Applying recovery biomarkers to calibrate self-report measures of sodium and potassium in the hispanic community health study/study of latinos.

This corrects the article DOI: 10.1038/jhh.2016.98.

Applying recovery biomarkers to calibrate self-report measures of sodium and potassium in the Hispanic Community Health Study/Study of Latinos.

Measurement error in assessment of sodium and potassium intake obscures associations with health outcomes. The level of this error in a diverse US Hispanic/Latino population is unknown. We investigated the measurement error in self-reported dietary intake of sodium and potassium and examined differences by background (Central American, Cuban, Dominican, Mexican, Puerto Rican and South American). In 2010-2012, we studied 447 participants aged 18-74 years from four communities (Miami, Bronx, Chicago and San Diego), obtaining objective 24-h urinary sodium and potassium excretion measures. Self-report was captured from two interviewer-administered 24-h dietary recalls. Twenty percent of the sample repeated the study. We examined bias in self-reported sodium and potassium from diet and the association of mismeasurement with participant characteristics. Linear regression relating self-report with objective measures was used to develop calibration equations. Self-report underestimated sodium intake by 19.8% and 20.8% and potassium intake by 1.3% and 4.6% in men and women, respectively. Sodium intake underestimation varied by Hispanic/Latino background (P<0.05) and was associated with higher body mass index (BMI). Potassium intake underestimation was associated with higher BMI, lower restaurant score (indicating lower consumption of foods prepared away from home and/or eaten outside the home) and supplement use. The R2 was 19.7% and 25.0% for the sodium and potassium calibration models, respectively, increasing to 59.5 and 61.7% after adjusting for within-person variability in each biomarker. These calibration equations, corrected for subject-specific reporting error, have the potential to reduce bias in diet-disease associations within this largest cohort of Hispanics in the United States.

Clinical Implications of Recent Findings from the Antihypertensive and Lipid-Lowering Treatment To Prevent Heart Attack Trial (ALLHAT) and Other Studies of Hypertension.

Several recent comparative trials in hypertension have reported that similar blood pressure reductions may not necessarily translate into similar reductions in risk for cardiovascular complications. Thus, the method used to lower blood pressure may be important. In the Antihypertensive and Lipid-Lowering Treatment To Prevent Heart Attack Trial (ALLHAT), low-dose chlorthalidone as the first-line drug was superior to doxazosin. The 25% higher risk for major cardiovascular events associated with doxazosin was attributed primarily to a doubling in the risk for heart failure. A meta-analysis of patients with type 2 diabetes mellitus suggested that despite achieving similar blood pressure reductions, angiotensin-converting enzyme inhibitors are superior to other antihypertensive drugs in reducing the risk for acute myocardial infarction and cardiovascular events, but not stroke. Although individual comparative trials have failed to show conclusively that calcium-channel blockers differ from other antihypertensive drugs, a meta-analysis that included all published trials concluded that calcium-channel blockers are inferior to other classes of drugs in reducing the risk for acute myocardial infarction and heart failure. These observations suggest not only that antihypertensive drugs may have important mechanisms of action apart from blood pressure lowering but also that effective treatment is not a matter of simply lowering blood pressure. These findings have potential implications for the regulatory approval of antihypertensive agents, revisions of treatment guidelines, the design of future randomized trials comparing different antihypertensive drugs and, most important, the selection of drugs for the treatment of hypertensive patients.

Trend of stroke hospitalization, United States, 1988-1997.

BACKGROUND AND PURPOSE: Age-adjusted stroke mortality in the United States has declined in recent decades. However, the course of stroke incidence is less certain. To address this issue, we determined trends of stroke hospitalization and in-hospital case fatality during 1988-1997. METHODS: Stroke hospitalization was estimated from National Hospital Discharge Survey as numerator and Current Population Survey as denominator. Hospitalization rates were determined and stratified by patient characteristics. Average length of hospital stay was also determined. In-hospital mortality was specified by sex, age, and other patient characteristics. The change in these rates over 10 years and average annual percent changes were calculated. RESULTS: During 1988-1997, age-adjusted stroke hospitalization rate increased 18.6% (from 560 to 664/100 000; P=0.043), while total hospitalization increased from 592 811 to 821 760. This increase was limited to persons aged >/=65 years. Patients in the South had the highest stroke hospitalization rates, and those in the West had the lowest. Overall, 58% of strokes were classified as ischemic, 13% as hemorrhagic, and 29% as other. Over these 10 years, stroke patients having coincident diabetes, hypertension, and congestive heart failure increased 17.4% (P=0.17), 34% (P=0.05), and 31% (P=0.091), respectively. The average length of hospital stay fell from 11.1 to 6.2 days (44.1%; P=0.012). As a result, despite an increase in hospitalizations for stroke, the total person-days in hospital actually decreased by 22% (P=0.06). CONCLUSIONS: The declining age-adjusted stroke mortality in the United States has not been accompanied by a fall in hospitalization over recent years. Thus far, however, decrease in length of stay has more than offset increased admission. At the same time, the sharp drop in hospital case fatality rates suggests that continuing decline in stroke mortality may be due, in large part, to improved survival after acute stroke.

High and low serum potassium associated with cardiovascular events in diuretic-treated patients.

OBJECTIVE: To determine the relationship of moderately high and low concentrations of serum potassium with cardiovascular disease events among treated hypertensive patients. DESIGN: An observational cohort study with prospectively collected data. SETTING: A worksite treatment program for mild hypertension. PATIENTS: All program participants with baseline and at least one annual follow-up measure of serum potassium; 7,653 individuals with 6.7 years mean follow-up met these criteria. MAIN OUTCOME MEASURES: Outcome events were admissions to hospital because of cardiovascular disease, and deaths. The research question regarding serum potassium categories was formulated after data collection. The serum potassium concentration (mean +/- 2SD) of the study population was used to define low (3.0-3.5 mmol/l), high (5.1-5.9 mmol/l) and middle (3.6-5.0 mmol/l) categories. RESULTS: Individuals with low (n = 146) and high (n = 226) serum potassium had significantly greater risk for cardiovascular disease events than those in the middle category (n = 7,281). Multivariate adjusted hazard ratios from Cox models were 2.6 [95% confidence intervals (CI) 1.5-4.4] for the low potassium group and 1.7 (95% CI 1.0-2.7) for the high potassium group, with the middle group as reference. Among 1,679 individuals who regularly took diuretics, hazard ratios were 4.3 (95% CI 2.4-7.9) for the low potassium group and 6.7 (95% CI 2.8-15.9) for the high group. Neither low nor high potassium was significantly associated with outcome events for those not regularly using diuretics. CONCLUSIONS: These data confirm an association of mild hypokalemia with increased cardiovascular events among diuretic-treated hypertensive patients. In addition, we have found a similar increased cardiovascular risk associated with modest hyperkalemia among these patients. Whether modification of these serum potassium concentrations would alter that risk remains to be determined.

Serum uric acid as a cardiovascular risk factor for heart disease.

Cardiovascular risk factors are those environmental, behavioral, genetic, and/or personal factors whose presence indicates a heightened risk of subsequent vascular disease events. Smoking, hypertension, and hyperlipidemia, initially identified by astute clinicians, were all subsequently confirmed and defined as risk factors through formal prospective epidemiologic study, long before evidence of causality was available. Ultimately, clinical trials demonstrated a reversible contribution of both high blood pressure and elevated lipids to stroke and heart disease. As a result, these risk factors are now the cornerstones for both assessment of relative cardiovascular risk and targets for preventive intervention. The criterion for risk factor status is a strong, consistent, timely, and statistically significant association to disease events that is independent of and unconfounded by other known risk factors. The purpose of this review is to assess available data to determine whether or not serum uric acid meets the standard for designation as a risk factor.

History of treatment for depression: risk factor for myocardial infarction in hypertensive patients.

OBJECTIVE: Psychological factors have been suspected of contributing to the development of cardiovascular disease. This study examined the relationship between a self-reported history of treatment for depression and subsequent myocardial infarction among treated hypertensive patients. METHODS: Participants (5564) in a union-sponsored, hypertension control program in New York City, who entered the program during 1981-1994 without a history of cardiovascular disease and who were asked whether they had been treated for depression, were followed in a prospective cohort study. The primary outcome of interest was hospitalization or death due to myocardial infarction. RESULTS: At entry, 3.5% of men and 6.4% of women reported a history of treatment for depression. During 4.9 years (average) of follow-up, 112 fatal and nonfatal myocardial infarctions were recorded. The sex-adjusted relative risk of myocardial infarction was 2.24 (confidence interval = 1.13-4.45). Controlling for known cardiovascular risk factors with multivariate proportional hazards models, history of treatment for depression was significantly associated with subsequent myocardial infarction (hazard ratio = 2.10, confidence interval = 1.04-4.23). CONCLUSIONS: A self-reported history of treatment for depression is independently associated with subsequent myocardial infarction in treated hypertensive patients without prior cardiovascular disease. Whether additional or different treatment for depression will be cardioprotective is unknown and merits further study.

Health outcomes associated with calcium antagonists compared with other first-line antihypertensive therapies: a meta-analysis of randomised controlled trials.

BACKGROUND: Several observational studies and individual randomised trials in hypertension have suggested that, compared with other drugs, calcium antagonists may be associated with a higher risk of coronary events, despite similar blood-pressure control. The aim of this meta-analysis was to compare the effects of calcium antagonists and other antihypertensive drugs on major cardiovascular events. METHODS: We undertook a meta-analysis of trials in hypertension that assessed cardiovascular events and included at least 100 patients, who were randomly assigned intermediate-acting or long-acting calcium antagonists or other antihypertensive drugs and who were followed up for at least 2 years. FINDINGS: The nine eligible trials included 27,743 participants. Calcium antagonists and other drugs achieved similar control of both systolic and diastolic blood pressure. Compared with patients assigned diuretics, beta-blockers, angiotensin-converting-enzyme inhibitors, or clonidine (n=15,044), those assigned calcium antagonists (n=12,699) had a significantly higher risk of acute myocardial infarction (odds ratio 1.26 [95% CI 1.11-1.43], p=0.0003), congestive heart failure (1.25 [1.07-1.46], p=0.005), and major cardiovascular events (1.10 [1.02-1.18], p=0.018). The treatment differences were within the play of chance for the outcomes of stroke (0.90 [0.80-1.02], p=0.10) and all-cause mortality (1.03 [0.94-1.13], p=0.54). INTERPRETATION: In randomised controlled trials, the large available database suggests that calcium antagonists are inferior to other types of antihypertensive drugs as first-line agents in reducing the risks of several major complications of hypertension. On the basis of these data, the longer-acting calcium antagonists cannot be recommended as first-line therapy for hypertension.

Serum potassium and cardiovascular mortality.

BACKGROUND: The impact of serum potassium on mortality is inadequately defined. OBJECTIVE: To determine the association of serum potassium with mortality. METHODS: We analyzed NHANES I Epidemiological Follow-up Study data from 1974-1992. Of 2,992 subjects with baseline serum potassium, 156 were excluded because their vital status was not known. A total of 2,836 subjects with serum potassium within 2.7-5.4 mmol/L were studied. All-cause and cardiovascular mortality were assessed controlling for sociodemographic status, smoking, medical history, and clinical characteristics. RESULTS: At baseline, mean age was 46.6 years, and mean serum potassium was 4.07 mmol/L. Subjects were stratified into three groups by mean +/-1 standard deviation of serum potassium: low, 2.7-3.7 mmol/L (N = 477); middle, 3.8-4.4 mmol/L (N = 1,982); and high, 4.5-5.4 mmol/L (N = 377). The cardiovascular mortality rate per 1,000 person-years adjusted for age, gender, and race for the high serum potassium group (8.1) was significantly higher than the middle (5.3) and low (6.5) serum potassium groups. Further analysis, controlling for age, gender, race, smoking status, cholesterol, and history of diabetes, renal disease, and cardiovascular disease, revealed that the increased cardiovascular mortality among subjects with moderately increased serum potassium was most prominent in those reporting use of diuretics (hazard ratio, 2.65; 95% confidence interval [95% CI], 1.20 to 5.85) and those with abnormal renal function (hazard ratio, 1.89; 95% CI, 1.05 to 3.41). CONCLUSION: In this general population sample with mostly normal serum potassium, higher serum potassium was independently associated with increased cardiovascular mortality.

Salt, blood pressure, and human health.

The positive relation of sodium intake and blood pressure, first recognized a century ago, has been well established in ecological, epidemiological, and experimental human studies. Equally well established is the association of increasing blood pressure and cardiovascular morbidity and mortality. Indeed, the pharmacological capacity to reduce blood pressure has produced one of the great public health accomplishments of the 20th century. These two facts-the positive relation of blood pressure to strokes and heat attacks and the positive association of sodium intake to blood pressure-underlie the hypothesis that a reduction in sodium intake, by virtue of its hypotensive effect, might prevent strokes and heart attacks. Moreover, even if the effect on blood pressure were in the range of a 1- to 2-mm Hg decline in blood pressure for every 75- to 100-mmol difference in sodium intake, the impact of such a change, applied to the whole population, would be enormous. The problem with this appealing possibility is that a reduction in salt consumption of this magnitude has other-and sometimes adverse-health consequences. The question, therefore, is whether the beneficial hypotensive effects of sodium restriction will outweigh its hazards. Unfortunately, few data link sodium intake to health outcomes, and that which is available is inconsistent. Without knowledge of the sum of the multiple effects of a reduced sodium diet, no single universal prescription for sodium intake can be scientifically justified.

Excess risk of myocardial infarction in patients treated with antidepressant medications: association with use of tricyclic agents.

PURPOSE: Several studies have found that depression and the use of antidepressant medications are associated with an increased risk of cardiovascular disease. We assessed the association between the use of antidepressant drugs and myocardial infarction, and whether that association differs between the tricyclic and selective serotonin reuptake inhibitor (SSRI) classes of medication. PARTICIPANTS AND METHODS: We compared the experience of a cohort of 2,247 working, union health plan members who received at least one prescription for an antidepressant in an accrual period of 1991-1992 with that of 52,750 members who did not. Patients were followed for up to 4.5 years (minimum 6 months). Three antidepressant medication classes were defined: tricyclics, SSRIs, and others. The primary outcome was hospitalization or death due to myocardial infarction. RESULTS: Adjusted for age and sex, antidepressant users had a relative risk of myocardial infarction of 2.2 (95% confidence interval [CI] 1.3 to 3.7) compared with nonusers of antidepressants. There were 16 myocardial infarctions among 1,650 users of tricyclic antidepressants, 2 among 655 SSRI users, and none among 279 users of other antidepressants. Adjusting for age, gender, baseline heart disease, diabetes, hypertension, hyperlipidemia, anxiety, and cancer, the relative risk of myocardial infarction was 2.2 (95% CI 1.2 to 3.8) in users of tricyclic agents and 0.8 (95% CI 0.2 to 3.5) in users of SSRIs, as compared with subjects who did not use antidepressants. CONCLUSION: The association between use of tricyclic antidepressants, but not SSRIs, with an increased risk of myocardial infarction in our patients suggests that an earlier report that there is no difference in risk between the antidepressant classes, based on short-term studies, may not apply to long-term adverse cardiovascular outcomes.

Plasma renin activity in the emergency department and its independent association with acute myocardial infarction.

Elevated plasma renin activity (PRA) is associated with increased risk of future myocardial infarction (MI) in ambulatory hypertensive patients. The present study evaluated the relationship of PRA to the diagnosis of acute MI in patients presenting to an emergency department with suspected acute MI. PRA was measured upon entry to the emergency department, before any acute treatment, as part of the standard evaluation of 349 consecutive patients who were hospitalized for suspected MI. Diagnosis of acute MI was confirmed in 73 patients, and ruled out in 276. They did not differ in age (65.9 +/- 2 v 66.1 +/- 1 years), systolic (143 +/- 4 v 140 +/- 2 mm Hg), or diastolic (81 +/- 2 v 81 +/- 1 mm Hg) pressures. Median PRA was 2.7-fold higher in acute MI (0.89 v 0.33 ng/L/s; P < .001). In a multivariate analysis controlling for other cardiac risk factors and prior drug therapy, PRA as a continuous variable was the predominant independent factor associated with acute MI (P < .0001), followed by white race (P = .002) and history of hypertension (P = .047). The height of the PRA level upon entry to the emergency department was directly and independently associated with the diagnosis of acute MI. These new findings extend earlier reports because they encompass acute MI patients, include both hypertensive and normotensive patients, and control for potentially confounding variables. Based on these observations, a randomized clinical trial is warranted to determine whether measurement of PRA in acute MI could refine the process by which treatments are applied.

Therapeutic benefits of ACE inhibitors and other antihypertensive drugs in patients with type 2 diabetes.

OBJECTIVE: To assess whether ACE inhibitors are superior to alternative agents for the prevention of cardiovascular events in patients with hypertension and type 2 diabetes. RESEARCH DESIGN AND METHODS: This study is a review and meta-analysis of randomized controlled trials that included patients with type 2 diabetes and hypertension who were randomized to an ACE inhibitor or an alternative drug, were followed for > or =2 years, and had adjudicated cardiovascular events. RESULTS: A total of 4 trials were eligible. The Appropriate Blood Pressure Control in Diabetes (ABCD) trial (n = 470) compared enalapril with nisoldipine, the Captopril Prevention Project (CAPPP) (n = 572) compared captopril with diuretics or beta-blockers, the Fosinopril Versus Amlodipine Cardiovascular Events Trial (FACET) (n = 380) compared fosinopril with amlodipine, and the U.K. Prospective Diabetes Study (UKPDS) (n = 758) compared captopril with atenolol. The cumulative results of the first 3 trials showed a significant benefit of ACE inhibitors compared with alternative treatments on the outcomes of acute myocardial infarction (63% reduction, P < 0.001), cardiovascular events (51% reduction, P < 0.001), and all-cause mortality (62% reduction, P = 0.010). These findings were not observed in the UKPDS. The ACE inhibitors did not appear to be superior to other agents for the outcome of stroke in any of the trials. None of the findings were explained by differences in blood pressure control. CONCLUSIONS: Compared with the alternative agents tested, ACE inhibitors may provide a special advantage in addition to blood pressure control. The question of whether atenolol is equivalent to captopril remains open. Conclusive evidence on the comparative effects of antihypertensive treatments will come from large prospective randomized trials.

Dietary potassium intake and stroke mortality.

BACKGROUND AND PURPOSE: An inverse relationship of dietary potassium to stroke mortality in a small community has been previously reported. To further assess this association in a larger sample, we examined data from the first National Health and Nutrition Examination Survey (NHANES I) Epidemiological Follow-up Study. METHODS: We analyzed baseline data during 1971-1975 and follow-up through 1992. Dietary potassium intake, determined by 24-hour dietary recall at baseline, was available for 9866 subjects. Stroke mortality was recorded through 1992 follow-up. RESULTS: Mean age and dietary potassium at baseline were 55 years and 2084 mg/d; blacks reported significantly lower potassium intake than whites (1606 versus 2178 mg/24 h). During an average of 16.7 years of follow-up, there were 304 stroke deaths. For men, stratified by tertile of dietary potassium intake, age-adjusted stroke mortality rates per 1000 person-years for the lowest dietary potassium group were significantly higher than for the highest intake group, for both whites (1.94 versus 1.17; relative risk, 1.66; 95% CI, 1.32 to 2.14) and blacks (5.08 versus 1.19; relative risk, 4.27; 95% CI, 1.88 to 9. 19). For women, there was no significant difference in stroke mortality between similar levels of potassium intake for either whites (1.61 versus 1.42; relative risk, 1.13; 95% CI, 0.84 to 1.66) or blacks (2.46 versus 3.04; relative risk, 0.80; 95% CI, 0.21 to 2. 01). After stratification by hypertensive status, stroke mortality rates were significantly different by tertile of dietary potassium only for hypertensive men. There was no stroke mortality difference by potassium intake among hypertensive women or nonhypertensive men and women. Multivariate analysis, in which we controlled for caloric intake and other baseline cardiovascular risk factors, revealed that only among black men and hypertensive men was lower dietary potassium intake a predictor of stroke mortality. CONCLUSIONS: The previous finding of an association of increasing dietary potassium intake with decreasing stroke mortality has been detected only among black men and hypertensive men in this study.

Serum uric acid and cardiovascular mortality the NHANES I epidemiologic follow-up study, 1971-1992. National Health and Nutrition Examination Survey.

CONTEXT: Although many epidemiological studies have suggested that increased serum uric acid levels are a risk factor for cardiovascular mortality, this relationship remains uncertain. OBJECTIVE: To determine the association of serum uric acid levels with cardiovascular mortality. DESIGN AND SETTING: Cross-sectional population-based study of epidemiological follow-up data from the First National Health and Nutrition Examination Survey (NHANES I) from 1971-1975 (baseline) and data from NHANES I Epidemiologic Follow-up Study (NHEFS). PARTICIPANTS: A total of 5926 subjects who were aged 25 to 74 years and had serum uric acid level measurements at baseline. MAIN OUTCOME MEASURES: Ischemic heart disease mortality, total cardiovascular mortality, and all-cause mortality, compared by quartiles of serum uric acid level. RESULTS: In an average of 16.4 years of follow-up, 1593 deaths occurred, of which 731 (45.9%) were ascribed to cardiovascular disease. Increased serum uric acid levels had a positive relationship to cardiovascular mortality in men and women and in black and white persons. Deaths due to ischemic heart disease in both men and women increased when serum uric acid levels were in the highest quartile compared with the lowest quartile (men, >416 vs <321 micromol/L; risk ratio, 1.77 [95% confidence interval [CI], 1.08-3.98]; women, >333 vs <238 micromol/l; risk ratio, 3.00 [95% CI, 1.45-6.28]). Cox regression analysis showed that for each 59.48-micromol/L increase in uric acid level, cardiovascular mortality and ischemic heart disease mortality increased. Hazard ratios for men were 1.09 (95% CI, 1.02-1.18) and 1.17 (95% CI, 1.06-1.28), and for women were 1.26 (95% CI, 1.16-1.36) and 1.30 (95% CI, 1.17-1.45), respectively, after adjustment for age, race, body mass index, smoking status, alcohol consumption, cholesterol level, history of hypertension and diabetes, and diuretic use. Further analysis, stratifying by cardiovascular risk status, diuretic use, and menopausal status, confirmed a significant association of uric acid and cardiovascular mortality in all subgroups except among men using diuretics (n=79) and men with 1 or more cardiovascular risk factors (n=1140). CONCLUSION: Our data suggest that increased serum uric acid levels are independently and significantly associated with risk of cardiovascular mortality.