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Biomedical subjects

K Liu

Publications and source records attributed to K Liu.

At least 505 records · Page 28Linked to original sources
PubMed1988

Relationships of low density lipoprotein cholesterol with age and other factors: a cross-sectional analysis of the CARDIA study.

Presumed evolution of low density lipoprotein cholesterol (LDL-C) was studied in a baseline cross-sectional survey of 4955 18-30 year old men and women of various sociodemographic backgrounds. Specifically studied were the influences on LDL-C and the change of LDL-C with age of race, gender, education, diet, physical activity, fatness and fitness. Men increased about 20 mg/dl per 10 years of age, while women increased about 3 mg/dl. Increasing education was found to be associated with higher LDL-C in blacks, but with lower LDL-C in whites. Higher Keys diet score and body mass index were positively associated with LDL-C, while higher total caloric intake, vigorous physical activity, duration on a treadmill exercise test and usual intake of alcohol were negatively associated with LDL-C. The finding of a different relationship of LDL-C to increasing education in whites than in blacks suggests a cultural or behavioral influence in rate of increase in LDL-C.

Adolescent↗
PubMed1987

The role of relative weight in the positive association between age and serum cholesterol in men and women.

With advancing age from youth on, there is an increase in mean serum cholesterol level of populations in "western" industrialized countries. Since serum cholesterol is one of the established major risk factors for premature coronary heart disease, it is important to explore the degree to which this age trend is physiologic or due to modern life styles. This study used cross-sectional data for 19,730 white men and 13,872 white women from the Chicago Heart Association Detection Project in Industry to investigate one aspect of this question: does weight explain the association between age and serum cholesterol, in particular whether older age is associated with higher serum cholesterol in the absence of overweight. The relationships among age, relative weight, and serum cholesterol were examined through assessment of mean serum cholesterol levels in 25 subgroups stratified by age (18-24, 25-34, 35-44, 45-54, 55-64) and by relative weight (less than 100, 100-109, 110-119, 120-134, greater than or equal to 135). Age and serum cholesterol were positively associated with each other. In women, it was a simple, linear relationship. In men, the degree of this positive association was less in people over age 35-44 than people in younger ages. These age-cholesterol patterns were present in men and women at desirable weight. However, in men aged 18-54, the positive association between age and prevalence of marked hypercholesterolemia (serum cholesterol greater than or equal to 250) was lower in people at desirable relative weight in comparison to those at higher relative weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Recruitment in the Coronary Artery Disease Risk Development in Young Adults (Cardia) Study.

Coronary Artery Disease Risk Development in Young Adults (CARDIA) is a longitudinal study designed to trace the development of risk factors for coronary heart disease in 5100 individuals 18-30 years old. The study will compare, by cross-sectional and longitudinal analyses, trends and processes involved in risk factor development by sex, race, age, and other sociodemographic characteristics. Participants for the approximately 4 1/2-hour baseline examination were randomly selected and recruited by telephone from census tracts in Minneapolis and Chicago, by telephone exchanges within the Birmingham city limit, and from lists of the Kaiser-Permanente Health Plan membership in Oakland and Berkeley. A major issue was the desirability of sampling approximately equal numbers by age, race, sex, and education as compared with sampling numbers representative of the population base. The recruitment goal of 5100 was achieved on schedule.

Adolescent↗
PubMed1987

Coffee consumption and mortality in the Chicago Western Electric Company Study.

The relations between coffee consumption and 19-year mortality from all causes, coronary heart disease, and non-coronary causes were assessed in 1,910 white males aged 40-56 years in 1957-1958 from the Chicago Western Electric Company Study. Mortality rates, adjusted for age, serum cholesterol, diastolic blood pressure, and smoking status, were compared for those consuming 0-1, 2-3, 4-5, and 6+ cups of coffee per day; coffee intake, measured at the first anniversary examination, included both caffeinated and decaffeinated intake. Mortality from all causes was greatest in the highest and lowest intake groups. The increased mortality in the 6+ cups per day group was due to coronary heart disease, while the increased mortality in the lowest intake group was due to noncoronary causes. The adjusted relative risk of coronary heart disease death for those drinking 6+ cups of coffee per day compared with those drinking less was 1.71 (95 per cent confidence limits 1.27, 2.30). This increased risk of coronary heart disease death was present in both smokers and nonsmokers, with adjusted relative risks of 1.62 and 2.21, respectively (95 per cent confidence limits 1.17, 2.24 and 1.06, 4.62). The increased mortality from non-coronary causes in the lowest intake group was due primarily to increased mortality from cancer and cardiovascular diseases other than coronary heart disease. The results of this study support the hypothesis that those who drink 6+ cups of coffee per day may be at an increased risk of death from coronary heart disease.

Adult↗
PubMed1987

Variability of urinary sodium and potassium excretion in north Chinese men.

Variability of urine sodium (Na), potassium (K) and sodium/potassium (Na/K) excretion was studied in a sample of 50 employed normotensive male health professionals aged 27-50 in Beijing, China. Six 24-h urine specimens were collected from each participant during night-time (12-h) and daytime (12-h) fractions. The estimated ratio of intra- to inter-individual variances was 2.12 for night-time and 1.48 for 24-h urine Na, and 1.85 and 1.54, respectively, for urine K. Based on these values, six night-time and four 24-h urine specimens are necessary to reduce to 15% the diminution of a correlation between urine Na and another physiological variable. The corresponding numbers are five and four, respectively, for urinary K measurement. These data suggest that the ratio of within-person variation to between-person variation in Na excretion is smaller in these Chinese men than in Americans. The dietary Na intake of Chinese men can therefore be characterized with fewer urine specimens than are required for western populations. Night-time urinary Na and K showed good concordance with those from 24-h specimens in distinguishing high or low Na and K intake. These findings indicate that in large-scale epidemiological studies, overnight specimens may be adequate for classifying individuals with regard to Na and K intake.

Adult↗
PubMed1987

Sex differential in the relationship of electrocardiographic ST-T abnormalities to risk of coronary death: 11.5 year follow-up findings of the Chicago Heart Association Detection Project in Industry.

The independent contributions of ST segment depression and/or T wave abnormality (ST-T abnormalities) on the baseline resting electrocardiogram to risk of 11.5 year coronary heart disease (CHD) mortality were explored among 9203 white men and 7818 white women who were 40 to 64 years old and without definite CHD at entry in the Chicago Heart Association Detection Project in Industry. At baseline, prevalence rates of ST-T abnormalities were age related for both sexes, and at every age the rate was higher in women than men (age-adjusted prevalence rates 12.3% and 8.1%, respectively). Univariate analysis showed that ST-T abnormalities were associated with significantly increased risk of death from CHD for both men and women. However, men with ST-T abnormalities had much greater age-adjusted and multiple risk factor-adjusted absolute excess risk and relative risk than women with such electrocardiographic abnormalities. When baseline age, diastolic pressure, serum cholesterol, cigarettes/day, history of diabetes, and baseline use of antihypertensive medication were included in the multivariate analysis, ST-T abnormalities remained significantly related to death from CHD in men but not women. The interaction term between sex and ST-T abnormalities was at a borderline level of statistical significance by Cox regression analysis. In conclusion, ST-T abnormalities indicate an increased risk of subsequent death from CHD independent of major coronary risk factors for middle-aged U.S. men, but this is not clearly so for women.

Adult↗
PubMed1986

Relationship of clinical diabetes and asymptomatic hyperglycemia to risk of coronary heart disease mortality in men and women.

This epidemiologic study explored the sex differential in risk of death from coronary heart disease in persons with or without clinically diagnosed diabetes or asymptomatic hyperglycemia. Use was made of 9-year follow-up data from the Chicago Heart Association Detection Project in Industry for 11,220 white men and 8,030 white women aged 35-64 years at entry to the Project (November 1967-January 1973). Both clinically diagnosed diabetes and asymptomatic hyperglycemia were associated with an increased risk of death from coronary heart disease. The extent of this association was greater in women than in men in regard to relative risk. However, absolute excess risk for both diabetics and those with asymptomatic hyperglycemia was larger for men than for women. Clinical diabetes appeared to be an independent risk factor for coronary heart disease in both men and women based on multivariate Cox regression analyses. On the other hand, for men, no significant independent effect of asymptomatic hyperglycemia was apparent. Women with asymptomatic hyperglycemia had significantly higher coronary heart disease death rates than normoglycemic women, with adjustment for major coronary heart disease risk factors; in multivariate analyses, the relationship of asymptomatic hyperglycemia to risk of coronary heart disease was of borderline significance (p = 0.054). This study indicates the independent associations of diabetes and possibly asymptomatic hyperglycemia with coronary heart disease mortality, with greater relative significance in women than in men.

Adult↗
PubMed1986

The role of weight in the positive association between age and blood pressure.

This study used cross-sectional data for 19,704 white men and 13,895 white women from the Chicago Heart Association Detection Project in Industry (November 1967 to January 1973) to investigate whether weight explains the association between age and blood pressure, and in particular, whether age is associated with blood pressure and hypertension in the absence of overweight. The relations among age, relative weight, and blood pressure were examined through assessment of mean blood pressure levels and prevalence of hypertension in 25 subgroups stratified by age (18-24, 25-34, 35-44, 45-54, and 55-64 years) and by relative weight (less than 100%, 100-109%, 110-119%, 120-134%, and greater than or equal to 135%). For all five relative weight groups, for both men and women, mean diastolic blood pressure was higher at successive ages. This phenomenon was also seen for systolic blood pressure after ages 35-44 years for men, and after ages 25-34 years for women. On the other hand, the higher the relative weight was, the higher the blood pressure was. Regression analysis demonstrated that the observed relation between age and blood pressure was consistent for all five relative weight groups, including those at desirable weight. These data indicate that for US subjects, age and blood pressure are generally associated in the absence of overweight.

Adolescent↗
PubMed1986

Timed overnight sodium and potassium excretion and blood pressure in steel workers in North China.

Three timed overnight urinary sodium (Na), potassium (K) and creatinine measurements, standardized to 8 h, as well as three blood pressures on corresponding consecutive days were obtained on a sample of 90 steel workers (40 men, 50 women) aged 34-56 years in Beijing, North China. For three indices of electrolyte excretion - absolute Na and K output/8 h, Na:K ratio and 8 h creatinine output - the ratios of intra- to inter-individual variations were less than 1.0 for men, but higher for women in contrast to findings for U.S. population groups of similar age. This fact, probably reflecting greater stability of day to day electrolyte intake by Chinese than Americans, enables reasonably precise characterization of dietary electrolyte intakes of individual Chinese, particularly men, with only a few timed overnight urine specimens. With 3-day mean values for each person, nominally significant (i.e. not adjusted for multiple testing) positive simple correlations were found for urinary Na, Na:K and Na:creatinine with blood pressure [both systolic (SBP) and diastolic (DBP)] for men; and women for Na:K with SBP and DBP, but Na:creatinine with SBP only. With control for age, body mass index and pulse in multivariate analyses, only the relationship of Na:K and Na:creatinine to SBP and DBP remained significant for men; a similar, though less strong and consistent, trend was found for women, and K was inversely related to SBP for women. These data are consistent with an association between habitual intake of sodium and risk of hypertension, and also suggest that habitual potassium intake may have a countervailing influence in this regard.

Adult↗
PubMed1986

Case-mix differences between hospital-based and freestanding skilled nursing facilities. A review of the evidence.

Many health care services are available in both hospital and freestanding settings. Hospital-based providers are usually much more expensive than freestanding providers. According to Medicare data, costs in hospital-based skilled nursing facilities (SNFs) are twice those of freestanding facilities. While critics charge that this is the result of inefficiency, hospitals counter that higher costs are caused by treatment of sicker patients and provision of higher-quality care. This paper analyzes the research on the case-mix differences between hospital-based and freestanding SNFs. On the basis of this analysis, it appears that hospital-based facilities tend to serve more severely ill patients (i.e., have a more difficult case mix) than do freestanding facilities. Case-mix differences, however, appear to explain less than half of the cost differential between the two types of facilities.

Costs and Cost Analysis↗
PubMed1986

Prospective payment for Medicare skilled nursing facilities: background and issues.

Strong interest by Congress in a Medicare prospective payment system for skilled nursing facilities (SNF's) resulted in a major study by the Health Care Financing Administration on the Medicare SNF benefit. This article highlights findings from that study, which addressed the following: the Medicare SNF benefit, utilization and expenditures, the Medicare SNF industry, problems with the current Medicare SNF reimbursement system, efforts to develop a Medicare SNF case-mix measure, and case-mix differences between hospital-based and freestanding SNF's. In addition, we discuss the implications of the study findings for the design of a Medicare SNF prospective payment system (PPS).

Costs and Cost Analysis↗
PubMed1986

The feasibility of using case mix and prospective payment for Medicare skilled nursing facilities.

Congress, at the time it asked for a feasibility study of the use of prospective payment for hospital care delivered to Medicare patients, also asked for a study of the Medicare skilled nursing facility (SNF) benefit. The information and commentary in this paper are based on the history and findings of the recent Health Care Financing Administration study of the SNF benefit. We discuss the technical, administrative, and policy issues that need to be addressed to implement a patient-level case-mix adjustment for reimbursing SNFs under Medicare. We conclude that conditions are currently not ideal for implementing a patient-level case-mix adjustment for Medicare SNFs. Future research may be able to remedy some of the impediments to adapting case-mix adjustments for SNFs.

Activities of Daily Living↗
PubMed1986

Serum lipid response to oat product intake with a fat-modified diet.

Healthy adult volunteers (no. = 208), men and women aged 30 to 65 years, participated in a 12-week study on dietary fat modification plus oat product ingestion (60 gm/day) to test whether moderate daily intake of oat bran and oatmeal enhanced serum lipid response. During weeks 0 to 6, all participants followed the American Heart Association fat-modified eating style. At 6 weeks, participants were randomly assigned to one of three groups. All participants continued to follow the fat-modified eating pattern; groups 1 and 2 were asked during weeks 7 to 12 to consume two servings of either oat bran or oatmeal per day, for a total of 60 gm/day isocalorically substituted for other carbohydrates. Group 3 ingested no oat products. At baseline, the group mean cholesterol level was 208.4 mg/dl. After 6 weeks of dietary fat intervention, the level was 197.6--a fall of 10.8 mg/dl (5.2%). At 12 weeks, the mean serum cholesterol level fell further, by 5.6, 6.5, and 1.2 mg/dl for groups 1, 2, and 3, respectively. Group mean weight loss was small--1.9 lb during the first 6 weeks and 0.6 to 0.8 for the three groups during weeks 7 to 12. Reported oat product ingestion was 39 and 35 gm per person per day, respectively, for groups 1 and 2 (2.2 and 1.4 servings per person per day, respectively). Dietary fat composition remained similar among the three groups during weeks 7 to 12. Pooled results indicated that the addition of oat products at a moderate and practical level enhanced serum lipid response (p less than .05) to a fat-modified eating pattern among free-living adults.

Adult↗