Reconstitution of membrane proteins into liposomes: application to energy-transducing membrane proteins.
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Detergents↗
Biomedical subjects
D Levy
Publications and source records attributed to D Levy.
Left atrial size and the risk of stroke and death. The Framingham Heart Study.
BACKGROUND: The medical literature contains conflicting reports on the association of left atrial (LA) enlargement with risk of stroke. The relation of LA size to risk of stroke and death in the general population remains largely unexplored. METHODS AND RESULTS: Subjects 50 years of age and older from the Framingham Heart Study were studied to assess the relations between echocardiographic LA size and risk of stroke and death. During 8 years of follow-up, 64 of 1371 (4.7%) men and 73 of 1728 (4.2%) women sustained a stroke, and 296 (21.6%) men and 271 (15.7%) women died. Sex-specific Cox proportional-hazards models were adjusted for age, hypertension, diabetes, atrial fibrillation, smoking, ECG left ventricular (LV) hypertrophy, and congestive heart failure or myocardial infarction. After multivariable adjustment, for every 10-mm increase in LA size, the relative risk of stroke was 2.4 in men (95% CI, 1.6 to 3.7) and 1.4 in women (95% CI, 0.9 to 2.1); the relative risk of death was 1.3 in men (95% CI, 1.0 to 1.5) and 1.4 in women (95% CI, 1.1 to 1.7). Adjusting for ECG LV mass/height attenuated the relation of LA size to stroke and death. CONCLUSIONS: After multivariable adjustment, LA enlargement remained a significant predictor of stroke in men and death in both sexes. The relation of LA enlargement to stroke and death appears to be partially mediated by LV mass.
Aged↗
Thrombopoietin activates a STAT5-like factor in hematopoietic cells.
Thrombopoietin (TPO) is a newly cloned cytokine which is the major regulator of circulating platelet levels, acting on both proliferation and differentiation of megakaryocytes. We have investigated the ability of TPO to activate the JAK/STAT pathway in megakaryocytic cell lines. We used either the granulocyte-macrophage colony-stimulating factor (GM-CSF)- and/or erythropoietin (EPO)-dependent UT7 cell line in which the murine TPO receptor (mumpl) had been transfected (mumpl-UT7 transfectants) or the MO7E and DAMI cells which express endogenous human TPO receptors. We demonstrated that TPO activates the kinase JAK2 and a STAT5-like transcriptional factor but not STAT1, STAT2, STAT3 or STAT4, in a very rapid and transient manner. In order to better ascertain the specificity of the activation of STAT5-related factor by TPO, we investigated the effect of other cytokines/growth factors. Both GM-CSF and EPO activated the STAT5-like factor. In contrast, neither interferon (IFN)-gamma nor the mitogenic stem cell factor (SCF) activated STAT5, although IFN-gamma did activate STAT1 in those cells. The hematopoietic DNA binding activity related to STAT5 was identified as a p97 tyrosine-phosphorylated protein band which exhibited identical gel mobility to the mammary STAT5. Because v-mpl, a truncated form of the TPO receptor c-mpl, was shown to be oncogenic, we tested the activity of v-mpl on STAT5 and found STAT5 constitutively activated in two different v-mpl-expressing cells, the transiently transfected Cos7 cells and the stable v-mpl-UT7 transfectants. Overall, our data indicate that STAT5 is widely expressed in hematopoietic cells and activated by a number of cytokines, including TPO, GM-CSF and EPO, but not by IFN-gamma or SCF.
Animals↗
Prolactin, growth hormone, erythropoietin and granulocyte-macrophage colony stimulating factor induce MGF-Stat5 DNA binding activity.
The molecular components which mediate cytokine signaling from the cell membrane to the nucleus were studied. Upon the interaction of cytokines with their receptors, members of the janus kinase (Jak) family of cytoplasmic protein tyrosine kinases and of the signal transducers and activators of transcription (Stat) family of transcription factors are activated through tyrosine phosphorylation. It has been suggested that the Stat proteins are substrates of the Jak protein tyrosine kinases. MGF-Stat5 is a member of the Stat family which has been found to confer the prolactin response. MGF-Stat5 can be phosphorylated and activated in its DNA binding activity by Jak2. The activation of MGF-Stat5 is not restricted to prolactin. Erythropoietin (EPO) and growth hormone (GH) stimulate the DNA binding activity of MGF-Stat5 in COS cells transfected with vectors encoding EPO receptor and MGF-Stat5 or vectors encoding GH receptor and MGF-Stat5. The activation of DNA binding by prolactin, EPO and GH requires the phosphorylation of tyrosine residue 694 of MGF-Stat5. The transcriptional induction of a beta-casein promoter luciferase construct in transiently transfected COS cells is specific for the prolactin activation of MGF-Stat5; it is not observed in EPO- and GH-treated cells. In the UT7 human hematopoietic cell line, EPO and granulocyte-macrophage colony stimulating factor activate the DNA binding activity of a factor closely related to MGF-Stat5 with respect to its immunological reactivity, DNA binding specificity and molecular weight. These results suggest that MGF-Stat5 regulates physiological processes in mammary epithelial cells, as well as in hematopoietic cells.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Association between increased estrogen status and increased fibrinolytic potential in the Framingham Offspring Study.
BACKGROUND: Although extensive evidence indicates that estrogen is responsible for the markedly decreased cardiovascular risk of premenopausal women, the mechanism through which estrogen might exert its protective effect has not been adequately explained. Since thrombosis is now recognized to play an important role in the onset of cardiovascular disease, we investigated the relation between estrogen status and fibrinolytic potential, a determinant of thrombotic risk. METHODS AND RESULTS: We determined levels of plasminogen activator inhibitor (PAI-1) antigen and tissue plasminogen activator (TPA) antigen in 1431 subjects from the Framingham Offspring Study. Fibrinolytic potential was compared between subjects with high estrogen status (premenopausal women and postmenopausal women receiving hormone replacement therapy) and low estrogen status (men and postmenopausal women not receiving hormone replacement therapy). In all comparisons, subjects with high estrogen status had greater fibrinolytic potential (lower PAI-1 levels) than subjects with low estrogen status. First, postmenopausal women receiving estrogen replacement therapy had lower levels of PAI-1 than those not receiving therapy (13.0 +/- 0.5 versus 19.5 +/- 1.0 ng/mL, P < .001). Second, premenopausal women had lower levels of PAI-1 than men of a similar age (14.8 +/- 0.6 versus 20.3 +/- 0.8 ng/mL, P < .001); this sex difference diminished when postmenopausal women not receiving hormone replacement therapy were compared with men of a similar age (19.6 +/- 0.7 versus 21.1 +/- 0.7 ng/mL, P = .089). Third, premenopausal women had markedly lower levels of PAI-1 antigen than postmenopausal women not receiving estrogen therapy (14.8 +/- 0.6 versus 19.5 +/- 1.0 ng/mL, P < .001). The between-group differences observed for TPA antigen were similar to those for PAI-1 antigen. CONCLUSIONS: Each of these comparisons indicates that the cardioprotective effect of estrogen may be mediated, in part, by an increase in fibrinolytic potential. These findings might provide at least a partial explanation for the protection against cardiovascular disease experienced by premenopausal women, and the loss of that protection following menopause.
Coronary Disease↗
Prognosis of left ventricular geometric patterns in the Framingham Heart Study.
OBJECTIVES: The goal of this study was to determine the incremental prognostic value of left ventricular geometric patterns beyond that provided by cardiovascular disease risk factors, including left ventricular mass. BACKGROUND: Left ventricular geometry may be classified into the following four mutually exclusive groups on the basis of left ventricular mass and relative wall thickness: concentric hypertrophy (increased mass and increased relative wall thickness), eccentric hypertrophy (increased mass and normal relative wall thickness), concentric remodeling (normal mass and increased relative wall thickness) and normal geometry (normal mass and normal relative wall thickness). The prognosis associated with these patterns in a population-based sample is not known. METHODS: Proportional hazards regression models were used to evaluate the prognostic importance of left ventricular geometry in 3,216 subjects in the Framingham Heart Study who were > or = 40 years old and free of clinically apparent cardiovascular disease, after adjustment for traditional cardiovascular risk factors and left ventricular mass. The follow-up period was 8 years. RESULTS: Subjects with concentric hypertrophy had the worst prognosis, followed by those with eccentric hypertrophy, concentric remodeling and normal geometry. Subjects with concentric hypertrophy also had the highest left ventricular mass. The association between type of geometry and prognosis was largely attenuated by adjustment for baseline differences in left ventricular mass. The odds ratio for incident cardiovascular disease in subjects with concentric hypertrophy compared with those who had normal geometry was 1.3 (95% confidence interval [CI] 0.8 to 2.1) in men and 1.2 (95% CI 0.6 to 2.3) in women after adjustment for other cardiovascular risk factors, including left ventricular mass. CONCLUSIONS: In a population-based sample of subjects without cardiovascular disease, knowledge of left ventricular geometry provided little prognostic information beyond that available from left ventricular mass and traditional cardiovascular risk factors.
Adult↗
Determinants of echocardiographic aortic root size. The Framingham Heart Study.
BACKGROUND: Previous studies that evaluated the determinants of aortic root size have not yielded uniform results. We examined the relations of age, height, weight, body surface area, sex, and blood pressure to echocardiographically determined aortic root size in a population-based cohort. METHODS AND RESULTS: The study sample consisted of 1849 men and 2152 women in the Framingham Heart Study and Framingham Offspring Study who were free of clinically apparent cardiac disease when echocardiography was performed. Aortic root measurements were made by M-mode echocardiography using a leading-edge-to-leading-edge technique. The relations of age, height, weight, body surface area, and blood pressure variables (contemporary and those obtained 8 years before) to aortic root dimension were examined by use of sex-specific correlations and linear regression analyses. Age, height, weight, and sex emerged as the principal determinants of aortic root dimensions in adults (cumulative R2 = .2085 in men and .2327 in women). The additional effect of contemporary or previous blood pressure measures was small and revealed direct associations of aortic root dimension with mean arterial and diastolic blood pressures and inverse associations with pulse and systolic blood pressures. Previous blood pressure measurements did not contribute significantly to prediction of aortic root size once contemporary blood pressure variable entered the models. Results of regression analyses using a sex-pooled data set showed that on average, the aortic root measurement in women was 2.4 mm smaller than that of men of comparable age, height, and weight. Logistic regression was used to assess the likelihood of aortic root enlargement according to blood pressure levels. After adjustment for age, height, and weight, the odds ratio of aortic dilation for a 1-SD increment in systolic pressure was 0.70 (95% CI, 0.52 to 0.95) in men and 0.79 (95% CI, 0.60 to 1.04) in women; the odds ratio for a 1-SD increment in diastolic pressure was 1.22 (95% CI, 0.91 to 1.63) in men and 1.33 (95% CI, 1.01 to 1.73) in women. CONCLUSIONS: Age, height, weight, and sex emerged as the principal determinants of aortic root dimensions. The additional influences of blood pressure measurements were small; direct associations of aortic root dimensions with mean arterial and diastolic blood pressures and inverse associations with pulse and systolic blood pressures were observed. Additional prospective studies are needed to confirm these observations and to assess the impact of aortic root dimensions on the incidence of hypertension.
Adult↗
The incidence and natural history of knee osteoarthritis in the elderly. The Framingham Osteoarthritis Study.
OBJECTIVE: To determine the incidence of radiographic knee osteoarthritis (OA) and symptomatic OA (symptoms plus radiographic OA), as well as the rate of progression of preexisting radiographic OA in a population-based sample of elderly persons. METHODS: Framingham Osteoarthritis Study subjects who had knee radiographs and had answered questions about knee symptoms in 1983-1985 were reexamined in 1992-1993 (mean 8.1-year interval) using the same protocol. Subjects were defined as having new (incident) radiographic OA if they developed grade > or = 2 OA (at least definite osteophytes or definite joint space narrowing). New symptomatic OA was present if subjects developed a combination of knee symptoms and grade > or = 2 OA. Progressive OA was diagnosed when radiographs showing grade 2 disease at baseline showed grade > or = 3 disease on followup. RESULTS: Of 1,438 participants in the original study, 387 (26.9%) died prior to followup. Of the 1,051 surviving subjects, 869 (82.7%) participated in the followup study (mean +/- SD age 70.8 +/- 5.0 at baseline). Rates of incident disease were 1.7 times higher in women than in men (95% confidence interval [CI] 1.0-2.7), and progressive disease occurred slightly more often in women (relative risk = 1.4; 95% CI 0.8-2.5) but rates did not vary by age in this sample. Among women, approximately 2% per year developed incident radiographic disease, 1% per year developed symptomatic knee OA, and about 4% per year experienced progressive knee OA. CONCLUSION: In elderly persons, the new onset of knee OA is frequent and is more common in women than men. However, among the elderly, age may not affect new disease occurrence or progression.
Aged↗
Microsurgery versus radiosurgery in the treatment of small acoustic neurinomas.
Microsurgical preservation of the facial nerve during removal of acoustic neurinomas can hardly be compared with microsurgery of the eighth cranial nerve. Many more anatomical and pathogenetic factors are involved that need careful consideration. In small neurinomas, of grades I and II, total extirpation of the tumour with preservation of both the facial nerve and segments of the vestibulocochlear nerve not directly involved by the tumour has become a safe and practical technique. In small acoustic neurinomas immediate facial nerve function could be preserved in 88% and "useful hearing" could be preserved in 78%. A number of different types of tumour-cranial nerve relationships could be established in small acoustic neurinomas, showing also the effects of adjusted surgical techniques on the preservation of hearing. Optimal selective separation of cranial nerves from the tumour is only possible through open surgical intervention, while radiosurgery requires the irradiation of the entire tumour/nerve complex.
Adult↗
Endosaccular occlusion of basilar artery bifurcation aneurysms using electrically detachable coils.
Thirteen patients with basilar artery bifurcation aneurysms, treated by electrothrombosis using electrically detachable coils, are presented. Nine of them presented after hemorrhage, two with mass effect, and two were found coincidentally with other ruptured aneurysms. Selection for endovascular therapy was based on the following criteria: 1) poor clinical condition (Hunt and Hess III-V); 2) high surgical risk; 3) age and poor medical condition; 4) morphological features (small necked aneurysms). With endovascular Guglielmi detachable coils aneurysm occlusion ranging from 70-100% was achieved in all cases. All five small necked and two large broad necked aneurysms were totally occluded. Two large aneurysms had a 95% occlusion and two other large aneurysms were 90% occluded. In another patient with a large broad based aneurysm only an 80% occlusion was achieved, because of tortuosity of the vertebrobasilar system. Our last patient, who presented as grade V clinically, was partially treated with a 70% aneurysmal occlusion. The clinical results were excellent in 10 and good in 2. The only poor outcome was seen in the grade V patient. There was no morbidity or mortality related to therapy. The only complication was an asymptomatic dissecting aneurysm at the origin of the vertebral artery. Angiographic follow up time ranged from 6 to 20 months with a mean of 9 months. Four patients were treated too recently to have their angiographic follow up at 6 months. Two patients were lost to follow up. Clinical follow up ranged from 1 to 17 months with a mean of 8.9 months. The analysis of our cases clearly shows that aneurysms, which were densely packed with coils, especially if small necked, were less likely to be reperfused and showed a longlasting stable result. Large broad based aneurysms were more likely to be reopened by blood flow after the first procedure, especially if loosely filled with coils, and needed up to 3 interventions to achieve a satisfying result, whereas later in the series a high percentage rate of occlusion was seen after the first procedure. We consider now also a less than 100% occlusion acceptable, because most of the aneurysms will rupture at the dome, which was occluded in all our cases. We conclude, that this new endovascular method is a viable alternative in the treatment of posterior circulation aneurysms with a high surgical risk, in old patients and those in poor clinical and medical condition.
Adult↗
[Histoplasmosis, caused by Histoplasma capsulatum, and AIDS].
Histoplasma capsulatum histoplasmosis occurs frequently in endemic areas and with the AIDS outbreak, it appears as an opportunistic fungus involved in disseminated disease. We report the clinical, biological and treatment features of seven cases diagnosed in the CISIH of the Eastern part of Paris. Clinically, four patients were suffering from pulmonary symptoms, in three cases digestive disorders and in three cutaneous lesions. In all cases, the mycologic diagnosis was necessary. Amphotericin B and itraconazole were used as treatment for five patients (two died before the diagnosis was completed). Among these five subjects, four died (death was attributed to histoplasmosis in only one case). These observations emphasize the importance of this infection in HIV-infected patients coming from endemic areas.
AIDS-Related Opportunistic Infections↗
Improved electrocardiographic detection of echocardiographic left ventricular hypertrophy: results of a correlated data base approach.
OBJECTIVES: We used electrocardiographic (ECG) and echocardiographic measurements from 3,351 adults from the Framingham Heart Study to evaluate the performance of 10 ECG criteria in detecting left ventricular hypertrophy before and after adjustment for gender, age and obesity. BACKGROUND: Significant improvement in the sensitivity and specificity of ECG voltage-based criteria for detection of echocardiographic left ventricular hypertrophy using gender-specific criteria adjusted for age and obesity has been demonstrated. METHODS: Gender-specific correlation and regression analyses were used to identify the five most sensitive ECG criteria and to adjust them for age and obesity. Standard and truncated receiver operating characteristic curves were used to compare the selected criteria. RESULTS: Linear regression of left ventricular mass on ECG voltages, body mass index and age yielded considerably stronger relations for women than for men because of the greater correlation between ventricular mass and body mass index in women. Obesity and age adjustment of the five voltage criteria produced considerable improvement in their performance. The voltage sum of the R wave in lead aVL and the S wave in lead V3, alone and in combination with QRS duration, had a sensitivity at 95% specificity of 32% and 39%, respectively, in men and 46% and 51%, respectively, in women after adjustment. Tables of critical voltages for the adjusted criteria and representative performance values are presented. CONCLUSIONS: Incorporation of obesity and age in ECG algorithms consistently improves their performance in the detection of hypertrophy. The development of such criteria will enhance the utility of this inexpensive screening test. Such ECG approaches should be used in clinical trials to assess the efficacy of antihypertensive treatment to effect regression of left ventricular hypertrophy. A search for further improvements in the efficacy of ECG criteria for this purpose is warranted. Independent validation of this approach is needed.
Age Factors↗
Gender-specific reference M-mode values in adults: population-derived values with consideration of the impact of height.
OBJECTIVES: The purpose of this investigation was to derive population-based reference values for M-mode echocardiographic dimensions that can be applied in epidemiologic studies, clinical trials and clinical practice and to determine optimal methods for adjusting these dimensions for body size. BACKGROUND: M-mode echocardiography remains an important modality for studying cardiovascular disease; this is especially true with regard to detecting target organ damage in systemic hypertension. Most previously published reference values were derived from hospital-based series or relatively small samples and were not gender specific. METHODS: Using a sample of 288 men and 524 women who were between 20 and 45 years of age and who were free of cardiovascular disease, reference values were derived for end-diastolic and end-systolic left ventricular internal dimensions, left ventricular wall thickness and left atrial dimension. The relations between these dimensions and height, a measure of body size relatively independent of obesity, were investigated using various regression models. RESULTS: Nomograms for mean and 95th percentile values in men and women were constructed on the basis of linear regression models relating echocardiographic dimensions to height. Adjustment for body surface area greatly attenuated associations between obesity and cardiac dimensions in a separate healthy but less restricted sample of 411 men and 503 women. CONCLUSIONS: Gender-specific M-mode reference values and nomograms, with mean and 95th percentile values for echocardiographic dimensions as a function of height, are reported. The use of body surface area as means of body size adjustment is called into question.
Adult↗
Prevalence, clinical features and prognosis of diastolic heart failure: an epidemiologic perspective.
Numerous reports suggest that about one-third of patients with congestive heart failure do not have any abnormality of left ventricular systolic function. These patients presumably have heart failure on the basis of ventricular diastolic dysfunction. Our objective was to develop a comprehensive overview of published reports of the prevalence, clinical features and prognosis of diastolic heart failure and to offer recommendations for future studies. Thirty-one studies of patients with congestive heart failure with normal left ventricular systolic function were published in the time period from January 1970 through March 1995. These studies were identified with the use of computer-based searches in relevant data bases. Among patients with congestive heart failure, the prevalence of normal ventricular systolic performance in the published reports varies widely from 13% to 74%; the reported annual mortality rate also varies from 1.3% to 17.5%. The criteria for congestive heart failure, its chronicity and the age of the study sample affect the reported prevalence and prognosis of the disorder. The clinical signs and symptoms of diastolic heart failure are similar to those of patients with systolic heart failure, underscoring the need for evaluation of ventricular systolic function in patients with congestive heart failure. In the absence of any large-scale randomized clinical trial targeting these patients, the optimal treatment of diastolic heart failure is unclear. We conclude that the heterogeneity in previous studies of diastolic heart failure hinders the comparison of published reports. There is a need to conduct prospective, community-based investigations to better characterize the incidence, prevalence and natural history of diastolic heart failure. Randomized clinical trials are needed to determine optimal treatment strategies.
Diastole↗
Unexplained gradual-onset Q wave patterns. A case series from the Framingham Study.
Original cohort members of the Framingham Study were studied to determine prognosis associated with unexplained (gradual-onset) Q wave patterns detected on routine electrocardiograms (ECGs). Biennial ECGs were obtained on subjects beginning in 1948. The index ECG was read independently and then serially in relation to all previous tracings for evidence of myocardial infarction. Proportional hazards modeling was used to assess the risk for outcomes in those with unexplained (gradual-onset) Q wave patterns compared with subjects with unrecognized myocardial infarcts (abrupt-onset Q waves) and compared with referent subjects. Unexplained Q wave patterns developed in 53 men and 39 women. Subjects with unexplained Q wave patterns had less than 40% of the risk for myocardial infarction or coronary death as compared with those with unrecognized myocardial infarction after adjusting for risk factors (hazard ratio, 0.38; 95% confidence interval, 0.19, 0.78; P = .008) and a trend toward a lower risk for overall mortality (adjusted hazard ratio, 0.73; 95% confidence interval, 0.46, 1.16; P = .18). Risks for myocardial infarction or coronary death and overall mortality were similar in subjects with unexplained Q wave patterns and referent subjects in the fully adjusted models. Detection of prominent Q waves on an ECG requires comparison with prior tracings to differentiate the unexplained Q wave pattern from the unrecognized infarct, conditions that have significantly different prognostic implications.
Aged↗
Intrinsic defect in B cells of patients with hyper-immunoglobulin M syndrome.
We challenge the theory that the CD40-CD40 ligand is the only explanation for X-linked immunodeficiency in patients with hyper-immunoglobulin M (IgM) syndrome (HIGM1), and we demonstrate an intrinsic defect in the patients' B cells. Patients with HIGM1 have a defective CD40 ligand on their activated T-helper cells; therefore, they cannot receive signals for isotype switching when the cells are activated by T cell-dependent antigens. We activated mononuclear cells from three patients with HIGM1 and from three healthy blood donors with T cell-independent mitogens and studied their proliferative responses and Ig secretion. Normal murine plasma membrane fragments were implanted into peripheral blood mononuclear cells, and the cells were activated with Staphylococcus aureus Cowan I, pokeweed mitogen, and lipopolysaccharide. This implantation significantly augmented the proliferative responses to the mitogens in two patients. However, it augmented IGM secretion in response to B-cell mitogens in only one patient. No IgG or IgA response could be detected in the implanted mononuclear cells that originated from patients with HIGM1, unlike implanted mononuclear cells from healthy donors, which responded by IgM, IgG, and IgA antibody secretion following their stimulation with B-cell mitogens. The data suggest that the B cells of patients with HIGM1 possess an additional defect which prevents Ig isotype switching in response to T cell-independent mitogens. This defect is not located in the membrane receptors or within the membrane enzymes.
Adolescent↗
Fluctuations in visual neglect after stroke?
Clinical experience suggests that the visual neglect in stroke patients fluctuates over short periods of time. This fluctuation has been variously attributed to fatigue, time of day, previous activities, patient learning and compensation. Such fluctuations have clinical implications for the assessment and rehabilitation of visual neglect but do date no formal study has evaluated the extent of such fluctuation over the course of a day. Twenty-two patients with an acute stroke and 19 patients with convalescent stroke were examined for visual neglect twice on the same day using the Visual Neglect Recovery Index (VNRI), a valid and sensitive measure of the severity of neglect, which could be used to select acute patients for trials of treatment of neglect. The inter-test reliability was extremely high. In contrast to past clinical accounts most patients failed to show significant fluctuation. Although preliminary, this finding suggests that a single assessment of visual neglect, using the VNRI, could help select patients for treatment trials.
Aged↗
Influence of blood pressure on left atrial size. The Framingham Heart Study.
Increased left atrial size has been identified as a precursor of atrial fibrillation and of stroke once atrial fibrillation is manifest. Conflicting data exist regarding the effect of high blood pressure on left atrial size. Our objective was to evaluate the association of contemporary and long-term measures of blood pressure with echocardiographically determined left atrial size in a large, population-based cohort. The study sample consisted of 1849 male and 2152 female participants of the Framingham Heart Study and Framingham Offspring Study. All analyses were sex specific. In correlation analyses, systolic and pulse pressures were identified as statistically significant determinants of left atrial size after adjustment for age and body mass index, although the magnitudes of these relations were very modest (partial r < or = .10). Multivariable linear regression models showed the relative contributions of the pressure variables to the prediction of left atrial size to be substantially less than those of age and, in particular, body mass index. Furthermore, inclusion of left ventricular mass in these multivariable models eliminated or attenuated the associations of the pressure variables with left atrial size. In logistic analyses, increasing levels of the pressure variables were significantly predictive of left atrial enlargement. Subjects with 8-year average systolic pressure of 140 mm Hg or higher were twice as likely to have left atrial enlargement as those with values of 110 mm Hg or lower. Overall, in this population-based study sample, increased levels of systolic and pulse pressures (but not diastolic or mean arterial pressures) were significantly associated with increased left atrial size.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗