Michael H. Alderman

Statin Therapy and Risk of Developing Type 2 Diabetes: A Meta-Analysis

OBJECTIVE Although statin therapy reduces cardiovascular risk, its relationship with the development of diabetes is controversial. The first study (West of Scotland Coronary Prevention Study [WOSCOPS]) that evaluated this association reported a small protective effect but used nonstandardized criteria for diabetes diagnosis. However, results from subsequent hypothesis-testing trials have been inconsistent. The aim of this meta-analysis is to evaluate the possible effect of statin therapy on incident diabetes. RESEARCH DESIGN AND METHODS A systematic literature search for randomized statin trials that reported data on diabetes through February 2009 was conducted using specific search terms. In addition to the hypothesis-generating data from WOSCOPS, hypothesis-testing data were available from the Heart Protection Study (HPS), the Long-Term Intervention with Pravastatin in Ischemic Disease (LIPID) Study, the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT), the Justification for the Use of Statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER), and the Controlled Rosuvastatin Multinational Study in Heart Failure (CORONA), together including 57,593 patients with mean follow-up of 3.9 years during which 2,082 incident diabetes cases accrued. Weighted averages were reported as risk ratios (RRs) with 95% CIs using a random-effects model. Statistical heterogeneity scores were assessed with the Q and I2 statistic. RESULTS In the meta-analysis of the hypothesis-testing trials, we observed a small increase in diabetes risk (RR 1.13 [95% CI 1.03–1.23]) with no evidence of heterogeneity across trials. However, this estimate was attenuated and no longer significant when the hypothesis-generating trial WOSCOPS was included (1.06 [0.93–1.25]) and also resulted in significant heterogeneity (Q 11.8 [5 d.f.], P = 0.03, I2 = 57.7%). CONCLUSIONS Although statin therapy greatly lowers vascular risk, including among those with and at risk for diabetes, the relationship of statin therapy to incident diabetes remains uncertain. Future statin trials should be designed to formally address this issue.

Increased risk of bacterial pneumonia in HIV-infected intravenous drug users without AIDS.

Although patients with AIDS have been noted to be at risk for bacterial pneumonia as well as opportunistic infections, little is known about the risk of bacterial pneumonia in HIV-infected populations without AIDS. To determine the incidence of bacterial pneumonia in a well defined population of intravenous drug users (IVDUs), and to examine any association with HIV infection, we prospectively studied 433 IVDUs without AIDS, enrolled in a longitudinal study of HIV infection in an out-patient methadone maintenance program. At enrollment, 144 (33.3%) subjects were HIV-seropositive, 289 (66.7%) were seronegative. Over a 12-month period, 14 out of 144 (9.7%) seropositive subjects were hospitalized for community-acquired bacterial pneumonia, compared with six out of 289 (2.1%) seronegative subjects. The cumulative yearly incidence of bacterial pneumonia was 97 out of 1000 for seropositives and 21 out of 1000 for seronegatives (risk ratio = 4.7, P less than 0.001). Eleven out of 14 (78.6%) cases among the seropositive patients were due to either Streptococcus pneumoniae [5] or Hemophilus influenzae [6]. Two out of 14 (14.3%) cases among the seropositives were fatal. Stratifying by level of intravenous drug use indicated that even among subjects not reporting active intravenous drug use at study entry, eight out of 82 (9.8%) seropositives compared with three out of 211 (1.4%) seronegatives were hospitalized for bacterial pneumonia over the study period (risk ratio = 6.9, P less than 0.01). This study shows a markedly increased incidence of bacterial pneumonia associated with HIV infection in IVDUs without AIDS.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased cardiac performance in mild essential hypertension. Left ventricular mechanics.

To analyze cardiovascular dynamics in essential hypertension, 81 subjects with untreated mild essential hypertension (mean blood pressure, 112 +/- 14 mm Hg) and 87 normotensive subjects from the same working population were studied by echocardiography and simultaneous blood pressure determination. Hypertensive subjects had significantly higher pulse pressure, stroke volume index, cardiac index, left ventricular internal dimension, end-systolic pressure/volume ratio, end-systolic stress, left ventricular mass index, and relative wall thickness than normotensive subjects. Among both normotensive and hypertensive subjects, cardiac performance was closely dependent on afterload, as indicated by close inverse linear relationships between left ventricular fractional shortening and log end-systolic stress (r = -0.83 and -0.78 respectively; both, p less than 0.001). However, 19 of 81 hypertensive patients (23%) fell above the 95% confidence limits of this relationship in normotensive subjects (p less than 0.001 compared with that in normotensive subjects), with a bimodal distribution of fractional shortening as a percent of predicted in relation to end-systolic stress among patients with essential hypertension. This subgroup of hypertensive subjects, with increased resting cardiac performance independent of afterload, was similar in age to the remaining hypertensive subjects but had higher fractional shortening (41 +/- 5% vs 35 +/- 7%; p less than 0.001) and cardiac index (4.3 +/- 1.3 L/min/m2 vs 3.4 +/- 1.0 L/min/m2; p less than 0.005) and lower total peripheral resistance (1257 +/- 502 dyn sec cm-5 vs 1582 +/- 584 dyn sec cm-5 p less than 0.05) and left ventricular relative wall thickness (0.34 +/- 0.06 vs 0.42 +/- 0.10; p less than 0.005). Thus, analysis of cardiac mechanics detected a subset of patients with essential hypertension in whom increased cardiac function cannot be attributed either to relative youth or to supercompensatory left ventricular hypertrophy.

Clinical Events in High-Risk Hypertensive Patients Randomly Assigned to Calcium Channel Blocker Versus Angiotensin-Converting Enzyme Inhibitor in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial

The Antihypertensive and Lipid-Lowering treatment to prevent Heart Attack Trial (ALLHAT) provides a unique opportunity to compare the long-term relative safety and efficacy of angiotensin-converting enzyme inhibitor and calcium channel blocker–initiated therapy in older hypertensive individuals. Patients were randomized to amlodipine (n=9048) or lisinopril (n=9054). The primary outcome was combined fatal coronary heart disease or nonfatal myocardial infarction, analyzed by intention-to-treat. Secondary outcomes included all-cause mortality, stroke, combined cardiovascular disease (CVD), end-stage renal disease (ESRD), cancer, and gastrointestinal bleeding. Mean follow-up was 4.9 years. Blood pressure control was similar in nonblacks, but not in blacks. No significant differences were found between treatment groups for the primary outcome, all-cause mortality, ESRD, or cancer. Stroke rates were higher on lisinopril in blacks (RR=1.51, 95% CI 1.22 to 1.86) but not in nonblacks (RR=1.07, 95% CI 0.89 to 1.28), and in women (RR=1.45, 95% CI 1.17 to 1.79), but not in men (RR=1.10, 95% CI 0.92 to 1.31). Rates of combined CVD were higher (RR=1.06, 95% CI 1.00 to 1.12) because of higher rates for strokes, peripheral arterial disease, and angina, which were partly offset by lower rates for heart failure (RR=0.87, 95% CI 0.78 to 0.96) on lisinopril compared with amlodipine. Gastrointestinal bleeds and angioedema were higher on lisinopril. Patients with and without baseline coronary heart disease showed similar outcome patterns. We conclude that in hypertensive patients, the risks for coronary events are similar, but for stroke, combined CVD, gastrointestinal bleeding, and angioedema are higher and for heart failure are lower for lisinopril-based compared with amlodipine-based therapy. Some, but not all, of these differences may be explained by less effective blood pressure control in the lisinopril arm.

Baseline Characteristics of Participants in the Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

Diuretics and &bgr;-blockers have been shown to reduce the risk of cardiovascular morbidity and mortality in people with hypertension in long-term clinical trials. No study has compared newer more costly antihypertensive agents (calcium antagonists, ACE inhibitors, and &agr;-adrenergic blockers) with diuretics for reducing the incidence of cardiovascular disease in an ethnically diverse group of middle-aged and elderly hypertensive patients. The study is a randomized, double-blind, active-controlled clinical trial designed to determine whether the incidence of the primary outcome, fatal coronary heart disease or nonfatal myocardial infarction, differs between treatment initiation with a diuretic versus each of 3 other antihypertensive drugs. Men and women aged ≥55 years with at least 1 other cardiovascular disease risk factor were randomly assigned to chlorthalidone (12.5 to 25 mg/d), amlodipine (2.5 to 10 mg/d), lisinopril (10 to 40 mg/d), or doxazosin (2 to 8 mg/d) for planned follow-up of 4 to 8 years. This report describes the baseline characteristics of the Antihypertensive and Lipid Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) participants. A total of 42 448 participants were randomized from 625 sites in the United States, Canada, Puerto Rico, and the US Virgin Islands. The mean age was 67 years, with 35% aged ≥70 years. Among those randomized, 36% were black, 19% were Hispanic, and 47% were women. The sample includes a high proportion of people with diabetes (36%), patients with existing cardiovascular disease (47%), and smokers (22%). There were no important differences between the randomized treatment groups at baseline. ALLHAT will add greatly to our understanding of the management of hypertension by providing an answer to the following question: are newer antihypertensive agents similar, superior, or inferior to traditional treatment with diuretics?

ALLHAT Findings Revisited in the Context of Subsequent Analyses, Other Trials, and Meta-analyses

The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is reevaluated considering information from new clinical trials, meta-analyses, and recent subgroup and explanatory analyses from ALLHAT, especially those regarding heart failure (HF) and the association of drug treatment with new-onset diabetes mellitus (DM) and its cardiovascular disease (CVD) consequences. Chlorthalidone was superior to (1) doxazosin mesylate in preventing combined CVD (CCVD) (risk ratio [RR], 1.20; 95% confidence interval [CI], 1.13-1.27), especially HF (RR, 1.80; 95% CI, 1.40-2.22) and stroke (RR, 1.26; 95% CI, 1.10-1.46); (2) lisinopril in preventing CCVD (RR, 1.10; 95% CI, 1.05-1.16), including stroke (in black persons only) and HF (RR, 1.20; 95% CI, 1.09-1.34); and (3) amlodipine besylate in preventing HF, overall (by 28%) and in hospitalized or fatal cases (by 26%). Central independent blinded reassessment of HF hospitalizations confirmed each comparison. Results were consistent by age, sex, race (except for stroke and CCVD), DM status, metabolic syndrome status, and renal function level. Neither amlodipine nor lisinopril was superior to chlorthalidone in preventing end-stage renal disease overall, by DM status, or by renal function level. In the chlorthalidone arm, new-onset DM was not significantly associated with CCVD (RR, 0.96; 95% CI, 0.88-2.42). Evidence from subsequent analyses of ALLHAT and other clinical outcome trials confirm that neither alpha-blockers, angiotensin-converting enzyme inhibitors, nor calcium channel blockers surpass thiazide-type diuretics (at appropriate dosage) as initial therapy for reduction of cardiovascular or renal risk. Thiazides are superior in preventing HF, and new-onset DM associated with thiazides does not increase CVD outcomes.

Diagnostic heterogeneity in clinical trials for congestive heart failure

There are no uniform diagnostic criteria for congestive heart failure. To determine the pattern of diagnostic criteria used, reports of 51 randomized, double-blind, placebo-controlled, clinical drug trials published between 1977 and 1985 were reviewed. Only 23 (45%) of the trials specified objective diagnostic criteria beyond treatment history, clinical diagnosis, or functional class. Of these, there were two trials each for digoxin, hydralazine, amrinone, and metoprolol; for each pair, only one study showed therapy beneficial. Of the amrinone pair, the positive study required a lower ejection fraction (less than 30% compared with less than 45%) and selected patients with more clinical severity. Conversely, for metoprolol, the positive study specified a higher ejection fraction (less than 49% compared with less than 35%) and selected patients with clinically milder disease, suggesting that conflicting results may relate to differences in study population. Many studies of congestive heart failure are done without explicit diagnostic criteria. Criteria lack uniformity, and such discrepancies may explain conflicting results.

Vascular Disease among Hospitalized Multiple Sclerosis Patients

Background: We examined the prevalence of cardiac and cerebrovascular disease among hospitalized patients with and without multiple sclerosis (MS). Methods: This study used the Statewide Planning and Research Cooperate System data set of over 15 million hospitalizations in New York City from 1988 through 2002. We identified MS patients 40–84 years of age who were hospitalized for reasons other than MS or related complications. MS patients were matched 1:2 on age, gender, race/ethnicity, and insurance. Outcomes included a principal discharge diagnosis of ischemic heart disease [International Classification of Diseases, Ninth Revision (ICD-9) 410–414], myocardial infarction (ICD-9 410), and ischemic stroke (ICD-9 434, 436). Multivariate logistic regression was used to compare vascular disease outcomes in MS and non-MS patients controlling for demographic and clinical factors. Results: Our studyincluded 9,949 hospitalizations among MS patients and 19,898 hospitalizations for matched non-MS controls. MS patients were less likely to be hospitalized for ischemic heart disease (OR = 0.58, 95% CI = 0.51–0.66) or myocardial infarction (OR = 0.78, 95% CI = 0.64–0.96), but more likely to be hospitalized for ischemic stroke (OR = 1.66, 95% CI = 1.33–2.09) than matched non-MS controls. Conclusion: MS patients have decreased rates of hospital admission for ischemic heart disease and myocardial infarction, but increased rates of hospitalization for ischemic stroke as compared to the general non-MS population.

Clinical Significance of Incident Hypokalemia and Hyperkalemia in Treated Hypertensive Patients in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial

Concerns exist that diuretic-induced changes in serum potassium may have adverse effects in hypertensive patients. The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial, a large practice-based clinical trial, made it possible to examine consequences of observed changes in potassium during care in conventional practice settings. Normokalemic participants randomized to chlorthalidone (C) versus amlodipine or lisinopril as a first-step drug were stratified by year-1 potassium. Postyear-1 outcomes among hypokalemics (potassium, <3.5 mmol/L) and hyperkalemics (potassium, >5.4 mmol/L) were compared with normokalemics (potassium, 3.5–5.4 mmol/L). Year-1 hypokalemia incidence was 6.8%; incidence in C (12.9%) differed from amlodipine (2.1%; P<0.001) and lisinopril (1.0%; P<0.01). Hyperkalemia incidence (2.0%) was greater in lisinopril (3.6%) than in C (1.2%; P<0.01) or amlodipine (1.9%; P<0.01). Coronary heart disease occurred in 8.1% with hypokalemia, 8.0% with normokalemia, and 11.1% with hyperkalemia. Overall, mortality was higher in hypokalemics than in normokalemics (Cox hazard ratio, 1.21 [95% CI, 1.02–1.44]) with statistically significant (interaction, P<0.01) disparity in hazard ratios for the 3 treatment arms (hazard ratios, C=1.21, amlodipine=1.60, lisinopril=3.82). Hyperkalemia was associated with increased risk of combined cardiovascular disease (hazard ratio, 1.58 [95% CI, 1.15–2.18]) without significant treatment interactions. In conventional practice settings, the uncommon appearance of hyperkalemia was associated with increased cardiovascular disease risk. Hypokalemia was associated with increased mortality; however, the statistically significant heterogeneity in hazard ratios across treatment groups strongly suggests that the observed increase in mortality is unrelated to the specific effects of C. Thus, for most patients, concerns about potassium levels should not influence the clinicians decision about initiating hypertension treatment with low-moderate doses of thiazide diuretics (12.5–25.0 mg of C).

Hypertension guidelines: criteria that might make them more clinically useful.

Cardiovascular disease prevention depends on reduction of risk factors, including hypertension. Guidelines designed to improve management of hypertension are widely available. Their purpose is to assemble the available data from basic biomedical science, epidemiology, and clinical science in an accessible form with which physicians and patients can make reasoned decisions for individual cases. However, guidelines have been neither widely accepted, nor effectively implemented. We recommend a strategy for guideline preparation designed to yield a product more user friendly, accessible, and effective. Guideline recommendations and the evidence used to make them should be based on an explicit grading system. Relevant clinical as well as nonclinical factors must be considered. Moreover, because the goal of antihypertensive therapy is to prevent cardiovascular events, and the likelihood of such events is determined by multifactor or absolute risk assessment, risk, rather than level of blood pressure (BP), should determine the need for therapy. Similarly, the benefit of therapy must be assessed by reduction in cardiovascular disease morbidity and mortality.