Search PubMed⌕ Search

Biomedical subjects

G A Colditz

Publications and source records attributed to G A Colditz.

At least 271 records · Page 15Linked to original sources
PubMed1996

Toenail trace element levels and breast cancer: a prospective study.

The associations between toenail levels of five trace elements and breast cancer risk were studied among a cohort of 62,641 US women who provided toenail clippings and were free from diagnosed breast cancer in 1982. Among 433 cases of breast cancer identified during 4 years of follow-up and their matched controls, the odds ratios comparing the highest with the lowest quintiles and adjusted for established breast cancer risk factors were as follows: for arsenic, 1.12 (95% confidence interval (CI) 0.66-1.91); for copper, 0.91 (95% CI 0.59-1.42); for chromium, 0.96 (95% CI 0.61-1.52); for iron, 0.89 (95% CI 0.56-1.40); and for zinc, 1.09 (95% CI 0.70-1.70). Among postmenopausal women, a marginally significant positive association was observed between toenail chromium levels and breast cancer risk (odds ratio = 1.71, 95% CI 0.87-3.35) (p for trend = 0.07). However, the association between chromium and breast cancer risk was inverse among premenopausal women. Although data on the validity of toenail levels of certain of these elements are limited, these results do not provide evidence for an important effect of arsenic, copper, chromium, iron, or zinc on breast cancer risk.

Adult↗
PubMed1996

Birth weight and adult hypertension and obesity in women.

BACKGROUND: Low birth weight has been associated with an increased risk of hypertension, and high birth weight has been associated with increased adult body mass index. Published studies on adults have included only a small number of women. METHODS AND RESULTS: We studied 71 100 women in the Nurses Health Study I (NHS I) who were 30 to 55 years of age in 1976 and 92 940 women in the Nurses' Health Study II (NHS II) who were 25 to 42 years of age in 1989. Information on birth weight, blood pressure, physician-diagnosed hypertension, and other relevant variables was collected by biennial mailed questionnaire. Ninety-five percent of the women were white. Compared with women in the middle category of birth weight (NHS I, 7.1 to 8.5 lb; NHS II, 7.0 to 8.4 lb), the age-adjusted odds ratio of hypertension in NHS I women with birth weights < 5.0 lb was 1.39 (95% CI, 1.29 to 1.50); in NHS II, for birth weights < 5.5 lb, the age-adjusted odds ratio was 1.43 (95% CI, 1.31 to 1.56). There was no material change in the estimates after adjustment for other risk factors. In addition, compared with women in NHS I who weighed 7.1 to 8.5 lb at birth, those who weighed > 10 lb had an age-adjusted odds ratio of 1.62 (95% CI, 1.38 to 1.90) of being in the highest (> 29.2 kg/m2) versus the lowest (< 21.9 kg/ m2) quintile of body mass index in midlife. Similar results were seen in the NHS II cohort. CONCLUSIONS: Early life exposures affecting birth weight may be important in the development of hypertension and obesity in adults.

Adult↗
PubMed1996

Postmenopausal estrogen and progestin use and the risk of cardiovascular disease.

BACKGROUND: Estrogen therapy in postmenopausal women has been associated with a decreased risk of heart disease. There is little information, however, about the effect of combined estrogen and progestin therapy on the risk of cardiovascular disease. METHODS: We examined the relation between cardiovascular disease and postmenopausal hormone therapy during up to 16 years of follow-up in 59,337 women from the Nurses' Health Study, who were 30 to 55 years of age at base line. Information on hormone use was ascertained with biennial questionnaires. From 1976 to 1992, we documented 770 cases of myocardial infarction or death from coronary disease in this group and 572 strokes. Proportional-hazards models were used to calculate relative risks and 95 percent confidence intervals, adjusted for confounding variables. RESULTS: We observed a marked decrease in the risk of major coronary heart disease among women who took estrogen with progestin (multivariate adjusted relative risk, 0.39; 95 percent confidence interval, 0.19 to 0.78) or estrogen alone (relative risk, 0.60; 95 percent confidence interval, 0.43 to 0.83), as compared with women who did not use hormones [corrected]. However, there was no significant association between stroke and use of combined hormones (multivariate adjusted relative risk, 1.09; 95 percent confidence interval, 0.66 to 1.80) or estrogen alone (relative risk, 1.27; 95 percent confidence interval, 0.95 to 1.69). CONCLUSIONS: The addition of progestin does not appear to attenuate the cardioprotective effects of postmenopausal estrogen therapy.

Adult↗
PubMed1996

Prospective study of oral contraceptives and hypertension among women in the United States.

BACKGROUND: Oral contraceptives induce hypertension in approximately 5% of users of high-dose pills that contain at least 50 micrograms estrogen and 1 to 4 mg progestin, and small increases in blood pressure have been reported even among users of modern low-dose formulations. However, neither the responsible hormone in the oral contraceptive nor particular subgroups of women who might be susceptible to the hypertensive effect of oral contraceptives have been identified. METHODS AND RESULTS: In a prospective cohort study in the United States, 68 297 female nurses aged 25 to 42 years and free of diagnosed hypertension, diabetes, coronary heart disease, stroke, and cancer at baseline were followed up for 4 years. During 231 006 person-years of follow-up, 1567 incident cases of hypertension were diagnosed. Compared with women who had never used oral contraceptives, the age-adjusted relative risk was 1.5 (95% CI = 1.2 to 1.8) for current use and 1.1 (95% CI = 0.9 to 1.2) for past use. After adjustment for age, body mass index, hormones cigarette smoking, family history of hypertension, parity, physical activity, alcohol intake, and ethnicity, current users of oral contraceptives had an increased risk of development of hypertension (RR = 1.8; 95% CI = 1.5 to 2.3) compared with women who had never used them. The multivariate relative risk for past users was 1.2 (95% CI = 1.0 to 1.4). There were no important modifying effects of age, family history of hypertension, ethnicity, or body mass index. CONCLUSIONS: Current users of oral contraceptives had a significant, moderately increased risk of hypertension. However, among this group, only 41.5 cases per 10 000 person-years could be attributed to oral contraceptive use. Risk decreased quickly with cessation of oral contraceptives, and past users appeared to have only a slightly increased risk.

Adult↗
PubMed1996

Prospective study of regular aspirin use and the risk of breast cancer.

BACKGROUND: Evidence suggests that aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) can inhibit tumor development in the large bowel. An inverse association between the use of NSAIDs and the incidence of breast cancer has been observed, but this association has not been statistically significant in all studies. PURPOSE: We analyzed data from the prospective Nurses' Health Study to evaluate the influence of aspirin use on breast cancer risk. METHODS: We studied a population of 89,528 female registered nurses who reported no history of breast or other cancers (excluding nonmelanoma skin cancer) and who returned a mailed questionnaire in 1980 that elicited information concerning breast cancer risk factors and current and past aspirin use. Follow-up questionnaires were mailed to the participants every 2 years; the women were followed through 1992. Information concerning current aspirin use was obtained from each biennial questionnaire, except in 1986. Cases of breast cancer were identified through questionnaire responses, and permission was sought for a review of medical records to confirm the diagnoses. Our analysis was based on 2414 cases of invasive breast cancer, which included 2303 cases confirmed with medical records and 111 cases for which no records were obtained. Relative risks (RRs) with 95% confidence intervals (CIs), adjusted for age or age plus other known or potential breast cancer risk factors (i.e., multivariate), were calculated. RESULTS: Regular aspirin use (two or more tablets per week) in 1980 was unrelated to breast cancer incidence during the succeeding 12-year period (with no regular aspirin use as the referent, multivariate RR = 1.03; 95% CI = 0.95-1.12). The corresponding risk estimate for consistent regular aspirin use during the period from 1980 through 1988 was 1.01 (95% CI = 0.80-1.27). The risks were similar for heavy aspirin use (for more than two tablets per day [i.e., > 14 per week] in 1980 and in 1980 through 1988, the multivariate RRs [95% CIs] were 1.05 [0.89-1.23] and 1.09 [0.75-1.60], respectively) and for extended durations of regular use (e.g., for 20 years or more of regular use, multivariate RR = 1.00; 95% CI = 0.71-1.41). CONCLUSION: Our results indicate that regular aspirin use does not reduce the risk of breast cancer.

Adult↗
PubMed1996

Three-year follow-up of participants in a commercial weight loss program. Can you keep it off?

BACKGROUND: One third of Americans are obese, according to the 1988-1991 National Health and Nutrition Endpoint Survey III survey. Obesity increases the risk of death and a variety of chronic diseases. Numerous commercial weight loss programs demonstrate short-term success. OBJECTIVE: To assess maintenance of weight loss achieved during dieting. METHODS: We surveyed 192 participants in the Sandoz Nutrition (Sandoz Pharmaceuticals, Minneapolis, Minn) diet program approximately 3 years after participation. Initial date were supplied by the diet clinics and follow-up data, including weight at various points after the program, participation in other weight loss programs, and lifestyle variables, such as exercise, smoking, and television watching, were collected by a mailed questionnaire. RESULTS: On average, the group lost 22 kg during the diet program. After the follow-up period, the mean weight (mean, 102.6 kg) was only modestly less than the group's original weight at the start of the diet (mean, 105.9 kg). Twelve percent of the subjects maintained 75% of their weight loss after leaving the diet program, 57% maintained at least 5% of the loss, and 40% gained back more than they had lost during the diet. The frequency of exercise after the diet program was the strongest predictor of weight loss maintenance, while television viewing predicted a gain in weight. CONCLUSION: Given the apparent lack of substantial, long-term success at weight reduction, perhaps greater emphasis should be placed on prevention of obesity.

Commerce↗
PubMed1996

Calcium, vitamin D, and dairy foods and the occurrence of colon cancer in men.

To examine the associations between intakes of calcium, Vitamin D, and dairy foods and the risk of colon cancer, the authors analyzed data from a prospective study of 47,935 US male professionals, 40-75 years of age and free of cancer in 1986. Within this cohort, 203 new cases of colon cancer were documented between 1986 and 1992. After adjusting for age and total energy intake, the authors found that the intake of calcium from foods and supplements was inversely associated with colon cancer risk (relative risk (RR) = 0.58, 95% confidence interval (CI) 0.39-087 between high and low intakes of calcium). However, after adjusting for confounding variables, they found that the trend was no longer statistically significant (p = 0.22), and the relative risk for the highest quintile group of intake was attenuated: 0.75 (95% CI 0.48-1.15). Similar results were observed for total vitamin D intake; the age- and energy-adjusted relative risk was 0.54% (95% CI 0/34-0/85) for the highest versus lowest quintile group, and this was attenuated in the multivariate model (RR = 0.66, 95% CI 0.42-1.05). The inverse association was weaker for dietary vitamin D (RR highest vs. lowest quintile = 0.88. 95% CI 0.54-1.42) and strongest for vitamin D arising from vitamin supplements (RR = 0.48, 95% CI 0.22-1.02). Thus, it is possible that other components of multivitamin use rather than vitamin D accounted for the reduction in risk. Consumption of milk and fermented dairy products was not significantly associated with the risk of colon cancer; individuals consuming two or more glasses of "whole" or skim milk per day had a relative risk of 1.09 (95% CI 0.69-1.72), compared with those who consumed "whole or skim milk less than once a month. These prospective data do not support the hypothesis that calcium intake is strongly protective against colon cancer risk, although a modest association cannot be excluded.

Adult↗
PubMed1996

Nurses' health study: log-incidence mathematical model of breast cancer incidence.

BACKGROUND: In 1983, Pike et al. developed a mathematical model to quantify the effects of reproductive risk factors on the incidence of breast cancer. In 1994, we modified that model to correct some deficiencies in the original model, including a lack of terms for spacing of births and an inability to easily accommodate births after age 40 years. Our extended Pike model, while improving on the original, still has serious disadvantages, such as difficulty in translating model parameters into relative risks (RRs) and an incomplete fit to data that slightly overestimated incidence for premenopausal women with an early age at first birth and that underestimated incidence for post-menopausal women with a late age at first birth. PURPOSE: We undertook both the development of a new mathematical model to quantify the effects of reproductive risk factors on breast cancer incidence and validation of the model. METHODS: A new log-incidence model of breast cancer incidence was developed using nonlinear regression methods, and a study population consisting of 89,132 women in the Nurses' Health Study from which a total of 2249 incident cases of breast cancer were identified. Subjects were followed from the return of the 1976 Nurses' Health Study questionnaire until June 1, 1990, or until the last questionnaire was returned, until the development of any cancer, or until death, yielding 1,148,593 person-years of follow-up. The log-incidence models were fitted using iteratively reweighted least squares analysis. RESULTS: The log-incidence model provided a better fit to that data than the extended Pike model, with parameter estimates interpretable in terms of RRs. This new model can be fitted using standard commercially available statistical software. In the model, younger parous women are generally at slightly higher risk than nulliparous women, which is true for both the observed and expected RRs, and older parous women, aged 55-64 years with an early age at first birth, are at lower risk than nulliparous women,while older women with a late age at first birth are at substantially higher risk than nulliparous women. CONCLUSION: Log-incidence models, such as this one, provide an efficient framework for modeling the effect of lifestyle risk factors on breast cancer incidence that may be specifically targeted to certain time periods of a woman's reproductive life.

Adult↗
PubMed1996

Risk factors for breast cancer according to family history of breast cancer. For the Nurses' Health Study Research Group.

BACKGROUND: Family history of breast cancer is an established risk factor for this disease and is used to identify women at higher risk, although the impact of risk factors for breast cancer among women with a family history is not well defined. PURPOSE: Using a modified extended log-incidence Pike model, we prospectively examined the impact of risk factors for breast cancer among women with and without a family history of the disease. METHODS: Data analyzed were obtained prospectively from the Nurses' Health Study. Two thousand two hundred forty-nine incident cases of invasive breast cancer were identified in a cohort of 89,132 women aged 30-55 years in 1976 followed biennially through 1990 (1.1 million person years of follow-up). With the use of proportional hazards models, we evaluated the association between risk factors for breast cancer and risk among women with and those without a family history of the disease. We then fit a modified extended log-incidence Pike model to these data. RESULTS: Among women with a family history of breast cancer, reproductive risk factors has associations that were different from those observed among women without a family history of the disease. In particular, we observed little protection from later age at menarche, no protection from multiple births when compared with nulliparity, nor from early, as compared with later, age at first birth. Fitting these data to a model of breast cancer incidence on the basis of reproductive risk factors, we observed an adverse effect of first pregnancy on risk of breast cancer among women with a family history of breast cancer that was approximately 50% greater in magnitude than among women without a family history. Additional births after the first birth conveyed little protection for women with a family history. History of benign breast disease, past use of oral contraceptives, and use of postmenopausal hormones showed relative risks that did not differ between women with a family history and those without a family history of the disease. CONCLUSIONS: We observed a consistent increase in risk of breast cancer among women with a mother or sister history of the disease that was exacerbated by first pregnancy. Among women with a family history of breast cancer, the adverse effect of pregnancy persisted so that to age 70 years, parous women were at higher risk of breast cancer than nulliparous women. Among women without a family history of the disease, first pregnancy was associated with a smaller increase in risk, and early pregnancy and higher number of births were each associated with reduced breast cancer incidence.

Adult↗
PubMed1996

A prospective study of coffee drinking and suicide in women.

BACKGROUND: Among the many reported central nervous system effects of long-term caffeine use is improvement in mood. OBJECTIVE: To examine prospectively the relationship of coffee and caffeine intake to risk of death from suicide. METHODS: We conducted a 10-year follow-up study (1980 to 1990) in an ongoing cohort of 86 626 US female registered nurses aged 34 to 59 years in 1980, who were free of diagnosed coronary heart disease, stroke, or cancer. Information on coffee and caffeine intake was collected by a semiquantitative food frequency questionnaire in 1980. Deaths from suicide were determined by physician review of death certificates. RESULTS: Fifty-six cases of suicide occurred during 832 704 person-years of observation. Compared with non-drinkers of coffee, the age-adjusted relative risk of suicide in women who consumed two to three cups per day was 0.34 (95% confidence interval [CI, 0.17 to 0.68) and 0.42 (95% CI, 0.21 to 0.86) in women who consumed four or more cups per day (P for linear trend=.002). These findings remained essentially unchanged after adjusting for a broad range of potential confounding factors, including smoking habit, alcohol intake, medication use (diazepam and phenothiazine), history of comorbid disease (hypertension, hypercholesterolemia, or diabetes), marital status, and self-reported stress. A strong inverse relationship was similarly found for caffeine intake from all sources and risk of suicide. CONCLUSIONS: The data suggest a strong inverse association between coffee intake and risk of suicide. Whether regular intake of coffee or caffeine has clinically significant effects on the maintenance of affect or the prevention of depression merits further investigation in clinical trials and population-based prospective studies.

Adult↗
PubMed1996

Protein consumption and bone fractures in women.

Dietary protein increases urinary calcium losses and has been associated with higher rates of hip fracture in cross-cultural studies. However, the relation between protein and risk of osteoporotic bone fractures among individuals has not been examined in detail. In this prospective study, usual dietary intake was measured in 1980 in a cohort of 85,900 women, aged 35-59 years, who were participants in the Nurses' Health Study. A mailed food frequency questionnaire was used and incident hip (n = 234) and distal forearm (n = 1,628) fractures were identified by self-report during the following 12 years. Information on other factors related to osteoporosis, including obesity, use of postmenopausal estrogen, smoking, and physical activity, was collected on biennial questionnaires. Dietary measures were updated in 1984 and 1986. Protein was associated with an increased risk of forearm fracture (relative risk (RR) = 1.22, 95% confidence interval (Cl) 1.04-1.43, p for trend = 0.01) for women who consumed more than 95 g per day compared with those who consumed less than 68 g per day. A similar increase in risk was observed for animal protein, but no association was found for consumption of vegetable protein. Women who consumed five or more servings of red meat per week also had a significantly increased risk of forearm fracture (RR = 1.23, 95% Cl 1.01-1.50) compared with women who ate red meat less than once per week. Recall of teenage diet did not reveal any increased risk of forearm fracture for women with higher consumption of animal protein or red meat during this earlier period of life. No association was observed between adult protein intake and the incidence of hip fractures, though power to assess this association was low.

Adult↗
PubMed1996

Prospective assessment of breastfeeding and breast cancer incidence among 89,887 women.

BACKGROUND: The relation between breastfeeding and breast cancer risk has been examined in many studies; some have reported no association, and others a reduced risk, particularly among premenopausal women. In the only prospective cohort study, no association was found. We have assessed prospectively the association between breastfeeding and incidence of breast cancer among 89,887 women in the US Nurses' Health Study. METHODS: In 1986, participants were asked about the number of months they breastfed for all their children combined. Parous women with no history of cancer were included in this analysis. During 6 years of follow-up (513,015 person-years), 1,459 invasive breast cancer cases were diagnosed. FINDINGS: Relative to women who had never breastfed, no significant overall association was found--after adjusting for established risk factors for breast cancer--between a history of having breastfed and subsequent development of breast cancer (relative risk [RR] 0.93, 95% CI 0.83 -1.03). No inverse trend was observed with duration of breastfeeding; women who breastfed for 2 years of longer had a RR of 1.11 (0.90-1.38). Among women who had given birth only once, women who had breastfed their child experienced a lower incidence of breast cancer (RR 0.68, 0.46-1.00). Among premenopausal women, who tended to be near menopause due to the age structure of the cohort, the RR of breast cancer for those who had lactated was 1.16 (0.89-1.50). Premenopausal women who had lactated for 1 year or more had a RR of 1.10 (0.78-1.57). INTERPRETATION: These data suggest that there is no important overall association between breast-feeding and the occurrence of breast cancer.

Adult↗
PubMed1996

Coffee consumption and coronary heart disease in women. A ten-year follow-up.

OBJECTIVE--To assess the relationship between coffee consumption and risk of coronary heart disease (CHD) among women. DESIGN--Prospective cohort study with coffee consumption measured in 1980, 1984, and 1986, and follow-up through 1990. SETTING--Female registered nurses in the United States. PARTICIPANTS--A total of 85,747 US women 34 to 59 years of age in 1980 and without history of CHD, stroke, or cancer. MAIN OUTCOME MEASURE--Ten-year incidence of CHD (defined as nonfatal myocardial infarction or fatal CHD). RESULTS--During 10 years of follow-up we documented 712 cases of CHD. After adjustment for age, smoking, and other CHD risk factors, we found no evidence for any positive association between coffee consumption and risk of subsequent CHD. For women drinking six or more cups of caffeine-containing coffee per day in 1980, the relative risk was 0.95 (95% confidence interval, 0.73 to 1.26) compared with women who did not consume this beverage. Similarly, there was no association when the first 4 years of follow-up were excluded, when nonfatal and fatal CHD end points were examined separately, or when we updated coffee consumption in 1984 or 1986 and examined only CHD during the next 2-year interval. Further, there was no association with caffeine intake from all sources combined or with decaffeinated coffee consumption. CONCLUSIONS--These data indicate that coffee as consumed by US women is not an important cause of CHD.

Adult↗
PubMed1996

Television viewing as a cause of increasing obesity among children in the United States, 1986-1990.

BACKGROUND AND METHODS: The prevalence of obesity among children and adolescents has increased, and television viewing has been suggested as a cause. We examined the relation between hours of television viewed and the prevalence of overweight in 1990, and the incidence and remission of overweight from 1986 to 1990 in a nationally representative cohort of 746 youths aged 10 to 15 years in 1990 whose mothers were 25 to 32 years old. Overweight was defined as a body mass index higher than the 85th percentile for age and gender. RESULTS: We observed a strong dose-response relationship between the prevalence of overweight in 1990 and hours of television viewed. The odds of being overweight were 4.6 (95% confidence interval, 2.2 to 9.6) times greater for youth watching more than 5 hours of television per day compared with those watching 0 to 2 hours. When adjustments were made for previous overweight (in 1986), baseline maternal overweight, socioeconomic status, household structure, ethnicity, and maternal and child aptitude test scores, results were similar (odds ratio, 5.3; 95% confidence interval, 2.3 to 12.1). We also found significant relations between television viewing and increased incidence and decreased remission of overweight during this 4-year period, adjusted for baseline covariates. The adjusted odds of incidence were 8.3 (95% confidence interval, 2.6 to 26.5) times greater for youth watching more than 5 hours of television per day compared with those watching for 0 to 2 hours. Estimates of attributable risk indicate that more than 60% of overweight incidence in this population can be linked to excess television viewing time. CONCLUSION: Television viewing affects overweight among youth, and reductions in viewing time could help prevent this increasingly common chronic health condition.

Body Mass Index↗
PubMed1996

Hair dye use and the risk of developing systemic lupus erythematosus.

OBJECTIVE: To investigate the role of hair dye use in the etiology of systemic lupus erythematosus (SLE). METHODS: Participants included 106,391 women enrolled in the Nurses' Health Study, a prospective cohort study. The subjects were ages 30-55 years in 1976, and were free from SLE and any other connective tissue disease at the time of enrollment. In 1976, 1978, 1980, and 1982, subjects were classified as never-users or ever-users of permanent hair dye, based on self-report. Incidence rates of SLE meeting American College of Rheumatology classification criteria were ascertained and confirmed by chart review. RESULTS: Compared with never-users of permanent hair dye, the age-adjusted relative risks (RR) for the development of SLE among ever-users (n = 85 cases) was 0.96 (95% confidence interval [95% CI] 0.63-1.47). Duration of hair dye use was not related to risk of SLE. Women with 15 or more years of use had no increased risk (RR = 0.92, 95% CI 0.46-1.83). There was no relationship between frequency of use or time since first use and risk of SLE. The results were similar when less stringent criteria for SLE were used. CONCLUSION: We found no evidence that permanent hair dye use, age at first use, frequency of use, or duration of use is associated with the development of SLE.

Adult↗
PubMed1996

Disordered eating: can women accurately recall their binging and purging behaviors 10 years later?

OBJECTIVE: To test women's ability to recall their past binging and purging behaviors. DESIGN: Ten-year follow-up study of women who had participated in a cross-sectional survey during college. SUBJECTS: In 1982, a sample of freshman and senior women at a large university in the Boston area were questioned about their weight, dieting history, bulimic symptoms, and eating patterns, attitudes, and concerns. In 1992, all subjects who responded to the 1982 survey were followed up to assess changes in bulimic symptoms and ability to recall past behaviors. RESULTS: Among the 476 women who responded to both surveys, the percentage in 1992 who reported having ever binged and/or purged was less than the percentage in 1982, indicating that the recall of past behaviors was less than perfect. Denial in 1992 of ever having engaged in the behaviors ranged from 22% among the women who were self-inducing vomiting in 1982 to 64% among the women who had reported current fasting or strict dieting in 1982. Recall of past behaviors in 1992 was better among the women who had been current bingers or purgers in 1982. CONCLUSION: Our results demonstrate that ability to recall past binging and purging is only modest. Therefore to better understand the mental and physical health consequences of these behaviors this information should be collected prospectively.

Adult↗
PubMed1996

Physical activity, obesity, and risk of colorectal adenoma in women (United States).

The relationship between physical inactivity, body mass index (BMI) (wt[kg]/ht[m]2), and pattern of adipose distribution with risk of colorectal adenomas (precursors of cancer) was examined in 13,057 female nurses in the United States, 40 to 65 years of age in 1986, who had an endoscopy between 1986 and 1992. From 1986 to 1992, 439 participants were newly diagnosed with adenomas of the distal colorectum. After controlling for age, prior endoscopy, parental history of colorectal cancer, smoking, aspirin, and intakes of animal fat, dietary fiber, folate, methionine, and alcohol, physical activity was associated inversely with risk of large (> or = 1 cm) adenomas in the distal colon (relative risk [RR] = 0.57, 95 percent confidence interval [CI] = 0.30-1.08, comparing high and low quintiles of average weekly energy expenditure from leisure-time activities; P trend = 0.05). Much of the benefit came from activities of moderate intensity such as brisk walking. In addition, BMI was associated directly with risk of large adenomas in the distal colon (multivariate RR = 2.21 [CI = 1.18-4.16], P trend = 0.0001, for BMI > or = 29 cf < 21 kg/m2). Waist circumference and the waist-to-hip ratio (WHR) were not related significantly to adenoma independently of BMI, but women with both a high BMI and high WHR were at greater risk of large colon adenoma (multivariate RR = 1.99, CI = 0.98-4.05) than women with high BMI but relatively low WHR (multivariate RR = 1.35, CI = 0.61-2.97). BMI was not related to small (< 1 cm) adenoma risk but physical activity had an inverse association with small adenomas in the distal colon (multivariate RR = 0.68, CI = 0.40-1.15, P trend = 0.03). The relationships between BMI or physical activity were considerably weaker and inconsistent for rectal adenomas. These results, in women, support an inverse association between physical activity and occurrence or progression of adenomas in the distal colon; obesity is associated with an elevated risk of large adenomas.

Adenoma↗