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I-Min Lee

Publications and source records attributed to I-Min Lee.

At least 37 records · Page 2Linked to original sources
PubMed2005

A randomized trial of low-dose aspirin in the primary prevention of cardiovascular disease in women.

BACKGROUND: Randomized trials have shown that low-dose aspirin decreases the risk of a first myocardial infarction in men, with little effect on the risk of ischemic stroke. There are few similar data in women. METHODS: We randomly assigned 39,876 initially healthy women 45 years of age or older to receive 100 mg of aspirin on alternate days or placebo and then monitored them for 10 years for a first major cardiovascular event (i.e., nonfatal myocardial infarction, nonfatal stroke, or death from cardiovascular causes). RESULTS: During follow-up, 477 major cardiovascular events were confirmed in the aspirin group, as compared with 522 in the placebo group, for a nonsignificant reduction in risk with aspirin of 9 percent (relative risk, 0.91; 95 percent confidence interval, 0.80 to 1.03; P=0.13). With regard to individual end points, there was a 17 percent reduction in the risk of stroke in the aspirin group, as compared with the placebo group (relative risk, 0.83; 95 percent confidence interval, 0.69 to 0.99; P=0.04), owing to a 24 percent reduction in the risk of ischemic stroke (relative risk, 0.76; 95 percent confidence interval, 0.63 to 0.93; P=0.009) and a nonsignificant increase in the risk of hemorrhagic stroke (relative risk, 1.24; 95 percent confidence interval, 0.82 to 1.87; P=0.31). As compared with placebo, aspirin had no significant effect on the risk of fatal or nonfatal myocardial infarction (relative risk, 1.02; 95 percent confidence interval, 0.84 to 1.25; P=0.83) or death from cardiovascular causes (relative risk, 0.95; 95 percent confidence interval, 0.74 to 1.22; P=0.68). Gastrointestinal bleeding requiring transfusion was more frequent in the aspirin group than in the placebo group (relative risk, 1.40; 95 percent confidence interval, 1.07 to 1.83; P=0.02). Subgroup analyses showed that aspirin significantly reduced the risk of major cardiovascular events, ischemic stroke, and myocardial infarction among women 65 years of age or older. CONCLUSIONS: In this large, primary-prevention trial among women, aspirin lowered the risk of stroke without affecting the risk of myocardial infarction or death from cardiovascular causes, leading to a nonsignificant finding with respect to the primary end point.

Age Factors↗
PubMed2005

Dietary intakes of fruit, vegetables, and fiber, and risk of colorectal cancer in a prospective cohort of women (United States).

OBJECTIVE: Although animal studies suggest an inverse association between consumption of plant foods and risk of colorectal cancer, many observational data have failed to support such an association. We prospectively examined the association between dietary intakes of fruit, vegetables, and fiber and colorectal cancer risk in a large female cohort from the Women's Health Study. METHODS: Among 39,876 healthy women aged >/=45 years at baseline, 36,976 with baseline self-reported information on dietary intakes and other risk factors for colorectal cancer were included in the analyses. During an average follow-up of 10 years, 223 women were diagnosed with colorectal cancer. Intakes of fruit, vegetables, and fiber were assessed by a baseline food-frequency questionnaire. The analyses were carried out using the Cox proportional hazards regression and all tests were two-sided. RESULTS: Intakes of fruit, vegetables, and the specific subgroups were not found to be associated with colorectal cancer risk. Multivariate relative risks (RRs) comparing the highest with lowest quintile were 0.79 (95% CI=0.49-1.27,p for trend =0.30) for fruit intake, and 0.88 (95% CI=0.56-1.38,p for trend=0.30) for vegetables intake. Similarly, intake of total fiber was not associated with colorectal cancer risk; the RR for the highest relative to lowest quintile was 0.75 (95% CI=0.48-1.17,p for trend=0.12). However, higher intake of legume fiber was associated with a lower risk of colorectal cancer; the RR for the highest versus slowest quintile was 0.60 (95% CI=0.40-0.91,p for trend=0.02). CONCLUSIONS: Our data offer little support for associations between intakes of fruit, vegetables, and fiber, and colorectal cancer risk. However, our data suggest that legume fiber and/or other related sources may reduce risk of colorectal cancer.

Colorectal Neoplasms↗
PubMed2005

Weight change and risk of developing type 2 diabetes.

OBJECTIVE: To examine the association between weight change and risk of type 2 diabetes and whether initial weight modifies the association. RESEARCH METHODS AND PROCEDURES: This is a prospective cohort study of 20,187 alumni from Harvard University and the University of Pennsylvania. At baseline in 1962 or 1966, men (mean age, 45.9 years) reported their weight, height, and other risk factors. They also had had their weight and height measured at university entry (mean age, 18.5 years). Participants were followed from baseline to 1998 for type 2 diabetes. RESULTS: During follow-up, 1223 men developed type 2 diabetes. Weight gain significantly increased the risk of this disease. The multivariate relative risks associated with BMI change from university entry to baseline of <-0.5, +/-0.5, >0.5 to 1.0, >1.0 to 1.5, >1.5 to 2.0, >2.0 to 3.0, and >3.0 kg/m(2) per decade were 0.88, 1.00 (referent), 1.29, 2.09, 2.69, 4.67, and 7.02, respectively (p for trend < 0.0001). Even among men with a low initial BMI < 21 kg/m(2), weight gain significantly increased risk; the corresponding relative risks were (no cases), 1.00 (referent), 1.00, 1.93, 2.47, 4.82, and 7.68, respectively (p for trend < 0.0001). DISCUSSION: A low initial BMI does not ameliorate the increase in risk of type 2 diabetes with weight gain. Avoidance of weight gain, even among lean individuals, is important to reduce the risk of this disease.

Adult↗
PubMed2005

Past physical activity, current physical activity, and risk of coronary heart disease.

PURPOSE: Middle-aged and older women who are physically active have decreased risk of coronary heart disease (CHD); however, little is known about how physical activity during young adulthood influences activity during middle age and older, and CHD risk. We examined the relationship between 1) physical activity during young adulthood and middle age, and 2) physical activity during each time period and CHD occurring in middle age or older. METHODS: Cohort study of 39,876 healthy U.S. female health professionals, age > or = 45 yr, in the Women's Health Study. Physical activity was reported at baseline. Additionally, physical activity in high school and age 18-22 yr was reported on the 24-month follow-up survey. Women were followed for an average of 9 yr, after the 24-month survey, for CHD occurrence (N = 477). RESULTS: Among 37,169 eligible participants at baseline, the most active women (vigorous physical activity 10-12 months x yr) during high school and age 18-22 yr were more than twice as likely to meet physical activity recommendations at baseline than the least active women (no vigorous activity) during high school and age 18-22 yr (multivariate-adjusted odds ratio = 2.43; 95% C.I. 2.24, 2.63). At baseline, the most active women (> or = 1500 kcal x wk(-1)) had a 39% lower risk of CHD during follow-up than the least active (<200 kcal x wk(-1)) (multivariate-adjusted relative risk = 0.61; 95% C.I. 0.46, 0.81). However, physical activity during young adulthood was not associated with risk of CHD occurring during middle age and older. CONCLUSION: Women who are physically active during young adulthood are more likely to be active when middle-aged and older, when rates of CHD increase, and physical activity during middle-age predicts lower risk of CHD.

Adolescent↗
PubMed2005

Perceived exertion during prepregnancy physical activity and preeclampsia risk.

PURPOSE: Studies have shown that absolute intensity of physical activity is associated with reduced risk of preeclampsia. This analysis was performed to examine whether relative intensity may also be related to preeclampsia risk. METHODS: Using data from a case-control study conducted from 1998 to 2002, the authors assessed the relation between perceived exertion (i.e., relative intensity) during usual recreational physical activity in the year before pregnancy and risk of preeclampsia. In a structured interview conducted during postpartum hospitalization, 244 preeclampsia cases and 470 normotensive controls provided details on their recreational physical activities in the year before pregnancy. RESULTS: Participants who reported feeling very strenuous to maximal exertion during usual prepregnancy physical activity were 78% less likely to have developed preeclampsia than those who reported negligible or minimal exertion (adjusted odds ratio 0.22, 95% confidence interval 0.11-0.44). A significant trend was noted of decreased preeclampsia risk with increased perceived exertion (P < 0.001). This association was independent of prepregnancy adiposity, and was also apparent among the subset of participants who did not meet physical activity guidelines in the year before pregnancy. CONCLUSIONS: In this study, relative intensity of recreational physical activity performed during the year before pregnancy was associated with a decreased risk of preeclampsia.

Adolescent↗
PubMed2004

Dietary fat and fatty acids and risk of colorectal cancer in women.

The authors examined the association of intakes of different types of fat and fatty acids with risk of colorectal cancer using data from the Women's Health Study, a randomized trial of low-dose aspirin and vitamin E carried out among 39,876 healthy US women aged >/=45 years. Among the 37,547 women eligible for the present study, 202 developed colorectal cancer during an average follow-up period of 8.7 years (1993-2003). Intakes of dietary fat and its food sources were assessed at baseline by food frequency questionnaire. Cox proportional hazards regression was used to estimate relative risks and 95% confidence intervals. Total fat intake was not related to colorectal cancer risk, nor were intakes of the different types of fat and major fatty acids. However, the authors observed a positive association between intake of fried foods away from home and colorectal cancer risk (highest quintile vs. lowest: relative risk = 1.86, 95% confidence interval: 1.09, 3.16; p for trend = 0.01). These prospective cohort data provide little support for an association between dietary fat and colorectal cancer risk. However, intake of fried foods and/or other factors related to their intake may be associated with colorectal cancer development. This finding warrants further examination.

Aged↗
PubMed2004

The "weekend warrior" and risk of mortality.

Physical activity improves health, and current recommendations encourage daily exercise. However, little is known about any health benefits associated with infrequent bouts of exercise (e.g., 1-2 episodes/week) that generate the recommended energy expenditure. The authors conducted a prospective cohort study among 8,421 men (mean age, 66 years) in the Harvard Alumni Health Study, without major chronic diseases, who provided details about physical activity on mailed questionnaires in 1988 and 1993. Men were classified as "sedentary" (expending <500 kcal/week), "insufficiently active" (500-999 kcal/week), "weekend warriors" (>/=1,000 kcal/week from sports/recreation 1-2 times/week), or "regularly active" (all others expending >/=1,000 kcal/week). Between 1988 and 1997, 1,234 men died. The multivariate relative risks for mortality among the sedentary, insufficiently active, weekend warriors, and regularly active men were 1.00 (referent), 0.75 (95% confidence interval (CI): 0.62, 0.91), 0.85 (95% CI: 0.65, 1.11), and 0.64 (95% CI: 0.55, 0.73), respectively. In stratified analysis, among men without major risk factors, weekend warriors had a lower risk of dying, compared with sedentary men (relative risk = 0.41, 95% CI: 0.21, 0.81). This was not seen among men with at least one major risk factor (corresponding relative risk = 1.02, 95% CI: 0.75, 1.38). These results suggest that regular physical activity generating 1,000 kcal/week or more should be recommended for lowering mortality rates. However, among those with no major risk factors, even 1-2 episodes/week generating 1,000 kcal/week or more can postpone mortality.

Aged↗
PubMed2004

Prospective study of gestational diabetes mellitus risk in relation to maternal recreational physical activity before and during pregnancy.

Physical activity has been associated with a reduced risk of gestational diabetes mellitus, but inferences have been hampered by recall and selection bias. The authors examined the relation between recreational physical activity before and during pregnancy and risk of gestational diabetes mellitus in a prospective cohort study. In 1996-2000, 909 normotensive, nondiabetic women in Seattle and Tacoma, Washington, were questioned during early gestation about physical activity performed during the year before and 7 days prior to the interview during pregnancy. Compared with inactive women, women who participated in any physical activity during the year before experienced a 56% risk reduction (relative risk (RR) = 0.44, 95% confidence interval (CI): 0.21, 0.91). Women spending >/=4.2 hours/week engaged in physical activity experienced a 76% reduction in gestational diabetes mellitus risk (RR = 0.24, 95% CI: 0.10, 0.64), and those expending >/=21.1 metabolic equivalent-hours/week experienced a 74% reduction (RR = 0.26, 95% CI: 0.10, 0.65) compared with inactive women. Physical activity during pregnancy was also associated with reductions in gestational diabetes mellitus risk. Women who engaged in physical activity during both time periods experienced a 69% reduced risk (RR = 0.31, 95% CI: 0.12, 0.79). Findings suggest that efforts to increase maternal physical activity may contribute to substantial reductions in gestational diabetes mellitus risk.

Adult↗
PubMed2004

Dietary glycemic load and risk of colorectal cancer in the Women's Health Study.

Although diet is believed to influence colorectal cancer risk, the long-term effects of a diet with a high glycemic load are unclear. The growing recognition that colorectal cancer may be promoted by hyperinsulinemia and insulin resistance suggests that a diet inducing high blood glucose levels and an elevated insulin response may contribute to a metabolic environment conducive to tumor growth. We prospectively followed a cohort of 38 451 women for an average of 7.9 years and identified 174 with incident colorectal cancer. We used baseline dietary intake measurements, assessed with a semiquantitative food-frequency questionnaire, to examine the associations of dietary glycemic load, overall dietary glycemic index, carbohydrate, fiber, nonfiber carbohydrate, sucrose, and fructose with the subsequent development of colorectal cancer. Cox proportional hazards models were used to estimate relative risks (RRs). Dietary glycemic load was statistically significantly associated with an increased risk of colorectal cancer (adjusted RR = 2.85, 95% confidence interval [CI] = 1.40 to 5.80, comparing extreme quintiles of dietary glycemic load; P(trend) =.004) and was associated, although not statistically significantly, with overall glycemic index (corresponding RR = 1.71, 95% CI = 0.98 to 2.98; P(trend) =.04). Total carbohydrate (adjusted RR = 2.41, 95% CI = 1.10 to 5.27, comparing extreme quintiles of carbohydrate; P(trend) =.02), nonfiber carbohydrate (corresponding RR = 2.60, 95% CI = 1.22 to 5.54; P(trend) =.02), and fructose (corresponding RR = 2.09, 95% CI = 1.13 to 3.87; P(trend) =.08) were also statistically significantly associated with increased risk. Thus, our data indicate that a diet with a high dietary glycemic load may increase the risk of colorectal cancer in women.

Adult↗
PubMed2004

Body mass index and mortality among US male physicians.

PURPOSE: To assess the relationship between body mass index and mortality in a population homogeneous in educational attainment and socioeconomic status. METHODS: We analyzed the association between body mass index (BMI) and both all-cause and cause-specific mortality among 85,078 men aged 40 to 84 years from the Physicians' Health Study enrollment cohort. RESULTS: During 5 years of follow-up, we documented 2856 deaths (including 1212 due to cardiovascular diseases and 891 due to cancer). In age-adjusted analyses, we observed a U-shaped relation between BMI and all-cause mortality; among men who never smoked a linear relation was observed with no increase in mortality among leaner men (P for trend, <0.001). Among never smokers, in multivariate analyses adjusted for age, alcohol intake, and physical activity, the relative risks of all-cause mortality increased in a stepwise fashion with increasing BMI. Excluding the first 2 years of follow-up further strengthened the association (multivariate relative risks, from BMI<20 to > or = 30 kg/m2, were 0.93, 1.00, 1.00, 1.16, 1.45, and 1.71 [P for trend, <0.001]). In all age strata (40-54, 55-69, and 70-84 years), never smokers with BMIs of 30 or greater had approximately a 70% increased risk of death compared with the referent group (BMI 22.5-24.9). Higher levels of BMI were also strongly related to increased risk of cardiovascular mortality, regardless of physical activity level (P for trend, <0.01). CONCLUSIONS: All-cause and cardiovascular mortality was directly related to BMI among middle-aged and elderly men. Advancing age did not attenuate the increased risk of death associated with obesity. Lean men (BMI<20) did not have excess mortality, regardless of age.

Adult↗
PubMed2004

A case-control study of maternal recreational physical activity and risk of gestational diabetes mellitus.

Despite the maternal and infant morbidity associated with gestational diabetes mellitus (GDM), few modifiable risk factors have been identified. We explored the relation between recreational physical activity performed during the year before and during the first 20 weeks of pregnancy and the risk of GDM. 155 GDM cases and 386 normotensive, non-diabetic pregnant controls provided information about the type, intensity, frequency, and duration of physical activity performed during these time periods. Women who participated in any recreational physical activity during the first 20 weeks of pregnancy, as compared with inactive women, experienced a 48% reduction in risk of GDM (odds ratio [OR] = 0.52; 95% confidence interval [CI] 0.33-0.80). The number of hours spent performing recreational activities and the energy expended were related to a decrease in GDM risk. No clear patterns related to distance walked and pace of walking emerged. Daily stair climbing, when compared with no stair climbing, was associated with a 49-78% reduction in GDM risk (P for trend <0.011). Recreational physical activity performed during the year before the index pregnancy was also associated with statistically significant reductions in GDM risk, but women who engaged in physical activity during both time periods experienced the greatest reduction in risk (OR = 0.40; 95% CI 0.23-0.68). These data suggest that recreational physical activity performed before and/or during pregnancy is associated with a reduced risk of GDM.

Adult↗
PubMed2004

Body mass index and risk of colorectal cancer in women (United States).

OBJECTIVE: Epidemiologic data relating obesity to risk of colorectal cancer in women have been inconclusive. Two recent studies have suggested that the association may be modified by estrogen status; BMI was positively associated with colorectal cancer risk among women with high estrogen exposures [premenopausal women, and postmenopausal women who currently received postmenopausal hormone therapy (PMH)]. We prospectively investigated the role of BMI in colorectal cancer risk along with the modifying effects of estrogen in a large cohort from the Women's Health Study. METHODS: Among 39,876 apparently healthy women aged > or = 45 years at baseline (54% of them were postmenopausal), 37,671 were eligible for the present study. During an average of 8.7 years of follow-up, 202 women had a confirmed diagnosis of colorectal cancer. Baseline BMI was calculated by dividing self-reported weight in kilograms by height in meters squared. RESULTS: The multivariate relative risks (RRs) and 95% confidence interval (CI) of colorectal cancer were 1.72 (1.12-2.66) for 27-29.9 kg/m2, and 1.67 (1.08-2.59) for > or = 30 kg/m2, as compared with BMI < 23 kg/m2 ( p for trend = 0.02). This positive association was seen primarily in the proximal colon ( p for trend = 0.004). When the association was further examined according to PMH use among postmenopausal women, we found that both current and never users with higher BMI were at a greater risk of colorectal cancer ( p for interaction between BMI and PMH use = 0.33). As compared with BMI < 23 kg/m2, the multivariate RRs and 95% CI for 27-29.9 and > or = 30 kg/m2 were 1.98 (0.98-3.99) and 1.41 (0.65-3.06) among current users, and 1.05 (0.42-2.65) and 2.91 (1.40-6.06) among never users. CONCLUSIONS: These data suggest that higher BMI was associated with an elevated risk of colorectal cancer, and the positive relationship was not altered by estrogen exposure among postmenopausal women.

Aged↗
PubMed2004

Dietary glycemic load and breast cancer risk in the Women's Health Study.

A diet with a high glycemic load (GL) may contribute to a metabolic environment that enhances tumorigenesis. Little is known, however, about whether high glycemic diets increase breast cancer risk in women. We examined the associations between baseline measurements of dietary GL and overall glycemic index (GI) and subsequent breast cancer in a cohort of 39,876 women, ages 45 years or older, participating in the Women's Health Study. During a mean of 6.8 years of follow-up there were 946 confirmed cases of breast cancer. We found no association between dietary GL [multivariable-adjusted relative risk (RR), 1.01; confidence interval (CI), 0.76-1.35, comparing extreme quintiles; P for trend = 0.96] or overall GI (corresponding RR, 1.03; CI, 0.84-1.28; P for trend = 0.66) and breast cancer risk in the cohort as a whole. Exploratory analyses stratified by baseline measurements of menopausal status, physical activity, smoking history, alcohol use, and history of diabetes mellitus, hypertension, or hypercholesterolemia showed no significant associations, except in the subgroup of women who were premenopausal and reported low levels of physical activity (GL multivariable-adjusted RR, 2.35; CI, 1.03-5.37; P for trend = 0.07; GI multivariable-adjusted RR, 1.56; CI, 0.88-2.78; P for trend = 0.02, comparing extreme quintiles). Although we did not find evidence that a high glycemic diet increases overall breast cancer risk, the increase in risk in premenopausal women with low levels of physical activity suggests the possibility that the effects of a high glycemic diet may be modified by lifestyle and hormonal factors. Prospective studies of a larger sample size and longer duration are warranted to confirm our findings.

Breast Neoplasms↗
PubMed2003

Sex hormone levels and risk of cardiovascular events in postmenopausal women.

BACKGROUND: Despite diffuse effects of sex hormones on the cardiovascular system, few prospective studies have examined the relationship of plasma androgens and estrogens with risk of cardiovascular disease (CVD) in postmenopausal women. METHODS AND RESULTS: A nested case-control study was performed among women in the Women's Health Study. Two hundred women who developed CVD were matched 1:1 by age, smoking, and postmenopausal hormone therapy (HT) to controls who remained free of CVD. We measured testosterone, estradiol, and sex hormone binding globulin (SHBG) levels and calculated free androgen index (FAI), free estradiol index, and the FAI/free estradiol index ratio. Results were stratified by HT use. Among HT nonusers, cases had significantly higher androgen profiles (higher median FAI and lower SHBG levels) than controls. After adjustment for age, smoking, use of aspirin, vitamin E, and alcohol, family history of myocardial infarction, and physical activity, nonusers in the lowest SHBG quartile had an OR of 2.25 (95% CI, 1.03 to 4.91) for CVD, and there were significant trends across FAI quartiles (P for trend=0.03). Additional adjustment for body mass index, hypertension, diabetes, and elevated cholesterol eliminated associations with SHBG and FAI. Among women using HT, no significant differences in hormones or SHBG were observed among women who developed CVD and controls. CONCLUSIONS: Among HT nonusers, lower SHBG and higher FAI levels were noted among postmenopausal women who developed CVD events, but this was not independent of body mass index and other cardiovascular risk factors. Estradiol levels were not associated with risk of CVD in HT users or nonusers.

Cardiovascular Diseases↗
PubMed2003

Recreational physical activity during pregnancy and risk of preeclampsia.

The potential benefits and risks of physical activity before and during pregnancy are not well studied. We studied the relation between recreational physical activity and the risk of preeclampsia in a case-control study of 201 preeclamptic and 383 normotensive pregnant women. Participants provided information about the type, intensity, frequency, and duration of physical activity performed during the first 20 weeks of pregnancy and during the year before pregnancy. Women who engaged in any regular physical activity during early pregnancy, compared with inactive women, experienced a 35% reduced risk of preeclampsia (odds ratio, 0.65; 95% confidence interval [CI], 0.43 to 0.99). Compared with inactive women, those engaged in light or moderate activities (ie, activities with metabolic-equivalent scores <6) experienced a 24% reduced risk of preeclampsia (95% CI, 0.48 to 1.20). The corresponding reduction for women participating in vigorous activities (metabolic equivalent scores > or =6) was 54% (95% CI, 0.27 to 0.79). Brisk walking (average walking pace > or =3 mi/h), when compared with no walking at all, was associated with a 30% to 33% reduction in preeclampsia risk. Stair climbing was inversely associated with the risk of preeclampsia (P for trend=0.039). Recreational physical activity performed during the year before pregnancy was associated with similar reductions in preeclampsia risk. These data suggest that regular physical activity, particularly when performed during the year before pregnancy and during early pregnancy, is associated with a reduced risk of preeclampsia.

Adult↗