Diabetes Mellitus and Coronary Heart Disease in the Elderly

Asymmetric dimethylarginine as a risk factor for cardiovascular disease in Japanese patients with type 2 diabetes mellitus

AIMS

Although asymmetric dimethylarginine (ADMA) is known to be involved in the developing process of cardiovascular diseases (CVD), little is known about the effects of ADMA on atherosclerosis in Asian patients with diabetes, who have the racial feature of lower body mass index (BMI) and decreased capacity of insulin secretion and sensitivity.

METHODS

We employed 55 Japanese patients with type 2 diabetes mellitus (mean age, 64·2 years; 56% men) in a 6-month-longitudinal study and 450 patients (mean age, 62·7 years; 56% men) in a cross-sectional study and examined the association of serum ADMA with atherosclerosis parameters [intima-media thickness (IMT) and brachial-ankle pulse wave velocity (baPWV)] as well as with the presence of CVD.

RESULTS

In the longitudinal study, multiple regression analysis showed that basal serum ADMA level had a significantly positive association with changes in IMT (β=0·35, P=0·03) independently of age, duration of diabetes, BMI, blood pressure, low-density lipoprotein and high-density lipoprotein (LDL and HDL) cholesterol, HbA(1c) , and renal function. In the cross-sectional study, the serum ADMA level was significantly and positively associated with the presence of CVD (odds ratio=7·22, 95% confidence interval 1·29-40·40, P=0·02, by logistic analysis) and with baPWV (β=0·14, P <0·01, by multiple regression analysis). In contrast, serum symmetric dimethylarginine level, a structural isomer of ADMA, was associated neither with parameters for atherosclerosis nor with the presence of CVD in both studies.

CONCLUSIONS

Serum ADMA is a predictor of atherosclerosis and associated with the presence of CVD in Japanese patients with type 2 diabetes mellitus.

Serum DHEA-S level is associated with the presence of atherosclerosis in postmenopausal women with type 2 diabetes mellitus

We investigated the relationship between serum dehydroepiandrosterone-sulfate (DHEA-S) and insulin-like growth factor-I (IGF-I) to various parameters for atherosclerosis in type 2 diabetes. The levels of DHEA-S and IGF-I are known to decrease with aging and thereby might be associated with an increased risk of cardiovascular disease. One hundred forty-eight men and 106 postmenopausal women with type 2 diabetes were assessed in a cross-sectional study. Serum DHEA-S and IGF-I concentrations were measured and brachial-ankle pulse wave velocity (baPWV) and ultrasonographically-evaluated intima-media thickness (IMT) were assessed. Although simple regression analysis showed that log(DHEA-S) and IGF-I in men and log(DHEA-S) in women were significantly and inversely correlated with baPWV and IMT, only log(DHEA-S) in women was still significantly and inversely correlated with these atherosclerotic parameters after multiple regression analysis was adjusted for age, duration of diabetes, BMI, HbA(1C), systolic blood pressure, LDL-Cholesterol (C), serum creatinine, and smoking (Brinkman index). Serum DHEA-S level seemed to be associated with atherosclerosis in diabetic postmenopausal women independent of age, body stature, diabetic status, and other atherosclerotic risk factors, and might be a useful addition to other parameters for assessing the risk of atherosclerosis in this population.

Lipid Management and the Elderly

Advancing age is an independent risk factor for the development of coronary heart disease. However, the significance of hypercholesterolemia as a cardiovascular risk factor in the elderly, has been widely debated. While no large-scale, randomized clinical trial has been conducted to evaluate cholesterol lowering solely in the elderly, evidence from older subgroups in several intervention trials supports the efficacy of lowering elevated low-density lipoprotein cholesterol for reducing cardiovascular risk in the elderly. Furthermore, although the relative risk of hyper-cholesterolemia for coronary heart disease incidence may be attenuated with advancing age, the population-wide impact of treating elevated cholesterol levels in the elderly would be large, due to the high frequency of coronary heart disease in the elderly. This article reviews key issues in the management of hyper-cholesterolemia with respect to coronary heart disease risk reduction in the elderly.

Cardiovascular Disease Risk Reduction in Older Adults

Preventing cardiovascular events in older persons presents unique challenges to clinicians. Cardiovascular disease accounts for a large amount of disability and mortality in older persons. Older persons are often faced with unique and multiple challenges to health, including cognitive decline, social isolation, financial constraints, and physical disabilities. As more and more older persons are enrolled in studies that aim to better understand coronary heart disease and its prevention, new information is becoming available that allow clinicians to improve outcomes in the older adult. The most recent updates in the area of medical management, as well as updates of recommendations for lifestyle changes, including physical activity and dietary recommendations for older persons at risk, are presented in this article.

Aging with cardiopulmonary disease: the rehab perspective

Cardiac disease is a leading cause of disability. This article reviews the epidemiology, pathophysiology, and risk factors for coronary heart disease. We explore the latest research in risk stratification, exercise training, and screening for cardiac rehabilitation in the elderly patient. The rehabilitation specialist will see how this select population differs in their medical and rehabilitative needs.

Efficacy of thrombolysis in younger and older adult patients suffering their first acute q-wave myocardial infarction

OBJECTIVES

Advancing age is an independent predictor of increased mortality after acute myocardial infarction (AMI). Several hypotheses have been developed to try to explain this phenomenon, but data available about the efficacy of thrombolytic therapy in older patients are still not conclusive. The goal of this study was to investigate the efficacy of thrombolysis in adult and older patients who suffered their first AMI.

DESIGN

Retrospective cohort study.

SETTING

A coronary care unit.

PARTICIPANTS

The sample included 244 younger (aged <65, n = 166) and older (age 65, n = 78) adult patients suffering their first Q-wave AMI, all receiving thrombolysis with human-recombinant tissue-type plasmin-ogen activator (100 mg total dose within 2.5 hours of the onset of AMI.

MEASUREMENTS

Infarct size was estimated by isoenzyme creatine kinase-myoglobin (CK-MB) release, measuring the area under the curve as a function of time. ST elevation, the sum of ST elevation above the baseline, and the sum of R wave height in precordial leads V1-V6 were evaluated using 12-lead electrocardiograms. Myocardial reperfusion was calculated when ST-segment elevation decreased more than 60 with respect to the most abnormal peak detected.

RESULTS

CK-MB peak level was significantly smaller in younger patients than in older ones (P< .01) and was significantly correlated with increasing age (P< .0001). Area under the 36-hour CK-MB curve was lower in younger patients than in older ones (P< .0001) and was well correlated with increasing age (P< .01). Reperfusion time was significantly shorter in younger patients (P< .05), and age was significantly correlated with reperfusion time (P< .001).

CONCLUSIONS

Infarct size was greater and reperfusion time was longer in older patients than in younger ones with first Q-wave AMI treated with thrombolysis. Infarct size and reperfusion time were linearly correlated with increasing age. These findings may help explain the increase in mortality due to AMI observed with advancing age.

Diabetes mellitus in a subgroup of older Mexicans: prevalence, association with cardiovascular risk factors, functional and cognitive impairment, and mortality

OBJECTIVES

To examine the prevalence and effects of diabetes mellitus in a subgroup of older Mexicans to allow comparisons to older persons of Mexican origin living in the United States.

DESIGN

Longitudinal study.

SETTING

High-rise retirement housing in Mexico City.

PARTICIPANTS

Seven hundred eighty-five public servants and their family members aged 65 and older.

MEASUREMENTS

Geriatric survey of function; mental status and depression; a physical examination; and blood samples for glucose and cholesterol.

RESULTS

The prevalence of diabetes mellitus in this population was 15.1%, substantially lower than the prevalence reported in people of Mexican origin living in the United States. Nondiabetics were more obese than diabetics. Diabetes mellitus was more common in men than women. The mortality rate was greater in diabetics than nondiabetics (relative risk=1.73, P <.05). Diabetics had more coronary artery disease and were more likely to die from myocardial infarction and neoplasms than nondiabetics. Diabetics were more likely to be functionally impaired (P <.0001) but no more likely to fall or to have fractures. Diabetics did not differ from nondiabetics in cognitive impairment or level of dysphoria.

CONCLUSION

These studies highlight some important similarities and differences in comparing a middle class subgroup of older diabetics in Mexico City with diabetics of Mexican origin living in the United States.

Femoral artery wall thickness and stiffness in evaluation of peripheral vascular disease in type 2 diabetes mellitus

Stiffening and thickening of arterial wall are two important components of atherosclerosis. The purpose of this study was to evaluate the effects of femoral artery wall stiffness on clinical manifestation of peripheral vascular disease (PVD) in type 2 diabetes mellitus. The subjects were 315 patients with type 2 diabetes. Presence of intermittent claudication and/or leg pain at rest and reduced ankle-brachial blood pressure index (ABI<0.9) were used as a subjective and an objective index of PVD, respectively. Femoral artery intima-media thickness (FA-IMT) and stiffness parameter beta (FA-stiffness beta) were measured by ultrasound methods. Symptomatic patients (N=58) showed greater values for both FA-IMT and FA-stiffness beta than those without symptom (N=257). Similarly, patients with reduced ABI (N=56) had greater FA-IMT and FA-stiffness beta than those without (N=259). However, correlation between FA-IMT and FA-stiffness beta was not impressive, especially in the symptomatic patients. To evaluate the effect of FA-stiffness beta on PVD symptoms, the subjects were divided into three subgroups according to FA-IMT, and then FA-stiffness beta was compared between those with and without PVD symptoms in each subgroup. The symptomatic patients had greater FA-stiffness beta values than the asymptomatic subjects in all the three subgroups. Multiple logistic regression analysis indicated that the presence of PVD symptoms was associated more closely with increased FA-stiffness beta than with increased FA-IMT, whereas reduced ABI was associated more closely with FA-IMT than with FA-stiffness beta. These data suggest that stiffening of arterial wall has a significant impact on PVD manifestations, particularly on the leg symptoms, in patients with type 2 diabetes.

Atypical presentation of acute myocardial infarction in 3 age groups

OBJECTIVE

The purpose of this study was to compare the clinical manifestations of first-time acute myocardial infarction (AMI) in 3 age groups of men and women who presented to the emergency departments of 3 acute tertiary care hospitals.

DESIGN

An exploratory, descriptive design was used, and there were 2 phases to the project. Phase 1 was a retrospective chart audit of a systematic random sample of patient charts, and phase 2 included a structured interview of a prospective random sample of emergency and intensive care unit nurses and physicians. The data were collected by using a chart audit tool and a semistructured interview, respectively.

SETTING

The study took place at a western Canada university affiliated with acute tertiary care centres.

SAMPLE

A systematic random sample of 153 (105 men and 48 women) patient charts were audited from the health records departments of 3 acute care hospitals. All of the patients had experienced a first-time AMI. In addition, a random sample of emergency/intensive care unit nurses (n = 60) and physicians (n = 18) was interviewed.

RESULTS

The results indicate that a statistically significant number of the oldest (75 years or older) male patients present with atypical manifestations of AMI compared with the men in the younger age groups (P =.005). The same trend was not noted for female patients. The results of the study are limited with respect to the small number of women in each age category. Caution must therefore be exercised in generalizing the results to the target population of women with AMI. The atypical manifestations are described. The results of the interviews revealed that many clinicians do not look for different clinical manifestations when assessing older patients.

CONCLUSIONS

It is essential that nurses and physicians accurately assess patients with AMI, especially patients in the older age groups who may be presenting atypically. It is also important that professional and nonprofessional public health education initiatives include information regarding both typical and atypical presentation of AMI, particularly in the older patient.

Effect of fenofibrate on progression of coronary-artery disease in type 2 diabetes: the Diabetes Atherosclerosis Intervention Study, a randomised study

BACKGROUND

Atherosclerosis is the most common complication of diabetes. Correction of hyperglycaemia helps to prevent microvascular complications but has little effect on macrovascular disease. Post-hoc analyses of diabetic subpopulations in lipid intervention trials suggest that correction of lipoprotein abnormalities will lead to a decrease in coronary-artery disease. The Diabetes Atherosclerosis Intervention Study (DAIS) was specifically designed to assess the effects of correcting lipoprotein abnormalities on coronary atherosclerosis in type 2 diabetes.

METHODS

731 men and women with type 2 diabetes were screened by metabolic and angiographic criteria. 418 were randomly assigned micronised fenofibrate (200 mg/day) or placebo for at least 3 years. They were in good glycaemic control (mean haemoglobin A1c 7.5%), had mild lipoprotein abnormalities, typical of type 2 diabetes, and at least one visible coronary lesion. Half had no previous clinical coronary disease. Initial and final angiograms followed a standard protocol and were analysed by a computer-assisted quantitative approach. Missing data for the primary endpoints (minimum lumen diameter, mean segment diameter, and mean percentage stenosis) were imputed. Analyses were by intention to treat.

FINDINGS

Total plasma cholesterol, HDL-cholesterol, LDL-cholesterol, and triglyceride concentrations all changed significantly more from baseline in the fenofibrate group (n=207) than in the placebo group (n=211). The fenofibrate group showed a significantly smaller increase in percentage diameter stenosis than the placebo group (mean 2.11 [SE 0.594] vs 3.65 [0.608]%, p=0.02), a significantly smaller decrease in minimum lumen diameter (-0.06 [0.016] vs -0.10 [0.016] mm, p=0.029), and a non-significantly smaller decrease in mean segment diameter (-0.06 [0.017] vs -0.08 [0.018] mm, p=0.171). The trial was not powered to examine clinical endpoints, but there were fewer in the fenofibrate group than the placebo group (38 vs 50).

INTERPRETATION

DAIS suggests that treatment with fenofibrate reduces the angiographic progression of coronary-artery disease in type 2 diabetes. This effect is related, at least partly, to the correction of lipoprotein abnormalities, even those previously judged not to need treatment.

[Unstable angina in the elderly: clinical, profile, management and mortality at three months. The PEPA Registry Data]

INTRODUCTION AND OBJECTIVES

Few reports in the literature have studied the characteristics and management of unstable angina in the elderly in Spain. The aim of this study was to analyze the clinical characteristics and the use of diagnostic and therapeutic resources in patients > or = 70 years of age.

PATIENTS AND METHODS

A total of 1,551 patients > or = 70 years of age were included out of 4,115 included in the PEPA registry with a follow up of 90 days. These patients were compared with 2,564 < 70 years.

RESULTS

In comparison, the elderly (76 +/- 5 years) versus the younger group (58 +/- 8.5 years) included a higher proportion of women (43 vs 27%), diabetics (30 vs 23%)and hypertensive patients (60 vs 49%) with a lower proportion (p < 0.001) of hypercholesterolemia (33 vs 43%), smoking (40 vs 60%) or family history (9 vs 17%). A previous history of angina (49 vs 35%) or infarction (38 vs31%) and comorbidity was found to be significantly more frequent in the elderly, with a worse previous functional class (NYHA > 2 out of 34 vs 15%). The elderly were treated with fewer invasive procedures (25 vs 44%) or catheterization (26 vs 36%) and they were more frequently controlled with medical treatment (86 vs 83%) although with a lower use of beta blockers (45 vs 53%). The mortality at 3 months was greater in the elderly (7.4 vs 3.0%;p < 0.005) with age being an independent predictor of bad prognosis. Cox multivariate analysis showed the age, ST segment depression, diabetes and heart failure on admission to be predictors of bad prognosis in the elderly.

CONCLUSIONS

A different pattern is observed in cardiovascular risk factors with a more unfavorable clinical profile in elderly patients with unstable angina. The management of these patients is less aggressive and the mortality is greater. Diabetes, heart failure and ST segment depression on admission are independent predictors of bad prognosis in elderly patients.

Diabetes mellitus, coronary heart disease incidence, and death from all causes in African American and European American women: The NHANES I epidemiologic follow-up study

Few data are available on risk for coronary heart disease in African American women with diabetes mellitus, a well-established coronary risk factor in European American women. This study tests the hypothesis that medical history of diabetes predicts coronary heart disease incidence in African American women in a national cohort. Participants in the NHANES I Epidemiologic Follow-up Study in this analysis were 1035 African American and 5732 European American women aged 25-74 years without a history of coronary heart disease. Average follow-up for survivors was 19 years (maximum 22 years). Risk of incident coronary heart disease by baseline diabetes status was estimated. Proportional hazards analyses for African American women aged 25-74 revealed significant associations of coronary heart disease risk with diabetes after adjusting for age (RR = 2.40; 95% CI, 1.58-3.64, P < 0.01). After adjusting for age, smoking, and low education, there was an elevated risk in diabetics age 25-74 (RR = 2. 34; 95% CI, 1.54-3.56, P < 0.01); this association did not differ significantly from that for European American women. Excess coronary incidence in African American compared to European American women aged 25-64 was statistically explained by controlling for diabetes history, age, education, and smoking but only partly explained by age and diabetes history. In African American women aged 25-74, diabetes was also associated with increased coronary heart disease, cardiovascular, and all-cause mortality. The population attributable risk of coronary heart disease incidence associated with a medical history of diabetes was 8.7% in African American women and 6.1% in European American women. Medical history of diabetes was a significant predictor of coronary heart disease incidence and mortality in African American women and explained some of the excess coronary incidence in younger African American compared to European American women.