Use of iDXA spine scans to evaluate total and visceral abdominal fat.

OBJECTIVES: Abdominal fat may be a better predictor than body mass index (BMI) for risk of metabolically-related diseases, such as diabetes, cardiovascular disease, and some cancers. We sought to validate the percent fat reported on dual energy X-ray absorptiometry (DXA) regional spine scans (spine fat fraction, SFF) against abdominal fat obtained from total body scans using the iDXA machine (General Electric, Madison, WI), as previously done on the Prodigy model. METHODS: Total body scans and regional spine scans were completed on the same day (N = 50). In alignment with the Prodigy-based study, the following regions of interest (ROI) were assessed from total body scans and compared to the SFF from regional spine scans: total abdominal fat at (1) lumbar vertebrae L2-L4 and (2) L2-Iliac Crest (L2-IC); (3) total trunk fat; and (4) visceral fat in the android region. Separate linear regression models were used to predict each total body scan ROI from SFF; models were validated by bootstrapping. RESULTS: The sample was 84% female, a mean age of 38.5 ± 17.4 years, and mean BMI of 23.0 ± 3.8 kg/m2 . The SFF, adjusted for BMI, predicted L2-L4 and L2-IC total abdominal fat (%; Adj. R2 : 0.90) and total trunk fat (%; Adj. R2 : 0.88) well; visceral fat (%) adjusted R2 was 0.83. Linear regression models adjusted for additional participant characteristics resulted in similar adjusted R2 values. CONCLUSIONS: This replication of the strong correlation between SFF and abdominal fat measures on the iDXA in a new population confirms the previous Prodigy model findings and improves generalizability.

Visceral adiposity and cancer survival: a review of imaging studies.

Although obesity is a well-known risk factor for cancer, the association between obesity and cancer survival remains controversial. This is partially due to the inability of conventional obesity measures to directly assess adiposity or adipose tissue distribution. As a metabolic organ, visceral adipose tissue (VAT) secrets a variety of cytokines and cytokine-like factors, potentially affecting cancer survival. The objective of this review was to investigate the influence of imaging-assessed VAT on cancer survival. A total of 22 studies assessing the impact of visceral adiposity on survival were included. Negative associations between VAT and survival were more frequently observed among patients with colorectal (four of six studies) and pancreatic (three of five studies) cancers, compared to higher VAT predicting longer survival in most studies of renal cell carcinoma patients (four of five studies). Methodological limitations, including unstandardised VAT measurement methods, lack of other body composition measurement (i.e. muscle mass), small sample size and heterogeneous cohort characteristics, may explain controversial findings related to the impact of VAT on cancer survival.

Dual energy X-ray absorptiometry spine scans to determine abdominal fat in postmenopausal women.

Body composition may be a better predictor of chronic disease risk than body mass index (BMI) in older populations. OBJECTIVES: We sought to validate spine fat fraction (%) from dual energy X-ray absorptiometry (DXA) spine scans as a proxy for total abdominal fat. METHODS: Total body DXA scan abdominal fat regions of interest (ROI) that have been previously validated by magnetic resonance imaging were assessed among healthy, postmenopausal women who also had antero-posterior spine scans (n = 103). ROIs were (1) lumbar vertebrae L2-L4 and (2) L2-Iliac Crest (L2-IC), manually selected by two independent raters, and (3) trunk, auto-selected by DXA software. Intra-class correlation coefficients evaluated intra and inter-rater reliability on a random subset (N = 25). Linear regression models, validated by bootstrapping, assessed the relationship between spine fat fraction (%) and total abdominal fat (%) ROIs. RESULTS: Mean age, BMI, and total body fat were 66.1 ± 4.8 y, 25.8 ± 3.8 kg/m2 and 40.0 ± 6.6%, respectively. There were no significant differences within or between raters. Linear regression models adjusted for several participant and scan characteristics were equivalent to using only BMI and spine fat fraction. The model predicted L2-L4 (Adj. R2 : 0.83) and L2-IC (Adj. R2 : 0.84) abdominal fat (%) well; the adjusted R2 for trunk fat (%) was 0.78. Model validation demonstrated minimal over-fitting (Adj. R2 : 0.82, 0.83, and 0.77 for L2-L4, L2-IC, and trunk fat, respectively). CONCLUSIONS: The strong correlation between spine fat fraction and DXA abdominal fat measures make it suitable for further development in postmenopausal chronic disease risk prediction models. Am. J. Hum. Biol. 28:918-926, 2016. © 2016Wiley Periodicals, Inc.

Habitual tea consumption and risk of osteoporosis: a prospective study in the women's health initiative observational cohort.

The purpose of this study was to prospectively investigate associations of habitual drinking of regular tea with bone mineral density and fracture risk. Study participants were a multiethnic postmenopausal cohort (n = 91,465) from the nationwide Women's Health Initiative Observational Study. These women were recruited in the United States and aged 50-79 years at the time of enrollment (1994-1998). The average follow-up time was 4.1 years. Habitual consumption of regular tea was assessed with a structured questionnaire at baseline. Clinical fractures during the follow-up were reported in questionnaires, and hip fractures were further confirmed by reviewing medical records. Bone mineral density measurements were conducted among a subgroup of women (n = 4,979) at three Women's Health Initiative bone mineral density centers using dual-energy x-ray absorptiometry. Multivariate analyses suggested a positive trend of increased total body bone mineral density with tea drinking (p < 0.05). However, results from the Cox proportional hazard models did not show any significant association between tea drinking and the risk of fractures at the hip and forearm/wrist. In conclusion, the results from this study indicate that the effect of habitual tea drinking on bone density is small and does not significantly alter the risk of fractures among the US postmenopausal population.

Correlates of serum alpha- and gamma-tocopherol in the Women's Health Initiative.

PURPOSE: There is increasing evidence that vitamin E (primarily alpha- and gamma-tocopherol) may reduce the risk of cardiovascular disease and some cancers, therefore it is important to understand factors that influence blood levels. METHODS: The correlates of serum alpha- and gamma-tocopherol were investigated among participants in the Women's Health Initiative (WHI), a 40-site disease prevention trial. Subjects were 1047 postmenopausal women aged 50-79 years, who provided fasting blood specimens and detailed information on diet, supplement use, and other factors at entry to the study (1994-96). RESULTS: Total serum cholesterol and triglycerides were highly correlated with serum alpha- and gamma-tocopherol concentrations and were controlled for in all analyses along with age, ethnicity and body mass index (BMI). Alpha and gamma-tocopherol were strongly negatively correlated (partial r = -0.69). The strongest predictor of serum tocopherols was average daily intake of vitamin E from supplements (partial r = 0.60 for alpha, r = -0.54 for gamma). Other factors associated with increased alpha- and/or decreased gamma-tocopherol concentrations were serum retinol and carotenoids, supplemental vitamin C, alpha-tocopherol intake from food, dietary fiber, and Hispanic ethnicity. Factors associated with lower alpha- and/or higher gamma-tocopherol concentrations included gamma-tocopherol intake from food, total fat intake, and BMI. Age, income, hormone use, and geographic location were "spuriously" associated with serum tocopherol levels through their association with supplement use, i.e., there was no such association among the subset of women not taking supplements. CONCLUSIONS: Vitamin E intake from supplements and BMI are the major independent predictors of serum tocopherol levels in women, whereas dietary factors only play a small role.

Reduction in fat intake is not associated with weight loss in most women after breast cancer diagnosis: evidence from a randomized controlled trial.

BACKGROUND: A reduction in dietary fat intake has been suggested as a method to promote weight loss in women at risk for breast cancer recurrence. METHODS: Weight change in response to diet intervention was examined in 1010 women who had completed treatment for Stage I, Stage II, or Stage IIIA (American Joint Committee on Cancer staging system) primary operable breast cancer during their first year of participation in a randomized, controlled, diet intervention trial to reduce risk of recurrence. Diet intervention was performed by telephone counseling and promoted a low fat diet that also was high in fiber, vegetables, and fruit. The comparison group was provided with general dietary guidelines to reduce disease risk. Multiple linear regression models were used to examine the relations among demographic and personal characteristics, changes in diet composition and exercise level, and change in body weight or body mass index. RESULTS: The average weight change in the 1-year period was 0.04 kg for the intervention group and 0.46 kg for the comparison group. For the total group, body weight was stable (+/- 5% baseline weight) for 743 women (74%), whereas 114 (11%) lost weight, and 153 (15%) gained weight. These distributions were similar in the two study groups inclusive of all study participants and for only those women with a baseline body mass index of > or = 25 kg/m2. Initial body mass index and changes in fiber and vegetable intakes, but not change in percent of energy obtained from fat, were associated independently with change in weight or body mass index. CONCLUSIONS: For most women at risk for breast cancer recurrence, diet intervention to promote a reduction in fat intake was not associated with significant weight loss. Testing the effect of a substantial change in diet composition on risk for breast cancer recurrence is unlikely to be confounded by weight loss in subjects who were the recipients of intensive intervention efforts.

Low-energy reporting in women at risk for breast cancer recurrence. Women's Healthy Eating and Living Group.

This study examined the extent of low-energy reporting and its relationship with demographic and lifestyle factors in women previously treated for breast cancer. This study used data from a large multisite clinical trial testing the efficacy of a dietary intervention to reduce risk for breast cancer recurrence (Women's Healthy Eating and Living Study). Using the Schofield equation to estimate energy needs and four 24-h dietary recalls to estimate energy intakes, we identified women who reported lower than expected energy intakes using criteria developed by G. R. Goldberg et al. (Eur. J. Clin. Nutr., 45: 569-581, 1991). We examined data from 1137 women diagnosed with stage I, stage II, or stage IIIA primary, operable breast cancer. Women were 18-70 years of age at diagnosis and were enrolled in the Women's Healthy Eating and Living Study between August 19, 1995, and April 1, 1998, within 4 years after diagnosis. The Goldberg criteria classified about one-quarter (25.6%) as low-energy reporters (LERs) and 10.8% as very LERs. Women who had a body mass index >30 were almost twice (odds ratio, 1.95) as likely to be LERs. Women with a history of weight gain or weight fluctuations were one and a half times as likely (odds ratio, 1.55) to be LERs as those who were weight stable or weight losers. Age, ethnicity, alcohol intake, supplement use, and exercise level were also related to LER. Characteristics (such as body mass index, age, ethnicity, and weight history) that are associated with low-energy reporting in this group of cancer survivors are similar to those observed in other populations and might affect observed diet and breast cancer associations in epidemiological studies.

Interplay between dietary inducers of GST and the GSTM-1 genotype in colon cancer.

The purpose of this study is to determine if cruciferous vegetables and coffee, two dietary inducers of glutatione-S-transferases, interact with GSTM-1 genotype to alter risk of colon cancer. Data were available on 1579 incident cases of adenocarcinoma of the colon and 1898 population-based controls. Intake of cruciferous vegetables, specific types of cruciferous vegetable, and coffee were not associated with colon cancer; GSTM-1 genotype did not modify these associations. However, age at diagnosis and cigarette smoking appeared to be important effect modifiers of the associations between GSTM-1, cruciferous vegetables and colon cancer. Among GSTM-1 null individuals, <55 years at diagnosis, we observed an inverse association between colon cancer and high levels of cruciferous vegetable intake relative to people who did not eat cruciferous vegetables (ORs 0.23 95% CI 0.10-0.54); broccoli was the cruciferous vegetable associated with the strongest inverse association (OR 0.30 95% CI 0.13-0.70). Among younger individuals who were GSTM-1 present (relative to those with GSTM-1 null), we observed an inverse association with colon cancer regardless of level of cruciferous vegetable intake (OR 0.74 95% CI 0.30-1.79 for no intake; OR 0.44 95% CI 0.21-0.92 for <4 servings/week; and OR 0. 44 95% CI 0.19-0.99 for >/=4 servings/week). These associations were further modified by cigarette smoking. People <65 years of age who smoked had a greater reduction in risk of colon cancer from consumption of cruciferous vegetables than non-smokers at the same age. In summary, although cruciferous vegetables do not appear to modify colon cancer risk in the total population, there are subgroups of the population for whom these vegetables may be important. These subgroups are defined mostly by age and smoking status.

Western diet, family history of colorectal cancer, NAT2, GSTM-1 and risk of colon cancer.

OBJECTIVE: In this study we examine the combined effects of Western diet, age at diagnosis, and genetic susceptibility. METHODS: We use data collected as part of an incident case-control study of colon cancer. Family history of colorectal cancer, N-acetyltransferase (NAT2), and glutathione-S-transferase (GSTM-1) are studied with Western diet and age at diagnosis. RESULTS: A significant interaction between age at time of diagnosis, Western dietary pattern, and family history of colorectal cancer (p for interaction = 0.03) was detected. Those with a family history of colorectal cancer who ate a predominantly Western diet were at increased risk of colon cancer (OR 14.0, 95% CI 3.9-50.1 for < or = 55 years; OR 7.7, 95% CI 2.0-29.1 for 56-66 years; OR 1.6, 95% CI 0.8-3.2 for > or = 67 years) compared to those without a family history of colorectal cancer and low levels of a Western diet. Associations with the Western diet were stronger than individual components of the dietary pattern. Neither NAT2 nor GSTM-1 showed significant interaction with Western diet. CONCLUSION: The extent to which diet comprising a Western dietary pattern influences risk of colon cancer is dependent on age. This dietary pattern also appears to modulate the colon cancer risk associated with a family history of colon cancer.

Lifestyle and colon cancer: an assessment of factors associated with risk.

Studies of the etiology of colon cancer indicate that it is strongly associated with diet and lifestyle factors. The authors use data from a population-based study conducted in northern California, Utah, and Minnesota in 1991-1995 to determine lifestyle patterns and their association with colon cancer. Data obtained from 1,993 cases and 2,410 controls were grouped by using factor analyses to describe various aspects of lifestyle patterns. The first five lifestyle patterns for both men and women loaded heavily on dietary variables and were labeled: "Western," "moderation," "calcium/low-fat dairy;" "meat and mutagens," and "nibblers, smoking, and coffee." Other important lifestyle patterns that emerged were labeled "body size," "medication and supplementation," "alcohol," and "physical activity." Among both men and women, the lifestyle characterized by high levels of physical activity was the most marked lifestyle associated with colon cancer (odds ratios = 0.42, 95% confidence interval: 0.32, 0.55 and odds ratio = 0.52, 95% confidence interval: 0.39, 0.69, for men and women, respectively) followed by medication and supplementation (odds ratio = 1.68, 95% confidence interval: 1.29, 2.18 and odds ratio = 1.63, 95% CI 1.23, 2.16, respectively). Other lifestyles that were associated with colon cancer were the Western lifestyle, the lifestyle characterized by large body size, and the one characterized by calcium and low-fat dairy. Different lifestyle patterns appear to have age- and tumor site-specific associations.

Factors associated with weight gain in women after diagnosis of breast cancer. Women's Healthy Eating and Living Study Group.

OBJECTIVE: To identify the factors associated with weight gain after diagnosis of breast cancer in a heterogeneous population of women. DESIGN: Descriptive cross-sectional study. SUBJECTS: 1,116 patients who had been diagnosed with stage I, stage II, or stage IIIA primary, operable breast cancer within the previous 4 years. Patients were recruited during enrollment into a diet intervention trial to reduce risk for breast cancer recurrence. Analysis Demographic data, weight history, and physical activity information obtained by questionnaire and medical information obtained by chart review; dietary assessment based on four 24-hour dietary recalls collected by telephone. Associations between weight change after the diagnosis of breast cancer and prediction variables were examined using univariate and multiple linear regression analyses. RESULTS: Overall, 60% of the subjects reported weight gain, 26% reported weight loss, and 14% reported no change in weight after the diagnosis of breast cancer. The overall mean weight change was a gain of 2.7 kg (6 lb). Factors positively and independently associated with weight gain were time since diagnosis of breast cancer, adjuvant chemotherapy, African-American ethnicity, current energy intake, and postmenopausal status at time of study entry. Factors inversely and independently associated with weight gain were prediagnosis body mass index, age at diagnosis, education level, and exercise index score. APPLICATIONS: Higher energy intake and lower level of physical activity are independently associated with increased risk for weight gain after the diagnosis of breast cancer. Strategies to modify these behaviors are likely to influence the long-term pattern of weight change.

Intake of fluids and methylxanthine-containing beverages: association with colon cancer.

Although diet and its constituents have been studied extensively as risk factors for colon cancer, much less is known about how specific types of fluid influence colon cancer risk. In this study, we explored associations between colon cancer and total fluids, water and methylxanthine-containing beverages such as coffee, tea and cola; data were obtained from 1,993 incident cases of colon cancer and 2,410 population-based controls living in California, Utah and Minnesota. Our primary objective was to determine the influence on associations of amount consumed, confounding and effect modification. We observed few important differences between colon cancer and fluid consumption for all subjects combined. Among men, low levels of coffee intake were associated with an increased risk of colon cancer relative to non-consumers of coffee (OR 1.32, 95% CI 1.02-1.67), while at high levels of consumption, an inverse association was observed (OR 0.81, 95% CI 0.58-1.12). The observed associations were only slightly influenced by consumption of water or other potential confounding factors, but changing the referent group to those consuming one cup of coffee per day or less resulted in a stronger association and a more significant inverse linear trend (OR 0.71, 95% CI 0.53-0.96). The associations with coffee and caffeine- and methylxanthine-containing beverages were strongest for proximal tumors in men. High levels of water intake, however, were protective for distal tumors (OR for men 0.68, 95% CI 0.49-0.96). Assessment of the impact of smoking on associations between colon cancer and coffee showed a significant interaction between smoking and coffee for both men and women.

Meat consumption, genetic susceptibility, and colon cancer risk: a United States multicenter case-control study.

Meat consumption may especially increase risk of colon cancer when the meat is prepared at high temperatures and consumed by subjects with an inherited susceptibility to well-done meat. In this United States case-control study, the association between meat consumption, genetic susceptibility, and colon cancer risk was studied. Meat consumption data were available from a detailed diet history questionnaire and from questions about methods of preparation. Molecular variants in the carcinogen-metabolizing genes NAT2 and GSTM1 were determined in DNA extracted from WBCs. A total of 1542 cases and 1860 population-based controls were included in these analyses. The amount of red and white meat consumed was not associated with overall colon cancer risk. Processed meat consumption was weakly positively associated with colon cancer risk in men only (odds ratio for highest versus lowest quintile of intake = 1.4, 95% confidence interval = 1.0-1.9). The frequency of fried, broiled, baked, or barbecued meat, use of drippings, and doneness of meat were not significantly associated with risk. The Mutagen Index, as an estimate for exposure to mutagenic or carcinogenic substances, was slightly positively associated with colon cancer risk in men (odds ratio = 1.3, 95% confidence interval = 1.0-1.7). No significant associations with colon cancer risk were observed for different NAT2 and GSTM1 gene variants. The observed associations with processed meat and the Mutagen Index were strongest for those with the intermediate or rapid NAT2 acetylator phenotype. Associations were not markedly influenced by lack of the GSTM1 gene. This study provides little support for an association between meat consumption and colon cancer risk but does provide some, albeit not strong, evidence for a modifying effect of molecular variants of the NAT2 gene.

Does nutritionist review of a self-administered food frequency questionnaire improve data quality?

OBJECTIVE: This study sought to evaluate the benefit of utilizing a nutritionist review of a self-administered food frequency questionnaire (FFQ), to determine whether accuracy could be improved beyond that produced by the self-administered questionnaire alone. DESIGN: Participants randomized into a dietary intervention trial completed both a FFQ and a 4-day food record (FR) at baseline before entry into the intervention. The FFQ was self-administered, photocopied and then reviewed by a nutritionist who used additional probes to help complete the questionnaire. Both the versions before nutritionist review and after nutritionist review - were individually compared on specific nutrients to the FR by means, correlations and per cent agreement into quintiles. SETTINGS AND SUBJECTS: Three hundred and twenty-four people, a subset of participants from the Polyp Prevention Trial - a randomized controlled trial examining the effect of a low-fat, high-fibre, high fruit and vegetable dietary pattern on the recurrence of adenomatous polyps - were recruited from clinical centres at the University of Utah, University of Buffalo, Memorial Sloan Kettering Cancer Center in New York and Kaiser Permanente Medical Program in Oakland. RESULTS: Reviewing the FFQ increased correlations with the FR for every nutrient, and per cent agreement into quintiles for all nutrients except calcium. Energy was underestimated in both versions of the FFQ but to a lesser degree in the version with review. CONCLUSIONS: One must further evaluate whether the increases seen with nutritionist review of the FFQ will enhance our ability to predict diet-disease relationships and whether it is cost-effective when participant burden and money spent utilizing trained personnel are considered.

Comparison of the Block and the Willett self-administered semiquantitative food frequency questionnaires with an interviewer-administered dietary history.

The performances of two commonly used diet instruments, the Block and the Willett food frequency questionnaires, were compared with a longer, interviewer-administered diet history. Participants in a case-control study on diet and colon cancer were interviewed between 1990 and 1994 in northern California, Utah, and Minnesota by trained nutritionists using a validated diet history. Two separate subsamples of participants were asked to complete either the Block or the Willett questionnaire exactly 5 days after they completed the original diet history. Data were analyzed separately by subsample comparing either the Block or the Willett questionnaire with the original diet history by using means, correlations, quintile agreement, and odds ratios for the relation between several nutrients and colon cancer. The Block and the Willett questionnaires generally provided lower absolute intake estimates than did the original diet history; however, the Block questionnaire underestimated more than did that by Willett. Both correlations and quintile agreement were slightly better for the Willett questionnaire than for that by Block when compared with the original diet history. In general, point estimates obtained from either the Block or the Willett questionnaire fell within the confidence intervals of the estimates of the odds ratios obtained from the original diet history, and no real difference in significance levels appeared. Although the Block and Willett questionnaires differed slightly from each other and from our original diet history in estimating absolute nutrients and ranking or classifying individuals, they were very similar in their ability to predict disease outcome.

Risk of colon cancer associated with a family history of cancer or colorectal polyps: the diet, activity, and reproduction in colon cancer study.

The Diet, Activity, and Reproduction in Colon Cancer (DARCC) study is a large, multi-center case-control study of colon cancer. We examined family histories of cancer among first-degree relatives obtained by computer-assisted in-person interviews from the DARCC to study the impact of family histories of several cancers and colorectal polyps on colon cancer risk. We examined familial cancer risks both by treating a family history of polyps or cancer as a covariate in a logistic regression model, and by comparing cancer or polyp incidence among relatives of cases to incidence among relatives of controls in a proportional hazards model. There were few differences between the odds ratios (OR) or confidence intervals (CI) generated from logistic regression models and the hazard rate ratios (HRR) generated from the proportional hazards models. Overall, the OR of colon cancer among subjects with a family history of colorectal cancer was 1.77. There were only minor differences in risk by sex, age and subsite. A family history of colorectal polyps also increased risk by about the same amount as a family history of colorectal cancer. The increased risk associated with a family history of polyps did not appear to decrease with age.

Eating patterns and risk of colon cancer.

Colon cancer has been associated with several nutrients and foods. The authors used data from a population-based study conducted in Northern California, Utah, and Minnesota to examine associations between dietary eating patterns and risk of developing colon cancer. Through factor analysis, detailed dietary intake data obtained from 1,993 cases (diagnosed in 1991-1994) and 2,410 controls were grouped into factors that were evaluated for relations with lifestyle characteristics and colon cancer risk. Several dietary patterns emerged. The dietary patterns with the most variation were labeled "Western," "prudent," "high fat/sugar dairy," "substituters," and "drinkers." The "Western" dietary pattern was associated with a higher body mass index and a greater intake of total energy and dietary cholesterol. The "prudent" pattern was associated with higher levels of vigorous leisure time physical activity, smaller body size, and higher intakes of dietary fiber and folate. Persons who had high scores on the "drinker" pattern were also more likely to smoke cigarettes. The "Western" dietary pattern was associated with an increased risk of colon cancer in both men and women. The association was strongest among people diagnosed prior to age 67 years (for men, odds ratio (OR)=1.96, 95% confidence interval (CI) 1.22-3.15; for women, OR=2.02, 95% CI 1.21-3.36) and among men with distal tumors (OR=2.25, 95% CI 1.47-3.46). The "prudent" diet was protective, with the strongest associations being observed among people diagnosed prior to age 67 years (men: OR=0.63, 95% CI 0.43-0.92; women: OR=0.58, 95% CI 0.38-0.87); associations with this dietary pattern were also strong among persons with proximal tumors (men: OR=0.55, 95% CI 0.38-0.80; women: OR=0.64, 95% CI 0.45-0.92). Although "substituters" (people who substituted low fat dairy products for high fat dairy products, margarine for butter, poultry for red meat, and whole grains for refined grains) were at reduced risk of colon cancer, the reduction in risk was not statistically significant. These data support the hypothesis that overall dietary intake pattern is associated with colon cancer, and that the dietary pattern associated with the greatest increase in risk is the one which typifies a Western-style diet.

Body size and the risk of colon cancer in a large case-control study.

OBJECTIVE: To investigate the risks of height, weight and body fat distribution associated with colon cancer in subcategories of gender, age and site in the colon. Interaction with family history of colorectal cancer is also examined. DESIGN: Case-control study of diet, anthropometry and colon cancer risk. SUBJECTS: Nineteen hundred and eighty-three colon cancer cases (age 30-79 y) and 2400 age and gender matched population controls. MEASUREMENTS: Height, weight and waist and hip circumferences were obtained by trained interviewers. Body Mass Index (BMI) and Waist-Hip Ratio (WHR) were calculated. RESULTS: Of all anthropometric measurements examined, only BMI was consistently associated with an increased risk of colon cancer. The test for trend for BMI was significant for men and women overall and for the majority of subgroups examined. In younger persons those with a family history of colorectal cancer had a greater risk of colon cancer associated with BMI (Men odds ratio (OR) = 7.76, 95% confidence interval (CI) 2.60, 23.1; Women OR = 4.85, 95% CI 2.33, 10.12) comparing the third tertile to the first, than those with no family history (Men OR = 1.70, 95% CI 1.25, 2.32; Women OR = 1.53, 95% CI 1.22, 1.92). WHR, after controlling for BMI was not associated with colon cancer in men, and was associated with a slight increase in women (primarily in those with distal tumors). CONCLUSION: This study contributes to mounting evidence that excess weight is associated with an increased risk of colon cancer.

Performance of a shortened telephone-administered version of a quantitative food frequency questionnaire.

PURPOSE: We evaluated the performance of a telephone-administered food frequency questionnaire in a study of 190 men and women, 30-79 years of age, who participated as controls in a study of colon cancer. METHODS: The telephone version of the questionnaire was modified from a longer food frequency questionnaire originally administered in person to each of the participants. One month later, the telephone questionnaire was administered to a subgroup of 190 participants and readministered to 169 members of the subgroup two weeks later to assess the reproducibility and comparative validity of the instrument. RESULTS: The unadjusted correlation for energy between the original in-person full food frequency questionnaire and the abbreviated telephone version was 0.69. The median energy intake from the telephone version was 17% lower in men and 23% lower in women. The energy and sex-adjusted correlation coefficients for other nutrients ranged from 0.45 for vitamin E to 0.78 for fiber. The intraclass correlation coefficients to measure reproducibility ranged from 0.62 for animal protein to 0.83 for folate. CONCLUSIONS: These data indicate that this brief, telephone-administered questionnaire is reproducible and provides a ranking of nutrient intake comparable to that provided by a full in-person interview.

Dietary sugar and colon cancer.

It has been hypothesized that levels of triglycerides, glucose, and insulin are associated with risk of colon cancer and that diets high in simple sugars increase risk of colon cancer because of their impact on these factors. Limited epidemiological evidence supports the association between simple carbohydrates and risk of colon cancer. Using data from a population-based case-control study (n = 1993 cases and 2410 controls), we examined the associations between dietary sugars, foods containing high level of sugars, and dietary glycemic index (GI) and colon cancer. A dietary GI was developed to estimate metabolic response to a diet that may increase plasma glucose levels. Dietary data were obtained using a validated diet history questionnaire. High levels of sucrose intake were associated with increased risk of colon cancer among younger men [odds ratio (OR) for highest quintile relative to lowest, 1.59; 95% confidence interval (CI), 1.07-2.37]. There was also a trend of increasing colon cancer risk associated with a higher sucrose:dietary ratio for proximal tumors in both men and women. Individuals with proximal tumors who consumed a diet ranked as having a high GI were at increased risk (for men, comparing highest quintile to lowest quintile: OR, 1.58; 95% CI, 1.06-2.36; P trend 0.04; for women: OR, 1.72; 95% CI, 1.11-2.67; P trend 0.04). Those at greatest risk from a high dietary GI were those who were sedentary (for men, relative to those who were most active and had a low-GI diet: OR, 3.46; 95% CI, 1.78-6.70; for women: OR, 2.00; 95% CI, 0.98-4.07). We also observed that people who had a high sucrose: dietary fiber ration and who also were sedentary and had a large body mass index were at increased risk (OR, 4.58; 95% CI, 2.33-8.98) relative to those who had a low sucrose:dietary fiber ratio, were active, and had low body mass indices. These findings support previous reports that dietary sugars, especially diet high in simple carbohydrates relative to complex carbohydrates, increase risk of colon cancer, possibly through their impact on plasma glucose levels.