Search PubMed⌕ Search

Biomedical subjects

M Szklo

Publications and source records attributed to M Szklo.

At least 73 records · Page 4Linked to original sources
PubMed1995

Correlates of body fat distribution. Variation across categories of race, sex, and body mass in the atherosclerosis risk in communities study. The Atherosclerosis Risk in communities (ARIC) Study Investigators.

Though central adiposity is a strong, independent risk factor for cardiovascular and all-cause mortality, relatively little is known about its determinants. To characterize the association of central adiposity with several of its possible determinants, while describing variability in these associations across sex, race, and level of body mass index, we conducted a cross-sectional survey of 15,800 white and African-American men and women ages 45 to 64 years participating in the Atherosclerosis Risk in Communities baseline survey, 1987 to 1989. After adjustment for other possible determinants, African Americans had markedly larger subscapular skinfold thickness and subscapular/triceps ratios than did whites, while whites had larger waist/hip ratios. Large, statistically significant variations in waist/hip ratio associations with age, percent of weight gained after age 25, smoking, and physical activity in the workplace existed across categories of sex, race, and body mass index. Based on our findings, we concluded that major variation exists in the waist/hip ratio and in its associations with its possible determinants across categories of race, sex and obesity.

Adipose Tissue↗
PubMed1995

Relationship of headache to phase of the menstrual cycle among young women: a daily diary study.

We investigated the relationship between headache occurrence and phase of the menstrual cycle in a 4-month daily diary study of 74 women, 22 to 29 years old, residing in Washington County, Maryland. We selected subjects from women reporting a history of migraine symptoms and at least two migraine headache attacks per month in a 1986 to 1987 population-based survey. Data collection was from March 1987 through April 1988. By using detailed headache symptom information collected daily, we classified headaches into four categories: migraine with aura, migraine without aura, tension-type, and all other headaches. Odds ratios were separately estimated for the individual headache types and all types combined during each of three phases of the menstrual cycle. Risk of migraine without aura was significantly elevated during the first 3 days of menstruation (odds ratio, 1.66; 95% confidence interval, 1.21 to 2.26), but headache risk was not significantly increased during the 2 days immediately preceding onset of menstruation or on the estimated day of ovulation (day 14 before the onset of menstruation). Participants reported headaches on 28% of the study days overall, suggesting that onset of menstruation is an independent but not exclusive precipitating factor for headache attacks among young adult women with migraine. Our data show that onset of menstruation only accounts for a small proportion of migraine attacks among young women with frequent episodes of migraine.

Adult↗
PubMed1994

Dietary n-3 polyunsaturated fatty acids and smoking-related chronic obstructive pulmonary disease. Atherosclerosis Risk in Communities Study Investigators.

BACKGROUND: Fish contain n-3 polyunsaturated fatty acids, principally eicosapentaenoic acid and docosahexaenoic acid, which are known to interfere with the body's inflammatory response and may be of benefit in chronic inflammatory conditions. METHODS: We studied the relation between the dietary intake of n-3 fatty acids and chronic obstructive pulmonary disease (COPD) in 8960 current or former smokers participating in a population-based study of atherosclerosis. Intake of fatty acids was estimated with a dietary questionnaire. The presence of COPD was assessed by a questionnaire on respiratory symptoms and by spirometry. Three case definitions of COPD were used: symptoms of chronic bronchitis (667 subjects), physician-diagnosed emphysema reported by the subject (185 subjects), and spirometrically detected COPD (197 subjects). RESULTS: After control for pack-years of smoking, age, sex, race, height, weight, energy intake, and educational level, the combined intake of eicosapentaenoic acid and docosahexaenoic acid was inversely related to the risk of COPD in a quantity-dependent fashion. The adjusted odds ratio for the highest quartile of intake as compared with the lowest quartile was 0.66 for chronic bronchitis (95 percent confidence interval, 0.52 to 0.85; P < 0.001 for linear trend across the range of intake values), 0.31 for physician-diagnosed emphysema (95 percent confidence interval, 0.18 to 0.52; P for linear trend, 0.003), and 0.50 for spirometrically detected COPD (95 percent confidence interval, 0.32 to 0.79; P for linear trend, 0.007). CONCLUSIONS: A high dietary intake of n-3 fatty acids may protect cigarette smokers against COPD.

Aged↗
PubMed1994

Active and passive smoking are associated with increased carotid wall thickness. The Atherosclerosis Risk in Communities Study.

BACKGROUND: Active cigarette smoking has been established as a potent risk factor for carotid atherosclerosis in clinical populations; however, neither the role of active smoking in general populations nor the impact of environmental tobacco smoke has been well described. METHODS: The association between carotid artery wall thickness and cigarette smoking was studied in 12,953 black and white men and women, aged 45 to 65 years, examined in the Atherosclerosis Risk in Communities Study. Participants were classified as current smokers (n = 3525), past smokers (n = 4315), never smokers reporting weekly exposure to environmental tobacco smoke (ETS or "passive smoking") of at least 1 hour (n = 3339), or never smokers reporting no weekly exposure to ETS (n = 1774). Carotid artery intimal-medial thickness (IMT) was measured by B-mode ultrasound. RESULTS: Increased IMT was observed in each category, in order from smallest to greatest increase: never smokers not exposed to ETS, never smokers exposed to ETS, past smokers, and current smokers. The larger IMT observed in the nonsmoking group exposed to ETS compared with the nonsmokers not exposed persisted after control for diet, physical activity, body mass index, alcohol intake, education, and major cardiovascular risk factors. Among past and current smokers, increased pack-years of exposure was associated with increased IMT. Among nonsmoking men exposed to ETS, there was a significant increase in IMT with increasing number of hours per week of ETS exposure. CONCLUSIONS: These data confirm the strong relationship between active smoking and carotid artery IMT and provide initial evidence that passive smoking exposure is related to greater IMT. Increasing exposure to cigarette smoke (either pack-years of active smoking or hours of ETS) was significantly related to increased IMT.

Aged↗
PubMed1994

Hair dye use and other risk factors for leukemia and pre-leukemia: a case-control study. Italian Leukemia Study Group.

A case-control study was carried out to examine the relation of three subtypes of leukemia cells and refractory anemia with excess of blasts to selected behavioral and environmental factors. Cases aged 15 years or older were recruited in three hospitals located in Rome, Bologna, and Pavia, respectively. Outpatients who were either normal or had nonneoplastic hematologic disorders and were seen in the same hospitals as the cases were enrolled as controls. Two hundred fifty-two patients with acute myeloid leukemia, 100 with acute lymphocytic leukemia, 111 with refractory anemia with excess of blasts, 156 with chronic myeloid leukemia, and 1,161 controls were included in the study. Refractory anemia with excess of blasts and chronic myeloid leukemia were included because they are regarded as forms of pre-leukemia. Odds ratio estimates were generally imprecise, but associations were suggested between specific case subtypes and exposure to dark hair dye, selected occupations (shoemaker, painter, electrician, child care), residence in houses built with tuff, and smoking. Although the exploratory nature of the study and its limited statistical power preclude firm conclusions, its results are consistent with those of previous studies, and are in general biologically plausible.

Adolescent↗
PubMed1994

Does dietary vitamin A protect against airway obstruction? The Atherosclerosis Risk in Communities (ARIC) Study Investigators.

A recent report based on data from the first National Health and Nutrition Examination Survey suggested that low intake of vitamin A may be associated with a greater risk of airway obstruction. We attempted to replicate these findings in a population-based sample of middle-aged adults (n = 15,743) who participated in the baseline examination of the Atherosclerosis Risk in Communities (ARIC) Study. Vitamin A intake was estimated from a 66-item food frequency questionnaire, and the presence of airway obstruction was determined by spirometry. Although airway obstruction was associated in ARIC with well-established risk factors such as age, sex, and smoking, there was little evidence for a role of vitamin A. With only one exception, vitamin A intake was unrelated to airway obstruction in all smoking categories using either categorical or continuous measures of lung function (FEV1, FVC, FEV1/FVC). Only among current smokers in the upper tertile of lifetime cigarette smoking (> 41 pack-years) was the odds ratio of having airway obstruction for the lowest quartile of vitamin A intake compared with the highest quartile elevated (1.7 [95% confidence interval 1.1 to 2.7]). Despite some biological plausibility that vitamin A intake may prevent obstructive lung disease, the inability to demonstrate association in a larger population study, with better estimation of usual dietary intake, casts doubt on the existence of causal relationship.

Airway Obstruction↗
PubMed1993

Association of hormone-replacement therapy with various cardiovascular risk factors in postmenopausal women. The Atherosclerosis Risk in Communities Study Investigators.

BACKGROUND: Most epidemiologic studies of cardiovascular disease in postmenopausal women suggest that estrogen-replacement therapy has a protective effect. The effects of the use of estrogen combined with progestin are less well studied. METHODS: To examine the associations of hormone-replacement therapy with concentrations of plasma lipids and hemostatic factors, fasting serum concentrations of glucose and insulin, and blood pressure, we studied 4958 postmenopausal women participating in a population-based investigation. Using cross-sectional data, we classified the women into four groups according to their use of hormone-replacement therapy: current users of estrogen alone, current users of estrogen with progestin, nonusers who had formerly used these hormones, nonusers who had never used them. RESULTS: Current users had higher mean levels of high-density lipoprotein cholesterol, its subfractions high-density lipoprotein2 and high-density lipoprotein3, and apolipoprotein A-I than nonusers and lower mean levels of low-density lipoprotein cholesterol, apolipoprotein B, lipoprotein(a), fibrinogen, antithrombin III, and fasting serum glucose and insulin. However, current users of estrogen alone had higher triglyceride, factor VII, and protein C levels than either nonusers or current users of estrogen with progestin. After making certain assumptions, we estimated that the findings, if causal, would translate into a reduction of 42 percent in the risk of coronary heart disease in users of hormones as compared with nonusers. Women using estrogen with progestin would have an even greater estimated benefit. CONCLUSIONS: A randomized trial is needed to eliminate possible selection biases in our observational study that are related to the prescription of replacement hormones. Nevertheless, hormone-replacement therapy appears to be associated with a favorable physiologic profile, which probably mediates its protective effects on cardiovascular disease. The use of estrogen combined with progestin appears to be associated with a better profile than the use of estrogen alone.

Apolipoproteins↗
PubMed1993

A prospective study of blood pressure and serum creatinine. Results from the 'Clue' Study and the ARIC Study.

OBJECTIVES: To describe associations of past and current blood pressure levels with serum creatinine levels and hypercreatinemia in the general population. POPULATION: 1399 middle-aged residents of Washington County, Maryland, who had their blood pressure measured during a cancer screening campaign in 1974 (the "Clue" Study) and had their blood pressure and serum creatinine level measured in an atherosclerosis risk factors study from 1986 through 1989 (the Atherosclerosis Risk in Communities [ARIC] Study). DESIGN: Nonconcurrent prospective study. The outcome variables were serum creatinine level and hypercreatinemia (serum creatinine > 115 mumol/L in men, > 97 mumol/L in women) measured from 1986 through 1989. Main predictors were 1986-1989 blood pressure values (cross-sectional association) and 1974 blood pressure values (longitudinal association). Gender-adjusted associations were assessed and compared by linear and logistic regression. RESULTS: Both serum creatinine and hypercreatinemia were better predicted by past than by current blood pressure values. Creatinine values exhibited a gradual and statistically significant association with blood pressure levels measured in 1974, even across "normal" values of blood pressure and creatinine. The association with 1986-1989 blood pressure measurements was weaker and nonsignificant. The odds of hypercreatinemia in 1986-1989 were increased 1.5-fold to twofold, with a 20 mm Hg increment in 1974 blood pressure values, but the odds remained constant across 1986-1989 blood pressure values. CONCLUSIONS: Blood pressure and creatinine level are associated in the general population. The observed association was stronger when a number of years had elapsed between the assessments of blood pressure and creatinine level. These findings are consistent with the hypothesis that blood pressure elevations, even below the hypertensive range, may induce early renal damage.

Blood Pressure↗
PubMed1993

Consistent lack of association between breast cancer and oral contraceptives using either hospital or neighborhood controls.

BACKGROUND: Case-control studies of oral contraceptive use and breast cancer have used neighborhood, population, or hospital controls. METHODS: To determine whether this association differs according to type of controls, interview data from 131 incident cases of breast cancer were compared with those of 189 hospital controls and 182 neighborhood controls Study subjects were white females recruited between 1973 and 1975 from among residents of Baltimore City and County ages 18 to 59 years. RESULTS: Adjusted relative odds of breast cancer related to ever versus never use of oral contraceptives were 1.0 and 0.8, using hospital and neighborhood controls, respectively. Relative odds did not increase proportionally to duration of oral contraceptive use or to progestogen potency. Although few subjects had used oral contraceptives for more than 2 years, almost all pill brands contained more than 49 micrograms of ethinyl estradiol or of mestranol. CONCLUSIONS: Results from the present study do not support the hypothesis that early preparations of oral contraceptives increased breast cancer risk among white women, regardless of whether controls are neighbors of the cases or hospital patients. However, its conclusions cannot be generalized to women who began taking the pill before their first full-term birth or took it for more than 2 years.

Adolescent↗
PubMed1993

Past infection by Chlamydia pneumoniae strain TWAR and asymptomatic carotid atherosclerosis. Atherosclerosis Risk in Communities (ARIC) Study Investigators.

PURPOSE: To determine whether past infection by Chlamydia pneumoniae strain TWAR is associated with asymptomatic atherosclerosis. Previous studies have linked this organism with symptomatic coronary heart disease. SUBJECTS AND METHODS: Between 1986 and 1989, 15,800 men and women aged 45 to 64 years were examined as part of the Atherosclerosis Risk in Communities Study, a prospective cohort study of atherosclerosis being conducted in 4 United States communities. The examination included B-mode ultrasonography of the carotid arteries and an assessment of cardiovascular disease risk factors. Carotid wall thickening (blood-intima to medial-adventitial interface) in the absence of clinical cardiovascular disease was considered evidence of asymptomatic atherosclerosis. In 1991, IgG antibody titers to TWAR were assayed by microimmunofluorescence in stored sera from 326 case-control pairs matched by age group, race, sex, examination period, and field center. A titer of 1:8 or higher was considered a positive TWAR antibody response. RESULTS: Seventy-three percent of atherosclerosis cases had serologic evidence of past TWAR infection versus 63% of controls (matched odds ratio 1.76; 95% confidence interval, 1.21 to 2.57). After adjustment for age, hypertension, diabetes, cigarette smoking, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and education, the odds ratio for atherosclerosis was essentially unchanged at 2.00 (95% confidence interval, 1.19 to 3.35). The association was stronger for individuals aged 45 to 54 years than for those aged 55 to 64 years. CONCLUSION: There was a significant cross-sectional association between past TWAR infection and asymptomatic atherosclerosis. This organism may be a contributor to the pathogenesis of atherosclerosis.

Age Factors↗
PubMed1993

Salt and gastric cancer: a case-control study in Puerto Rico.

A total of 136 incident intestinal type gastric cancer cases and 151 age-comparable population controls were interviewed in Puerto Rico about their dietary habits with special emphasis on dietary salt consumption. All interviews were conducted at home using a quantitative dietary frequency instrument. The weekly intake of foods was estimated from the reported frequency of consumption and portion size according to a food model. The dietary salt exposure was estimated from the intake of nine selected food items which are highly salted food items commonly consumed in Puerto Rico. A strong (odds ratio [OR] = 3.34) and statistically significant (P < 0.001) unadjusted difference was found between cases and controls regarding dietary salt exposure. A statistically significant dose response for the index of salt exposure and gastric cancer was also found. The association remained positive and statistically significant after simultaneously adjusting for the confounding effects of sex, education and cigarette smoking.

Adenocarcinoma↗
PubMed1993

Carotid artery intimal-medial wall thickening and plasma homocyst(e)ine in asymptomatic adults. The Atherosclerosis Risk in Communities Study.

BACKGROUND: Plasma levels of homocyst(e)ine are elevated in certain patients with occlusive arterial diseases. We extended these findings to asymptomatic adults. METHODS AND RESULTS: We determined plasma homocyst(e)ine levels in 287 pairs of asymptomatic adults. Cases and controls were defined on the basis of intimal-medial thickness of the carotid wall as measured by B-mode ultrasound. Study subjects had no history of atherosclerotic disease and were selected from a probability sample of 15,800 men and women between 45 and 64 years old. Subjects with thickened intimal-medial carotid walls (cases) had higher plasma homocyst(e)ine levels than controls (p < 0.001). The odds ratio for having a thickened carotid artery wall was 3.15 (p < 0.001) for subjects in the top quintile of plasma homocyst(e)ine levels (> 10.5 mumol/L) compared with those in the bottom quintile (< 5.88 mumol/L). CONCLUSIONS: The present study as well as observations on the common occurrence of elevated plasma homocyst(e)ine levels in patients with occlusive arterial diseases suggest that clinical trials should be conducted to determine whether normalization of hyperhomocyst(e)inemia may prevent progression of atherosclerosis.

Arteriosclerosis↗
PubMed1993

Alcohol consumption and ultrasonographically assessed carotid artery wall thickness and distensibility. The Atherosclerosis Risk in Communities (ARIC) Study Investigators.

BACKGROUND: Although much has been written in recent years about the relation between alcohol and atherosclerotic disease, controversy exists as to whether and how alcohol exerts an effect on atherosclerosis in different sites. METHODS AND RESULTS: We tested the hypothesis that alcohol consumption is associated inversely with carotid atherosclerosis in a population sample of 45- to 64-year-old men and women who participated in the Atherosclerosis Risk in Communities (ARIC) Study and were free of cardiovascular disease at a baseline examination in 1987 to 1989. B-mode ultrasonography was used to determine carotid artery intimal-medial wall thickness and distensibility as indices of the degree of atherosclerosis. The level of alcohol consumption in the ARIC sample was generally low. Age-adjusted mean values of alcohol consumed (grams per week) were 72.0 for white and 74.3 for nonwhite men and 24.8 for white and 11.2 for nonwhite women. After adjustments for age, artery depth, education, body mass index, sport index, cigarette-years of smoking, low-density lipoprotein cholesterol, and diabetes mellitus, there was no significant cross-sectional association of reported current alcohol intake with either carotid artery wall thickness (among white and nonwhite men and nonwhite women) or distensibility (in any of the four sex-race groups). Among white women, the adjusted mean value of carotid artery wall thickness tended to be higher in light to moderate drinkers than in never or rare drinkers, but the difference across drinking status categories was of borderline statistical significance (P = .04) and may be of little biological importance. CONCLUSIONS: The ARIC Study found no material cross-sectional association between current alcohol intake and carotid atherosclerosis but provides an opportunity in the future to study atherosclerosis progression and incident events in relation to alcohol consumption in a large population sample of men and women.

Alcohol Drinking↗
PubMed1992

Leukocyte count correlates in middle-aged adults: the Atherosclerosis Risk in Communities (ARIC) Study.

Cross-sectional associations between leukocyte count and sociodemographic and cardiovascular risk factors were investigated in 14,679 participants aged 45-64 years in the Atherosclerosis Risk in Communities Study carried out in four US communities in 1986-1989. Leukocyte count was strongly associated with present or past history of cigarette smoking and was higher in males than in females and in white subjects than in black subjects. Among never smokers, no sex differences were evident after adjustment for other risk factors. Race-associated differences were substantially reduced after other factors were taken into account in multivariate analyses. In never smokers, leukocyte count was higher in those who reported poor health, and it was inversely associated with high density lipoprotein cholesterol, forced expiratory volume at 1 second, physical activity, and, among whites, height and socioeconomic indicators. It was directly associated with indices of body weight and body fat, heart rate, blood pressure, hemoglobin, platelet count, uric acid, fasting insulin and glycemia, triglycerides, fibrinogen, antithrombin III, protein C, factors VII and VIII, and von Willebrand factor. The associations of leukocyte count with cardiovascular risk factors may either represent manifestation of subclinical disease or suggest that leukocyte count is part of the causal chain leading to atherosclerosis. Alternatively, the relation of leukocyte count to cardiovascular disease may be confounded by risk factors and thus be noncausal.

Arteriosclerosis↗
PubMed1992

Childhood weight and growth rate as predictors of adult mortality.

The effect of rate of growth and relative weight in childhood on adult mortality was studied among 13,146 persons whose weights and heights were measured between the ages of 5 and 18 years in Hagerstown, Maryland, during the period 1933-1945. Relative weight was defined internally, age- and sex-specific Z-scores for height and weight were calculated using national standards, and height and weight velocities were measured as annual increments. Associations between growth parameters (pre- and postpubertal) and mortality through 1985 were investigated in subjects who matched the 1963 and 1975 private health censuses of Washington County, Maryland, using a nested case-control design. Odds ratios of mortality increased linearly with prepubertal relative weight (p less than 0.05 for both sexes combined) and with postpubertal relative weight in females (p less than 0.01). The associations between growth velocities or attained height with mortality tended to be inverse, although not statistically significant. These results are compatible with the existence of positive associations of overweight in school-age children with long-term mortality and seem to allay fears that harm could come from increased growth rates in childhood. Without jeopardizing growth, the avoidance of overweight in childhood might reduce mortality in middle age.

Adolescent↗
PubMed1992

Distributions of hemostatic variables in blacks and whites: population reference values from the Atherosclerosis Risk in Communities (ARIC) Study.

The Atherosclerosis Risk in Communities Study measured hemostatic variables in nearly 16,000 men and women, aged 45 to 64 years, from four US communities. This report, based on the first 12,681 participants, presents distributions of fibrinogen concentration, factor VII activity, factor VIII activity, von Willebrand factor antigen, protein C antigen, antithrombin III activity, and activated partial thromboplastin time. Many of the hemostatic variables differed between blacks and whites, and by sex and age. For example, compared to whites, blacks had higher mean values of fibrinogen, factor VIII, von Willebrand factor, and antithrombin III, and lower mean values of protein C. Some seasonal fluctuations in hemostatic variables were noted; most notably, mean values of factor VII were lowest and protein C were highest in subjects examined in the summer compared to those examined during the other seasons. These results provide population-based reference values on blacks and whites for those interested in the relation of hemostasis to disease.

Arteriosclerosis↗
PubMed1991

Herpes simplex virus type 2: a possible interaction with human papillomavirus types 16/18 in the development of invasive cervical cancer.

A case-control study of 766 histologically confirmed incident cases of invasive cervical cancer and 1,532 hospital and community controls was conducted in Latin America to evaluate the etiologic role of herpes simplex virus type 2 (HSV-2) and to examine whether HSV-2 interacts with other risk factors. In addition to a personal interview, all subjects were asked to donate blood samples and cervical swabs for assessment of exposure to HSV-2 and human papillomaviruses (HPVs) respectively. Ninety-eight percent of cases and 91% of controls agreed to the interview and blood collection. Women testing positive for HSV-2 antibodies were found to have a 60% increased risk of cervical cancer compared with seronegative women (95% CI = 1.3, 1.9). Control for education, sexual and reproductive behavior, prior Pap-smear screening, smoking, oral contraceptive use, HPV-6/11 DNA, or HPV-16/18 DNA detection did not materially affect this estimate. No effect modification of HSV-2 by age, HPV-6/11 DNA, pregnancies, oral contraceptive use or cigarette smoking was observed. However, a significant interaction was detected between HSV-2 and HPV-16/18. Compared with women testing negative to both virus types, those positive for HSV-2 alone had a RR of 1.2 (95% CI = 0.9, 1.6), those positive for HPV-16/18 DNA alone had a RR of 4.3 (95% CI = 3.0, 6.0), and those positive for both viruses had a RR of 8.8 (95% CI = 5.9, 13.0). These findings corroborate recent laboratory evidence of a possible biological interaction between HSV-2 and HPV-16/18 in the development of cervical cancer. Further confirmatory studies are needed, given concerns with potential misclassification of exposure by the laboratory assays utilized.

Adult↗