PubMed Health⌕ Search

Biomedical subjects

M Szklo

Publications and source records attributed to M Szklo.

At least 19 recordsLinked to original sources
PubMed2002

Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease.

Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58,515 women with invasive breast cancer and 95,067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19-1.45, P<0.00001) for an intake of 35-44 g per day alcohol, and 1.46 (1.33-1.61, P<0.00001) for >/=45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1% per 10 g per day, P<0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers=1.03, 95% CI 0.98-1.07, and for current smokers=0.99, 0.92-1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver.

Adult↗
PubMed2001

Prospective assessment of estrogen replacement therapy and cognitive functioning: atherosclerosis risk in communities study.

Studies of humans have not confirmed the suggestion from animal studies that estrogen replacement therapy may have an inverse relation with cognitive function decline. Because many of these studies have been marred by design or methodological problems, such as a small sample size, failure to control for confounding variables, or the use of a cross-sectional design, the present study was conducted in a large cohort of middle-aged postmenopausal women participating in the Atherosclerosis Risk in Communities (ARIC) Study. The study population consisted of 2,859 women aged 48-67 years, whose cognitive function was tested at the second (1990-1992) and fourth (1996-1998) visits of the ARIC Study using three instruments: the Delayed Word Recall Test, Digit Symbol Subtest of the Wechsler Adult Intelligence Scale-Revised, and Word Fluency Test. After multiple adjustment, no consistent patterns of cognitive changes between the two cohort visits could be detected according to current use or duration of use of estrogen replacement therapy. Thus, the results of the present study do not support the hypothesis that estrogen replacement therapy may slow age-related cognitive decline, at least as it applies to relatively young postmenopausal women.

Aged↗
PubMed2001

Relative androgen excess and increased cardiovascular risk after menopause: a hypothesized relation.

Many studies have investigated the role of estrogen during menopause; however, less attention has been paid to the role of androgen. Given the possible opposite effects of estrogen and androgen on cardiovascular disease risk, it is suggested that relative androgen excess may better predict the increased risk of cardiovascular disease in women over the age of 50 years than estrogen levels alone. Three phases of hormonal milieu changes are hypothesized as a better way to identify the hormone-cardiovascular disease risk association. A first phase, prepause, occurs before estrogen levels decline (approximately 2 years before menopause). A second phase, interpause, occurs from the end of prepause until approximately age 55. A third phase, postpause, occurs after interpause. The duration of the interpause phase, characterized by relative androgen excess, may be an independent risk factor of cardiovascular disease. This hypothesis could provide a basis for further clinical and epidemiologic research, and it could have important implications for establishing the initiation and duration of estrogen replacement therapy use as a means to prevent cardiovascular disease.

Aged↗
PubMed2001

Neighborhood of residence and incidence of coronary heart disease.

BACKGROUND: Where a person lives is not usually thought of as an independent predictor of his or her health, although physical and social features of places of residence may affect health and health-related behavior. METHODS: Using data from the Atherosclerosis Risk in Communities Study, we examined the relation between characteristics of neighborhoods and the incidence of coronary heart disease. Participants were 45 to 64 years of age at base line and were sampled from four study sites in the United States: Forsyth County, North Carolina; Jackson, Mississippi; the northwestern suburbs of Minneapolis; and Washington County, Maryland. As proxies for neighborhoods, we used block groups containing an average of 1000 people, as defined by the U.S. Census. We constructed a summary score for the socioeconomic environment of each neighborhood that included information about wealth and income, education, and occupation. RESULTS: During a median of 9.1 years of follow-up, 615 coronary events occurred in 13,009 participants. Residents of disadvantaged neighborhoods (those with lower summary scores) had a higher risk of disease than residents of advantaged neighborhoods, even after we controlled for personal income, education, and occupation. Hazard ratios for coronary events in the most disadvantaged group of neighborhoods as compared with the most advantaged group--adjusted for age, study site, and personal socioeconomic indicators--were 1.7 among whites (95 percent confidence interval, 1.3 to 2.3) and 1.4 among blacks (95 percent confidence interval, 0.9 to 2.0). Neighborhood and personal socioeconomic indicators contributed independently to the risk of disease. Hazard ratios for coronary heart disease among low-income persons living in the most disadvantaged neighborhoods, as compared with high-income persons in the most advantaged neighborhoods were 3.1 among whites (95 percent confidence interval, 2.1 to 4.8) and 2.5 among blacks (95 percent confidence interval, 1.4 to 4.5). These associations remained unchanged after adjustment for established risk factors for coronary heart disease. CONCLUSIONS: Even after controlling for personal income, education, and occupation, we found that living in a disadvantaged neighborhood is associated with an increased incidence of coronary heart disease.

Coronary Disease↗
PubMed2001

Alcohol consumption with age: a cross-sectional and longitudinal study of the Atherosclerosis Risk in Communities (ARIC) study, 1987-1995.

Previous cross-sectional and longitudinal studies assessing the association between age and drinking are inconsistent. Evaluating 15,425 Black and White men and women from four communities, this study sought to determine whether there was a consistent relation between age and drinking in cross-sectional and longitudinal analyses and to determine change in drinking status and level of consumption (occasional, light to moderate, and heavier drinkers) at follow-up. Cross-sectional analyses of drinking were performed for Atherosclerosis Risk in Communities examinations 1 (1987-1989) and 3 (1993-1995). The changes in drinking status and level were determined for the 12,565 persons with information at both examinations. Prevalence of drinking was generally inversely associated with age in the cross-sectional analyses for all ethnic/gender groups, and drinking prevalence decreased over the 6 years of follow-up for all except Black women. Only among Black drinkers was younger age associated with a higher level of alcohol consumption in both cross-sectional and prospective analyses. Thus, whether drinking prevalence declines, the amount consumed by drinkers is decreased, or whether both factors contribute to the decrease appears to vary with ethnicity and gender. The change in drinking level was substantial with more than 40% of baseline drinkers reporting drinking cessation or a different level of consumption at follow-up.

Age Distribution↗
PubMed2001

Cardiovascular risk factors and cognitive decline in middle-aged adults.

OBJECTIVE: To perform serial neuropsychological assessments to detect vascular risk factors for cognitive decline in the Atherosclerosis Risk in Communities cohort, a large biracial, multisite, longitudinal investigation of initially middle-aged individuals. METHODS: The authors administered cognitive assessments to 10,963 individuals (8,729 white individuals and 2,234 black individuals) on two occasions separated by 6 years. Subjects ranged in age at the first assessment from 47 to 70 years. The cognitive assessments included the delayed word recall (DWR) test, a 10-word delayed free recall task in which the learning phase included sentence generation with the study words, the digit symbol subtest (DSS) of the Wechsler Adult Intelligence Scale-Revised and the first-letter word fluency (WF) test using letters F, A, and S. RESULTS: In multivariate analyses (controlling for demographic factors), the presence of diabetes at baseline was associated with greater decline in scores on both the DSS and WF (p < 0.05), and the presence of hypertension at baseline was associated with greater decline on the DSS alone (p < 0.05). The association of diabetes with cognitive decline persisted when analysis was restricted to the 47- to 57-year-old subgroup. Smoking status, carotid intima-media wall thickness, and hyperlipidemia at baseline were not associated with change in cognitive test scores. CONCLUSIONS: Hypertension and diabetes mellitus were positively associated with cognitive decline over 6 years in this late middle-aged population. Interventions aimed at hypertension or diabetes that begin before age 60 might lessen the burden of cognitive impairment in later life.

Adult↗
PubMed2001

Risk factors for uterine leiomyoma: a practice-based case-control study. I. African-American heritage, reproductive history, body size, and smoking.

The authors conducted a case-control study among premenopausal women in the Baltimore, Maryland, area to examine the associations of uterine leiomyoma with ethnicity and hormone-related characteristics. Cases of uterine leiomyoma (n = 318) were surgically or sonographically first confirmed between January 1990 and June 1993. A total of 394 controls were selected from women who were visiting their gynecologist for a routine checkup. Data were collected through telephone interviews and abstraction of medical records; 77.8% of eligible cases and 78.0% of eligible controls were interviewed. Positive adjusted associations were observed between risk of uterine leiomyoma and self-described African-American ethnicity (vs. Whites: odds ratio (OR) = 9.4; 95% confidence interval (CI): 5.7, 15.7), early menarche (<11 years vs. >13 years: OR = 2.4; 95% CI: 1.1, 5.6), and high body mass index (upper quartile vs. lower quartile: OR = 2.3; 95% CI: 1.4, 3.8). Inverse associations were observed with use of oral contraceptives (current use vs. never use: OR = 0.2, 95% CI: 0.1, 0.6) and duration of smoking (> or =19 years vs. never: OR = 0.6; 95% CI: 0.4, 1.1). Younger ages at infertility diagnosis and at first and last childbirth were more common among cases; however, analyses of data on tumor location suggested that these associations represent predominantly consequences of uterine leiomyoma. These results suggest that development of uterine leiomyoma is associated with increased exposure to ovarian hormones. Possible reasons for the very elevated risk among African-American women need further investigation.

Adolescent↗
PubMed2001

Risk factors for uterine leiomyoma: a practice-based case-control study. II. Atherogenic risk factors and potential sources of uterine irritation.

In this case-control study, the authors analyzed associations of uterine leiomyoma with atherogenic risk factors and potential sources of uterine irritation. The study included 318 case women with uterine leiomyoma that was first confirmed between 1990 and 1993 in the Baltimore, Maryland, area and 394 controls selected from women visiting the same gynecologists' offices for routine reasons. Telephone interviews were conducted with 77.8% of eligible cases and 78.0% of eligible controls. Compared with participants with no hypertension history, increased risks were observed among participants with any history of hypertension (odds ratio (OR) = 1.7; 95% confidence interval (CI): 1.0, 2.8), hypertension requiring medication (OR = 2.1; 95% CI: 1.1, 4.1), hypertension diagnosed at ages less than 35 years (for hypertension requiring medication, OR = 2.7; 95% CI: 1.0, 7.6), and hypertension of 5 or more years' duration (for hypertension requiring medication, OR = 3.1; 95% CI: 1.2, 8.2). Estimates of associations with diabetes history were very imprecise but followed similar patterns. Adjusted associations were observed with pelvic inflammatory disease (three or more episodes vs. none: OR = 3.7; 95% CI: 0.9, 15.9), chlamydial infection (history vs. no history: OR = 3.2; 95% CI: 0.8, 13.7), and use of an intrauterine device when it caused infectious complications (use vs. no use: OR = 5.3; 95% CI: 1.8, 16.3). Risk of uterine leiomyoma was also associated in a graded fashion with frequency of perineal talc use (daily use vs. no use: OR = 2.2; 95% CI: 1.4, 3.1). The authors conclude that nonhormonal factors may influence risk of uterine leiomyoma.

Adolescent↗
PubMed2000

Prevalence of type 2 diabetes mellitus among persons with hepatitis C virus infection in the United States.

BACKGROUND: Hepatitis C virus (HCV) infection may contribute to the development of diabetes mellitus. This relationship has not been investigated at the population level, and its biological mechanism remains unknown. OBJECTIVE: To examine the prevalence of type 2 diabetes among persons with HCV infection in a representative sample of the general adult population of the United States. DESIGN: Cross-sectional national survey. SETTING: The Third National Health and Nutrition Examination Survey, 1988-1994. PARTICIPANTS: 9841 persons older than 20 years of age for whom data on HCV infection and diabetes were complete. MEASUREMENTS: The presence of diabetes was ascertained by using American Diabetes Association guidelines based on fasting plasma glucose measurement and medication history. Presence of HCV infection was assessed by testing for serum HCV-specific antibodies (anti-HCV). RESULTS: Of the 9841 persons evaluated, 8.4% had type 2 diabetes and 2.1% were anti-HCV positive. Type 2 diabetes occurred more often in persons who were older, were nonwhite, had a high body mass index, and had low socioeconomic status. Type 2 diabetes was less common in persons who acknowledged previous illicit drug use. After adjustment for these factors, persons 40 years of age or older with HCV infection were more than three times more likely than those without HCV infection to have type 2 diabetes (adjusted odds ratio, 3.77 [95% CI, 1.80 to 7.87]). None of the 19 persons with type 1 diabetes were anti-HCV positive. CONCLUSION: In the United States, type 2 diabetes occurs more often in persons with HCV infection who are older than 40 years of age.

Adult↗
PubMed2000

Incident type 2 diabetes mellitus in African American and white adults: the Atherosclerosis Risk in Communities Study.

CONTEXT: Although the excess prevalence of type 2 diabetes mellitus in African Americans is well established, few studies have compared incident diabetes in African American and white persons. OBJECTIVES: To compare risk of incident diabetes in African American vs white adults and to identify explanatory factors for racial disparities. DESIGN: Prospective cohort study using baseline data collected from 1986 to 1989 from the ongoing Atherosclerosis Risk in Communities (ARIC) Study, with 9 years of follow-up. SETTING AND PARTICIPANTS: A total of 2646 African American and 9461 white adults aged 45 to 64 years without diabetes at baseline, sampled from 4 US communities. MAIN OUTCOME MEASURES: Incident type 2 diabetes, ascertained by self-report of physician diagnosis, use of diabetes medications, or fasting glucose level of at least 7.0 mmol/L (126 mg/dL), compared among white and African American subjects and by presence of potentially modifiable risk factors. RESULTS: Diabetes incidence per 1000 person-years was about 2.4-fold greater in African American women (25.1 [95% confidence interval [CI], 22.4-28.1] vs 10.4 [95% CI, 9.4-11.4]) and about 1.5-fold greater in men (23.4 [95% CI, 19.9-27.2] vs 15.9 [95% CI, 14.6-17.2]) than in their white counterparts (P<.001). Results from proportional hazards regression models indicated that racial differences in potentially modifiable risk factors, particularly adiposity, accounted for 47.8% of the excess risk in African American women but accounted for little excess risk in African American men. Compared with their white counterparts, African American men and women had higher blood pressures before diabetes onset (diastolic blood pressure difference=5.6 mm Hg in women and 8.4 mm Hg in men; P=.005). CONCLUSIONS: Our data indicate that compared with their white counterparts, middle-aged African Americans are at greater risk of developing type 2 diabetes and have higher blood pressure prior to development of diabetes. In women, almost 50% of this excess risk might be related to potentially modifiable factors.

Black People↗
PubMed2000

Serum albumin level as a predictor of incident coronary heart disease: the Atherosclerosis Risk in Communities (ARIC) study.

Various studies have reported an inverse association between serum albumin level and incident coronary heart disease (CHD), though biologic mechanisms have not been established. The authors examined the association between serum albumin level and CHD in the Atherosclerosis Risk in Communities cohort, comprising 14,506 White and African-American middle-aged men and women. The mean albumin level in this population was 3.9 g/dl (standard deviation 0.3). During 5.2 years of follow-up, 470 incident CHD events occurred. The hazard ratio for incident CHD associated with a 1-standard deviation decrease in serum albumin level was 1.26 (95% confidence interval (CI): 1.15, 1.38) after adjustment for age, gender, and ethnicity and 1.18 (95% CI: 1.07, 1.30) after additional adjustment for covariates related to CHD. Hazard ratios were similar across gender and ethnic groups. However, there was statistically significant effect modification by smoking status, with hazard ratios of 1.01 (95% CI: 0.84, 1.22) among never smokers, 1.09 (95% CI: 0.92, 1.30) among former smokers, and 1.35 (95% CI: 1.17, 1.54) among current smokers. Further adjustment for factors related to renal disease, nutrition, platelet aggregation, inflammation, use of angiotensin-converting enzyme inhibitors, and hemostasis factors attenuated the albumin-CHD relation only slightly. In this study, serum albumin was inversely associated with incident CHD at the baseline examination in current smokers but not in never or former smokers. Albumin level may be a marker of susceptibility to the inflammatory response that results from smoking.

Biomarkers↗
PubMed2000

Trends in plasma cholesterol levels in the atherosclerosis risk in communities (ARIC) study.

BACKGROUND: Data from the Atherosclerosis Risk in Communities (ARIC) cohort study were examined both cross-sectionally and intraindividually to confirm recent findings from population-based studies showing a decline in total cholesterol (TC) levels in the United States. METHODS: For the cross-sectional analysis, mean plasma TC levels from 15,792 participants aged 45-64 at baseline visit, and who were selected randomly from four U.S. communities, were examined for each year covered by the first cohort visit (1987, 1988, and 1989). Ninety-three percent of the cohort participants returned for the follow-up visit (1990, 1991, and 1992), and were included in the assessment of intraindividual TC trends. RESULTS: Both mean TC and prevalence of hypercholesterolemia (defined as plasma cholesterol concentration >/=240 mg/dl) consistently declined over the 3 years covered by visit 1 for all age-gender-race groups. For 1987, 1988, and 1989, mean TC values (mg/dl) were, respectively, 220.3, 216.7, and 214.1 (annual average change, -1.4%, P < 0.001). For these same years, hypercholesterolemia prevalence rates were 30. 0, 27.8, and 25.3% (annual average change, -7.8%, P < 0.001). The mean plasma TC also decreased within individuals between the two visits across race, gender, and age decade categories. With the exception of black men, this decline was more marked for older than younger subjects, but no consistent differences were seen between the racial groups. However, in whites, decreases were greater for men than for women. Expected results were seen when these changes were correlated with changes in cardiovascular risk factors between the two visits. CONCLUSION: The current study results are consistent with those of previous studies, and confirm the notion that preventive programs appear to be effective in reducing mean population TC levels.

Arteriosclerosis↗
PubMed2000

Orthostatic hypotension and the incidence of coronary heart disease: the Atherosclerosis Risk in Communities study.

We examined the association between orthostatic hypotension (OH) at baseline examination (1987-1989) and the incidence of coronary heart disease (CHD) over an average of 6 years, among 12,433 black and white middle-aged men and women participating in the Atherosclerosis Risk in Communities (ARIC) study. OH was defined as a SBP decrease > or = 20 mm Hg or a DBP decrease > or = 10 mm Hg after changing from supine to standing. CHD events included definite or probable myocardial infarctions (MI), silent MI, and fatal CHD. Five percent of participants had OH. Prevalence increased with advancing age and was more common among those with cardiovascular disease (CVD)-related comorbidities and risk factors. Those with OH had an increased risk of CHD (hazard ratio [HR] = 3.49, 95% confidence interval [CI] = 2.58, 4.73). This association was attenuated after controlling for age, ethnicity, gender, comorbid conditions, and CVD risk factors (HR = 1.85, 95% CI = 1.31, 2.63).

Age Factors↗