The association between physical activity, potential intermediate biomarkers and lung cancer risk was investigated in a study of 230 cases and 648 controls nested within the European Prospective Investigation of Cancer and Nutrition. Data on white blood cell aromatic-DNA adducts by 32P-postlabeling and glutathione (GSH) in red blood cells were available from a subset of cases and controls. Compared to the first quartile, the fourth quartile of recreational physical activity was associated with lower lung cancer risk [odds ratio=0.56 (0.35–0.90)], higher GSH levels [+1.87 micro mole GSH/gram haemoglobin, p=0.04] but not with the presence of high levels of adducts [odds ratio=1.05 (0.38–2.86)]. Despite being associated with recreational physical activity, in these small scale pilot analyses GSH levels were not associated with lung cancer risk, [odds ratio=0.95 (0.84 – 1.07) per unit increase in glutathione levels]. Household and occupational activity was not associated with lung cancer risk or biomarker levels.
physical activity; lung cancer; biomarkers; molecular epidemiology
To examine the association of baseline and lifetime ethanol intake with cancer of the pancreas in the European Prospective Investigation into Cancer and Nutrition (EPIC).
Included in this analysis were 478,400 subjects, of whom detailed information on the intake of alcoholic beverages at baseline and over lifetime was collected between 1992 and 2000. During a median follow-up time of 8.9 years, 555 non-endocrine pancreatic cancer cases were observed. Multivariate Cox proportional hazard models were used to examine the association of ethanol intake at recruitment and average lifetime ethanol intake and pancreatic cancer adjusting for smoking, height, weight, and history of diabetes.
Overall, neither ethanol intake at recruitment [relative risk (RR) = 0.94, 95% confidence interval (CI) 0.69–1.27 comparing 30+ g/d vs. 0.1–4.9 g/d] nor average lifetime ethanol intake (RR=0.95, 95% CI 0.65–1.39) were associated with pancreatic cancer risk. High lifetime ethanol intake from spirits/liquor at recruitment tended to be associated with a higher risk (RR=1.40, 95% CI 0.93–2.10 comparing 10+ g/d vs. 0.1–4.9 g/d), but no associations were observed for wine and beer consumption.
These results suggest no association of alcohol consumption with the risk of pancreatic cancer.
Ethanol; pancreatic cancer; epidemiology; EPIC
The food frequency questionnaire approach to dietary assessment is ubiquitous in nutritional epidemiology research. Food records and recalls provide approaches that may also be adaptable for use in large epidemiologic cohorts, if warranted by better measurement properties. The authors collected (2007–2009) a 4-day food record, three 24-hour dietary recalls, and a food frequency questionnaire from 450 postmenopausal women in the Women’s Health Initiative prospective cohort study (enrollment, 1994–1998), along with biomarkers of energy and protein consumption. Through comparison with biomarkers, the food record is shown to provide a stronger estimate of energy and protein than does the food frequency questionnaire, with 24-hour recalls mostly intermediate. Differences were smaller and nonsignificant for protein density. Food frequencies, records, and recalls were, respectively, able to “explain” 3.8%, 7.8%, and 2.8% of biomarker variation for energy; 8.4%, 22.6%, and 16.2% of biomarker variation for protein; and 6.5%, 11.0%, and 7.0% of biomarker variation for protein density. However, calibration equations that include body mass index, age, and ethnicity substantially improve these numbers to 41.7%, 44.7%, and 42.1% for energy; 20.3%, 32.7%, and 28.4% for protein; and 8.7%, 14.4%, and 10.4% for protein density. Calibration equations using any of the assessment procedures may yield suitable consumption estimates for epidemiologic study purposes.
bias (epidemiology); biological markers; diet; energy intake; epidemiologic methods; measurement error; nutrition assessment
There is extensive evidence that increases in blood and tissue concentrations of steroid hormones and of insulin-like growth factor I (IGF-I) are associated with breast cancer risk. However, studies of common variation in genes involved in steroid hormone and IGF-I metabolism have yet to provide convincing evidence that such variants predict breast cancer risk. The Breast and Prostate Cancer Cohort Consortium (BPC3) is a collaboration of large US and European cohorts. We genotyped 1416 tagging single nucleotide polymorphisms (SNPs) in 37 steroid hormone metabolism genes and 24 IGF-I pathway genes in 6292 cases of breast cancer and 8135 controls, mostly Caucasian, postmenopausal women from the BPC3. We also imputed 3921 additional SNPs in the regions of interest. None of the SNPs tested was significantly associated with breast cancer risk, after correction for multiple comparisons. The results remained null when cases and controls were stratified by age at diagnosis/recruitment, advanced or nonadvanced disease, body mass index, with or without in situ cases; or restricted to Caucasians. Among 770 estrogen receptor-negative cases, an SNP located 3′ of growth hormone receptor (GHR) was marginally associated with increased risk after correction for multiple testing (Ptrend = 1.5 × 10−4). We found no significant overall associations between breast cancer and common germline variation in 61 genes involved in steroid hormone and IGF-I metabolism in this large, comprehensive study. Although previous studies have shown that variations in these genes can influence endogenous hormone levels, the magnitude of the effect of single SNPs does not appear to be sufficient to alter breast cancer risk.
B-vitamins are essential for one-carbon metabolism and have been linked to colorectal cancer (CRC). Although associations with folate have frequently been studied, studies on other plasma vitamins B2, B6, and B12 and CRC are scarce or inconclusive.
Nested case-control study within the European Prospective Investigation into Cancer and Nutrition, including 1365 incident CRC cases and 2319 controls matched for study center, age, and sex. We measured the sum of B2 species riboflavin and flavin mononucleotide, and the sum of B6 species pyridoxal 5′-phosphate, pyridoxal, and 4-pyridoxic acid as indicators for vitamin B2 and B6 status, as well as vitamin B12 in plasma samples collected at baseline. In addition, we determined eight polymorphisms related to one-carbon metabolism. Relative risks (RRs) for CRC were estimated using conditional logistic regression, adjusted for smoking, education, physical activity, BMI, alcohol consumption, and intakes of fiber, red- and processed meat.
RRs comparing highest to lowest quintile (95% confidence interval, Ptrend) were: 0.71 (0.56–0.91, 0.02) for vitamin B2, 0.68 (0.53–0.87, <0.001) for vitamin B6, and 1.02 (0.80–1.29, 0.19) for vitamin B12. The associations for vitamin B6 were stronger in males who consumed ≥ 30g alcohol/day. The polymorphisms were not associated with CRC.
Higher plasma concentrations of vitamins B2 and B6 are associated with a lower CRC risk.
This European population-based study is the first to indicate that vitamin B2 is inversely associated with CRC, and is in agreement to previously suggested inverse associations of vitamin B6 with CRC.
Plasma vitamins B2, B6, and B12; genetic variants; colorectal cancer; prospective study
The timing of puberty is highly variable1. We carried out a genome-wide association study for age at menarche in 4,714 women and report an association in LIN28B on chromosome 6 (rs314276, minor allele frequency (MAF) = 0.33, P = 1.5 × 10−8). In independent replication studies in 16,373 women, each major allele was associated with 0.12 years earlier menarche (95% CI = 0.08–0.16; P = 2.8 × 10−10; combined P = 3.6 × 10−16). This allele was also associated with earlier breast development in girls (P = 0.001; N = 4,271); earlier voice breaking (P = 0.006, N = 1,026) and more advanced pubic hair development in boys (P = 0.01; N = 4,588); a faster tempo of height growth in girls (P = 0.00008; N = 4,271) and boys (P = 0.03; N = 4,588); and shorter adult height in women (P = 3.6 × 10−7; N = 17,274) and men (P = 0.006; N = 9,840) in keeping with earlier growth cessation. These studies identify variation in LIN28B, a potent and specific regulator of microRNA processing2, as the first genetic determinant regulating the timing of human pubertal growth and development.
A potential dual role of folate in colorectal cancer (CRC) is currently subject to debate. Previous studies on plasma folate and CRC risk were small and inconclusive. We therefore investigate associations between plasma folate, a number of relevant folate-related polymorphisms and CRC risk. In this nested case-control study within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, 1367 incident CRC cases were matched to 2325 controls for study center, age and sex. Risk ratios (RR) were estimated with conditional logistic regression and further adjusted for smoking, education, physical activity, and intake of alcohol and fiber. Overall analyses did not reveal associations of plasma folate with CRC. The RR (95% CI), Ptrend) for the fifth vs. the first quintile of folate status was 0.94 ((0.74; 1.20), 0.44). The polymorphisms MTHFR 677C→T, MTHFR 1298A→C, MTR 2756A→G, MTRR 66A→G, and MTHFD1 1958G→A were not associated with CRC risk. However, in individuals with the lowest plasma folate concentrations, the MTHFR 677TT genotype showed a statistically non-significant increased CRC risk (RR (95% CI, Ptrend) TT vs. CC =1.39 (0.87; 2.21), 0.12), whereas in those with the highest folate concentrations showed a non-significant decreased CRC risk (RR TT vs. CC=0.74 (0.39; 1.37), 0.34). The SLC19A1 80G→A showed a positive association with CRC risk (RR AA vs. GG1.30 (1.06; 1.59), <0.01).
Within this large European prospective multicenter study we did not observe an association of CRC risk with plasma folate status, nor with the MTHFR polymorphisms.
Plasma folate; genetic variants; colorectal cancer; prospective study
Previous studies have reported that shorter mean telomere length in lymphocytes is associated with increased susceptibility to common diseases of aging, and may be predictive of cancer risk. However, most analyses have examined retrospectively-collected case-control studies.
Mean telomere length was measured using high-throughput quantitative Real Time PCR. Blood for DNA extraction was collected after cancer diagnosis in the East Anglian SEARCH Breast (2243 cases, 2181 controls) and SEARCH Colorectal (2249 cases, 2161 controls) studies. Prospective case-control studies were conducted for breast cancer (199 cases) and colorectal cancer (185 cases), nested within the EPIC-Norfolk cohort. Blood has been collected at least 6 months prior to diagnosis, and was matched to DNA from two cancer-free controls per case.
In the retrospective, SEARCH studies, the age-adjusted Odds Ratios for shortest (Q4) vs. longest (Q1) quartile of mean telomere length was 15.5 (95%CI 11.6–20.8), p-het=5.7×10−75; with a ‘per quartile’ p-trend=2.1×10−80 for breast cancer, and 2.14 (95%CI 1.77–2.59), p-het=7.3×10−15; with a ‘per quartile’ p-trend=1.8×10−13 for colorectal cancer. In the prospective, EPIC study, the comparable Odds Ratios [Q4 vs. Q1] were 1.58 (95%CI 0.75–3.31), p-het=0.23 for breast cancer, and 1.13 (95%CI 0.54–2.36), p-het=0.75 for colorectal cancer risk.
Mean telomere length was shorter in retrospectively-collected cases than in controls but the equivalent association was markedly weaker in the prospective studies. This suggests that telomere shortening largely occurs after diagnosis, and may not, therefore, be of value in cancer prediction.
A research framework based on the personal characteristic defined by a sense of coherence (SOC) focuses on the effective use of resources to maintain good health.
To test the hypothesis that individual differences in SOC are associated with healthier lifestyle choices independently of social class and education.
Design and setting
Cross sectional. Population based cohort study recruited through 35 general practice registers. Reported dietary intakes of alcohol, fruit and vegetables, fibre, saturated fat, non‐discretionary salt (sodium), and total sugars were assessed by food frequency questionnaire. Current cigarette smoking, physical inactivity, and SOC were assessed through questionnaires.
7863 men and 10 424 women. Residents of Norfolk (UK).
Compared with participants with the weakest SOC, those with the strongest were 28% less likely to be current smokers (odds ratio 0.72 (95% confidence interval (CI), 0.58 to 0.89)), 36% less likely to be physically inactive (0.64 (0.55 to 0.75)), and reportedly consumed on average 63 g/day more fruit and vegetables (95% CI, 46 to 80), and 1.2 g/day more fibre (0.8 to 1.6). These associations were independent of age, sex, social class, and education. For physical inactivity and consumption of fruit, vegetables, and fibre, these differences exceeded those observed between the extremes of social class and education.
Individual differences in SOC are associated with healthy lifestyle choices independently of social class and education, and may therefore aid the design of future health promotion interventions.
sense of coherence; smoking; physical activity; alcohol; diet
To investigate the association between fish and seafood intake and new-onset type 2 diabetes.
RESEARCH DESIGN AND METHODS
This was a population-based prospective cohort (European Prospective Investigation of Cancer [EPIC]-Norfolk) study of men and women aged 40–79 years at baseline (1993–1997). Habitual fish and seafood intake (white fish, oily fish, fried fish, and shellfish) was assessed using a semiquantitative food frequency questionnaire and categorized as less than one or one or more portions/week. During a median (interquartile range) follow-up of 10.2 (9.1–11.2) years, there were 725 incident diabetes cases among 21,984 eligible participants.
Higher total fish intake (one or more versus less than one portions/week) was associated with a significantly lower risk of diabetes (odds ratio [OR] 0.75 [95% CI 0.58–0.96]), in analyses adjusted for age, sex, family history of diabetes, education, smoking, physical activity, dietary factors (total energy intake, alcohol intake, and plasma vitamin C) and obesity (BMI and waist circumference). White fish and oily fish intakes were similarly inversely associated with diabetes risk, but the associations were not significant after adjustment for dietary factors (oily fish) or obesity (white fish). Fried fish was not significantly associated with diabetes risk. Consuming one or more portions/week of shellfish was associated with an increased risk of diabetes (OR 1.36 [1.02–1.81]) in adjusted analyses.
Total, white, and oily fish consumption may be beneficial for reducing risk of diabetes, reinforcing the public health message to consume fish regularly. Greater shellfish intake seems to be associated with an increased risk of diabetes, warranting further investigation into cooking methods and mechanisms.
Elevated blood pressure is a common, heritable cause of cardiovascular disease worldwide. To date, identification of common genetic variants influencing blood pressure has proven challenging. We tested 2.5m genotyped and imputed SNPs for association with systolic and diastolic blood pressure in 34,433 subjects of European ancestry from the Global BPgen consortium and followed up findings with direct genotyping (N≤71,225 European ancestry, N=12,889 Indian Asian ancestry) and in silico comparison (CHARGE consortium, N=29,136). We identified association between systolic or diastolic blood pressure and common variants in 8 regions near the CYP17A1 (P=7×10−24), CYP1A2 (P=1×10−23), FGF5 (P=1×10−21), SH2B3 (P=3×10−18), MTHFR (P=2×10−13), c10orf107 (P=1×10−9), ZNF652 (P=5×10−9) and PLCD3 (P=1×10−8) genes. All variants associated with continuous blood pressure were associated with dichotomous hypertension. These associations between common variants and blood pressure and hypertension offer mechanistic insights into the regulation of blood pressure and may point to novel targets for interventions to prevent cardiovascular disease.
Smoking is an established risk factor for pancreatic cancer; however, detailed examination of the association of smoking intensity, smoking duration, and cumulative smoking dose with pancreatic cancer is limited. The authors analyzed pooled data from the international Pancreatic Cancer Cohort Consortium nested case-control study (1,481 cases, 1,539 controls). Odds ratios and 95% confidence intervals were calculated by using unconditional logistic regression. Smoking intensity effects were examined with an excess odds ratio model that was linear in pack-years and exponential in cigarettes smoked per day and its square. When compared with never smokers, current smokers had a significantly elevated risk (odds ratio (OR) = 1.77, 95% confidence interval (CI): 1.38, 2.26). Risk increased significantly with greater intensity (≥30 cigarettes/day: OR = 1.75, 95% CI: 1.27, 2.42), duration (≥50 years: OR = 2.13, 95% CI: 1.25, 3.62), and cumulative smoking dose (≥40 pack-years: OR = 1.78, 95% CI: 1.35, 2.34). Risk more than 15 years after smoking cessation was similar to that for never smokers. Estimates of excess odds ratio per pack-year declined with increasing intensity, suggesting greater risk for total exposure delivered at lower intensity for longer duration than for higher intensity for shorter duration. This finding and the decline in risk after smoking cessation suggest that smoking has a late-stage effect on pancreatic carcinogenesis.
pancreas; pancreatic neoplasms; smoking; tobacco use cessation
Pooled data were analyzed from the NCI Pancreatic Cancer Cohort Consortium (PanScan) to study the association between pre-diagnostic anthropometric measures and risk of pancreatic cancer.
PanScan applied a nested case-control study design and included 2,170 cases and 2,209 controls. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using unconditional logistic regression for cohort-specific quartiles of body mass index (BMI), weight, height, waist circumference, and waist-to-hip ratio (WHR), as well as conventional BMI categories: underweight (<18.5 kg/m2), normal (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), obese (30.0-34.9 kg/m2), and severely obese (≥35.0 kg/m2). Models were adjusted for potential confounders.
Among all subjects, a positive association between increasing BMI and risk of pancreatic cancer was observed (adjusted OR for the highest vs. lowest BMI quartile = 1.33, 95% CI = 1.12-1.58, Ptrend < 0.001). Among men, the adjusted OR for pancreatic cancer for the highest vs. lowest quartile of BMI was 1.33 (95% CI = 1.04-1.69, Ptrend <0.03). Among women, the adjusted OR for pancreatic cancer for the highest quartile of BMI was 1.34 (95% CI = 1.05-1.70, Ptrend = 0.01). Increased WHR was associated with increased risk of pancreatic cancer among women (adjusted OR for the highest vs. lowest quartile = 1.87, 95% CI = 1.31-2.69, Ptrend = 0.003) but less so in men.
The findings provide strong support for a positive association between BMI and pancreatic cancer risk. In addition, centralized fat distribution may increase pancreatic cancer risk, especially in women.
Anthropometry; body mass index; cohort consortium; obesity; pancreatic cancer
The aim of this study is to investigate to what extent occupational exposures may explain socioeconomic inequalities in lung cancer incidence after adjusting for smoking and dietary factors. Analyses were based on a subsample of the European Prospective Investigation into Cancer and Nutrition (EPIC study), a prospective cohort. Analyses included 703 incident lung cancer cases among men in Denmark, the UK, Germany, Italy, Spain and Greece. Socioeconomic position was measured using the highest level of education. Estimates of relative indices of inequality (RII) were computed with Cox regression models. We first adjusted for smoking (with detailed information on duration and quantity) and dietary factors (fruits and vegetables consumption) and then for occupational exposures. Exposure to three carcinogens (asbestos, heavy metals and polycyclic aromatic hydrocarbons) was analyzed. Occupational exposures explained 14% of the socioeconomic inequalities remaining after adjustment for smoking and fruits and vegetables consumption. Inequalities remained nevertheless statistically significant. The RII decreased from 1.87 (95% CI: 1.36–2.56) to 1.75 (1.27–2.41). The decrease was more pronounced when adjusting for asbestos than for heavy metals or PAH. Analyses by birth cohort suggested an effect of occupational exposures among older men, while due to small number of endpoints no conclusion could be drawn about the role of occupational exposures in educational inequalities among younger men. Our study revealed that the impact of occupational exposures on socioeconomic inequalities in cancer incidence, rarely studied until now, exists while of modest magnitude.
Cohort Studies; Educational Status; Humans; Incidence; Lung Neoplasms; epidemiology; etiology; Male; Occupational Exposure; adverse effects; Proportional Hazards Models; Prospective Studies; Socioeconomic Factors; Lung cancer incidence; education; men; occupational exposure
The authors previously reported equations, derived from the Nutrient Biomarker Study within the Women's Health Initiative, that produce calibrated estimates of energy, protein, and percentage of energy from protein consumption from corresponding food frequency questionnaire estimates and data on other factors, such as body mass index, age, and ethnicity. Here, these equations were applied to yield calibrated consumption estimates for 21,711 women enrolled in the Women's Health Initiative dietary modification trial comparison group and 59,105 women enrolled in the observational study. These estimates were related prospectively to total and site-specific invasive cancer incidence (1993–2005). In combined cohort analyses that do not control for body mass, uncalibrated energy was not associated with total cancer incidence or site-specific cancer incidence for most sites, whereas biomarker-calibrated energy was positively associated with total cancer (hazard ratio = 1.18, 95% confidence interval: 1.10, 1.27, for 20% consumption increase), as well as with breast, colon, endometrial, and kidney cancer (respective hazard ratios of 1.24, 1.35, 1.83, and 1.47). Calibrated protein was weakly associated, and calibrated percentage of energy from protein was inversely associated, with total cancer. Calibrated energy and body mass index associations were highly interdependent. Implications for the interpretation of nutritional epidemiology studies are described.
bias (epidemiology); biological markers; diet; energy intake; epidemiologic methods; neoplasms; nutrition assessment; proteins
Studies in many countries have reported higher lung cancer incidence and mortality in individuals with lower socioeconomic status.
To investigate the role of smoking in these inequalities, we used data from 391,251 participants in the European Prospective Investigation into Cancer and Nutrition study, a cohort of individuals in 10 European countries. We collected information on smoking (history and quantity) and education through questionnaires at study entry and gathered data on lung cancer incidence for a mean of 8.4 years. Socioeconomic status was defined as the highest attained level of education, and participants were grouped by sex and region of residence (Northern Europe, Germany, or Southern Europe). Relative indices of inequality (RIIs) of lung cancer risk unadjusted and adjusted for smoking were estimated using Cox regression models. Additional analyses were performed by histologic type.
During the study period, 939 men and 692 women developed lung cancer. Inequalities in lung cancer risk (RIImen=3.62, 95% confidence interval [CI] = 2.77 to 4.73, 117 vs 52 per 100,000 person-years for lowest vs highest education level; RIIwomen=2.39, 95% CI = 1.77 to 3.21, 46 vs 25 per 100,000 person-years) decreased after adjustment for smoking but remained statistically significant (RIImen=2.29, 95% CI = 1.75 to 3.01; RIIwomen=1.59, 95% CI = 1.18 to 2.13). Large RIIs were observed among men and women in Northern European countries and among men in Germany, but inequalities in lung cancer risk were reverse (RIIs < 1) among women in Southern European countries. Inequalities differed by histologic type. Adjustment for smoking reduced inequalities similarly for all histologic types and among men and women in all regions.
Self reported smoking consistently explains approximately 50% of the inequalities in lung cancer risk due to differences in education.
Adult; Aged; Confounding Factors (Epidemiology); Educational Status; Europe; epidemiology; Female; Food Habits; Fruit; Humans; Incidence; Lung Neoplasms; epidemiology; etiology; pathology; Male; Middle Aged; Odds Ratio; Proportional Hazards Models; Prospective Studies; Questionnaires; Risk Assessment; Risk Factors; Sex Factors; Smoking; adverse effects; epidemiology; Social Class; Vegetables; lung cancer incidence; cohort study; Europe; EPIC; men; women; smoking; diet; education
We conducted a two-stage genome-wide association study (GWAS) of pancreatic cancer, a cancer with one of the poorest survival rates worldwide. Initially, we genotyped 558,542 single nucleotide polymorphisms in 1,896 incident cases and 1,939 controls drawn from twelve prospective cohorts plus one hospital-based case-control study. In a combined analysis adjusted for study, sex, ancestry and five principal components that included an additional 2,457 cases and 2,654 controls from eight case-control studies, we identified an association between a locus on 9q34 and pancreatic cancer marked by the single nucleotide polymorphism, rs505922 (combined P=5.37 × 10-8; multiplicative per-allele odds ratio (OR) 1.20; 95% CI 1.12-1.28). This SNP maps to the first intron of the ABO blood group gene. Our results are consistent with earlier epidemiologic evidence suggesting that people with blood group O may have a lower risk of pancreatic cancer than those with groups A or B.
We have conducted a three-stage, comprehensive single nucleotide polymorphism (SNP)-tagging association study of ESR1 gene variants (SNPs) in more than 55 000 breast cancer cases and controls from studies within the Breast Cancer Association Consortium (BCAC). No large risks or highly significant associations were revealed. SNP rs3020314, tagging a region of ESR1 intron 4, is associated with an increase in breast cancer susceptibility with a dominant mode of action in European populations. Carriers of the c-allele have an odds ratio (OR) of 1.05 [95% Confidence Intervals (CI) 1.02–1.09] relative to t-allele homozygotes, P = 0.004. There is significant heterogeneity between studies, P = 0.002. The increased risk appears largely confined to oestrogen receptor-positive tumour risk. The region tagged by SNP rs3020314 contains sequence that is more highly conserved across mammalian species than the rest of intron 4, and it may subtly alter the ratio of two mRNA splice forms.
OBJECTIVE—Accumulating evidence suggests that energy-dense foods predispose to obesity and that such foods may also be associated with an increased risk of type 2 diabetes, but there is limited evidence. Our aim was to investigate whether there is an independent association between dietary energy density and incidence of diabetes.
RESEARCH DESIGN AND METHODS—The European Prospective Investigation of Cancer (EPIC)-Norfolk Cohort Study was a population-based prospective study of individuals aged 40–79 years at baseline. We calculated energy density for overall diet (all solids and drinks) using food frequency questionnaires. During 12 years of follow-up, we documented 725 new-onset cases of diabetes among 21,919 participants without diabetes, cancer, or cardiovascular disease at baseline.
RESULTS—Baseline energy density (adjusted for age, sex, and baseline BMI) was higher in those who developed type 2 diabetes (mean 3.08 kJ/g [95% CI 3.03–3.13]) than in those who remained nondiabetic (3.01 kJ/g [3.00–3.02]) (P = 0.012). Energy density was positively associated with incident diabetes (odds ratio 1.21 per unit increase [95% CI 1.06–1.38]) adjusted for known risk factors. There was a 60% higher risk of diabetes (1.60 [1.19–2.16]) in the highest quintile of energy density (range 3.55–7.97 kJ/g) compared with the lowest quintile (1.04–2.43 kJ/g) in adjusted analysis.
CONCLUSIONS—This is the first large population-based prospective study to report that an energy-dense diet may be associated with increased risk of development of diabetes, independent of baseline obesity. The potential public health impact of a low–energy-dense diet on reducing the risk of diabetes deserves further study.
Gonadotropin releasing hormone (GNRH1) triggers the release of follicle stimulating hormone and luteinizing hormone from the pituitary. Genetic variants in the gene encoding GNRH1 or its receptor may influence breast cancer risk by modulating production of ovarian steroid hormones. We studied the association between breast cancer risk and polymorphisms in genes that code for GNRH1 and its receptor (GNRHR) in the large National Cancer Institute Breast and Prostate Cancer Cohort Consortium (NCI-BPC3).
We sequenced exons of GNRH1 and GNRHR in 95 invasive breast cancer cases. Resulting single nucleotide polymorphisms (SNPs) were genotyped and used to identify haplotype-tagging SNPs (htSNPS) in a panel of 349 healthy women. The htSNPs were genotyped in 5,603 invasive breast cancer cases and 7,480 controls from the Cancer Prevention Study-II (CPS-II), European Prospective Investigation on Cancer and Nutrition (EPIC), Multiethnic Cohort (MEC), Nurses' Health Study (NHS), and Women's Health Study (WHS). Circulating levels of sex steroids (androstenedione, estradiol, estrone and testosterone) were also measured in 4713 study subjects.
Breast cancer risk was not associated with any polymorphism or haplotype in the GNRH1 and GNRHR genes, nor were there any statistically significant interactions with known breast cancer risk factors. Polymorphisms in these two genes were not strongly associated with circulating hormone levels.
Common variants of the GNRH1 and GNRHR genes are not associated with risk of invasive breast cancer in Caucasians.
Common variants at only two loci, FTO and MC4R, have been reproducibly associated with body mass index (BMI) in humans. To identify additional loci, we conducted meta-analysis of 15 genome-wide association studies for BMI (n > 32,000) and followed up top signals in 14 additional cohorts (n > 59,000). We strongly confirm FTO and MC4R and identify six additional loci (P < 5 × 10−8): TMEM18, KCTD15, GNPDA2, SH2B1, MTCH2 and NEGR1 (where a 45-kb deletion polymorphism is a candidate causal variant). Several of the likely causal genes are highly expressed or known to act in the central nervous system (CNS), emphasizing, as in rare monogenic forms of obesity, the role of the CNS in predisposition to obesity.
Recently, the rs6232 (N221D) and rs6235 (S690T) SNPs in the PCSK1 gene were associated with obesity in a meta-analysis comprising more than 13 000 individuals of European ancestry. Each additional minor allele of rs6232 or rs6235 was associated with a 1.34- or 1.22-fold increase in the risk of obesity, respectively. So far, only one relatively small study has aimed to replicate these findings, but could not confirm the association of the rs6235 SNP and did not study the rs6232 variant. In the present study, we examined the associations of the rs6232 and rs6235 SNPs with obesity in a population-based cohort consisting of 20 249 individuals of European descent from Norfolk, UK. Logistic regression and generalized linear models were used to test the associations of the risk alleles with obesity and related quantitative traits, respectively. Neither of the SNPs was significantly associated with obesity, BMI or waist circumference under the additive genetic model (P > 0.05). However, we observed an interaction between rs6232 and age on the level of BMI (P = 0.010) and risk of obesity (P = 0.020). The rs6232 SNP was associated with BMI (P = 0.021) and obesity (P = 0.022) in the younger individuals [less than median age (59 years)], but not among the older age group (P = 0.81 and P = 0.68 for BMI and obesity, respectively). In conclusion, our data suggest that the PCSK1 rs6232 and rs6235 SNPs are not major contributors to common obesity in the general population. However, the effect of rs6232 may be age-dependent.
Haem in red meat (RM) stimulates the endogenous production of mutagenic nitroso compounds (NOC). Processed (nitrite-preserved red) meat additionally contains high concentrations of preformed NOC. In two studies, of a fresh RM versus a vegetarian (VEG) diet (six males and six females) and of a nitrite-preserved red meat (PM) versus a VEG diet (5 males and 11 females), we investigated whether processing of meat might increase colorectal cancer risk by stimulating nitrosation and DNA damage. Meat diets contained 420 g (males) or 366 g (females) meat/per day. Faecal homogenates from day 10 onwards were analysed for haem and NOC and associated supernatants for genotoxicity. Means are adjusted for differences in male to female ratios between studies. Faecal NOC concentrations on VEG diets were low (2.6 and 3.5 mmol/g) but significantly higher on meat diets (PM 175 ± 19 nmol/g versus RM 185 ± 22 nmol/g; P = 0.75). The RM diet resulted in a larger proportion of nitrosyl iron (RM 78% versus PM 54%; P < 0.0001) and less nitrosothiols (RM 12% versus PM 19%; P < 0.01) and other NOC (RM 10% versus PM 27%; P < 0.0001). There was no statistically significant difference in DNA breaks induced by faecal water (FW) following PM and RM diets (P = 0.80). However, PM resulted in higher levels of oxidized pyrimidines (P < 0.05). Surprisingly, VEG diets resulted in significantly more FW-induced DNA strand breaks than the meat diets (P < 0.05), which needs to be clarified in further studies. Meats cured with nitrite have the same effect as fresh RM on endogenous nitrosation but show increased FW-induced oxidative DNA damage.
To identify common variants influencing body mass index (BMI), we analyzed genome-wide association data from 16,876 individuals of European descent. After previously reported variants in FTO, the strongest association signal (rs17782313, P = 2.9 × 10−6) mapped 188 kb downstream of MC4R (melanocortin-4 receptor), mutations of which are the leading cause of monogenic severe childhood-onset obesity. We confirmed the BMI association in 60,352 adults (per-allele effect = 0.05 Z-score units; P = 2.8 × 10−15) and 5,988 children aged 7–11 (0.13 Z-score units; P = 1.5 × 10−8). In case-control analyses (n = 10,583), the odds for severe childhood obesity reached 1.30 (P = 8.0 × 10−11). Furthermore, we observed overtransmission of the risk allele to obese offspring in 660 families (P (pedigree disequilibrium test average; PDT-avg) = 2.4 × 10−4). The SNP location and patterns of phenotypic associations are consistent with effects mediated through altered MC4R function. Our findings establish that common variants near MC4R influence fat mass, weight and obesity risk at the population level and reinforce the need for large-scale data integration to identify variants influencing continuous biomedical traits.
Results from the majority of studies show little association between circulating concentrations of vitamin D and prostate cancer risk, a finding that has not been demonstrated in a wider European population, however. The authors examined whether vitamin D concentrations were associated with prostate cancer risk in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (1994–2000). Serum concentrations of 25-hydroxyvitamin D were measured in 652 prostate cancer cases matched to 752 controls from 7 European countries after a median follow-up time of 4.1 years. Conditional logistic regression models were used to calculate odds ratios for prostate cancer risk in relation to serum 25-hydroxyvitamin D after standardizing for month of blood collection and adjusting for covariates. No significant association was found between 25-hydroxyvitamin D and risk of prostate cancer (highest vs. lowest quintile: odds ratio = 1.28, 95% confidence interval: 0.88, 1.88; P for trend = 0.188). Subgroup analyses showed no significant heterogeneity by cancer stage or grade, age at diagnosis, body mass index, time from blood collection to diagnosis, or calcium intake. In summary, the results of this large nested case-control study provide no evidence in support of a protective effect of circulating concentrations of vitamin D on the risk of prostate cancer.
prostatic neoplasms; serum; vitamin D; 25-hydroxyvitamin D 2