a group without LVH. Group I (without LVH) or I-L (with LVH) received a half dose of benazepril (2.5 mg daily), Group II (without LVH) or II-L (with LVH) received a normal daily dose of 5 mg benazepril, and Group III (without LVH) or III-L (with LVH) discontinued the administration of the ACE inhibitor. The follow-up period was 1 year and, during the study, blood pressure was maintained at less than 140/90 mmHg. If the blood pressure control was not satisfactory, benidipine, a calcium antagonist, and/or furosemide, a loop diuretic, and/or guanabenz, a central acting antihypertensive agent, were administered. In the diabetic patients with LVH, the administration of a normal dose of benazepril inhibited the decline of renal function and cardiac function (CrCl: 24.2 +/- 1.5 to 22.0 +/- 2.5 ml/min; EF (ejection fraction): 56 +/- 3 to 54 +/- 6%) compared to the other two groups. In patients without LVH, a half dose of benazepril preserved renal function (23.4 +/- 2.6 to 22.0 +/- 3.1 ml/min; EF: 54 +/- 3 to 56 +/- 3%). Discontinuation of the administration of ACE inhibitor led to the further progression of renal dysfunction and decreases in EF in patients with or without LVH. Our results provide some indications for the use of ACE inhibitors in diabetic patients when renal dysfunction and/or cardiac hypertrophy are present.

The Diabcare-Asia 1998 study--outcomes on control and complications in type 1 and type 2 diabetic patients

The aim of this study was to describe the glycaemic and metabolic control and diabetes-related complications in type 1 and type 2 Asian patients.

METHODS

Data of diabetes patients from 230 diabetes centres in 12 Asian regions were collected on a retrospective-prospective basis through review of medical records, interview and laboratory assessments. Analysis of glycated haemoglobin (HbA1c) was carried out in central laboratories appointed by Bio-Rad. The data collection case record forms were scanned electronically.

RESULTS

22177 patients with valid data made up the analysis population. Among patents with type 1 and type 2 diabetes, there was a higher proportion of women than men (53% vs. 47% for type 1 patients and 56% vs. 44% for type 2 diabetes). Hypertension (61%) and overweight (40% with BMI > or = 25 kg/m2 were common in type 2 patients. Dyslipidaemia was also present in at least half of both types of patients. Control of glycaemia (mean HbA,1c and fasting blood glucose [FBG]) was poor in type 1 (9.9 +/- 2.5%; 10.2 +/- 5.2 mmol/l) and type 2 patients (8.5 +/- 2.0%; 8.9 +/- 3.4 mmol/l). Glycaemia in the majority of both types of patients fell short of those stipulated by various guidelines. In type 2 patients, glycaemia deteriorated (HbA1c > 7.5%, FBG > or = 7.0 mmol/l) with duration of diabetes > 7 years. Both types of diabetes appear to share a similar high prevalence of complications of cataract, retinopathy and neuropathy, although the prevalence of cataract (27%) and neuropathy (35%) was higher in type 2 diabetes. Screening for microalbuminuria was not common.

CONCLUSIONS

The Inadequate metabolic and hypertension control, especially in type 2 patients, needs to be addressed.

Choices and goals in the treatment of the diabetic hypertensive patient

The number of people living in the United States who have diabetes and high blood pressure is over 11 million and rising. Together, these two diseases are devastating to the whole body if not aggressively controlled. The tight recommendations put forth by the Joint National Committee VI for better control of blood pressure and control of proteinuria have helped diminish further organ failure in patients with hypertension and diabetes. Combination therapy has been found to be very effective, and one arm should be an angiotensin converting enzyme inhibitor.

Microalbuminuria: what is it? Why is it important? What should be done about it?

Microalbuminuria (MA) is defined as persistent elevation of albumin in the urine, of 30-300 mg/day (20-200 microg/min). These values are less than the values detected by routine urine dipstick testing, which does not become positive until protein excretion exceeds 300-500 mg/day. Use of the albumin-to-creatinine ratio is recommended as the preferred screening strategy for all diabetic patients. MA is measured in spot morning urine obtained from the patient in the office and sent for measurement of both albumin and creatinine. A value above 0.03 mg/mg suggests that albumin excretion is above 30 mg/day and therefore MA is present. MA should be checked annually in everyone, and every 6 months within the first year of treatment to assess the impact in patients started on antihypertensive therapy. MA is an established risk factor for renal disease progression in type 1 diabetes and its presence is the earliest clinical sign of diabetic nephropathy. In addition, a number of studies suggest that MA is an important risk factor for cardiovascular disease and defines a group at high risk for early cardiovascular mortality in both type 2 diabetes and essential hypertension. MA also signifies abnormal vascular permeability and the presence of atherosclerosis. Among nondiabetic patients with essential hypertension, MA is associated with higher blood pressures, increased serum total cholesterol, and reduced serum high-density lipoprotein cholesterol. Thus, taken together these data support the concept that the presence of MA is the kidney's notice to the physician/patient that there is a problem with the vasculature. MA can be reduced, and progression to overt proteinuria prevented, by aggressive blood pressure reduction. The National Kidney Foundation recommends that blood pressure levels be maintained at or below 130/80 mm Hg in anyone with diabetes or renal disease. This should be accomplished with antihypertensive agents that prevent the rise in MA and hence prevent development of proteinuria. Such agents are angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and, to a lesser extent, Beta blockers, non-dihydropyridine calcium antagonists, and diuretics. In summary, the presence of MA is a marker of endothelial dysfunction and a harbinger of markedly enhanced cardiovascular risk. All patients with diabetes and/or hypertension should be screened for the presence of microalbuminuria with use of spot morning urine. To maximize prevention of MA development, the following goals should be instituted: 1) blood pressure should be maintained at less than 130/80 mm Hg and a low-salt, moderate-potassium diet instituted; 2) in diabetics, HbA1c should be kept at less than 7%; 3) in obese patients, a weight loss program should be implemented, with a goal BMI of less than 30; and 4) the physician and patient, working together, should maintain low-density lipoprotein cholesterol at less than 120 mg/dL, and less than 100 mg/dL if diabetes is present. (c)2001 by Le Jacq Communications, Inc.

Are angiotensin-converting enzyme inhibitors the best treatment for hypertension in type 2 diabetes?

The influence of hypertension on the clinical course and complications of type 2 diabetes is well established. With a special focus on angiotensin-converting enzyme inhibitors, this paper will review recently published results of prospective studies addressing two important aspects: the degree of blood pressure control, and the choice of antihypertensive regimen, in the prevention of complications in hypertensive type 2 diabetic patients. None of the recent studies have shown worse outcomes in patients treated with angiotensin-converting enzyme inhibitor-based regimens compared with alternative treatments. Some studies have suggested that angiotensin-converting enzyme inhibitor-based antihypertensive regimens may be superior to alternative treatments in reducing the risk of micro- and macrovascular complications, whereas other studies found similar effects for beta-blockers or calcium antagonists. Several trials showed beneficial effects of angiotensin-converting enzyme inhibitors over calcium antagonists, and have raised concerns about the use of dihydropyridine calcium antagonists in these patients. However, it remains to be determined whether there should be more reserved use of calcium antagonists in such patients, in the light of more major trials showing the safety and efficacy of calcium antagonists in preventing cardiovascular and renal endpoints. The degree of reduction of blood pressure rather than the choice of a particular drug may be the most important factor. Studies focusing on renal endpoints suggest that angiotensin-converting enzyme inhibitors have a better antiproteinuric effect than other agents, but this phenomenon is not always reflected by a more beneficial effect of angiotensin-converting enzyme inhibitors on the decline in glomerular filtration rate. In many ways, the question of whether angiotensin-converting enzyme inhibitors are the best class of agent in these patients is academic. Angiotensin-converting enzyme inhibitors are sufficiently safe, and, according to recent evidence, equally or more effective than other classes of agents. Tight blood pressure control is usually achievable only with a combination of agents. On the basis of available evidence, it appears that angiotensin-converting enzyme inhibitors, together with a low-dose cardioselective beta-blocker and a diuretic, should be used in most hypertensive type 2 diabetes patients, with calcium antagonists serving as reserve drugs in case of insufficient blood pressure control.