Plan and operation of the NHANES I Epidemiologic Followup Study, 1992

OBJECTIVES: The NHANES I Epidemiologic Followup Study (NHEFS) is a longitudinal study that uses as its baseline those adult persons 25-74 years of age who were examined in the first National Health and Nutrition Examination Survey (NHANES I). NHEFS was designed to investigate the association between factors measured at baseline and the development of specific health conditions. The three major objectives of NHEFS are to study morbidity and mortality associated with suspected risk factors, changes over time in participants' characteristics, and the natural history of chronic disease and functional impairments. METHODS: Tracing and data collection in the 1992 Followup were undertaken for the 11,195 subjects who were not known to be deceased in the previous surveys. No additional information was collected in the 1992 NHEFS for the 3,212 subjects who were known to be deceased before the 1992 NHEFS data collection period. RESULTS: By the end of the 1992 NHEFS survey period, 90.0 percent of the 11,195 subjects in the 1992 Followup cohort had been successfully traced. Interviews were conducted for 9,281 subjects. An interview was conducted for 8,151 of the 8,687 surviving subjects; 551 interviews were administered to a proxy respondent because the subject was incapacitated. A proxy interview was conducted for 1,130 of the 1,392 decedents identified in the 1992 NHEFS. In addition, 10,535 facility stay records were collected for 4,162 subjects reporting overnight facility stays. Death certificates were obtained for 1,374 of the 1,392 subjects who were identified as deceased since last contact. Approximately 32 percent of the NHEFS cohort is known to be deceased with a death certificate available for 98 percent of the 4,604 NHEFS decedents.     

Comparison of two surveys of hospitalization: the National Hospital Discharge Survey and the NHANES I Epidemiologic Followup Study

OBJECTIVES: This report compares hospitalization data from the NHANES I Epidemiologic Followup Study (NHEFS) with data from the National Hospital Discharge Survey (NHDS), the benchmark for hospitalization in the United States, for men and women 35 years and older for the period 1971-87. The comparison is intended to help analysts evaluate the validity and generality of analyses based on the NHEFS. METHODS: Hospital stays per 1,000 population and average lengths of stay are compared year by year for each age-sex group and for the entire period. Regression analyses test for differences between the two surveys by age and sex, and for differences in trends over time and the effect of the Medicare program's prospective hospital payment system. RESULTS: Hospital stays per 1,000 population were lower in NHEFS than in NHDS in all age-sex groups at the beginning of the period, but the differences had almost disappeared by 1987. Lengths of stay, although somewhat longer in NHEFS, matched NHDS more closely. Differentials by age and sex were similar in the two surveys for both hospital stays per 1,000 population and length of hospital stay. With its extensive information on baseline risk factors, the NHEFS offers a unique opportunity to study determinants of hospitalization in a representative sample of U.S. adults. The evaluation presented here suggests two points for researchers who want to use the NHEFS. First, including age as a control should largely correct for differences in age distribution between NHEFS and NHDS. Second, a time trend should also be included to capture the effects of several factors that caused the count of stays to be low in the early years of NHEFS followup.     

Multivariate risk estimation for coronary heart disease: the Busselton Health Study

Coronary heart disease (CHD) is a multifactorial disease and CHD risk should be estimated by assessing all cardiovascular risk factors simultaneously. Simply adding up the number of factors with 'at risk' values fails to identify high-risk subjects with multiple risk factors at moderately elevated values. A more efficient approach is to use a quantitative multivariate risk score. A number of overseas studies have produced CHD risk scoring systems for men. There are few risk scores developed for women and no CHD risk scores have been developed from Australian data. This study used data on CHD risk factors and morbidity/mortality follow-up for the 1978 Busselton Health Survey participants to provide age-specific estimates of absolute risk of CHD hospitalisation or death, and to develop multivariate CHD risk scoring systems for men and women. The scores are based on age, blood pressure, anti-hypertensive medication, total and HDL cholesterol, smoking, diabetes, left ventricular hypertrophy and previous history of CHD. The generalisability and applicability of these risk estimation systems to Australian populations in the late 1990s is discussed.     

Long-term prognosis of different forms of coronary heart disease: the Reykjavik Study

BACKGROUND: While coronary heart disease (CHD) is a serious and often fatal disease the prognosis is variable and major effort has been invested in risk stratification. The purpose of this study was to examine the relation between long-term prognosis and risk factors in different clinical categories of CHD. METHODS: A general population sample of 9141 men, aged 34-79 at entry into the study was divided into six groups with respect to manifestations of CHD at entry: I. Symptomatic infarction. II. Silent or unrecognized infarction. III. Angina pectoris with ischaemic changes on ECG. IV. Angina without ischaemic changes. V. Angina by Rose questionnaire but not confirmed by a physician. VI. No manifestations of CHD. RESULTS: The risk factor profile varied considerably between the different categories and by life-table analysis marked differences in survival were demonstrated between the groups. The risk factors maintained their detrimental effects on prognosis in the presence of CHD. Thus, age, serum total cholesterol, impaired glucose tolerance and smoking were found by Cox's regression to be statistically significant independent risk factors of CHD mortality among men having manifestations of CHD (groups I-V). Furthermore, the composite risk score, a measure of the overall risk factor exposures had marked effect on the prognosis of the various CHD groups. When the comprehensive risk factor score for both CHD mortality and all-cause mortality was accounted for marked differences persisted in the long-term prognosis. Compared to those without CHD the infarct groups had about a 7.6- and 3.7-fold risk of dying from CHD and all causes respectively. Those with angina had from 2.5- to 3.2-fold risk of CHD mortality and 1.7- to 2.2-fold risk of all-cause mortality depending on the subgroup of angina, again compared to those without manifestations of CHD. CONCLUSION: Different categories of CHD had different risk factor profiles and the long-term prognosis resulted from a complex interplay between those factors and the diagnostic category of CHD. The risk factors maintained their detrimental effects on prognosis in the presence of CHD and after accounting for the comprehensive risk factor score marked differences persisted in the long-term prognosis, being worst for those having suffered a myocardial infarction, either symptomatic or silent.     

Depression and coronary heart disease: observations and questions

Coumarin-related compounds, auraptene and umbelliferone, have been isolated from the cold-pressed oil of natsumikan (Citrus natsudaidai HAYATA), and tested as inhibitors of tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced Epstein-Barr virus activation in Raji cells. The 50% inhibitory concentration (IC50) of auraptene (18 microM) was almost equal to that of genistein. Umbelliferone, which lacks a geranyloxyl group present in auraptene, was less active (IC50 = 450 microM). In a two-stage carcinogenesis experiment with 7,12-dimethylbenz[a] anthracene (topical application at 0.19 mumol) and TPA (topical application at 1.6 nmol) in ICR mouse skin, topical application of auraptene (at 160 nmol) significantly reduced tumor incidence and the numbers of tumors per mouse by 27% (P < 0.01) and 23% (P < 0.05), respectively. Auraptene at a concentration of 50 microM markedly suppressed superoxide (O2-) generation induced by 100 microM TPA in differentiated human promyelocytic HL-60 cells. Having no O2(-)-scavenging potential, auraptene may inhibit the multicomponent NADPH oxidase system. Inhibition of intracellular hydroperoxide formation in differentiated HL-60 cells by auraptene was also confirmed by flow-cytometric analysis using 2',7'-dichlorofluorescein diacetate as a fluorescence probe. Quantitative analyses using high-performance liquid chromatography showed the occurrence of auraptene not only in both the peels and sarcocarps of natsumikan, but also in those of hassaku orange (C. hassaku) and grapefruit (C. paradisi), and even in their bottled fresh juice form. These results indicate that auraptene is a chemopreventer of skin tumorigenesis, and implies that suppression of leukocyte activation might be the mechanism through which it inhibits tumor promotion.     

Cholesterol and coronary heart disease: screening and treatment

The prevention of coronary heart disease would represent a major saving to the NHS. Systematic review of evidence relating to screening for CHD and its prevention suggests that blood cholesterol measurement on its own is a poor predictor of risk. The evidence suggests that lifestyle changes and drug treatments other than cholesterol-lowering drugs are the most cost-effective approach to prevention. Nurses should ensure that all risk factors are assessed and a range of preventive measures considered in situations where CHD is a potential risk.     

老年冠心病69例心率震荡分析及临床意义研究

心率震荡(HRT)是指单个室性早搏后出现的窦性心律先加速随后减速的现象,是心脏自主神经对室性早搏出现的快速调节反应,反映了窦房结的双相变时功能.是一项新的简单、实用、无创的心脏事件预测指标.我们对60例老年冠心病患者的HRT指标进行分析并随访观察,以探讨其特点及临床意义.     

Circadian rhythmic fractal scaling of heart rate variability in health and coronary artery disease

BACKGROUND: In clinical cardiology, heart rate variability is a putative index of autonomic cardiovascular function. Signs of reduced vagal activity are not only associated with an enhanced risk of sudden cardiac death, but such impaired heart rate variability became a new predictor of sudden cardiac death and other mortality in patients with a variety of diseased states. HYPOTHESIS: It is postulated (1) that the time structure (chronome) of heart rate variability in clinical health includes a circadian rhythm and deterministic chaos, the latter gauged by the correlation dimensions of RR intervals; and (2) that this chronome is altered in patients with coronary artery disease (CAD). METHODS: From 24-h Holter records of 11 healthy controls and 10 patients with CAD, 500-s sections around 02:00, 06:00, 10:00, 14:00, 18:00 and 22:00 hours were analyzed for smoothed RR intervals sampled at 4 Hz. Correlation integrals were estimated for embedding dimensions from 1 to 20 with a 1.0-s time lag, using an algorithm modified from Grassberger and Procaccia. The Wilcoxon signed-rank test compares circadian end points assessed by cosinor between the CAD patients and age-matched controls. RESULTS: A circadian rhythm characterizes the correlation dimension of healthy subjects peaking during the night (p < 0.005). Patients with CAD have a lowered correlation dimension (p < 0.05) and an altered circadian variation which requires the consideration of an approximately 12-h (circasemidian) component. CONCLUSION: The results demonstrate the sensitivity of circadian rhythms for the detection of disease. A partial 24- to 12-h (circadian-to-circasemidian) frequency multiplication (or partial variance transposition) in CAD of the correlation dimension, apart from being a potential clue to the etiology of the disease, adds a new feature to a chronocardiology combining, with the fractal scaling, an assessment of circadian and circasemidian components as measures of predictable variability to be tested for use in diagnosis, prognosis, and as putative guides to treatment timing.     

Depression and the risk of coronary heart disease in the Normative Aging Study

BACKGROUND: Epstein-Barr virus (EBV) infection is common after liver transplantation in children and is associated with the risk of posttransplant lymphoproliferative disorders (PTLD). METHODS: This retrospective study examined the frequency of gastrointestinal (GI) symptoms and the risk of PTLD in pediatric liver recipients who developed symptomatic EBV infection. We reviewed 172 children who received orthotopic liver transplants between March 1988 to December 1994. Twenty-two cases were retransplants. The mean age at transplantation was 3.7 years (range, 0.1-17 years). The immunosuppressive regimens consisted of induction therapy with Minnesota antilymphocyte globulin/antithymocyte globulin/OKT3 in most cases and maintenance therapy with prednisone and either cyclosporine or tacrolimus (FK506). RESULTS: After 1 year of minimum follow-up, 54 of 172 patients had symptomatic EBV infections (confirmed by serology, histology, or whole blood polymerase chain reaction. At the time of infection, 38.5% (21/54) had either diarrhea or GI bleeding or both. PTLD developed in 11 patients (6.4%). The incidence of PTLD was 42.9% (9/21) when GI bleeding or diarrhea was associated with EBV infections, compared with 6.1% (2/33) when EBV infection was not associated with GI symptoms. Seven of 10 (70%) patients with GI bleeding and 2 of 11 (18.2%) with diarrhea developed PTLD. Of seven patients examined by endoscopy for GI bleeding, two had biopsy-proven PTLD of the GI tract, whereas one of two patients examined by endoscopy for diarrhea had biopsy-proven PTLD. DISCUSSION: In summary, a high incidence of PTLD was found in patients who developed GI bleeding or diarrhea associated with EBV infection after pediatric liver transplantation. In these patients, endoscopy and biopsy may lead to early diagnosis of PTLD.     

Renal stones and coronary heart disease

The relationship between risk factors for coronary heart disease (CHD) and renal stone disease has been studied in a population of more than 2000 middle-aged men. The only positive association found was a slight increase in diastolic BP among stone formers and a higher stone prevalence in untreated hypertensives. Furthermore, the prevalence of a history of renal stones in male survivors of myocardial infarction (MI) was similar to that found in the population study. An investigation of the vitamin D intake by means of a dietary questionnaire revealed no differences between stone formers, healthy controls and MI survivors. Contrary to other reports, the present study indicates that the risk factor profile for CHD in stone formers is similar to that in the general population.     

High-density lipoproteins and coronary heart disease

High-density lipoproteins (HDLs) play an important role in the process of reverse cholesterol transport, the pathway by which the cholesterol in extrahepatic tissues is transported through plasma to the liver for recycling or for excretion from the body in bile. The concentration of HDL cholesterol is a powerful inverse predictor of the development of coronary heart disease, leading to a widely held view that HDL protects against the development of atherosclerosis. The mechanism by which HDLs protect is unknown. To date, no studies have been designed specifically to test the proposition that increasing the concentration of HDL cholesterol translates into a reduction in coronary risk. Nevertheless, in a subgroup of the Helsinki Heart Study, it was found that a substantial proportion of the beneficial effect of gemfibrozil was explicable in terms of an increase in the concentration of HDL cholesterol.