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Biomedical subjects

G A Colditz

Publications and source records attributed to G A Colditz.

At least 19 recordsLinked to original sources
PubMed2006

A prospective study of postmenopausal hormone use and ovarian cancer risk.

The relationship between postmenopausal hormone use (PMH) and ovarian cancer risk is unclear, particularly for specific hormone formulations, but recent studies suggest that there is a positive association. We conducted a prospective observational study with 82,905 postmenopausal women, including 389 ovarian cancers, in the Nurses' Health Study from 1976 to 2002. Compared with never users of PMH, both current and past users of > or =5 years had a significantly elevated risk of ovarian cancer (RR=1.41, 95% confidence interval (CI) 1.07-1.86 and relative risk (RR)=1.52, 95% CI 1.01-2.27, respectively). Examined by hormone type in continuous years, use of unopposed estrogen was associated with a significant increase in the risk of epithelial ovarian cancer (P for trend <0.001; RR for 5-year increment of use=1.25, 95% CI 1.12-1.38). Use of estrogen plus progestin (RR for 5-year increment of use=1.04, 95% CI 0.82-1.32) was not significantly associated with ovarian cancer risk. Generally, results were similar for serous tumours (RR for 5-year increment of unopposed estrogen use=1.23, 95% CI 1.07-1.40) and slightly stronger for endometrioid tumours (RR for 5-year increment of unopposed estrogen use=1.53, 95% CI 1.20-1.94). Recency of use was not significantly associated with ovarian cancer risk, but statistical power was limited here.

Cohort Studies↗
PubMed2006

Cyclin D1 A870G polymorphism and the risk of colorectal cancer and adenoma.

Cyclin D1 (CCND1) plays a key role in cell cycle control, particularly in the transition from G1 to S phase, which is regulated by cyclin-dependent kinases. A common adenine to guanine polymorphism (A870G) in the CCND1 gene has been associated with a longer-life protein and an increased risk of colorectal cancer and adenoma in some studies. Among subjects with hereditary nonpolyposis colorectal cancer, the A870G polymorphism has also been associated with a younger age of onset of colorectal cancer. We analysed 181 colorectal cancer cases and 475 matched controls and 524 adenoma cases and 517 matched controls within women in the Nurses' Health Study (NHS) cohort, 171 colorectal cancer cases and 347 matched controls and 372 adenoma cases and 712 matched controls nested within men in the Health Professionals' Follow-Up Study (HPFS) cohort, and 258 colorectal cancer cases and 415 matched controls within men in the Physicians' Health Study (PHS) cohort to assess the risk associated with the CCND1 A870G genotype. Moreover, we assessed whether CCND1 genotype modified the effect of a sporadic (nonsyndromic) family history of colorectal cancer as well as the effect of other dietary and lifestyle risk factors for colorectal cancer and adenoma. In all cohorts combined, the CCND1 polymorphism did not show statistically significant associations to risk of colorectal cancer (odds ratio (OR) for A allele carriers, 1.04; 95% confidence interval (95% CI), 0.82-1.32) or adenoma (OR, 0.96; 95% CI, 0.79-1.18). The CCND1 A870G genotype was associated with a modest, although nonsignificantly elevated risk of colorectal cancer (OR, 1.59; 95% CI, 0.98-2.57) in women. In contrast, the polymorphism was not associated with increased risk of adenoma in either men or women. Among participants with the A870G genotype, a family history of colorectal cancer conferred a substantially greater risk of colorectal cancer in the women (P for interaction=0.06) and adenoma in the men (P for interaction=0.02). Current postmenopausal hormone (PMH) use was associated with a significant reduction in the risk of colorectal cancer and adenoma among women with the A870G genotype, whereas there was no effect of PMH use among those with the GG genotype. The CCND1 polymorphism appeared to confer a modest elevation in the risk of colorectal cancer among women. Moreover, the A870G genotype may enhance the protective effect of postmenopausal oestrogen use on the development of colorectal neoplasia.

Adenoma↗
PubMed2005

A candidate gene approach to searching for low-penetrance breast and prostate cancer genes.

Most cases of breast and prostate cancer are not associated with mutations in known high-penetrance genes, indicating the involvement of multiple low-penetrance risk alleles. Studies that have attempted to identify these genes have met with limited success. The National Cancer Institute Breast and Prostate Cancer Cohort Consortium--a pooled analysis of multiple large cohort studies with a total of more than 5,000 cases of breast cancer and 8,000 cases of prostate cancer--was therefore initiated. The goal of this consortium is to characterize variations in approximately 50 genes that mediate two pathways that are associated with these cancers--the steroid-hormone metabolism pathway and the insulin-like growth factor signalling pathway--and to associate these variations with cancer risk.

Breast Neoplasms↗
PubMed2004

Genetic variation in XRCC1, sun exposure, and risk of skin cancer.

The XRCC1 gene is involved in the base excision repair pathway. We assessed the associations of polymorphisms and haplotypes in XRCC1 with skin cancer risk in a nested case-control study within the Nurses' Health Study (219 melanoma, 286 squamous cell carcinoma (SCC) and 300 basal cell carcinoma (BCC), and 873 controls). We genotyped four haplotype-tagging single-nucleotide polymorphisms (Arg194Trp, C26602T, Arg399Gln, and Gln632Gln). There was no significant difference in frequency distribution between cases and controls for any of the five inferred common haplotypes. We observed that the 399Gln allele was inversely associated with SCC risk. This inverse association was only seen among those who had five or more lifetime sunburns, those with a family history of skin cancer, and those in the highest tertile of cumulative sun exposure in a bathing suit, but not among those with low risk defined by these risk factors. We also observed a significant association of the carriage of 194Trp allele with increased SCC risk, which was modified by family history of skin cancer. These two polymorphisms were not associated with BCC or melanoma risk. Our data suggest that the Arg194Trp and Arg399Gln polymorphisms may be differently associated with skin cancer risk according to exposure dose and skin cancer type.

Adult↗
PubMed2004

Modifiable risk factors for cancer.

Over 6 million people around the world die from cancer each year. Modifiable risk factors have been linked to a wide range of malignancies, including cancers of the oropharynx, oesophagus, larynx, lung, kidney, bladder, pancreas, skin, stomach, ovary, breast, cervix, uterus, prostate, and colon. Research indicates that over half of all cancers in developed countries could be prevented if we implemented population-wide measures to promote the following behaviours: reduce tobacco use, increase physical activity, control weight, improve diet, limit alcohol, utilise safer sex practices, get routine cancer screening tests, and avoid excess sun exposure.

Alcohol Drinking↗
PubMed2004

Association of weight change, weight control practices, and weight cycling among women in the Nurses' Health Study II.

OBJECTIVE: To assess the association of weight cycling with weight change, weight control practices, and bulimic behaviors. METHODS: A nested study of 2476 young and middle-aged women in the Nurses' Health Study II who provided information on intentional weight losses between 1989 and 1993. SAMPLE: In total, 224 women who were severe cyclers, 741 women who were mild cyclers, 967 age- and BMI-matched controls (noncyclers), and 544 women who did not weight cycle and maintained their weight between 1989 and 1993 completed a questionnaire in 2000-2001 assessing recent intentional weight losses, weight control practices, and weight concerns. RESULTS: After controlling for age and body mass index (BMI) in 1993, when weight cycling was initially assessed, mild cyclers gained an average of 6.7 pounds (lbs) more and severe cyclers gained approximately 10.3 lbs more than noncyclers between 1993 and 2001. Weight cyclers preferred to change their diet rather than to exercise to control their weight. Severe weight cyclers were less likely than noncyclers to use frequent exercise as a weight control strategy (odds ratio [OR]=0.8, 95% confidence interval (CI) 0.6-1.1). Cyclers were also more likely than noncyclers to engage in binge eating (mild cyclers: OR=1.8, 95% CI 1.4-2.4; and severe cyclers: OR=2.5, 95% CI 1.7-3.5). Independent of weight cycling status, age, and BMI, women who engaged in binge eating gained approximately 5 lbs more than their peers (P<0.001). CONCLUSIONS: Weight cycling was associated with greater weight gain, less physical activity, and a higher prevalence of binge eating. Low levels of activity and binge eating may be partially responsible for the large amount of weight regained by weight cyclers.

Adult↗
PubMed2004

Snack food intake does not predict weight change among children and adolescents.

OBJECTIVE: To assess whether intake of snack foods was associated with weight change among children and adolescents. METHODS: Prospective study of 8,203 girls and 6,774 boys, 9-14 y of age in 1996, in an ongoing cohort study who completed at least two questionnaires between 1996 and 1999. Intake of snack foods was assessed in 1996-1998 with a validated food frequency questionnaire designed specifically for children and adolescents. The outcome measure was change in age- and gender-specific z-score of body mass index (BMI). RESULTS: Boys consumed more snack foods than girls during the entire study period. After controlling for Tanner stage of development, age, height change, activity, and inactivity, there was no relation between intake of snack foods and subsequent changes in BMI z-score among the boys (beta=-0.004), but snack foods had a weak inverse association (beta=-0.007, P<0.05) with weight change among the girls. However, the results were confounded by dieting status, which had a significant positive independent association with BMI change. After controlling for dieting status and whether the mother was overweight, the association between servings per day of snack foods and subsequent changes in BMI z-score were not significant in either gender. DISCUSSION: Our results suggest that although snack foods may have low nutritional value, they were not an important independent determinant of weight gain among children and adolescents.

Adolescent↗
PubMed2004

Changes in intake of fruits and vegetables in relation to risk of obesity and weight gain among middle-aged women.

OBJECTIVE: To examine the changes in intake of fruits and vegetables in relation to risk of obesity and weight gain among middle-aged women. DESIGN: Prospective cohort study with 12 y of follow-up conducted in the Nurses' Health Study. SUBJECTS: A total of 74,063 female nurses aged 38-63 y, who were free of cardiovascular disease, cancer, and diabetes at baseline in 1984. MEASUREMENTS: Dietary information was collected using a validated food frequency questionnaire, and body weight and height were self-reported. RESULTS: During the 12-y follow-up, participants tended to gain weight with aging, but those with the largest increase in fruit and vegetable intake had a 24% of lower risk of becoming obese (BMI> or =30 kg/m2) compared with those who had the largest decrease in intake after adjustment for age, physical activity, smoking, total energy intake, and other lifestyle variables (relative risk (RR), 0.76; 95% confidence interval (CI), 0.69-0.86; P for trend <0.0001). For major weight gain (> or =25 kg), women with the largest increase in intake of fruits and vegetables had a 28% lower risk compared to those in the other extreme group (RR, 0.72; 95% CI, 0.55-0.93; P=0.01). Similar results were observed for changes in intake of fruits and vegetables when analyzed separately. CONCLUSIONS: Our findings suggest that increasing intake of fruits and vegetables may reduce long-term risk of obesity and weight gain among middle-aged women.

Adult↗
PubMed2003

Physical activity and risk of breast cancer in premenopausal women.

Physical activity appears to be inversely related to risk of breast cancer, yet the results remain inconsistent. To evaluate this relation among premenopausal women and examine variation in risk according to level of obesity and use of oral contraceptives (OCs), the authors examined data from the Nurses' Health Study II. During 10 years of follow-up, 849 cases of invasive premenopausal breast cancer were confirmed. Physical activity was assessed by self-report at baseline and during follow-up using a validated questionnaire. Total physical activity was unrelated to risk of breast cancer. Women engaging in >or=27 metabolic equivalent (MET)-h week(-1) had a multivariate-adjusted relative risk (RR) of 1.04 (95% confidence interval (CI) 0.82-1.33) compared to those in the <3 MET-h week(-1) category. Among women with a BMI >or=30 kg m(-2), we observed a significant positive dose-response relation (P=0.04). Activity was unrelated to breast cancer risk at lower levels of BMI. A test for interaction between activity and BMI (<30, >or=30 kg m(-2)) was statistically significant (P=0.02). Among current OC users, higher activity was associated with a non-significantly lower risk of breast cancer (RR=0.59, 95% CI 0.30-1.16 for >or=27 vs <9 MET-h week(-1), P for linear trend=0.14). These results show no overall association between physical activity and risk of breast cancer among premenopausal women, but suggest that the effect of physical activity could be substantially modified by the underlying degree of adiposity. The potential interactions between physical activity, adiposity, and current use of OCs require further study.

Adult↗
PubMed2003

Dietary intakes of vitamins A, C, and E and risk of melanoma in two cohorts of women.

Within the two Nurses' Health Study cohorts of US women, we examined whether higher intakes of vitamin C, vitamin E, retinol, or individual tocopherols or carotenoids are associated with a lower risk of melanoma. We confirmed 414 cases of invasive melanoma among over 162,000 Caucasian women aged 25-77 years during more than 1.6 million person-years of follow-up. Diet was measured every 4 years with a food frequency questionnaire and supplement use was reported every 2 years. Several measures of sun sensitivity were assessed and included in proportional hazards models. We found that vitamins A, C, E and their individual components were not associated with a lower risk of melanoma. Only retinol intake from foods plus supplements appeared protective within a subgroup of women who were otherwise at low risk based on nondietary factors (relative risk (RR)=0.39, 95% confidence interval (CI) 0.22-0.71 for >/=1,800 vs 400 microg day(-1), P for linear trend=0.01). Contrary to expectation, we observed higher risks of melanoma with greater intakes of vitamin C from food only (RR=1.43, 95% CI 1.01-2.00 for >/=175 vs <90 mg day(-1), P for linear trend=0.05) and a significant positive dose-response with frequency of orange juice consumption (P=0.008). Further research is needed to determine whether another component in foods such as orange juice may contribute to an increase in risk.

Adult↗
PubMed2003

Caffeine, postmenopausal estrogen, and risk of Parkinson's disease.

BACKGROUND: Men who regularly consume caffeinated drinks have a lower risk of PD than do nondrinkers, but this relation has not been found in women. Because this sex difference could be due to hormonal effects, the authors examined prospectively the risk of PD according to use of postmenopausal hormones and caffeine intake among participants in the Nurses' Health Study. METHODS: The study population comprised 77,713 women free of PD, stroke, or cancer at baseline, who were postmenopausal at baseline or reached menopause before the end of the study. During 18 years of follow-up the authors documented 154 cases of PD. RESULTS: Overall, the risk of PD was similar in women using hormones and women who never used hormones (relative risk 1.02, 95% CI 0.69 to 1.52). Use of hormones, however, was associated with a reduced risk of PD among women with low caffeine consumption (RR 0.39, 95% CI 0.13 to 1.17), and with increased risk among women with high caffeine consumption (RR 2.44, 95% CI 0.75 to 7.86; p for interaction = 0.01). Among hormone users, women consuming six or more cups of coffee per day had a fourfold higher risk of PD (RR 3.92, 95% CI 1.49 to 10.34; p = 0.006) than did women who never drink coffee. CONCLUSION: These results suggest that caffeine reduces the risk of PD among women who do not use postmenopausal hormones, but increases risk among hormone users. Clinical trials of caffeine or estrogens in women should avoid the combined use of these agents.

Adult↗
PubMed2003

Cholecystectomy and the risk for developing colorectal cancer and distal colorectal adenomas.

Earlier work describes a modest association between cholecystectomy and the risk of colorectal cancer. We conducted a prospective study of 85 184 women, 36-61 years old, who had no history of cancer to evaluate whether known risk factors for colorectal cancer, including dietary history, that have not been controlled for in previous analyses can help explain the observed association. During 16 years of follow-up, 877 cases of colorectal cancer were documented and 1452 women who underwent endoscopy during the follow-up time were diagnosed with distal adenomas. After adjustment for age and other known or suspected risk factors, we found a significant, positive association between cholecystectomy and the risk of colorectal cancer (multivariate relative risk RR 1.21, 95% CI 1.01-1.46). The risk was highest for cancers of the proximal colon (RR 1.34, 95% CI 0.97-1.88) and the rectum (RR 1.58, 95% CI 1.05-2.36). However, we did not observe a significant association between cholecystectomy and distal colorectal adenomas. In this large prospective cohort study, a history of cholecystectomy appears to increase modestly the risk of colorectal cancer, even after adjustment for other colorectal cancer risk factors.

Adenoma↗
PubMed2003

Association between fruit and vegetable intake and change in body mass index among a large sample of children and adolescents in the United States.

OBJECTIVE: To assess whether intake of fruits and vegetables was associated with change in body mass index (BMI) among a large sample of children and adolescents in the United States. DESIGN: Prospective cohort study of children and adolescent who were 9-14 y of age in 1996, when the study began. SUBJECTS: The subjects included 8203 girls and 6715 boys in an ongoing cohort study who completed at least two questionnaires between 1996 and 1999. MEASUREMENTS: Fruit and vegetable intake was assessed in 1996-1998 with a validated food frequency questionnaire designed specifically for children and adolescents. The outcome measure was change in age- and gender-specific z-score of BMI (kg/m(2)). Self-reported weight and height, which were used to calculate BMI, were collected annually from 1996 to 1999. RESULTS: During 3 years of follow-up, annual changes in BMI were slightly greater among the boys than the girls. After controlling for Tanner stage of development, age, height change, activity and inactivity, which are known or suspected predictors of change in BMI, among the girls there was no relation between intake of fruits, fruit juice, or vegetables (alone or combined) and subsequent changes in BMI z-score. Among the boys, intake of fruit and fruit juice was not predictive of changes in BMI, however, vegetables intake was inversely related to changes in BMI z-score (beta per serving=-0.003). However, after adjusting for caloric intake, the magnitude of the effect was diminished and no longer significant. CONCLUSION: Our results suggest that the recommendation for consumption of fruits and vegetables may be well founded, but should not be based on a beneficial effect on weight regulation.

Adolescent↗
PubMed2003

Longitudinal study of skipping breakfast and weight change in adolescents.

BACKGROUND: Several cross-sectional studies reported that heavier children eat breakfast less often. However, no longitudinal studies have addressed whether skipping breakfast leads to excessive weight gain. OBJECTIVE: To investigate whether skipping breakfast was prospectively associated with changes in body fatness. METHODS: A cohort of >14000 boys and girls from all over the US, 9- to 14-y-old in 1996, returned annual mailed questionnaires (1996-1999) for the Growing Up Today Study. We analyzed change in body mass index (BMI; kg/m(2)) over three 1-y periods among children who reported breakfast frequency. RESULTS: Children who reported that they never eat breakfast had lower energy intakes than those who eat breakfast nearly every day. Children who were more physically active reported higher energy intakes, as did those who reported more time watching television/videos and playing videogames. Like previous studies, skipping breakfast was associated with overweight, cross-sectionally. However, overweight children who never ate breakfast lost BMI over the following year compared to overweight children who ate breakfast nearly every day (boys: -0.66 kg/m(2) (s.e.=0.22); girls: -0.50 kg/m(2) (s.e.=0.14)). But normal weight children who never ate breakfast gained weight relative to peers who ate breakfast nearly every day (boys: +0.21 kg/m(2) (s.e.=0.13); girls: +0.08 kg/m(2) (s.e.=0.05)). Breakfast frequency was positively correlated with self-reported quality of schoolwork. CONCLUSIONS: Overweight children who never eat breakfast may lose body fat, but normal weight children do not. Since numerous studies link skipping breakfast to poorer academics, children should be encouraged to eat breakfast.

Achievement↗
PubMed2002

MAOB intron 13 and COMT codon 158 polymorphisms, cigarette smoking, and the risk of PD.

BACKGROUND: A polymorphism (G to A transition) in intron 13 of the mitochondrial enzyme monoamine oxidase B (MAOB) gene may modify, alone or by interacting with the catechol-O-methyltransferase (COMT(LL)) genotype (low enzymatic activity), the risk of idiopathic PD. Also, the association between never smoking and PD risk may be present only in people with the MAOB G allele. METHODS: The authors studied two ongoing prospective cohorts-the Nurses' Health Study (121,700 women aged 30 to 55 in 1976) and the Health Professionals' Follow-up Study (51,529 men aged 40 to 75 in 1986). They identified new PD cases through 1996, selected random control subjects matched on age and study cohort, and obtained DNA samples from blood or buccal smears from 85% of the eligible cases and 84% of the control subjects. They included genotypes from 214 cases and 449 control subjects, all Caucasian. RESULTS: The odds ratio of PD was 1.2 (95% CI 0.9, 1.7) for MAOB genotypes G/GG/GA compared with genotypes A/AA, and 1.1 (0.7, 1.8) for COMT genotypes LL compared with HH. The odds ratio (95% CI) was 1.7 (0.7, 3.9) for those with MAOB G/GG and COMT(LL) genotypes compared with those with MAOB A/AA and COMT(HH). There was a strong association between never smoking and PD risk in all groups defined by MAOB and COMT genotypes. CONCLUSION: The findings do not support a major role of the MAOB intron 13 polymorphism in the development of PD, either by itself or by interacting with smoking.

Adult↗
PubMed2002

Gallstones, cholecystectomy, and the risk for developing pancreatic cancer.

We examined the relation between gallstones, cholecystectomy, and the development of pancreatic cancer in the Nurses' Health Study and the Health Professionals Follow-up Study. Among 104,856 women and 48,928 men without cancer at baseline, we documented 349 cases of pancreatic cancer during up to 16 years of follow-up. Participants were classified according to a history of gallstones or cholecystectomy. The age-adjusted relative risk of pancreatic cancer following cholecystectomy or diagnosis of gallstones was 1.31 (95% CI, 0.93-1.83). However, adjustment for other pancreatic cancer risk factors attenuated the association (RR=1.11, 95% CI, 0.78-1.56); this risk did not increase with increasing time following cholecystectomy or gallstones. Gallstones or cholecystectomy do not appear to be significant risk factors for pancreatic cancer.

Adult↗
PubMed2002

A prospective study of the relationship between body mass index and cataract extraction among US women and men.

BACKGROUND: Obesity may influence several physiologic processes involved in cataract formation such as oxidative stress, glycosylation and osmotic stress. OBJECTIVE: To examine the association between increased body mass index (BMI) and the incidence of cataract extraction. DESIGN AND SETTING: The Nurses' Health Study and the Health Professionals Follow-up Study, both prospective cohort studies of US women and men. SUBJECTS: A total of 87 682 women and 45 549 men aged 45 y and older who did not have diagnosed cataract or cancer at baseline (1980 for women, 1986 for men). MEASUREMENTS: Cataract extractions occurring between baseline and 1996, confirmed by medical records. RESULTS: During 16 y of follow-up in the women, and 10 y in the men, (1 097 997 person-y), 4430 incident cases were documented. Compared to participants with BMI less than 23 kg/m(2), those with BMI greater than or equal to 30 kg/m(2) had 36% higher risk of any type of cataract (pooled multivariate relative risk (RR), 1.36; 95% CI, 1.23-1.49) after adjusting for smoking, age and lutein/zeaxanthin intake. The association was strongest for posterior subcapsular (PSC) cataract (pooled multivariate RR, 1.99; 95% CI, 1.55-2.55). With adjustment for diabetes, the RR of obesity associated with posterior subcapsular cataract was 1.68 (95% CI, 1.30-2.17). Obesity was not significantly associated with nuclear cataract. CONCLUSION: Obesity increases the risk of developing cataract overall, and of PSC cataract in particular; the etiology of PSC cataract may be mediated at least in part by glucose intolerance and insulin resistance, even in the absence of clinical diabetes.

Aged↗