Differences in leisure-time physical activity levels between blacks and whites in population-based samples: The Minnesota heart survey

Energy expenditure in leisure-time physical activity (LTPA) was measured using the Minnesota LTPA Questionnaire in 35- to 74-year-old black and white residents of Minneapolis-St. Paul, Minnesota. Estimates of the geometric mean LTPA energy expenditure were 129 and 204 kcal per day for black and white men (p<.05) and 91 and 123 kcal per day for black and white women (p<.05). The percentage of individuals expending 2000 kcal or more per week in LTPA was significantly lower in black men than white men (25 vs. 35%; p=.01) but was not different in black versus white women (18 vs. 17%). Although black men and women reported greater occupational physical activity than their white counterparts, LTPA and job activity were unrelated in all race and sex groups. In both races, LTPA energy expenditure declined with age. LTPA increased with level of formal education, and the largest LTPA difference between blacks and whites was observed in those who had a high-school diploma or less. Blacks had lower participation rates than whites in most of the individually assessed physical activities. Additional research is needed on the determinants and promoters of LTPA in population subgroups.The research was funded by National Heart, Lung, and Blood Institute Research Grant R01 HL 23727 and National Research Award T32 HL 07328-10.     

Change in waist-hip ratio with weight loss and its association with change in cardiovascular risk factors.

We investigated whether weight loss decreases the waist-hip ratio (WHR) in overweight men and women, and whether changes in WHR relates to change in cardiovascular risk factors, independent of change in weight. Weight loss correlated significantly with decreases in the circumference of the waist and hips, and decreases in WHR in men and women. At comparable levels of weight loss, men had greater decreases in the waist, and smaller decreases in the hips than women, resulting in greater decreases in WHR. Cardiovascular risk factors improved significantly with weight loss. However, after controlling for weight loss, there was no evidence that change in WHR or change in circumference measures were related to change in risk factors. These data suggest that WHR is modifiable by weight loss, especially in men, but that change in WHR may not be independently related to changes in cardiovascular risk factors.     

Immunoassay method validation for a modified EMIT phencyclidine assay.

Immunoassay drug testing methods, that have been modified from the manufacturers' recommended procedure to be used for the analysis of federally regulated specimens or other forensic samples require evaluation to ensure their scientific validity. These validation studies must demonstrate the accuracy, precision, and linearity of the modified immunoassay around the cutoff concentration, substantiate adequate rate separation, and verify the ability of the assay to differentiate positive and negative samples. Modification of the EMIT d.a.u. phencyclidine assay in order to achieve the federally mandated cutoff concentration of 25 ng/mL is common. This study describes the validation of a modified EMIT phencyclidine assay and a protocol that allows for the evaluation of similarly modified immunoassays.     

Type A behavior and its association with cardiovascular disease prevalence in Blacks and Whites: The Minnesota heart survey

Population-based surveys were conducted in 1985 and 1986 to measure the prevalence of coronary heart disease (CHD) history and risk factors in Black and White adults. Type A behavior was measured by the Jenkins Activity Survey (JAS). JAS scores were associated with age (negatively), education (positively), and sex (men>women) but were largely unrelated to CHD risk factors. Blacks had significantly lower age- and education-adjusted Type A and component scores than Whites, more so formen than women. Univariate analysis indicated that a history of angina and/or heart attack was positively associated with the Type A score in both Blacks and Whites. Following adjustment for known cardiovascular risk factors, Type A score remained positively and significantly associated with CHD prevalence. These findings are consistent with other cross-sectional studies and suggest that Type A behavior, as measured by the JAS, may increase the risk of CHD in both Blacks and Whites. Follow-up of these cohorts may help to clarify the complex relationship of Type A behavior to the risk of CHD.Supported by a National Heart, Lung and Blood Institute Grant (RO1-23727).     

Consumption of 'low-yield' cigarettes: its frequency and relationship to serum thiocyanate.

To determine the use and possible health risks of low-yield cigarettes, we ascertained the cigarette brands and serum thiocyanate (SCN) levels of 2,561 adult smokers (age 25-74) in population-based samples of seven upper Midwestern communities during 1980-82. Brands were coded according to December 1981 Federal Trade Commission (FTC) ratings for "tar", nicotine, and carbon monoxide (CO). Compared to 1980 data from the National Center for Health Statistics for the United States as a whole, a greater proportion of smokers in these communities smoked low-yield brands. More people with higher education than lesser and more women than men smoked low-yield cigarettes. Greater proportions of older people (65-75 years) than younger people (less than 65 years) smoked cigarettes in the highest and lowest brand yield categories. SCN, adjusted for number of cigarettes smoked and for sex, was only weakly associated with brand ratings for "tar" (r = +.12), nicotine (R = +.11), and CO (r = +.15). Furthermore, the gradient in SCN between lowest and highest quintiles of brand strength was less than 16 per cent--much lower than the 300-500 per cent gradient in smoke components implied by FTC ratings. These data add to the evidence that smoking low-yield cigarettes may not be significantly less hazardous than smoking high-yield brands.     

Cigarette smoking and cessation behaviors among urban blacks and whites

Smoking behaviors among blacks and whites were studied in a population-based sample of 2,626 residents of Minneapolis-St. Paul, MN. More blacks than whites were found to be smokers, before and after adjusting for age and education differences. More whites than blacks were former smokers, but the prevalence of those who had never smoked was comparable for whites and blacks. Among smokers, the mean number of cigarettes smoked per day was lower among blacks than whites, but more blacks were found to smoke cigarettes with high "tar" (dry particulate matter) and nicotine content. Men smokers were found to smoke more than women smokers, young people smoked more than older people, and those with a high school education or less smoked more than those with more than a high school education. Smoking cessation behavior consisted mostly of a variety of strategies that began with reducing cigarette consumption, followed by changing to lower tar brands, attempting to quit, and actually quitting. In general, a higher percentage of whites than blacks reported smoking cessation behaviors. A greater percentage of white than black women had tried cigarette brands lower in tar and nicotine within the previous year. Among men, a lower percentage of black than white smokers had tried quitting, and fewer black men planned to quit in the future. Blacks appeared to lag behind whites in their efforts to quit smoking. Smoking behavior continues to be problematic for both blacks and whites. Studies are needed to explain better the racial differences in smoking and smoking cessation behaviors, and to facilitate programs to encourage cessation.     

Is whole grain intake associated with reduced total and cause-specific death rates in older women? The Iowa Women's Health Study.

OBJECTIVES: This study sought to determine whether nutrient-rich whole grains reduce mortality risk. METHODS: The study included 38,740 Iowa women, aged 55 to 69 years. A food frequency questionnaire was used to obtain data on grain intake. RESULTS: Median whole grain intake quintiles ranged from a median of 0.2 to more than 3 servings per day. Women with higher intakes had healthier lifestyles and less baseline disease. The total death rate decreased in increasing quintiles, and the pattern repeated for cancer, cardiovascular disease, and other causes combined. Adjusted for lifestyle and baseline disease, the relative hazard rate ratio for total death was about 0.85 in daily consumers of whole grain. Findings persisted in strata of baseline healthy and diseased and were not explained by dietary fiber. Rates of total mortality, but not cardiovascular disease mortality, were higher among frequent consumers of refined grain. CONCLUSIONS: Total mortality risk was inversely associated with whole grain intake and positively associated with refined grain intake. Refined grains contributed more than 20% of energy intake, and whole grains contributed 1%. Substitution of whole for refined grain may reduce chronic disease risk in the United States.     

Physical activity and incident hypertension in black and white adults: the Atherosclerosis Risk in Communities Study

BACKGROUND: The epidemiologic observation that physical activity reduces the risk for hypertension has only been made for white men who self-reported hypertension. This study examined physical activity and clinically determined incident hypertension in black and white men and women of the Atherosclerosis Risk in Communities (ARIC) Study. METHODS: ARIC is a population-based prospective study with four U.S. clinic centers. The present analyses included 7,459 black and white adults 45-65 years of age. Hypertension (systolic/diastolic blood pressure >/= 140/90 mm Hg) was defined by blood pressure measured by a random-zero device or medication use. Physical activity was assessed with the Baecke questionnaire. RESULTS: After adjustment for age, baseline blood pressure, ARIC center, education, body mass index, waist-hip ratio, parental history of hypertension, cigarette smoking, alcohol consumption, and diet, white men in the highest quartile of leisure activity (primarily cycling and walking) had a 34% lower odds of developing hypertension over 6 years compared to the least active (OR = 0.66, 95% CI = 0.47-0.94; P for quartile trend = 0.01). Baseline activity was not associated with incident hypertension in white women or blacks. CONCLUSIONS: Leisure-time physical activity reduces the odds of hypertension in middle-aged white men. Additional studies in women and blacks are needed.     

Lung cancer risk reduction after smoking cessation: observations from a prospective cohort of women.

PURPOSE: We conducted this study because the duration of excess lung cancer risk among former smokers has been inconsistently reported, doubt has been raised regarding the population impact of smoking cessation, and differential risk reduction by histologic cell type after smoking cessation needs to be confirmed. METHODS: The Iowa Women's Health Study is a prospective cohort study of 41,836 Iowa women aged 55 to 69 years. In 1986, mailed questionnaires were used to collect detailed smoking history. Age-adjusted lung cancer incidence through 1999 was analyzed according to years of smoking abstinence. Relative risks were estimated using Cox regression analysis. RESULTS: There were 37,078 women in the analytic cohort. Compared with the never smokers, former smokers had an elevated lung cancer risk (relative risk, 6.6; 95% confidence interval, 5.0 to 8.7) up to 30 years after smoking cessation for all former smokers. However, a beneficial effect of smoking cessation was observed among recent and distant former smokers. The risk of adenocarcinoma remained elevated up to 30 years for both former heavier and former lighter smokers. CONCLUSION: The risk for lung cancer is increased for both current and former smokers compared with never smokers and declines for former smokers with increasing duration of abstinence. The decline in excess lung cancer risk among former smokers is prolonged compared with other studies, especially for adenocarcinoma and for heavy smokers, suggesting that more emphasis should be placed on smoking prevention and lung cancer chemoprevention.     

Comparison of computer-assigned Minnesota Codes with the visual standard method for new coronary heart disease events

The Minnesota Code is the most widely used electrocardiogram (ECG) classification system for epidemiologic studies and has been incorporated into several Computer algorithms. The authors compared the Modular ECG Analysis System (MC-MEANS) and NOVACODE computer ECG findings with the Visual coding standard for agreement and prognostic associations with coronary heart disease (CHD) events occurring during follow-up from 1987 to 1995 in 2,116 individuals participating in the Atherosclerosis Risk in Communities (ARIC) Study. The exact agreement between Visual and computer findings was greater than 90% for all Minnesota Code categories except Q-code, which was 77% for MC-MEANS and 81% for NOVACODE. Approximately 60% of all Q-codes were assigned by computer methods only. Among the 2,116 participants, there were 246 (11.6%) new coronary events. Unadjusted relative risks for codes assigned by the three methods were similar. When computer methods disagreed on code severity, the CHD occurrence rates for MC-MEANS-detected severer code versus NOVACODE-detected severer code were 21% and 7%, respectively. This study provides clear evidence that computers assign more and severer Minnesota Codes with similar prognostic importance as does the Visual method; it also alerts researchers to potential problems in pooling Minnesota Code data read by different methods.