Effect of hypertension on mortality in Pima Indians

Ethnic differences in prevalence and risk factors for hypertension in the Suriname Health Study: a cross sectional population study

BACKGROUND

Limited information is available about the prevalence, ethnic disparities, and risk factors of hypertension within developing countries. We used data from a nationwide study on non-communicable disease (NCD) risk factors to estimate, explore, and compare the prevalence of hypertension overall and in subgroups of risk factors among different ethnic groups in Suriname.

METHOD

The Suriname Health Study used the World Health Organization Steps design to select respondents with a stratified multistage cluster sample of households. The overall and ethnic specific prevalences of hypertension were calculated in general and in subgroups of sex, age, marital status, educational level, income status, employment, smoking status, residence, physical activity, body mass index (BMI), and waist circumference (WC). Differences in the prevalence between ethnic subgroups were assessed using the Chi-square test. We used several adjustment models to explore whether the observed ethnic differences were explained by biological, demographic, lifestyle, or anthropometric risk factors.

RESULTS

The prevalence of hypertension was 26.2 % (95 % confidence interval 25.1 %-27.4 %). Men had higher mean values for systolic and diastolic blood pressure compared to women. Blood pressure increased with age. The prevalence was highest for Creole, Hindustani, and Javanese and lowest for Amerindians, Mixed, and Maroons. Differences between ethnic groups were measured in the prevalence of hypertension in subcategories of sex, marital status, education, income, smoking, physical activity, and BMI. The major difference in association of ethnic groups with hypertension was between Hindustani and Amerindians.

CONCLUSION

The prevalence of hypertension in Suriname was in the range of developing countries. The highest prevalence was found in Creoles, Hindustani, and Javanese. Differences in the prevalence of hypertension were observed between ethnic subgroups with biological, demographic, lifestyle, and anthropometric risk factors. These findings emphasize the need for ethnic-specific research and prevention and intervention programs.

Stroke in American Indians and Alaska Natives: A Systematic Review

We conducted a systematic review of published studies on stroke epidemiology in American Indians and Alaska Natives (AI/ANs). We used MeSH terms and strict inclusion criteria to search PubMed, identifying a relevant sample of 57 refereed publications. We report a consensus view in which prevalent stroke is more common, and estimates of cerebrovascular risk factors are higher, among AI/ANs than among other US populations. Like other minority groups, AI/ANs suffer stroke at younger ages than do non-Hispanic Whites. However, data on AI/AN stroke mortality are significantly compromised by racial misclassification and nonrepresentative sampling. Studies correcting for these problems have found that stroke mortality rates among AI/ANs are among the highest of all US racial and ethnic groups. As with Black and non-Hispanic White stroke mortality, AI/AN stroke mortality varies by geographic region, with the highest rates in Alaska and the Northwest and the lowest in the Southwest. Our results underscore the need for a concerted national effort to collect accurate cross-sectional and longitudinal data on stroke in AI/ANs.

DreamTel; Diabetes risk evaluation and management tele-monitoring study protocol

BACKGROUND

The rising prevalence of type 2 diabetes underlines the importance of secondary strategies for the prevention of target organ damage. While access to diabetes education centers and diabetes intensification management has been shown to improve blood glucose control, these services are not available to all that require them, particularly in rural and northern areas. The provision of these services through the Home Care team is an advance that can overcome these barriers. Transfer of blood glucose data electronically from the home to the health care provider may improve diabetes management.

METHODS AND DESIGN

The study population will consist of patients with type 2 diabetes with uncontrolled A1c levels living on reserve in the Battlefords region of Saskatchewan, Canada. This pilot study will take place over three phases. In the first phase over three months the impact of the introduction of the Bluetooth enabled glucose monitor will be assessed. In the second phase over three months, the development of guidelines based treatment algorithms for diabetes intensification will be completed. In the third phase lasting 18 months, study subjects will have diabetes intensification according to the algorithms developed.

DISCUSSION

The first phase will determine if the use of the Bluetooth enabled blood glucose devices which can transmit results electronically will lead to changes in A1c levels. It will also determine the feasibility of recruiting subjects to use this technology. The rest of the Diabetes Risk Evaluation and Management Tele-monitoring (DreamTel) study will determine if the delivery of a diabetes intensification management program by the Home Care team supported by the Bluetooth enabled glucose meters leads to improvements in diabetes management.

TRIAL REGISTRATION

Protocol NCT00325624.

Correlates of preclinical cardiovascular disease in Indigenous and Non-Indigenous Australians: a case control study

Background

The high frequency of premature death from cardiovascular disease in indigenous Australians is often attributed to the high prevalence of risk factors, especially type II diabetes mellitus (DM). We evaluated the relationship of ethnicity to atherosclerotic burden, as evidenced by carotid intima-media thickness (IMT), independent of risk factor status.

Methods

We studied 227 subjects (147 men; 50 ± 13 y): 119 indigenous subjects with (IDM, n = 54), and without DM (InDM, n = 65), 108 Caucasian subjects with (CDM, n = 52), and without DM (CnDM, n = 56). IMT was measured according to standard methods and compared with clinical data and cardiovascular risk factors.

Results

In subjects both with and without DM, IMT was significantly greater in indigenous subjects. There were no significant differences in gender, body mass index (BMI), systolic blood pressure (SBP), or diastolic blood pressure (DBP) between any of the groups, and subjects with DM showed no difference in plasma HbA1c. Cardiovascular risk factors were significantly more prevalent in indigenous subjects. Nonetheless, ethnicity (β = -0.34; p < 0.0001), age (β = 0.48; p < 0.0001), and smoking (β = 0.13; p < 0.007) were independent predictors of IMT in multiple linear regression models.

Conclusion

Ethnicity appears to be an independent correlate of preclinical cardiovascular disease, even after correction for the high prevalence of cardiovascular risk factors in indigenous Australians. Standard approaches to control currently known risk factors are vital to reduce the burden of cardiovascular disease, but in themselves may be insufficient to fully address the high prevalence in this population.

Risk of progression to hypertension in a low-income Mexican population with prehypertension and normal blood pressure

BACKGROUND

Blood pressure (BP) levels below the prehypertensive category may be associated with the risk of developing hypertension. We estimated the incidence rates of hypertension in a low-income Mexican population according to several subcategories of baseline BP within normal and prehypertensive categories.

METHODS

In total, 1572 nonhypertensive men (n = 632) and nonpregnant women (n = 940), aged 35 to 64 years at baseline, were followed for a median of 5.8 years. Hypertension was defined as systolic blood pressure (SBP) >or=140 mm Hg, diastolic blood pressure (DBP) >or=90 mm Hg, or a self-reported physician's diagnosis with antihypertensive medications.

RESULTS

During follow-up, 267 subjects developed hypertension, of whom 83 were men and 184 were women. The age-adjusted incidence rate was higher in women (37.1 per 1000 person-years) than in men (23.7 per 1000 person-years). There was a significant association between BP levels at baseline and incidence of hypertension, even within the normal category. For the upper levels of normal SBP (110 to 119 mm Hg), the hazards ratio (HR) was 2.43 (95% confidence interval [CI], 1.50 to 3.93) in women and 2.44 (95% CI, 1.05 to 5.69) in men, compared with SBP <110 mm Hg. For the upper levels of normal DBP (70 to 79 mm Hg), the HR was 2.33 (95% CI, 1.65 to 3.31) in women and 1.80 (95% CI, 0.92 to 3.52) in men, compared with DBP <70 mm Hg, after adjustment for recognized predictors.

CONCLUSIONS

A high risk for the incidence of hypertension was associated with levels of BP, even within the normal category. This information could help define a population at high risk of progression to hypertension, to establish preventive measures.

Electrocardiographic abnormalities predict deaths from cardiovascular disease and ischemic heart disease in Pima Indians with type 2 diabetes

BACKGROUND

The association between electrocardiographic (ECG) abnormalities and deaths from cardiovascular diseases (CVD) and ischemic heart disease (IHD) has been reported in the general population, but there is little information regarding persons with type 2 diabetes.

METHODS

Minor and major ECG abnormalities were identified and classified according to the Minnesota Code in a longitudinal study of 1605 Pima Indians aged > or =35 years with type 2 diabetes. Underlying causes of death were determined by review of all available clinical records, autopsy reports, medical examiners' findings, and death certificates.

RESULTS

During a median follow-up of 14.1 years (range 0.1 to 33.8 years), there were 190 CVD deaths, 135 (71.1%) of which were attributable to IHD. The age-adjusted CVD death rates in men with none, minor, and major ischemic ECG abnormalities were 7.3, 12.2 and 27.8, and in women, 4.3, 4.8 and 12.5 per 1000 person-years, respectively. After adjustment for other co-variables in a multiple proportional hazards model, subjects with minor and major ischemic abnormalities on ECG had 1.22 (95% CI, 0.76-1.97) and 1.83 (95% CI, 1.21-2.76) times the CVD death rate, and 1.32 (95% CI, 0.70-2.50) and 2.12 (95% CI, 1.26-3.57) times the IHD death rate of those with no ischemic ECG abnormalities, respectively.

CONCLUSIONS

The CVD and IHD death rates were higher in men and in subjects with major ischemic ECG abnormalities. Major ischemic abnormalities on ECG predicted death after accounting for other cardiovascular risk factors, including proteinuria.

Proteinuria is a prognostic marker for cardiovascular mortality: NIPPON DATA 80, 1980-1999

BACKGROUND: Proteinuria has been considered to be a prognostic marker for persons with diabetes mellitus, but only a limited number of studies about the relationship between proteinuria and mortality among general population has been available.

METHODS: The subjects were 10,897 individuals who participated in the National Cardiovascular Survey conducted in 1980 and who were aged 30 years or older living in 300 districts that had been randomly selected throughout Japan. The vital records were confirmed in 1999 and 7,203 subjects (3,180 males and 4,023 females) without a history of hypertension, stroke, heart disease, renal disease, or diabetes mellitus at the start of the study were investigated.

RESULTS: There were 126,825 person-years of follow-up. During the observed period of time, 371 died of cardiovascular causes, including 171 stroke deaths and 74 coronary deaths. The risk of proteinuria for cardiovascular mortality was greater than unity for those with a normal serum creatinine level, after adjusting for age and other cardiovascular disease risk factors.

CONCLUSIONS: When contrasted with other cardiovascular disease risk factors, urinary protein is an independent risk factor for cardiovascular death among the Japanese population.

Diabetes outcomes in the Indian health system during the era of the Special Diabetes Program for Indians and the Government Performance and Results Act

OBJECTIVES

We reviewed changes in blood glucose, blood pressure, and cholesterol levels among American Indians and Alaska Natives between 1995 and 2001 to estimate the quality of diabetes care in the Indian Health Service (IHS) health care delivery system.

METHODS

We conducted a cross-sectional analysis of data from the Indian Health Service Diabetes Care and Outcomes Audit.

RESULTS

Adjusted mean Hemoglobin A1c (HbA1c) levels (7.9% vs 8.9%) and mean diastolic blood pressure levels (76 vs 79 mm Hg) were lower in 2001 than in 1995, respectively. A similar pattern was observed for mean total cholesterol (193 vs 208 mg/dL) and triglyceride (235 vs 257 mg/dL) levels in 2001 and 1995, respectively.

CONCLUSIONS

We identified changes in intermediate clinical outcomes over the period from 1995 to 2001 that may reflect the global impact of increased resource allocation and improvements in processes on the quality of diabetes care, and we describe the results that may be achieved when community, health program, and congressional initiatives focus on common goals.

Periodontal disease and mortality in type 2 diabetes

OBJECTIVE

Periodontal disease may contribute to the increased mortality associated with diabetes.

RESEARCH DESIGN AND METHODS

In a prospective longitudinal study of 628 subjects aged > or =35 years, we examined the effect of periodontal disease on overall and cardiovascular disease mortality in Pima Indians with type 2 diabetes. Periodontal abnormality was classified as no or mild, moderate, and severe, based on panoramic radiographs and clinical dental examinations.

RESULTS

During a median follow-up of 11 years (range 0.3-16), 204 subjects died. The age- and sex-adjusted death rates for all natural causes expressed as the number of deaths per 1,000 person-years of follow-up were 3.7 (95% CI 0.7-6.6) for no or mild periodontal disease, 19.6 (10.7-28.5) for moderate periodontal disease, and 28.4 (22.3-34.6) for severe periodontal disease. Periodontal disease predicted deaths from ischemic heart disease (IHD) (P trend = 0.04) and diabetic nephropathy (P trend < 0.01). Death rates from other causes were not associated with periodontal disease. After adjustment for age, sex, duration of diabetes, HbA1c, macroalbuminuria, BMI, serum cholesterol concentration, hypertension, electrocardiographic abnormalities, and current smoking in a proportional hazards model, subjects with severe periodontal disease had 3.2 times the risk (95% CI 1.1-9.3) of cardiorenal mortality (IHD and diabetic nephropathy combined) compared with the reference group (no or mild periodontal disease and moderate periodontal disease combined).

CONCLUSIONS

Periodontal disease is a strong predictor of mortality from IHD and diabetic nephropathy in Pima Indians with type 2 diabetes. The effect of periodontal disease is in addition to the effects of traditional risk factors for these diseases.

Pharmacological strategies for kidney function preservation: are there differences by ethnicity?

The prevalence of chronic kidney disease (CKD) is on the rise in all ethnic groups. This is because of the increased prevalence of obesity, diabetes mellitus, the metabolic syndrome, and the inadequate control of elevated blood pressure and other cardiovascular-renal risk factors, especially in ethnic minority populations. The implications of the aforementioned trends in risk factor prevalence and control are profound. Moreover, these trends negatively impact patient quality of life and place an enormous financial burden on the health care system for the provision of care to patients with CKD, end-stage renal disease (ESRD), and/or cardiovascular disease (CVD). Thus, it is of utmost importance to devise strategies that prevent kidney disease and delay progressive loss of kidney function in persons with CKD. Proven strategies include pharmacological interventions that lower blood pressure to less than target levels (<130/80 mm Hg), attainment of optimal glycemic control (Hb A1c <7%), and reducing urinary protein excretion. It is also possible, although yet unproven, that correction of anemia and aggressive treatment of dyslipidemia may forestall the loss of kidney function. In general, ethnic minorities are underrepresented in most large trials. Recently, a few outcome clinical trials in blacks have reinforced the lessons of kidney function preservation already learned in nonblack populations. That is, the reversible risk factors for CKD appear to be virtually identical and, at least in nondiabetic CKD, pharmacological targeting of the renin-angiotensin-aldosterone system (RAAS) with angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers preserves kidney function better than non-RAAS blood pressure-lowering regimens, especially when significant proteinuria exists. Although more CKD studies in ethnic minorities are needed, until they become available, the best available evidence from the existing clinical trial database should be applied to minorities with CKD-even when specific data are not available for a specific racial or ethnic group. Why this approach? First, there are no known unique risk factors for kidney disease in any ethnic group. Second, poor control of reversible risk factors for CKD is universal, particularly in blacks and other ethnic minorities. Thus, it is logical to predict that more efficient use of strategies proven to forestall loss of kidney function will reduce the excess of CKD and ESRD in ethnic minorities relative to non-minority populations. However, medical-based strategies alone are probably not enough. The global epidemic of obesity will fuel the growing population of persons, especially among ethnic minorities, with diabetes, the main cause of CKD, ESRD, and CVD. The obesity and diabetes epidemics are unlikely to abate without innovative and ultimately effective public health approaches.

Hypertension in older urban Native-American primary care patients

OBJECTIVES

To examine hypertension and its management in a population of older urban American Indians and Alaska Natives (AI/ANs).

DESIGN

Retrospective cohort study using medical record review.

SETTING

Urban health clinic serving predominantly AI/ANs in the Pacific Northwest.

PARTICIPANTS

Five hundred twenty-four AI/ANs aged 50 and older seen between 1994 and 1995.

MEASUREMENTS

Frequency of diagnosed hypertension, undiagnosed hypertension, comorbid conditions, hypertension treatment, control, and quality of care.

RESULTS

The prevalence of diagnosed hypertension was 38%, and the prevalence of possible undiagnosed hypertension was 23%. Patients with diagnosed hypertension were more likely to be obese (age-adjusted odds ratio (OR) = 3.5), have diabetes mellitus (DM) (OR = 2.2), depression (OR = 1.7), heart disease (OR = 3.8), or renal disease (OR = 5.6) than patients without hypertension. Undiagnosed hypertension was inversely associated with number of health problems (OR = 0.8). Eighty-one percent of diagnosed patients were treated pharmacologically, but no factors associated with nontreatment were identified. Diuretic and beta-blocker usage was low. Patients with DM used angiotensin-converting enzyme inhibitors more frequently than patients without DM (OR = 2.4). Blood pressure was well controlled in 37%, with men being less well controlled than women (OR = 0.5). Serum cholesterol, creatinine, and retinal screening were performed more often than urinalyses or electrocardiograms. Lifestyle-modification counseling was uncommon. Number of health problems was the most common factor associated with screening tests for end-organ disease.

CONCLUSION

Few studies have examined the care of older urban AI/ANs. Improvements are needed in adherence to recommendations for the detection, management, and monitoring of hypertension and its complications in older urban AI/ANs.

Association between initial systolic blood pressure and risk of developing a uremic crisis or of dying in dogs with chronic renal failure

OBJECTIVE

To determine whether high systolic blood pressure (SBP) at the time of initial diagnosis of chronic renal failure in dogs was associated with increased risk of uremic crisis, risk of dying, or rate of decline in renal function.

DESIGN

Prospective cohort study.

ANIMALS

45 dogs with spontaneous chronic renal failure.

PROCEDURE

Dogs were assigned to 1 of 3 groups on the basis of initial SBP (high, intermediate, low); Kaplan-Meier and Cox proportional hazards methods were used to estimate the association between SBP and development of a uremic crisis and death. The reciprocal of serum creatinine concentration was used as an estimate of renal function.

RESULTS

Dogs in the high SBP group were more likely to develop a uremic crisis and to die than were dogs in the other groups, and the risks of developing a uremic crisis and of dying increased significantly as SBP increased. A greater decrease in renal function was observed in dogs in the high SBP group. Retinopathy and hypertensive encephalopathy were detected in 3 of 14 dogs with SBP > or = 180 mm Hg. Systolic blood pressure remained high in 10 of 11 dogs treated with antihypertensive drugs.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that initial high SBP in dogs with chronic renal failure was associated with increased risk of developing a uremic crisis and of dying. Further studies are required to determine whether there is a cause-and-effect relationship between high SBP and progressive renal injury and to identify the risks and benefits of antihypertensive drug treatment.

Childhood obesity in Canada: a review of prevalence estimates and risk factors for cardiovascular diseases and type 2 diabetes

Childhood obesity in Canada has become increasingly prevalent over the past 2 decades. Despite inconsistencies regarding different anthropometric indicators, cut-offs, and reference populations, both regional and national investigations have revealed high numbers of overweight and obese children and adolescents. A number of risk factors and health consequences have been associated with increased levels of body fatness in youth. Specifically, risk factors for cardiovascular diseases (CVD) and type 2 diabetes are known to develop early in life and tend to emerge in clusters among overweight youngsters. Unhealthy lifestyle behaviours (i.e., physical inactivity), a genetic disposition, and a centralized body fat distribution, all contribute to increased risk. In order to prevent future generations of children from experiencing increased morbidity and mortality as overweight and obese adults, coordinated efforts at all levels (family, school, community, and government) must be established with a long-term commitment to promote healthy nutrition and physical activity behaviours in our youth.