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Biomedical subjects

B M Psaty

Publications and source records attributed to B M Psaty.

At least 91 records · Page 5Linked to original sources
PubMed1998

Replacing short-acting nifedipine with alternative medications at a large health maintenance organization.

In response to recent evidence about the safety of calcium channel blockers, Group Health Cooperative of Puget Sound (GHC), a large health maintenance organization, implemented a plan in April 1996 to reevaluate the medications of 1349 patients who were taking short-acting nifedipine. Following the intervention, 79.8% of patients taking short-acting nifedipine discontinued use, and 45.6% switched to once-daily felodipine. By presenting physicians and patients with recent evidence about the safety of short-acting nifedipine, a large health maintenance organization was able to motivate broad-scale changes to safer alternative drug therapies.

Aged↗
PubMed1998

Correlates and prevalence of benzodiazepine use in community-dwelling elderly.

OBJECTIVE: To describe the prevalence of benzodiazepine use, sociodemographic and physical health factors associated with use, dosages taken, and directions for use among individuals aged 65 years and older. DESIGN: Cross-sectional analysis of baseline data from the community-based, prospective observational Cardiovascular Health Study. PATIENTS/PARTICIPANTS: Medicare eligibility lists from four U.S. communities were used to recruit a representative sample of 5,201 community-dwelling elderly, of which 5,181 participants met all study criteria. MEASUREMENTS AND MAIN RESULTS: Among participants, 511 (9.9%) were taking at least one benzodiazepine, primarily anxiolytics (73%). Benzodiazepines were often prescribed to be taken pro re nata (PRN "as needed"), and 36.5% of prescriptions with instructions to be taken regularly were taken at a dose lower than prescribed. Reported over-the-counter (OTC) sleep aid medication use was 39.2% in benzodiazepine users and 3.3% in nonusers. In a multivariate logistic model, the significant independent correlates of benzodiazepine use were being white (odds ratio [OR] 1.9; 95% confidence interval [CI] 1.0, 3.4), female (OR 1.7; CI 1.4, 2.2), and living in Forsyth County, North Carolina, or Washington County, Maryland, compared with living in Sacramento County, California, or Allegheny County, Pennsylvania (OR 2.3; CI 1.4, 2.2); having coronary heart disease (OR 1.6; CI 1.2, 2.1), health status reported as poor or fair (OR 1.8; CI 1.4, 2.3), self-reported diagnosis of nervous or emotional disorder (OR 6.7; CI 5.1, 8.7), and reporting use of an OTC sleep aid medication (OR 18.7; CI 14.1, 24.7). CONCLUSIONS: One in 10 participants reported taking a benzodiazepine, most frequently an anxiolytic, often at a lower dose than prescribed and usually PRN. The high prevalence of OTC sleep aid medication and benzodiazepine use may place the patient at increased risk of psychomotor impairment. Physicians should assess OTC sleep aid medication use when prescribing benzodiazepines.

Aged↗
PubMed1998

New evidence on the prevention of cardiovascular events in hypertensive patients with type 2 diabetes.

Recent trials in hypertensive patients with type 2 diabetes reveal important differences in the risk for major cardiovascular events when individual agents are compared. In the Fosinopril Amlodipine Cardiovascular Events Trial (FACET), 380 patients with hypertension and type 2 diabetes were randomized to fosinopril or amlodipine and followed for up to 3.5 years to assess effects on serum lipids. Although both agents effectively controlled blood pressure, amlodipine caused a significantly greater decrease in systolic pressure. At the end of the trial, serum cholesterol, high-density lipoprotein cholesterol, triglycerides, HbA1c, serum glucose, plasma insulin, serum creatinine, and microalbuminuria were similar in both groups. The patients randomized to fosinopril were significantly less likely to experience the prospectively defined combined outcome of acute myocardial infarction (MI), hospitalized angina, or stroke compared to those randomized to amlodipine (RR 0.49; 95% CI 0.26-0.95). In the Appropriate Blood pressure Control in Diabetes (ABCD) trial, 470 patients with hypertension and type 2 diabetes who were randomized to long-acting nisoldipine had an adjusted sevenfold increased risk for acute MI compared to those randomized to enalapril (RR 7.0; 95% CI 2.3-21.4). In the Multicenter Isradipine Diuretic Atherosclerosis Study (MIDAS) trial, the patients with hypertension and above the median of HbA1c (> or =6.7%) randomized to isradipine had a threefold increased risk for major cardiovascular events compared to those randomized to hydrochlorothiazide (RR 2.81; 95% CI 1.09-7.26). These findings are supported by several observational studies. Therefore, evidence is emerging that angiotensin-converting enzyme inhibitors and low-dose diuretics may be more effective than calcium antagonists for prevention of cardiovascular events in hypertensive patients with diabetes or impaired glucose control.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1998

Birthweight and blood pressure among children in Harare, Zimbabwe.

AIM: To determine whether poor uterine growth may be associated with increased blood pressure and subsequent hypertension in adulthood. METHODS: A retrospective cohort study of 756 schoolchildren (mean age 6.5 years) was carried out in six low income areas in Harare city, Zimbabwe. Indices of intrauterine growth and blood pressure were assessed. RESULTS: Adjusted for current weight, the children's systolic blood pressure was inversely related to their birthweight; for each decreasing kg of birthweight, systolic blood pressure rose by 1.73 mm Hg (95% CI; 0.181 to 3.28). After adjustment for current weight, systolic blood pressure was also inversely associated with occipito-frontal circumference, but not with birth length or gestational age. Diastolic blood pressure was not associated with any of the intrauterine indices. CONCLUSION: Fetal size may be inversely related to systolic blood pressure in childhood in an African population.

Africa↗
PubMed1998

Risk of stroke in young women and two prothrombotic mutations: factor V Leiden and prothrombin gene variant (G20210A)

BACKGROUND AND PURPOSE: Factor V Leiden and a prothrombin gene variant, G20210A, are mutations associated with a thrombotic risk. The aim of our study was to assess whether these mutations increase the risk of stroke in women under 45 years of age. METHODS: We conducted a case-control study in western Washington state. Case patients were women aged 18 to 44 years with a first stroke (n = 106). Control subjects were women without stroke recruited from the same region by use of random-digit telephone dialing (n = 391). All were interviewed and provided blood specimens, which were genotyped for these mutations. RESULTS: Factor V Leiden was found in 0.9% of case patients, a single patient with a subarachnoid hemorrhage, and in 4.1% of control subjects. The odds ratio (OR) for any stroke was 0.2 (95% confidence interval [CI], 0.03 to 1.7). The prothrombin variant was found in 1.9% of case patients, 1 with a venous stroke and 1 with an ischemic stroke, and in 1.6% of control subjects. The OR for any stroke was 1.48 (95% CI, 0.14 to 9.17). ORs for stroke types were also not statistically significant. CONCLUSIONS: In this study, neither factor V Leiden nor the prothrombin variant (G20210A) was an important risk factor for stroke in young women. In this setting, screening for these mutations cannot be recommended. Unanswered by this study is whether screening would be useful in select patients, such as those with a strong family history of thrombophilia or those with venous strokes.

Adult↗
PubMed1998

Association of hypothyroidism and obstructive sleep apnea.

Obstructive sleep apnea (OSA) and hypothyroidism are relatively common disorders that have similar clinical features and are thought to be causally linked. We sought to determine the prevalence of previously unrecognized hypothyroidism in a series of patients evaluated for OSA and whether an association between hypothyroidism and OSA was present. Chart review was used to obtain information on thyroid function status, polysomnography results, levothyroxine use, and clinical signs and symptoms in 336 consecutive adult patients who underwent polysomnography for suspected OSA. In addition, levothyroxine use was determined in age- and sex-matched control subjects for the purposes of a case-control study. Among the patients without prior history of hypothyroidism who underwent polysomnography and thyroid function testing, four new cases or 1. 41% (95% CI 0.04-2.78) were found to have subclinical hypothyroidism. Our findings do not support routine thyroid screening by specialists in patients referred for polysomnography. The odds ratio of the association of prior history of hypothyroidism to OSA was 1. 47 (95% CI 0.8-2.8). Limitations in study design may have limited our ability to detect a statistically significant association between OSA and hypothyroidism.

Adult↗
PubMed1998

Postmenopausal estrogens and risk of myocardial infarction in diabetic women.

OBJECTIVE: The effect of hormone replacement therapy on the risk of myocardial infarction in diabetic women has not been well studied. We conducted a case-control study of postmenopausal estrogen use and risk of incident myocardial infarction (MI) in pharmacologically treated diabetic women enrolled at Group Health Cooperative of Puget Sound, a large health maintenance organization in the state of Washington. RESEARCH DESIGN AND METHODS: Case subjects (n = 212) were all postmenopausal women with treated diabetes who sustained an incident fatal or nonfatal MI between July 1986 and December 1994. Control subjects (n = 122) were treated diabetic women drawn from a stratified random sample of postmenopausal women without prior MI. Computerized pharmacy data and medical records were used to measure use of estrogens. Cardiovascular risk factors recorded from medical records, computerized pharmacy and laboratory data, and telephone interviews were used as adjustment variables. RESULTS: In this study 8.5% of case and 13.9% of control subjects were current users of estrogens. The relative risk (RR) of MI for current estrogen users was 0.51 (95% CI 0.22-1.15) relative to never users, adjusted for age, study year, weight, angina, and duration of treated diabetes. Among current estrogen users, risk of MI tended to decline with each additional year of estrogen use (adjusted RR = 0.78, 95% CI 0.56-1.08). Of those studied, 45.3% of case and 37.7% of control subjects were past users of estrogens (adjusted RR = 1.22, 95% CI 0.71-2.09). CONCLUSIONS: This study suggests that use of postmenopausal estrogens does not increase risk of MI in diabetic women and that sustained use may be of benefit.

Age Factors↗
PubMed1998

Factor V Leiden is not a risk factor for arterial vascular disease in the elderly: results from the Cardiovascular Health Study.

Coagulation factor V Leiden is a risk marker for venous thrombosis. For arterial thrombosis no large study to date has included population-based elderly patients. The Cardiovascular Health Study is a longitudinal study of 5,201 men and women over age 65. With 3.4-year follow-up, we studied 373 incident cases of myocardial infarction (MI), angina, stroke. or transient ischemic attack (TIA), and 482 controls. The odds ratios for each event with heterozygous factor V Leiden were: MI, 0.46 (95% CI 0.17 to 1.25); angina, 1.0 (95% CI 0.45 to 2.23); stroke, 0.77 (95% CI 0.35 to 1.70): TIA, 1.33 (95% CI 0.5 to 3.55); any outcome, 0.83 (95% CI 0.48 to 1.44). Adjustment for cardiovascular risk factors did not change relationships. In older adults factor V Leiden is not a risk factor for future arterial thrombosis.

Adult↗
PubMed1998

Correlates of antithrombin, protein C, protein S, and TFPI in a healthy elderly cohort.

The majority of fatal acute myocardial infarctions occur in the elderly. Since these events are predominantly thrombotic, we studied the cross-sectional associations of the anticoagulant proteins Antithrombin, Protein C, Protein S. and Tissue Factor Pathway Inhibitor (TFPI) in a subgroup (n = 400) of the Cardiovascular Health Study (a study of healthy men and women > or = 65 years) free of clinical cardiovascular disease (CVD). We did not observe any strong age-associated trends, although Protein C was lower in older women (p < or = 0.001), and TFPI was higher in older men (p < or = 0.01). The inhibitors were highly intercorrelated, and were associated with increased levels of inflammation-sensitive proteins (e.g., fibrinogen. plasminogen), lipids (especially total and LDL-cholesterol), and coagulation factors, such as Factors VIIc, IXc, and Xc. None was associated with the procoagulant markers Prothrombin Fragment F1-2 or Fibrinopeptide A. Only TFPI was associated with subclinical atherosclerosis: ankle-arm index and internal carotid artery stenosis, p trend < or = 0.01; and carotid wall thickness, p trend < or = 0.05. In multivariate analysis the independent predictors of TFPI were levels of fibrinogen; the fibrinolytic marker plasmin-antiplasmin complex; LDL-cholesterol; and carotid wall thickness (R2 for the model = 0.35). In summary, the inhibitors did not appear to increase with age, and were predominantly associated with inflammation markers and lipids. Since markers of thrombin production do increase with age, we hypothesize that an age-related hemostatic imbalance may ensue, with associated increased thrombotic risk. Only TFPI was associated with subclinical CVD, suggesting that it may more closely reflect endothelial damage.

Aged↗
PubMed1998

Assessing the sensitivity of regression results to unmeasured confounders in observational studies.

This paper presents a general approach for assessing the sensitivity of the point and interval estimates of the primary exposure effect in an observational study to the residual confounding effects of unmeasured variable after adjusting for measured covariates. The proposed method assumes that the true exposure effect can be represented in a regression model that includes the exposure indicator as well as the measured and unmeasured confounders. One can use the corresponding reduced model that omits the unmeasured confounder to make statistical inferences about the true exposure effect by specifying the distributions of the unmeasured confounder in the exposed and unexposed groups along with the effects of the unmeasured confounder on the outcome variable. Under certain conditions, there exists a simple algebraic relationship between the true exposure effect in the full model and the apparent exposure effect in the reduced model. One can then estimate the true exposure effect by making a simple adjustment to the point and interval estimates of the apparent exposure effect obtained from standard software or published reports. The proposed method handles both binary response and censored survival time data, accommodates any study design, and allows the unmeasured confounder to be discrete or normally distributed. We describe applications on two major medical studies.

Appetite Depressants↗
PubMed1997

Use of low-dose oral contraceptives and stroke in young women.

BACKGROUND: Low-dose oral contraceptives are widely used, but there are limited data on the cerebrovascular risks associated with these medications. OBJECTIVE: To determine whether use of low-dose oral contraceptives influences the risk for stroke. DESIGN: Population-based case-control study. SETTING: Women 18-44 years of age who resided in western Washington State between 1991 and 1995. PARTICIPANTS: Patients with ischemic stroke (n = 60), hemorrhagic stroke (n = 102), and other types of stroke (n = 11) and controls identified through random-digit dialing (n = 485). MEASUREMENTS: Details about oral contraceptive use and other risk factors for stroke were obtained through in-person interviews. RESULTS: The estimated incidences of hemorrhagic stroke and ischemic stroke were 6.4 and 4.3 per 100,000 women-years, respectively. Compared with women who had never used oral contraceptives (after adjustment for risk factors for stroke), current users of low-dose oral contraceptives had estimated odds ratios of 0.93 (95% CI, 0.37 to 2.31) for hemorrhagic stroke and 0.89 (CI, 0.27 to 2.94) for ischemic stroke. Compared with past users of oral contraceptives, current users had odds ratios of 1.41 (CI, 0.67 to 2.96) for hemorrhagic stroke and 1.37 (CI, 0.49 to 3.81) for ischemic stroke. For past users compared with never users, the odds ratios were 0.59 (CI, 0.30 to 1.18) for hemorrhagic stroke and 0.57 (CI, 0.25 to 1.32) for ischemic stroke. The odds ratio for hemorrhagic stroke in current users of low-dose oral contraceptives containing norgestrel or levonorgestrel was elevated (3.23 [CI, 1.24 to 8.41]). Among patients with hemorrhagic stroke, the odds ratio for aneurysmal bleeding associated with current use of low-dose oral contraceptives containing norgestrel or levonorgestrel was 4.46 (CI, 1.58 to 12.53). CONCLUSION: The overall risk for stroke and type of stroke was not increased among current users of low-dose oral contraceptives in the study population. Larger studies are needed to clarify both the relation of risk for stroke to past use of oral contraceptives and the possible association between current use of norgestrel-containing oral contraceptives and hemorrhagic stroke.

Adolescent↗
PubMed1997

Incidence of and risk factors for atrial fibrillation in older adults.

BACKGROUND: This study aimed to describe the incidence of atrial fibrillation (AF) among older adults during 3 years of follow-up. METHODS AND RESULTS: In this cohort study, 5201 adults > or = 65 years old were examined annually on four occasions between June 1989 and May 1993. At baseline, participants answered questionnaires and underwent a detailed examination that included carotid ultrasound, pulmonary function tests, ECG, and echocardiography. Subjects with a pacemaker or AF at baseline (n=357) were excluded. New cases of AF were identified from three sources: (1) annual self-reports, (2) annual ECGs, and (3) hospital discharge diagnoses. Cox proportional-hazards models were used to assess baseline risk factors as predictors of incident AF. Among 4844 participants, 304 developed a first episode of AF during an average follow-up of 3.28 years, for an incidence of 19.2 per 1000 person-years. The onset was strongly associated with age, male sex, and the presence of clinical cardiovascular disease. For men 65 to 74 and 75 to 84 years old, the incidences were 17.6 and 42.7, respectively, and for women, 10.1 and 21.6 events per 1000 person-years. In stepwise models, the use of diuretics, a history of valvular heart disease, coronary disease, advancing age, higher levels of systolic blood pressure, height, glucose, and left atrial size were all associated with an increased risk of AF. The use of beta-blockers and high levels of alcohol use, cholesterol, and forced expiratory volume in 1 second were associated with a reduced risk of AF. CONCLUSIONS: The incidence of AF in older adults may be higher than estimated by previous population studies. Left atrial size appears to be an important risk factor, and the control of blood pressure and glucose may be important in preventing the development of AF.

Adult↗
PubMed1997

A common prothrombin variant (20210 G to A) increases the risk of myocardial infarction in young women.

Using specimens from a population-based case control study among women ages 18 to 44 years in western Washington, we assessed the relationship between carriership of a genetic clotting factor II variant (20210 G-->A) and myocardial infarction (MI). The factor II variant was previously shown to be present in 1% to 2% of the population, to increase the levels of factor II, and to be associated with venous thrombotic disease. Personal interviews and blood samples were obtained from 79 women with a first myocardial infarction and 381 control women identified through random-digit telephone dialing. Polymerase chain reaction (PCR) method was used to determine the factor II genotypes. The factor II 20210 G to A transition was present more often in women with MI (5.1%) than among control women (1.6%). The age-adjusted odds ratio for MI was 4.0 (95% confidence interval 1.1 to 15.1). The relative risk was high when another major cardiovascular risk factor was also present, such as smoking (odds ratio 43.3, 95% confidence interval 6.7 to 281), and the risk seemed limited to those with other risk factors. These results, in which the effect of major coronary risk factors is enhanced fourfold to sixfold by the prothrombin variant, are similar to those previously reported for another genetic clotting abnormality, factor V Leiden. We conclude that factor II 20210 G to A increases the risk of myocardial infarction in young women, especially in the women with other major risk factors for coronary heart disease.

Adolescent↗
PubMed1997

Association of hepatitis C virus infection with mortality and graft survival in kidney-pancreas transplant recipients.

BACKGROUND: Although most studies have not demonstrated decreased patient or graft survival in kidney-alone allograft recipients infected with hepatitis C virus (HCV), the impact of HCV infection on patient and graft survival in HCV-infected kidney-pancreas recipients has not been studied. METHODS: We undertook a retrospective cohort analysis of 137 kidney-pancreas transplant recipients who were transplanted between January 1989 and May 1996. HCV infection was determined by a positive polymerase chain reaction. Relative risk of death and graft failure was calculated using the Cox proportional hazards model with time-dependent covariates. Relative risks were adjusted (aRR) to control for the number of OKT3-treated rejections and cytomegalovirus status of the recipient at the time of transplantation. RESULTS: Mean length of follow-up was 30.4 months in the HCV-infected patients compared with 31.7 months in noninfected patients. Seven (5.1%) patients were infected with HCV before transplant, one (1%) relapsed after transplantation, and four (2.9%) acquired the infection after transplantation. The HCV-infected group had a 3.7-fold (95% confidence interval [CI], 1.0-13.5) increased risk of death after transplant compared with the HCV-negative group, with an aRR of 5.5 (95% CI, 1.5-20.0). Death in the HCV-infected group (n=3) was generally the result of liver failure and sepsis, whereas death for those in the uninfected group (n=11) was primarily of cardiovascular origin. Patients infected with HCV were 3.4-fold (95% CI, 1.1-10.1) more likely to develop kidney graft failure than HCV-negative patients with an aRR of 5.1 (95% CI, 1.7-15.4). The risk of pancreatic allograft failure was not significantly increased. CONCLUSIONS: We conclude that HCV infection in kidney-pancreas transplant patients results in a significantly increased risk of kidney allograft failure and death.

Adult↗
PubMed1997

Myocardial infarction in young women in relation to plasma total homocysteine, folate, and a common variant in the methylenetetrahydrofolate reductase gene.

BACKGROUND: In a population-based study, we examined the relationship between the risk of myocardial infarction (MI) among young women and plasma total homocysteine (tHCY), folate, vitamin B12, and a common cytosine (C) to thymine (T) polymorphism in the gene for 5,10-methylenetetrahydrofolate reductase (MTHFR). METHODS AND RESULTS: In-person interviews and nonfasting blood samples were obtained from 79 women < 45 years old diagnosed with MI and 386 demographically similar control subjects living in western Washington state between 1991 and 1995. Compared with control subjects, case patients had higher mean tHCY concentrations (13.4+/-5.2 versus 11.1+/-4.4 micromol/L, P=.0004) and lower mean folate concentrations (12.4+/-13.4 versus 16.1+/-12.2 nmol/L, P=.018). There was no difference in vitamin B12 concentrations between case patients and control subjects (346.8+/-188.4 versus 349.7+/-132.4 pmol/L, P=.90). After adjusting for cardiovascular risk factors, we found that women with tHCY > or = 15.6 micromol/L were at approximately twice the risk of MI as women with tHCY < 10.0 micromol/L (OR, 2.3; 95% CI, 0.94 to 5.64). Women with folate > or = 8.39 nmol/L had an approximately 50% lower risk of MI than women with folate < 5.27 nmol/L (OR, 0.54; 95% CI, 0.23 to 1.28). There was no association with vitamin B12 concentration. Among control subjects, 12.7% were homozygous for the MTHFR T677 allele, and these women had higher plasma tHCY and lower plasma folate than women with other genotypes. Ten percent of case patients were homozygous for the T677 allele, and there was no association of homozygosity for T677 with MI risk (OR, 0.90; 95% CI, 0.31 to 2.29). CONCLUSIONS: These data support the hypothesis that elevated plasma tHCY and low plasma folate are risk factors for MI among young women. Although homozygosity for MTHFR T677 is related to increased plasma tHCY and low plasma folate, this genetic characteristic is not a risk factor for MI in this population.

Adult↗
PubMed1997

Duration of estrogen replacement therapy in relation to the risk of incident myocardial infarction in postmenopausal women.

BACKGROUND: There is little information about whether an increasing duration of estrogen replacement therapy is associated with a declining risk for myocardial infarction in postmenopausal women. OBJECTIVE: To conduct a population-based, case-control study among enrollees of the Group Health Cooperative (GHC) of Puget Sound, Seattle, Wash. SUBJECTS AND METHODS: Case subjects were all post-menopausal women who were enrolled in the GHC with an incident fatal or nonfatal myocardial infarction from July 1986 through December 1993. Control subjects were a stratified random sample of postmenopausal women who were enrolled in the GHC without myocardial infarction and matched to case subjects by age and calendar year. We reviewed the medical records of the 850 case subjects and 1974 control subjects and conducted telephone interviews with consenting survivors. Use of estrogen or estrogen and progestin was assessed using GHC's computerized pharmacy database. RESULTS: Among women who were currently using estrogen, a longer duration of use was inversely associated with a risk for myocardial infarction after adjustment for age, year of identification, diabetes mellitus, angina, and smoking. For categories of increasing duration of estrogen use (never, > 0-< 1.8 years, 1.8-< 4.2 years, 4.2-< 8.2 years, and > or = 8.2 years), the odds ratios for myocardial infarction were 1.00 (reference), 0.91, 0.70, 0.65, and 0.55 (for trend among the current users, P = .05). Among women who had used estrogen in the past, there was no evidence of decreasing risk with increasing duration of estrogen use. CONCLUSION: In this study, a long duration of hormone replacement therapy among women currently using estrogen was associated with a reduced risk for first myocardial infarction.

Adult↗