Timing of HPV16-E6 antibody seroconversion before OPSCC: findings from the HPVC3 consortium.

BACKGROUND: Human papillomavirus type 16 (HPV16)-E6 antibodies are detectable in peripheral blood before diagnosis in the majority of HPV16-driven oropharyngeal squamous cell carcinoma (OPSCC), but the timing of seroconversion is unknown. PATIENTS AND METHODS: We formed the HPV Cancer Cohort Consortium which comprises nine population cohorts from Europe, North America and Australia. In total, 743 incident OPSCC cases and 5814 controls provided at least one pre-diagnostic blood sample, including 111 cases with multiple samples. Median time between first blood collection and OPSCC diagnosis was 11.4 years (IQR = 6-11 years, range = 0-40 years). Antibodies against HPV16-E6 were measured by multiplex serology (GST fusion protein based Luminex assay). RESULTS: HPV16-E6 seropositivity was present in 0.4% of controls (22/5814; 95% CI 0.2% to 0.6%) and 26.2% (195/743; 95% CI 23.1% to 29.6%) of OPSCC cases. HPV16-E6 seropositivity increased the odds of OPSCC 98.2-fold (95% CI 62.1-155.4) in whites and 17.2-fold (95% CI 1.7-170.5) in blacks. Seropositivity in cases was more frequent in recent calendar periods, ranging from 21.9% pre-1996 to 68.4% in 2005 onwards, in those with blood collection near diagnosis (lead time <5 years). HPV16-E6 seropositivity increased with lead time: 0.0%, 13.5%, 23.7%, and 38.9% with lead times of >30 years (N = 24), 20-30 years (N = 148), 10-20 years (N = 228), and <10 years (N = 301 cases) (p-trend < 0.001). Of the 47 HPV16-E6 seropositive cases with serially-collected blood samples, 17 cases seroconverted during follow-up, with timing ranging from 6 to 28 years before diagnosis. For the remaining 30 cases, robust seropositivity was observed up to 25 years before diagnosis. CONCLUSIONS: The immune response to HPV16-driven tumorigenesis is most often detectable several decades before OPSCC diagnosis. HPV16-E6 seropositive individuals face increased risk of OPSCC over several decades.

Consumption of prunes as a source of dietary fiber in men with mild hypercholesterolemia.

Forty-one free-living adult men with mild hypercholesterolemia (5.2-7.5 mmol/L) voluntarily participated in an 8-wk crossover study designed to determine the effect of prunes as a source of fiber on plasma cholesterol and on fecal output and bile acid concentration. During the prune period, subjects supplemented their usual diets with 12 prunes (100 g; 6 g dietary fiber) daily. Plasma low-density-lipoprotein cholesterol was significantly lower after the prune period (3.9 mmol/L) than after the grape-juice-control period (4.1 mmol/L). Fecal bile acid concentration of lithocholic acid was significantly lower after the prune period (0.95 mg bile acid/g dry wt stool) than after the grape-juice-control period (1.20 mg bile acid/g dry wt stool). Both fecal wet and dry weights were approximately 20% higher after the prune period than after the grape-juice-control period. Total bile acids (mg/72 h) did not significantly differ between experimental periods.

Measurement characteristics of the Women's Health Initiative food frequency questionnaire.

PURPOSE: The Women's Health Initiative (WHI) is the largest research program ever initiated in the United States with a focus on diet and health. Therefore, it is important to understand and document the measurement characteristics of the key dietary assessment instrument: the WHI food frequency questionnaire (FFQ). METHODS: Data are from 113 women screened for participation in the WHI in 1995. We assessed bias and precision of the FFQ by comparing the intake of 30 nutrients estimated from the FFQ with means from four 24-hour dietary recalls and a 4-day food record. RESULTS: For most nutrients, means estimated by the FFQ were within 10% of the records or recalls. Precision, defined as the correlation between the FFQ and the records and recalls, was similar to other FFQs. Energy adjusted correlation coefficients ranged from 0.2 (vitamin B12) to 0.7 (magnesium) with a mean of 0.5. The correlation for percentage energy from fat (a key measure in WHI) was 0.6. Vitamin supplement use was common. For example, almost half of total vitamin E intake was obtained from supplements. Including supplemental vitamins and minerals increased micronutrient correlation coefficients, which ranged from 0.2 (thiamin) to 0.8 (vitamin E) with a mean of 0.6. CONCLUSIONS: The WHI FFQ produced nutrient estimate, that were similar to those obtained from short-term dietary recall and recording methods. Comparison of WHI FFQ nutrient intake measures to independent and unbiased measures, such as doubly labeled water estimates of energy expenditure, are needed to help address the validity of the FFQ in this population.

Diabetes mellitus--a priority health care issue for women.

Diabetes occurs in more than 13 million persons in the United States, and approximately 60% of the new cases are diagnosed in women. This review examines health issues related to women with diabetes mellitus. The following issues are discussed in the review. The prevalence of diabetes is higher in Native-American, black, and Hispanic women than in white women. Women with upper-body obesity are at risk for developing non-insulin-dependent diabetes mellitus (NIDDM) and women with diabetes are at risk for developing heart disease. Diabetes, obesity, and heart disease are all modifiable by nutrition. White women with diabetes derive approximately 40% of energy from fat, which is 10% greater than the national goal. Women with a history of gestational diabetes are at risk for developing NIDDM. Women with insulin-dependent diabetes mellitus (IDDM) are at high risk of developing complications in pregnancy, and pregnancy outcomes improve with preconceptual counseling. Women with IDDM are at risk for developing eating disorders, although not to a greater extent than the nondiabetic population. Women with diabetes are at risk for developing endometrial cancer. Both IDDM and NIDDM prevention clinical trials are in progress, although none target women specifically. Dietetics practitioners are encouraged to use local and national diabetes resources.

Measurement characteristics of 2 different self-monitoring tools used in a dietary intervention study.

OBJECTIVE: To examine the measurement characteristics of 2 self-monitoring tools, a food diary and fat scan, used in the dietary intervention of the Women's Health Trial: Feasibility in Minority Populations study. DESIGN: Comparison of fat intake reported on the self-monitoring tools to a criterion measure of fat intake, specifically the mean of a food frequency questionnaire and a 4-day food record. The main outcome measures were differences in fat grams and correlations between each of the self-monitoring tools and the criterion measure. SUBJECTS/SETTING: Six-month postrandomization data from 313 women aged 50 to 79 years who participated in the intervention group of the Women's Health Trial: Feasibility in Minority Populations study. RESULTS: Both self-monitoring tools underestimated fat intake compared to the criterion measure, the food diary by 9 g and the fat scan by 6 g. The self-monitoring instruments were better than chance at detecting a low-fat dietary pattern, however, and did not differ from each other in their ability to do so. APPLICATIONS/CONCLUSIONS: The self-monitoring tools were modestly precise as measures of fat intake, but neither was sufficiently accurate to be reliable as a sole assessment of dietary adherence. Dietetics professionals are encouraged to assess the measurement properties of self-monitoring tools to use them appropriately in supporting dietary changes.

Dietary fiber.

Most of our understanding of the physiologic effects of dietary fiber are derived from studies in adults. These investigations have indicated the potential problems with fiber consumption are most likely to occur if isolated polysaccharides or nonpurified fiber supplements are consumed excessively. Such problems include intestinal obstruction and significant reductions in nutrient availability. Inclusion of foods that contain dietary fiber such as fruits, vegetables, beans, and whole-grain products is unlikely to result in complications for most individuals. Young children may need to consume smaller servings of these foods than adults; however, their inclusion in the diet is an important part of meeting dietary recommendation for fiber intake. Excess consumption of fiber-supplemented foods (e.g., bran cereals) should be monitored to avoid appetite suppression that could limit selection of foods to maintain a balanced diet.

The effects of guar gum or wheat bran on the disappearance of 14C-labeled starch from the rat gastrointestinal tract.

An animal model was used to test the hypothesis that guar gum, a source of soluble fiber, will slow the disappearance of starch from the gastrointestinal tract. Male Wistar rats were adapted for 1 wk to a purified diet and then divided into three groups and given 30 min to consume a test meal. The test meal contained 5% fiber derived from guar gum (GG) or wheat bran (WB) or was fiber-free (FF), and each contained 2.5 microCi 14C-labeled starch. At 1, 2.5, or 5 h postprandial, a group from each dietary treatment was killed, and stomach, small and large intestine and cecum were removed to determine the distribution of radioactivity. The isotope emptied from the stomach at a similar rate for all three groups. The percent ingested dose in the small intestine (SI) was highest in the upper half at 1 h and highest in the lower half at 2.5 h for all groups. The percent ingested dose of 14C-starch was significantly higher from upper SI segments in the GG group than from those in the FF group at 2.5 and 5 h, whereas percent ingested dose did not differ in the upper SI segments in the WB group compared to the FF group at 1, 2.5 and 5 h. These data indicate that a viscous polysaccharide (GG) can delay the disappearance of starch from the SI whereas a source of insoluble fiber (WB) did not slow starch disappearance.

Prune fiber or pectin compared with cellulose lowers plasma and liver lipids in rats with diet-induced hyperlipidemia.

Previous research indicated that prunes in the diet of men with hypercholesterolemia lowered plasma and LDL cholesterol concentrations. To further study lipid metabolism in response to ingesting prunes, we conducted an animal study to test the hypotheses that fiber extracted from prunes, compared with purified cellulose, lowers plasma and liver cholesterol in rats with diet-induced hyperlipidemia and that the response is dose dependent. Rats were randomly assigned to one of five experimental diet groups. Four of the diets contained cholesterol and cholic acid to induce hyperlipidemia. The fiber source in the hyperlipidemic diets was 6% cellulose, 3% prune fiber, 6% prune fiber or 3% pectin. The fifth group, the nonhyperlipidemic control, was fed a diet containing 6% cellulose without cholesterol or cholic acid. Rats consumed one of the five diets ad libitum for 28 d, then were killed after 16 h without food. Plasma, LDL and liver cholesterol concentrations were higher in the hyperlipidemic control than the nonhyperlipidemic control and lower in the groups fed diets containing pectin or prune fiber than in the hyperlipidemic control group. No differences in plasma or liver cholesterol concentrations were detected between groups fed either dose level of prune fiber or between groups fed 6% prune fiber and pectin. These results indicate that fiber extracted from prunes lowers plasma and liver cholesterol in hyperlipidemic rats, although a dose-dependent response was not detected.

Differences in eating pattern labels between maintainers and nonmaintainers in the Women's Health Initiative.

OBJECTIVE: To describe how a sample of women in the Women's Health Initiative Dietary Modification Trial (WHIDM) labeled a healthy eating pattern and to compare these labels to their dietary maintenance. DESIGN: Participants completed a food frequency questionnaire and were divided into two maintenance groups, based on the percentage of energy derived from fat in their diets. Individual, semistructured interviews with the same subjects elicited information on labels they use to describe a healthy eating pattern. SUBJECTS/SETTINGS: Subjects were 100 postmenopausal women, 50 to 79 years of age, free of breast and colorectal cancer, and participating in a dietary intervention that consisted of 20% or less energy from fat. MAIN OUTCOME MEASURES: Percentage of energy from fat in the diet and labels used to define a healthy eating pattern. STATISTICAL ANALYSES PERFORMED: Multivariate analysis. RESULTS: The label "consistent/patterned" was a predictor of dietary nonmaintenance (p <.05). IMPLICATIONS: Future studies should use this information to re-educate nonmaintainers on compliance issues.

Evaluation of a simplified vitamin supplement inventory developed for the Women's Health Initiative.

OBJECTIVE: To evaluate the accuracy of a simplified inventory procedure for assessing nutrient intake from vitamin and mineral supplements. DESIGN: Participants brought their supplements to a clinic. An interviewer conducted the supplement inventory procedure, which consisted of recording data on the type of multiple vitamin and single supplements used. For the multiple vitamins, the interviewer recorded the exact dose for a subset of nutrients (vitamin C, calcium, selenium). For other nutrients, we imputed the dose in multiple vitamins. The dose of all single supplements was recorded. Labels of the supplements were photocopied and we transcribed the exact nutrient label data for the criterion measure. Spearman correlation coefficients were used to assess precision of nutrient intakes from the simplified inventory compared to the criterion measure. SETTING/SUBJECTS: Data are from 104 adult vitamin supplement users in Washington state. RESULTS: Correlation coefficients between nutrient intake estimated from the simplified inventory compared to the criterion measure were high (0.8-1.0) for those nutrients (vitamin C, calcium, selenium) for which the interviewer recorded the exact dose contained in multiple vitamins. However, for nutrients for which imputations were made regarding dose in multiple vitamins, correlation coefficients ranged from good (0.8 for vitamin E) to poor (0.3 for iron). CONCLUSIONS: The simplified inventory is rapid (4-5 min) and practical for large-scale studies. The precision of nutrient estimates using this procedure was variable, although excellent for the subset of nutrients for which the dose was recorded exactly. This study illustrates many of the challenges of collecting high quality supplement data.

(n-3) fatty acid supplementation in moderately hypertriglyceridemic adults changes postprandial lipid and apolipoprotein B responses to a standardized test meal.

The effects of (n-3) fatty acids on the postprandial state were investigated by monitoring the alimentary responses to identical test meals fed to adults [n = 11; fasting triacylglycerol (TG) 2.55 +/- 0.24 mmol/L; mean +/- SEM] after a self-selected diet baseline period (BLP) and then after a 6-wk (n-3) fatty acid period (FOP) [ approximately 5.2 g (n-3) fatty acids] and a 6-wk control oil period (COP) administered in random order. Samples were drawn immediately prior to the test meal (time 0) and then hourly from 2 to 6 h postmeal. Postprandial plasma triacylglycerol (TG) and TG-rich lipoprotein (TRL) TG apo B48, and B100 absolute concentrations were significantly lower after FOP than after COP or BLP, while plasma cholesterol was unchanged. Normalizing the results as increments over time 0 eliminated the diet effect on all but plasma TG. Time remained a significant effect for plasma TG, TRL TG, and TRL TC. Finally, only absolute TRL B48 and absolute and incremental plasma TG concentrations displayed significant time-diet interactions. These results suggest that postprandial TRL apo B reductions are likely caused by (n-3) fatty acid suppression of both hepatic and intestinal apoB secretion/synthesis. Altered TRL metabolism, i.e. changes in postprandial TG, cholesterol, apo B48, and increase in LDL particle size, may represent an additional mechanism for the reduced heart disease risk associated with fish [(n-3) fatty acid] consumption.