Biomedical subjects

B Caan

Publications and source records attributed to B Caan.

At least 19 recordsLinked to original sources

PubMed2006

The effect of conjugated equine oestrogen on diabetes incidence: the Women's Health Initiative randomised trial.

AIMS/HYPOTHESIS: Recent clinical trials have found that the combination of conjugated equine oestrogen (CEO) and medroxyprogesterone has a protective effect on the incidence of type 2 diabetes. To determine the effect of CEO alone on the incidence of diabetes mellitus in postmenopausal women, we analysed the results of the Women's Health Initiative oestrogen-alone trial. METHODS: The Women's Health Initiative is a randomised, double-masked trial comparing the effect of daily 0.625 mg CEO with placebo during 7.1 years of follow-up of 10,739 postmenopausal women who were aged 50-79 years and had previously had a hysterectomy. Diabetes incidence was ascertained by self-report of treatment with insulin or oral hypoglycaemic medication. Fasting glucose, insulin and lipoproteins were measured in an 8.6% random sample of study participants, at baseline and at 1, 3 and 6 years. RESULTS: The cumulative incidence of treated diabetes was 8.3% in the oestrogen-alone group and 9.3% in the placebo group (hazard ratio 0.88, 95% CI 0.77-1.01, p=0.072). During the first year of follow-up, a significant fall in insulin resistance (homeostasis model assessment of insulin resistance) in actively treated women compared with the control subjects (Year 1 baseline between-group difference -0.53) was seen. However, there was no difference in insulin resistance at the 3- or 6-year follow-up. CONCLUSIONS/INTERPRETATION: Postmenopausal therapy with oestrogen alone may reduce the incidence of treated diabetes. The effect is smaller than that seen with oestrogen plus progestin. CEO should not, however, be used with the intention of preventing diabetes, as its well-described adverse effects preclude long-term use for primary prevention.

Aged↗

PubMed2005

MTHFR variants reduce the risk of G:C->A:T transition mutations within the p53 tumor suppressor gene in colon tumors.

5,10-Methylene-tetrahydrofolate reductase (MTHFR) is a key enzyme in folate-mediated 1-carbon metabolism. Reduced MTHFR activity has been associated with genomic DNA hypomethylation. Methylated cytosines at CpG sites are easily mutated and have been implicated in G:C-->A:T transitions in the p53 tumor suppressor gene. We investigated 2 polymorphisms in the MTHFR gene (C677T and A1298C) and their associations with colon tumor characteristics, including acquired mutations in Ki-ras and p53 genes and microsatellite instability (MSI). The study population comprised 1248 colon cancer cases and 1972 controls, who participated in a population-based case-control study and had been analyzed previously for MSI, acquired mutations in Ki-ras, p53, and germline MTHFR polymorphisms. Multivariable-adjusted odds ratios are presented. Overall, MTHFR genotypes were not associated with MSI status or the presence of any p53 or Ki-ras mutation. Individuals with homozygous variant MTHFR genotypes had a significantly reduced risk of G:C-->A:T transition mutations within the p53 gene, yet, as hypothesized, only at CpG-associated sites [677TT vs. 677CC (referent group) OR = 0.4 (95% CI: 0.1-0.8) for CpG-associated sites; OR = 1.5 (0.7-3.6) for non-CpG associated sites]. Genotypes conferring reduced MTHFR activity were associated with a decreased risk of acquired G:C-->A:T mutations within the p53 gene occurring at CpG sites. Consistent with evidence on the phenotypic effect of the MTHFR C677T variant, we hypothesize that this relation may be explained by modestly reduced genomic DNA methylation, resulting in a lower probability of spontaneous deamination of methylated cytosine to thymidine. These results suggest a novel mechanism by which MTHFR polymorphisms can affect the risk of colon cancer.

Adult↗

PubMed2004

Meat intake and the recurrence of colorectal adenomas.

A large multicenter randomized controlled trial was re-assessed to check whether meat intake and a reduction in its consumption are associated with recurrence of adenomatous polyps of the large bowel, which are precursors of most colorectal malignancies. All subjects (n = 1905; 958 interventions and 947 controls) had one or more histologically confirmed colorectal adenomas removed during a colonoscopy within 6 months before randomization. The subjects were followed-up for approximately 4 years after randomization and a colonoscopy for detecting adenomas was conducted at the 1st and 4th year after randomization. Dietary variables were assessed at baseline (T0) and in conjunction with annual visits at the end of the 1st (T1), 2nd (T2), 3rd (T3) and 4th (T4) years. Odds ratios using logistic regression models for meat variables were estimated based on the average intake at T0, T1, T2, T3 and T4 (prior to the T4 colonoscopy) as well as change (T0-T4) in intake. In the intervention group, the total reduction in median intake of red meat from T0 to T4 was observed by the end of 1st year itself (30 and 31% for men and women, respectively). The analysis provide no evidence to suggest that lower intake or reduction in total and in red meat consumption during a period of 4 years reduces the risk of adenoma recurrence (including multiple or advanced adenoma), whereas the data suggest that high intake of fish is associated with lower risk of adenoma recurrence.

Adenoma↗

PubMed2001

Hormone replacement therapy and colorectal adenoma recurrence among women in the Polyp Prevention Trial.

BACKGROUND: Epidemiologic studies have suggested that estrogen may protect against the development of colorectal cancers and adenomatous polyps. We conducted a prospective study to evaluate the association between hormone replacement therapy (HRT) and adenoma recurrence among perimenopausal and postmenopausal women participating in the Polyp Prevention Trial, a randomized dietary intervention study of individuals with colorectal adenomas. METHODS: We used a questionnaire and interviews to collect detailed information, at baseline and at each of four annual study visits, from 620 women regarding hormone use, menopausal status, diet, alcohol consumption, and other risk factors. Adenoma recurrence was ascertained by complete colonoscopy at baseline and after 1 and 4 years. Logistic regression models were used to evaluate the association between hormone use and adenoma recurrence after adjusting for intervention group and for age and body mass index at baseline. All statistical tests were two-sided. RESULTS: Adenomas recurred in 200 women. There was no overall association between adenoma recurrence and either overall hormone use (odds ratio [OR] = 1.01; 95% confidence interval [CI] = 0.70 to 1.45), combined estrogen and progestin use (OR = 0.94; 95% CI = 0.57 to 1.56), or unopposed estrogen use (OR = 1.04; 95% CI = 0.68 to 1.59). HRT use was associated with a reduction in risk for recurrence of distal adenomas (OR = 0.56; 95% CI = 0.32 to 1.00) and a statistically nonsignificant increase in risk for recurrence of proximal adenomas (OR = 1.39; 95% CI = 0.85 to 2.26). We observed a statistically significant interaction between the HRT-adenoma recurrence association and age (P =.02). HRT was associated with a 40% reduced risk of adenoma recurrence among women older than 62 years (OR = 0.58; 95% CI = 0.35 to 0.97) but with an increased risk among women younger than 62 years (OR = 1.99; 95% CI = 1.11 to 3.55). CONCLUSIONS: HRT was not associated with a reduced risk for overall adenoma recurrence in this trial cohort, although there was a suggestion of an age interaction. The effect of age on the association needs to be confirmed in other adenoma recurrence trials.

Adenoma↗

PubMed2001

Implementation of a 4-y, high-fiber, high-fruit-and-vegetable, low-fat dietary intervention: results of dietary changes in the Polyp Prevention Trial.

BACKGROUND: The Polyp Prevention Trial (PPT) was a multicenter randomized clinical trial designed to determine the effects of a high-fiber (4.30 g/MJ), high-fruit-and-vegetable (0.84 servings/MJ), low-fat (20% of energy from fat) diet on the recurrence of adenomatous polyps in the large bowel. OBJECTIVE: Our goal was to determine whether the PPT intervention plan could effect change in 3 dietary goals and to examine the intervention's effect on the intake of other food groups and nutrients. DESIGN: Participants with large-bowel adenomatous polyps diagnosed in the past 6 mo were randomly assigned to either the intervention (n = 1037) or the control (n = 1042) group and remained in the trial for 4 y. Three dietary assessment instruments were used to measure dietary change: food-frequency questionnaires (in 100% of the sample), 4-d food records (in a 20% random cohort), and 24-h dietary recalls (in a 10% random sample). RESULTS: Intervention participants made and sustained significant changes in all PPT goals as measured by the dietary assessment instruments; the control participants' intakes remained essentially the same throughout the trial. The absolute differences between the intervention and control groups over the 4-y period were 9.7% of energy from fat (95% CI: 9.0%, 10.3%), 1.65 g dietary fiber/MJ (95% CI: 1.53, 1.74), and 0.27 servings of fruit and vegetables/MJ (95% CI: 0.25, 0.29). Intervention participants also reported significant changes in the intake of other nutrients and food groups. The intervention group also had significantly higher serum carotenoid concentrations and lower body weights than did the control group. CONCLUSION: Motivated, free-living individuals, given appropriate support, can make and sustain major dietary changes over a 4-y period.

Adenomatous Polyps↗

PubMed2000

Lack of effect of a low-fat, high-fiber diet on the recurrence of colorectal adenomas. Polyp Prevention Trial Study Group.

BACKGROUND: We tested the hypothesis that dietary intervention can inhibit the development of recurrent colorectal adenomas, which are precursors of most large-bowel cancers. METHODS: We randomly assigned 2079 men and women who were 35 years of age or older and who had had one or more histologically confirmed colorectal adenomas removed within six months before randomization to one of two groups: an intervention group given intensive counseling and assigned to follow a diet that was low in fat (20 percent of total calories) and high in fiber (18 g of dietary fiber per 1000 kcal) and fruits and vegetables (3.5 servings per 1000 kcal), and a control group given a standard brochure on healthy eating and assigned to follow their usual diet. Subjects entered the study after undergoing complete colonoscopy and removal of adenomatous polyps; they remained in the study for approximately four years, undergoing colonoscopy one and four years after randomization. RESULTS: A total of 1905 of the randomized subjects (91.6 percent) completed the study. Of the 958 subjects in the intervention group and the 947 in the control group who completed the study, 39.7 percent and 39.5 percent, respectively, had at least one recurrent adenoma; the unadjusted risk ratio was 1.00 (95 percent confidence interval, 0.90 to 1.12). Among subjects with recurrent adenomas, the mean (+/-SE) number of such lesions was 1.85+/-0.08 in the intervention group and 1.84+/-0.07 in the control group. The rate of recurrence of large adenomas (with a maximal diameter of at least 1 cm) and advanced adenomas (defined as lesions that had a maximal diameter of at least 1 cm or at least 25 percent villous elements or evidence of high-grade dysplasia, including carcinoma) did not differ significantly between the two groups. CONCLUSIONS: Adopting a diet that is low in fat and high in fiber, fruits, and vegetables does not influence the risk of recurrence of colorectal adenomas.

Adenoma↗

PubMed2000

Calcium, vitamin D, sunshine exposure, dairy products and colon cancer risk (United States).

OBJECTIVE: Epidemiologic studies on calcium, vitamin D and colon cancer are inconsistent, whereas experimental studies more regularly show a protective effect. To evaluate potential sources of inconsistencies, data from a large case-control study were analyzed, stratifying on potential effect modifiers. METHODS: Data were collected by certified interviewers in Northern California, Utah and Minnesota. Analyses included 1993 incident colon cancer cases and 2410 population-based controls. Multivariate logistic regression models included age, sex, BMI, family history, physical activity, intake of energy, dietary fiber, aspirin and NSAIDs. RESULTS: Dietary calcium was inversely associated with colon cancer risk in men (OR highest vs lowest quintile = 0.6, 95% CI = 0.5-0.9) and women (OR = 0.6, 95% CI = 0.4-0.9). No statistically significant associations were observed for dietary vitamin D or sunshine exposure. Consumption of total low-fat dairy products was associated with a statistically significantly decreased risk in men and women (ORs highest vs lowest category of intake = 0.8 and 0.7 respectively). Calcium supplement use was inversely associated with risk in both sexes (ORs use vs non-use = 0.8). Vitamin D supplements were inversely associated with risk in men (OR = 0.5) and women (OR = 0.6) but confidence limits included 1.0. CONCLUSIONS: These data provide additional support of an inverse association between high levels of calcium intake and colon cancer risk.

Aged↗

PubMed1999

Hormone replacement therapy and improved survival among postmenopausal women diagnosed with colon cancer (USA).

OBJECTIVES: Hormone replacement therapy (HRT) has been inversely associated with colon cancer incidence in several epidemiologic studies. In this study we used data from a population-based incident case-control study of colon cancer to evaluate the role of HRT use in survival after diagnosis with colon cancer. METHODS: Data from 815 postmenopausal women living in Utah, California, and Minnesota diagnosed between 1 September 1991 and 30 September 1994 were used to examine associations between HRT and survival. RESULTS: After adjusting for age at time of diagnosis, stage of disease at time of diagnosis, study center, and body mass index (BMI), we observed that women who had ever used HRT had a 30% lesser probability of dying of any cause and a 40% lower probability of dying from colon cancer specifically during the follow-up period. Further evaluation by years of HRT use showed that those who had used HRT for 4 or more years had the lowest risk of dying of colon cancer (hazard rate ratio 0.5, 95% confidence interval 0.3-0.9). Evaluation of other lifestyle variables with HRT use did not show significant confounding or effect modification. CONCLUSIONS: These findings suggest that HRT use may improve short-term survival after diagnosis with colon cancer; there is no suggestion that HRT use is detrimental to survival.

Adult↗

PubMed1998

Obesity, health services use, and health care costs among members of a health maintenance organization.

BACKGROUND: Obesity is an independent risk factor for a variety of chronic diseases and is therefore a potential source of avoidable excess health care expenditures. Previous studies of obesity and health care costs have used group level data, applying estimates of population-attributable risks to estimates of US total costs of care for each obesity-related disease. OBJECTIVE: To quantify the association between body mass index (BMI) and health services use and costs stratified by age and use source at the patient level, a level of detail not previously reported. METHODS: In 17,118 respondents to a 1993 health survey of members of a large health maintenance organization, we ascertained through computerized databases all hospitalizations, laboratory services, outpatient visits, outpatient pharmacy and radiology services, and the direct costs of providing these services during 1993. RESULTS: There was an association between BMI and annual rates of inpatient days, number and costs of outpatient visits, costs of outpatient pharmacy and laboratory services, and total costs (P < or = .003). Relative to BMI of 20 to 24.9, mean annual total costs were 25% greater among those with BMI of 30 to 34.9 (rate ratio, 1.25; 95% confidence interval, 1.10-1.41), and 44% greater among those with BMI of 35 or greater (rate ratio, 1.44; 95% confidence interval, 1.22-1.71). The association between BMI and coronary heart disease, hypertension, and diabetes largely explained these elevated costs. CONCLUSION: Given the high prevalence of obesity and the associated elevated rates of health services use and costs, there is a significant potential for a reduction in health care expenditures through obesity prevention efforts.

Adult↗

PubMed1998

Vitamin E and colon cancer: is there an association?

The role of vitamin E in the etiology and prevention of colon cancer is not clear. It is possible that various forms of vitamin E may act differently in colon tissue and may be effective chemopreventive agents. Previous reports of vitamin E and colon cancer have focused on alpha-tocopherol and have not considered other dietary forms of vitamin E. Data from a study of 1,993 cases and 2,410 controls were used to evaluate the associations between the four most common forms of dietary vitamin E and supplemental vitamin E and colon cancer. After adjusting for other health and life-style factors, we did not observe a statistically significant association between dietary tocopherols and colon cancer. There were, however, suggestions of an inverse association between total alpha-tocopherol equivalents and colon cancer among women diagnosed with colon cancer before the median age of the control population, 67 years [odds ratio (OR) = 0.66, 95% confidence interval (CI) = 0.36-1.22] and a direct association between gamma-tocopherol and colon cancer among these women (OR = 1.44, 95% CI = 0.92-1.93). Women diagnosed with colon cancer when > or = 67 years of age appeared to have some protection from use of vitamin E supplements (OR = 0.80, 95% CI = 0.56-1.15). These data offer only limited support for a protective effect of vitamin E and colon cancer after adjustment for other health and life-style factors.

Adult↗

PubMed1998

Differences in fertility associated with caffeinated beverage consumption.

OBJECTIVES: The effect of caffeine consumption on fertility was examined prospectively in 210 women. METHODS: Women reported on caffeinated beverage consumption and pregnancy status monthly. Odds ratios for becoming pregnant were calculated for both high and moderate vs low consumption. RESULTS: No significant association was found for any of the caffeinated beverages except tea. Drinking one-half cup or more of tea daily approximately doubled the odds of conception per cycle. CONCLUSIONS: These data suggest that caffeine may not be the responsible agent for variation in fertility associated with consumption of the beverages examined.

Adult↗

PubMed1998

NAT2, GSTM-1, cigarette smoking, and risk of colon cancer.

Cigarette smoking has been associated inconsistently with colon cancer. The extent to which genetic profile influences susceptibility to the inducement of colon cancer by cigarette smoking is not known. In this study, we evaluated the associations between smoking cigarettes and polymorphisms of the NAT2 and GSTM-1 genes using data obtained from an incident case-control study of 1993 cases of colon cancer and 2410 age- and sex- matched controls. Neither NAT2 nor GSTM-1 polymorphisms were significantly associated with colon cancer, except among older women, in whom the intermediate/rapid imputed phenotype was associated with increased risk of colon cancer [odds ratio (OR) = 1.4, 95% confidence interval (CI) = 1.0-1.81. Using several indicators of cigarette smoking, we observed no significant interaction between these genotypes and cigarette smoking and colon cancer. The major variation in association with colon cancer was from the amount of cigarette exposure, with those smoking a pack or more of cigarettes per day being at an approximately 40% increased risk of colon cancer; this association did not vary by genotype. However, those who stopped smoking 5-14 years prior to diagnosis and who where intermediate/rapid acetylators were at a slightly greater risk than those who were slow acetylators (for men, OR = 1.6, 95% CI = 1.0-2.4; for women, OR = 2.5, 95% CI = 1.4-4.4). Associations were similar when proximal and distal tumors were examined and separated for age at the time of diagnosis. The lack of an association does not rule out the possibility of other genetic polymorphisms interacting with cigarette smoke to cause colon cancer, nor does it take into account individual phenotypic variability.

Adult↗

PubMed1997

Energy balance and colon cancer--beyond physical activity.

Low levels of physical activity and high levels of energy intake and body mass have all been directly associated with colon cancer. The purpose of this study was to determine how physical inactivity interacts with other components of energy balance (energy intake and body mass) in determining colon cancer risk. Data were obtained from 2073 first primary cases of colon cancer and 2466 age- and sex-matched controls identified from 8 counties in Utah, the Northern California Kaiser Permanente Medical Care Program, and the Twin Cities metropolitan area in Minnesota. Recent and lifetime physical activity was assessed by intensity of activities performed at home, leisure, and at work; energy intake was estimated from an extensive diet history questionnaire; and body mass index (BMI) was calculated from measured height at the time of interview and reported weight for the referent year. For both men and women, lack of lifetime vigorous leisure-time activity was associated with increased risk of colon cancer [odds ratio (OR), 1.63 and 95% confidence interval (CI), 1.26-2.12 for men and OR, 1.59 and 95% CI, 1.21-2.10 for women, comparing the lowest to highest level of activity]. There were no differences in risk associated with physical activity by tumor site within the colon or by age at diagnosis. High levels of energy intake were also associated with increased risk of colon cancer in men and women (OR, 1.74 and 95% CI, 1.14-2.67 for men and OR, 1.70 and 95% CI, 1.07-2.70 for women). A large BMI was more associated with increased risk in men (OR, 1.94 and 95% CI, 1.49-2.54) than in women (OR, 1.45 and 95% CI, 1.08-1.94). Those at greatest risk of colon cancer were those who had the most unfavorable energy balance in that they were physically inactive, had high energy intakes, and had a large BMI (OR, 3.35 and 95% CI, 2.09-5.35). However, when physical activity was high, having a high energy intake and large BMI resulted in a nonsignificant increased colon cancer risk (OR, 1.28 and 95% CI, 0.81-2.03). This pattern was consistent between the sexes, but there was some evidence that men may be at higher risk than women, especially older women, as a result of unfavorable energy balance. These results support previous findings that physical inactivity, high energy intake, and large body mass are associated with increased risk of developing colon cancer. However, energy balance as a whole seems to be associated with risk of colon cancer. These findings suggest systemic metabolic influences on carcinogenesis and have important implications for prevention.

Adult↗

PubMed1997

Diet diversity, diet composition, and risk of colon cancer (United States).

In this study, we evaluate diet diversity, diet composition, and risk of colon cancer in an incident population-based study of 1,993 cases and 2,410 controls in the Kaiser Permanente Medical Care Program of Northern California, eight counties in Utah, and the Twin Cities area of Minnesota (United States). Ninety-one and one-half percent of the population were non-Hispanic White. Dietary intake was obtained using an adaptation of the CARDIA diet-history questionnaire. Diet diversity was defined as the number of unique food items reported; diversity also was explored within six major food groups. Composition of the diet was described by estimating the proportion of total number of food items contributed by major food groups. Younger individuals, higher educated individuals, and those who lived in larger households reported eating the most diverse diet. Total diet diversity was not associated with colon cancer. However, eating a diet with greater diversity of meats, poultry, fish, and eggs, was associated with a 50 percent increase in risk among all men (95 percent confidence interval [CI] = 1.1-2.0; P trend = 0.01), with slightly stronger associations for younger men and men with distal tumors. A diet with a greater number of refined grain products also was associated with increased risk among men (odds ratio [OR] = 1.7, CI = 1.3-2.3). Women who ate a diet with a more diverse pattern of vegetables were at approximately a 20 percent lower risk than women who had the least diverse diet in vegetables. Assessment of diet composition showed that men who consumed a large proportion of their food items from meat, fish, poultry, and eggs were at an increased risk, with the most marked association being for distal tumors (OR = 1.7, CI = 1.2-2.5). Women who consumed the largest percentage of their food items in the form of plant foods (fruits, vegetables, or whole grains) were at a reduced risk of developing colon cancer (OR = 0.7, CI = 0.5-1.0).

Adult↗

PubMed1997

Indexes of food and nutrient intakes as predictors of serum concentrations of nutrients: the problem of inadequate discriminant validity. The Polyp Prevention Trial Study Group.

Nutrient indexes derived from food-frequency questionnaires have generally been regarded as acceptably valid for epidemiologic purposes. Evaluations of these indexes, however, have considered only their convergent validity. We suggest that discriminant validity, or the ability to distinguish among exposures to different nutrients, is also important. Using baseline data from a large clinical trial, we tested the discriminant validity of indexes of intake of vitamin E, alpha-carotene, and beta-carotene. Our results suggest that the vitamin E index possesses neither convergent not discriminant validity, the alpha-carotene index adequate convergent and discriminant validity, and the beta-carotene index adequate convergent but no discriminant validity.

Biomarkers↗

PubMed1996

Randomized controlled trial of a low animal protein, high fiber diet in the prevention of recurrent calcium oxalate kidney stones.

Low protein diets are commonly prescribed for patients with idiopathic calcium nephrolithiasis, who account for > 80% of new diagnoses of kidney stones. This dietary advice is supported by metabolic studies and epidemiologic observational studies but has not been evaluated in a controlled trial. Using 1983-1985 data from three Northern California Kaiser Permanente Medical Centers, the authors randomly assigned 99 persons who had calcium oxalate stones for the first time to a low animal protein, high fiber diet that contained approximately 56-64 g daily of protein, 75 mg daily of purine (primarily from animal protein and legumes), one-fourth cup of wheat bran supplement, and fruits and vegetables. Intervention subjects were also instructed to drink six to eight glasses of liquid daily and to maintain adequate calcium intake from dairy products or calcium supplements. Control subjects were instructed only on fluid intake and adequate calcium intake. Both groups were followed regularly for up to 4.5 years with food frequency questionnaires, serum and urine chemistry analysis, and abdominal radiography; and they were urged to comply with dietary instructions. In the intervention group of 50 subjects, stones recurred in 12 (7.1 per 100 person-years) compared with two (1.2 per 100 person-years) in the control group; both groups received a mean of 3.4 person-years of follow-up (p = 0.006). After adjustment for possible confounding effects of age, sex, education, and baseline protein and fluid intake, the relative risk of a recurrent stone in the intervention group was 5.6 (95% confidence interval 1.2-26.1) compared with the control group. The authors conclude that advice to follow a low animal protein, high fiber, high fluid diet has no advantage over advice to increase fluid intake alone.

Adult↗

PubMed1996

Women gain weight 1 year after smoking cessation while dietary intake temporarily increases.

OBJECTIVE: To examine the relationship of dietary change to weight change in women who quit smoking and remained abstinent for 1 year. METHODS: For 1 year, 582 women participating in smoking cessation classes were studied. Weight, diet, and physical activity were measured at baseline and at 1, 6, and 12 months after smoking cessation. Multivariate regression models were used to predict 1-year weight change for the 139 women who remained abstinent. RESULTS: Women gained, on average, 9.9 lb over a 1-year period while increasing their intake of energy for 1 and 6 months but returning to baseline levels by 1 year. Sucrose, total carbohydrate, and fat intake increased significantly for the first month; fat and total carbohydrate intake remained at an increased level for 6 months. In unadjusted analyses, older women and those who smoked more cigarettes gained more weight than younger women and lighter smokers; lighter and heavier women gained more weight than women of intermediate weight. In adjusted analyses, age remained a significant factor and number of cigarettes remained of borderline significance. Change in energy intake was predictive of weight change only in women with the highest energy intake at baseline. APPLICATIONS: Dietitians should acknowledge that most women who quit smoking gain weight in the short term. Although many women increase their energy intake, change in energy level is only one factor in weight change. Over the long term, women with high baseline intakes appear to be able to affect their weight change by reducing their energy intake.

Adult↗

PubMed1996

The polyp prevention trial II: dietary intervention program and participant baseline dietary characteristics.

The Polyp Prevention Trial (PPT) is a multicenter randomized controlled trial to evaluate whether a low-fat, high-dietary fiber, high-fruit and -vegetable eating pattern will reduce the recurrence of adenomatous polyps of the large bowel. Men and women who had one or more adenomas removed recently were randomized into either the intervention (n = 1037) or control (n = 1042) arms. Food frequency questionnaire data indicate that PPT participants at the beginning of the trial consumed 36.8% of total energy from fat, 9.7 g of dietary fiber/1000 kcal, and 3.8 daily servings of fruits and vegetables. Baseline dietary characteristics, including intake of fat, fiber, and fruits and vegetables, as well as other macro- and micronutrients, were similar in the two study groups. The intervention participants receive extensive dietary and behavioral counseling to achieve the PPT dietary goals of 20% of total energy from fat, 18 g/1000 kcal of dietary fiber, and 5-8 daily servings (depending on total caloric intake) of fruits and vegetables. Control participants do not receive such counseling and are expected to continue their usual intake. Dietary intake in both groups is mentioned annually using a 4-day food record (also completed at 6 months by intervention participants only) and a food frequency questionnaire, with a 10% random sample of participants completing an annual unscheduled 24-h telephone recall. Blood specimens are drawn and analyzed annually for lipids and carotenoids. This article provides details on the rationale and design of the PPT dietary intervention program and describes the participant baseline dietary intake data characteristics.

Adenomatous Polyps↗