Han Chinese polycystic ovary syndrome risk variants in women of European ancestry: relationship to FSH levels and glucose tolerance.

STUDY QUESTION: Are PCOS risk variants identified in women of Han Chinese ethnicity also associated with risk of PCOS or the phenotypic features of PCOS in European women? SUMMARY ANSWER: One variant, rs2268361-T, in the intron of FSHR was associated with PCOS and lower FSH levels, while another variant rs705702-G near the RAB5B and SUOX genes was associated with insulin and glucose levels after oral glucose testing in women with PCOS of European ethnicity. WHAT IS KNOWN ALREADY: Three of the eleven variants associated with PCOS in the Han Chinese genome-wide association studies were also associated with PCOS in at least one European population when corrected for multiple testing (DENND1A, THADA and YAP1). However, additional replication is needed to establish the importance of these variants in European women and to determine the relationship to PCOS phenotypic traits. STUDY DESIGN, SIZE, DURATION: The study was a case-control examination in a discovery cohort of women with PCOS (n = 485) and controls (n = 407) from Boston (Boston 1). Replication was performed in women from Greece (cases n = 884 and controls n = 311) and an additional cohort from Boston (Boston electronic medical record (EMR); n = 350 cases and n = 1258 controls). PARTICIPANTS/MATERIALS, SETTINGS, METHODS: Women had PCOS defined by the National Institutes of Health criteria in Boston 1 and Greece (n = 783), with additional subjects fulfilling the Rotterdam criteria (hyperandrogenism, polycystic ovary morphology and regular menses) in Greece (n = 101). Controls in Boston and Greece had regular menstrual cycles and no hyperandrogenism. The second cohort from Boston was defined using the EMR and natural language processing. Allele frequencies for variants associated with PCOS in Han Chinese women were examined in PCOS cases and controls, along with the relationship to quantitative traits. MAIN RESULTS AND THE ROLE OF CHANCE: A variant rs2268361-T in an intron of FSHR was associated with PCOS (0.84 [0.76-0.93], OR [95% CI]; P = 0.002). The rs2268361-T was associated with lower FSH levels (-0.15 ± 0.05; P = 0.0029). A variant rs705702-G near RAB5B and SUOX was associated with insulin (-0.16 ± 0.05, P = 0.0029) and glucose levels (-0.20 ± 0.05, P = 0.0002) 120 min after an oral glucose test. LIMITATIONS, REASONS FOR CAUTION: The study was large and contained replication cohorts, but was limited by a small number of controls in the Greek cohort and a small number of cases in the second Boston cohort. The second Boston group was identified using electronic medical record review, but was validated for the cardinal features of PCOS. WIDER IMPLICATIONS OF THE FINDINGS: This study demonstrates a cross-ethnic PCOS risk locus in FSHR in women of European ancestry with PCOS. The variant may influence FSH receptor responsiveness as suggested by the associated change in FSH levels. The relationship between a variant near RAB5B and SUOX and glucose stimulated insulin and glucose levels suggests an influence of one of these genes on glucose tolerance, but the absence of a relationship with PCOS points to potential differences in the international PCOS patient populations. STUDY FUNDING/COMPETING INTERESTS: The project was supported by Award Number R01HD065029 from the Eunice Kennedy Shriver National Institute Of Child Health & Human Development, Award Number 1 UL1 RR025758, Harvard Clinical and Translational Science Center, from the National Center for Research Resources, award 1-10-CT-57 from the American Diabetes Association and the Partners Healthcare Center for Personalized Genetics Project Grant. C.K.W. is a consultant for Takeda Pharmaceuticals. TRIAL REGISTRATION NUMBER: NCT00166569.

The association of education with long-term weight change in the EPIC-PANACEA cohort.

BACKGROUND/OBJECTIVES: Cross-sectionally, educational attainment is strongly associated with the prevalence of obesity, but this association is less clear for weight change during adult life. The objective of this study is to examine the association between educational attainment and weight change during adult life in the European Prospective Investigation into Cancer and Nutrition (EPIC). SUBJECTS/METHODS: EPIC is a cohort study with 361,467 participants and up to 10 years of follow-up. Educational attainment was categorized according to the highest obtained school level (primary school or less, vocational secondary training, other secondary education and university). Multivariate mixed-effects linear regression models were used to study education in relation to weight at age 20 years (self-reported), to annual change in weight between age 20 years and measured weight at recruitment, and to annual change in weight during follow-up time. RESULTS: Higher educational attainment was associated with on average a lower body mass index (BMI) at age 20 years and a lower increase in weight up to recruitment (highest vs lowest educational attainment in men: -60 g per year (95% confidence interval (CI) -80; -40), women -110 g per year (95% CI -130; -80)). Although during follow-up after recruitment an increase in body weight was observed in all educational levels, gain was lowest in men and women with a university degree (high vs low education -120 g per year (95% CI -150; -90) and -70 g per year (95% CI -90; -60), respectively). CONCLUSIONS: Existing differences in BMI between higher and lower educated individuals at early adulthood became more pronounced during lifetime, which possibly impacts on obesity-related chronic disease risk in persons with lower educational attainment.

Fruits and vegetables consumption and the risk of histological subtypes of lung cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC).

OBJECTIVE: To examine the association between fruit and vegetable consumption and risk of different histological subtypes of lung cancer among participants of the European Prospective Investigation into Cancer and Nutrition study. METHODS: Multivariable Cox proportional hazard models were used to analyze the data. A calibration study in a subsample was used to reduce dietary measurement errors. RESULTS: During a mean follow-up of 8.7 years, 1,830 incident cases of lung cancer (574 adenocarcinoma, 286 small cell, 137 large cell, 363 squamous cell, 470 other histologies) were identified. In line with our previous conclusions, we found that after calibration a 100 g/day increase in fruit and vegetables consumption was associated with a reduced lung cancer risk (HR 0.94; 95% CI 0.89-0.99). This was also seen among current smokers (HR 0.93; 95% CI 0.90-0.97). Risks of squamous cell carcinomas in current smokers were reduced for an increase of 100 g/day of fruit and vegetables combined (HR 0.85; 95% CI 0.76-0.94), while no clear effects were seen for the other histological subtypes. CONCLUSION: We observed inverse associations between the consumption of vegetables and fruits and risk of lung cancer without a clear effect on specific histological subtypes of lung cancer. In current smokers, consumption of vegetables and fruits may reduce lung cancer risk, in particular the risk of squamous cell carcinomas.

A bivariate measurement error model for nitrogen and potassium intakes to evaluate the performance of regression calibration in the European Prospective Investigation into Cancer and Nutrition study.

OBJECTIVES: Within the European Prospective Investigation into Cancer and Nutrition (EPIC) study, the performance of 24-h dietary recall (24-HDR) measurements as reference measurements in a linear regression calibration model is evaluated critically at the individual (within-centre) and aggregate (between-centre) levels by using unbiased estimates of urinary measurements of nitrogen and potassium intakes. METHODS: Between 1995 and 1999, 1072 study subjects (59% women) from 12 EPIC centres volunteered to collect 24-h urine samples. Log-transformed questionnaire, 24-HDR and urinary measurements of nitrogen and potassium intakes were analysed in a multivariate measurement error model to estimate the validity of coefficients and error correlations in self-reported dietary measurements. In parallel, correlations between means of 24-HDR and urinary measurements were computed. Linear regression calibration models were used to estimate the regression dilution (attenuation) factors. RESULTS: After adjustment for sex, centre, age, body mass index and height, the validity coefficients for 24-HDRs were 0.285 (95% confidence interval: 0.194, 0.367) and 0.371 (0.291, 0.446) for nitrogen and potassium intakes, respectively. The attenuation factors estimated in a linear regression calibration model were 0.368 (0.228, 0.508) for nitrogen and 0.500 (0.361, 0.639) for potassium intakes; only the former was different from the estimate obtained using urinary measurements in the measurement error model. The aggregate-level correlation coefficients between means of urinary and 24-HDR measurements were 0.838 (0.637, 0.932) and 0.756 (0.481, 0.895) for nitrogen and potassium intakes, respectively. CONCLUSIONS: This study suggests that 24-HDRs can be used as reference measurements at the individual and aggregate levels for potassium intake, whereas, for nitrogen intake, good performance is observed for between-centre calibration, but some limitations are apparent at the individual level.

Use of dietary supplements in the European Prospective Investigation into Cancer and Nutrition calibration study.

BACKGROUND: Dietary supplement use is increasing, but there are few comparable data on supplement intakes and how they affect the nutrition and health of European consumers. The aim of this study was to describe the use of dietary supplements in subsamples of the 10 countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). METHODS: Specific questions on dietary supplement use were asked as a part of single 24-h recalls performed on 36,034 men and women aged 35-74 years from 1995 to 2000. RESULTS: Between countries, the mean percentage of dietary supplement use varied almost 10-fold among women and even more among men. There was a clear north-south gradient in use, with a higher consumption in northern countries. The lowest crude mean percentage of use was found in Greece (2.0% among men, 6.7% among women), and the highest was in Denmark (51.0% among men, 65.8% among women). Use was higher in women than in men. Vitamins, minerals or combinations of them were the predominant types of supplements reported, but there were striking differences between countries. CONCLUSIONS: This study indicates that there are wide variations in supplement use in Europe, which may affect individual and population nutrient intakes. The results underline the need to monitor consumption of dietary supplements in Europe, as well as to evaluate the risks and benefits.

Alcohol consumption patterns, diet and body weight in 10 European countries.

BACKGROUND/OBJECTIVES: Europe has the highest level of alcohol consumption in the world. As drinking patterns are important determinants of the beneficial and harmful effects of alcohol consumption, we investigated alcohol consumption in relation to nutrient intake, place of consumption, education and body weight in a sample of adults from 10 European countries. METHODS: A 24-h dietary recall interview was conducted on 13 025 men and 23 009 women, aged 35-74 years, from 27 centres participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Means and standard errors of alcohol consumption, adjusted for age, were calculated, stratified by gender and centre. RESULTS: In many centres, higher level drinkers (males consuming >24 g of ethanol/day, equivalent to >2 standard drinks and females consuming >12 g of ethanol/day equivalent to >1 standard drink) obtained more energy from fat and protein and less from sugar than did abstainers. The proportion of energy from starch tended to be higher for male and lower for female higher level drinkers than for abstainers. Female higher level drinkers had a lower body mass index than did abstainers, whereas male higher level drinkers generally weighed more. Male higher level drinkers were less educated than abstainers in Mediterranean countries, but were more educated elsewhere. Female higher level drinkers were usually more educated than were abstainers. Outside the home, consumption (both genders) tended to be at friends' homes, particularly among men in Northern and Central Europe, and in bars in Spain. CONCLUSIONS: This study reveals clear geographical differences in drinking habits across Europe, and shows that the characteristics of different alcohol consumption categories also vary.

Risk for invasive and borderline epithelial ovarian neoplasias following use of hormonal contraceptives: the Norwegian-Swedish Women's Lifestyle and Health Cohort Study.

The risk of ovarian epithelial neoplasia following use of hormonal contraceptives (HC) was examined in data from the Norwegian-Swedish Women's Lifestyle and Health cohort including 103551 women aged 30-49 years in 1991-92. Follow-up through 2000 produced 214 incident cases of histologically confirmed epithelial ovarian neoplasias (135 invasive and 79 borderline cases). Using the Cox proportional hazard models, ever having used HC was associated with a decreased relative risk of epithelial ovarian cancer of 0.6 (95% CI 0.5-0.8). The effect of duration of HC use was convincing (P for trend <0.0001), and more important than age at start of use or time since first or last use. There was no significant difference between the effects of combined oral contraceptives and progestins-only contraceptives on risk (P=0.98). Similarly, there was no significant difference between the effects of ever use of HC on invasive and borderline ovarian neoplasia (P=0.37). In this cohort, use of HC seems to reduce the risk of epithelial ovarian neoplasia markedly and persistently in relation to the duration of use.

Predictors for cod-liver oil supplement use--the Norwegian Women and Cancer Study.

OBJECTIVE: To assess the use of cod-liver oil supplements among Norwegian women and to examine dietary, lifestyle, demographic, and health factors associated with use of this supplement. DESIGN: Cross-sectional study. SETTING AND SUBJECTS: The study is based on data from a food frequency questionnaire from 1998 answered by 37,226 women aged 41-55 y, who in 1991/1992 participated in the Norwegian component of the European Prospective Investigation into Cancer and Nutrition (EPIC). The Norwegian EPIC cohort was based on a random nation-wide sample of Norwegian women. RESULTS: Cod-liver oil supplement use was reported by 44.7% of the participating women. Subjects with higher education, high physical activity level, and body mass index (BMI) in the normal range were more likely to use cod-liver oil supplements. Consumption did also increase with increased age as well as with increased reported consumption of fruits, vegetables, fatty fish, lean fish, and vitamin D (excluding the vitamin D contribution from cod-liver oil). Energy intake was higher among cod-liver oil users than nonusers. Whole-year daily users of cod-liver oil were also more likely to take other dietary supplements (OR=2.45, 95% CI: 2.28-2.62). Never smokers were more likely to use cod-liver oil supplements than current smokers. CONCLUSION: Use of cod-liver oil is associated with several sociodemographic factors, self-reported health issues, and intake of fish, fruit, and vegetables. When assessing the relationship between cod-liver oil use and occurrence of chronic diseases potential confounders need to be considered. Cod-liver oil use seemed not to be matched with vitamin D needs. Thus, emphasis on assessing vitamin D status by measuring levels in blood should be investigated further, in particular, among people living in northern latitudes.

Comparison of telephone vs face-to-face interviews in the assessment of dietary intake by the 24 h recall EPIC SOFT program--the Norwegian calibration study.

OBJECTIVE: To compare food group intakes in grams, total energy and energy contribution from macronutrients between two random samples of women, using a standardized computer program (EPIC SOFT) with either a face-to-face or a telephone 24 h recall interview design. METHODS: Two groups of Norwegian women living in Tromsø were drawn at random from the Norwegian Women and Cancer Study (NOWAC) cohort. The EPIC SOFT computer program was used to conduct single 24 h dietary recalls either by telephone or face to face. For the latter, 160 women were invited, of whom 111 responded positively (crude response rate=69.4%) and 102 were interviewed. For the telephone option, 180 were invited to participate, 109 responded positively (crude response rate=60.6%) and 103 were interviewed. RESULTS: The two groups of women were similar with respect to age, body mass index, basal metabolic rate, smoking, education, physical activity and special diet status. No statistically significant difference in dietary intake was found between interviews conducted by telephone and face-to-face, except for 'egg and egg products' (P<0.01), for which intake was higher in the telephone group. Total energy intake differed, but the difference was attributable to one interviewer. The distribution of energy-contributing nutrients was not significantly different between groups, except for reported energy percentage from protein (P=0.02), which was significantly higher in the face-to-face group. CONCLUSION: The telephone vs face-to-face interview design did not influence recalled diet when using the EPIC SOFT program.

Evaluation of under- and overreporting of energy intake in the 24-hour diet recalls in the European Prospective Investigation into Cancer and Nutrition (EPIC).

OBJECTIVE: To evaluate under- and overreporting and their determinants in the EPIC 24-hour diet recall (24-HDR) measurements collected in the European Prospective Investigation into Cancer and Nutrition (EPIC). DESIGN: Cross-sectional analysis. 24-HDR measurements were obtained by means of a standardised computerised interview program (EPIC-SOFT). The ratio of reported energy intake (EI) to estimated basal metabolic rate (BMR) was used to ascertain the magnitude, impact and determinants of misreporting. Goldberg's cut-off points were used to identify participants with physiologically extreme low or high energy intake. At the aggregate level the value of 1.55 for physical activity level (PAL) was chosen as reference. At the individual level we used multivariate statistical techniques to identify factors that could explain EI/BMR variability. Analyses were performed by adjusting for weight, height, age at recall, special diet, smoking status, day of recall (weekday vs. weekend day) and physical activity. SETTING: Twenty-seven redefined centres in the 10 countries participating in the EPIC project. SUBJECTS: In total, 35 955 men and women, aged 35-74 years, participating in the nested EPIC calibration sub-studies. RESULTS: While overreporting has only a minor impact, the percentage of subjects identified as extreme underreporters was 13.8% and 10.3% in women and men, respectively. Mean EI/BMR values in men and women were 1.44 and 1.36 including all subjects, and 1.50 and 1.44 after exclusion of misreporters. After exclusion of misreporters, adjusted EI/BMR means were consistently less than 10% different from the expected value of 1.55 for PAL (except for women in Greece and in the UK), with overall differences equal to 4.0% and 7.4% for men and women, respectively. We modelled the probability of being an underreporter in association with several individual characteristics. After adjustment for age, height, special diet, smoking status, day of recall and physical activity at work, logistic regression analyses resulted in an odds ratio (OR) of being an underreporter for the highest vs. the lowest quartile of body mass index (BMI) of 3.52 (95% confidence interval (CI) 2.91-4.26) in men and 4.80 (95% CI 4.11-5.61) in women, indicating that overweight subjects are significantly more likely to underestimate energy intake than subjects in the bottom BMI category. Older people were less likely to underestimate energy intake: ORs were 0.58 (95% CI 0.45-0.77) and 0.74 (95% CI 0.63-0.88) for age (> or =65 years vs. <50 years). Special diet and day of the week showed strong effects. CONCLUSION: EI tends to be underestimated in the vast majority of the EPIC centres, although to varying degrees; at the aggregate level most centres were below the expected reference value of 1.55. Underreporting seems to be more prevalent among women than men in the EPIC calibration sample. The hypothesis that BMI (or weight) and age are causally related to underreporting seems to be confirmed in the present work. This introduces further complexity in the within-group (centre or country) and between-group calibration of dietary questionnaire measurements to deattenuate the diet-disease relationship.