Lessons learned from a multi-data source research collaboration: The mirabegron post-authorization safety study program.

BACKGROUND: Many factors contribute to developing and conducting a successful multi-data source, non-interventional, post-authorization safety study (NI-PASS) for submission to multiple health authorities. Such studies are often large undertakings; evaluating and sharing lessons learned can provide useful insights to others considering similar studies. OBJECTIVES: We discuss challenges and key methodological and organizational factors that led to the delivery of a successful post-marketing requirement (PMR)/PASS program investigating the risk of cardiovascular and cancer events among users of mirabegron, an oral medication for the treatment of overactive bladder. RESULTS: We provide context and share learnings, including sections on research program collaboration, scientific transparency, organizational approach, mitigation of uncertainty around potential delays, validity of study outcomes, selection of data sources and optimizing patient numbers, choice of comparator groups and enhancing precision of estimates of associations, potential confounding and generalizability of study findings, and interpretation of results. CONCLUSIONS: This large PMR/PASS program was a long-term commitment from all parties and benefited from an effective coordinating center and extensive scientific interactions across research partners, scientific advisory board, study sponsor, and health authorities, and delivered useful learnings related to the design and organization of multi-data source NI-PASS.

Cardiovascular Risk in Users of Mirabegron Compared with Users of Antimuscarinic Treatments for Overactive Bladder: Findings from a Non-Interventional, Multinational, Cohort Study.

INTRODUCTION: During clinical trials, mirabegron, a ß3-adrenoreceptor agonist, was associated with increased vital signs vs placebo in patients with overactive bladder. OBJECTIVE: The purpose of this study was to compare incidence rates of adverse cardiovascular (CV) outcomes following mirabegron or antimuscarinic use. METHODS: We conducted an observational post-marketing safety study utilising real-world data. The study population was identified within five sources: Danish and Swedish National Registers, Clinical Practice Research Datalink (UK), Optum (USA) and Humana (USA). Episodes of time when patients were new users of mirabegron or antimuscarinics (October 2012-December 2018) were sourced from prescriptions and matched on propensity scores. Occurrences of major adverse cardiovascular events (MACE), acute myocardial infarction (AMI), stroke, CV mortality and all-cause mortality were identified. Outcome incidence rates and hazard ratios from Cox models were estimated. RESULTS: Overall, 152,026 mirabegron and 152,026 antimuscarinic episodes were matched. The population consisted of 63.1% women and 72.6% were ≥ 65 years old. There were no appreciable differences in the incidence rates of MACE, AMI or stroke between users of mirabegron and antimuscarinics. Incidence rates of CV mortality (hazard ratio 0.83, 95% confidence interval 0.73-0.95) and all-cause mortality (hazard ratio 0.80, 95% confidence interval 0.76-0.84) were no higher with mirabegron vs antimuscarinics. Results restricted to episodes at high risk for CV events or stratified by age (< 65 years, ≥ 65 years) or prior overactive bladder medication use were consistent with overall findings. CONCLUSIONS: This large, multinational study found no higher risk of MACE, AMI, stroke, CV mortality or all-cause mortality among users of mirabegron relative to users of antimuscarinics.

During clinical trials, mirabegron, which is a treatment for overactive bladder, was associated with small increases in heart rate and blood pressure. This study was conducted to compare the frequency of cardiac events following the use of mirabegron or antimuscarinics, a group of treatments also used to treat overactive bladder. We obtained the data for this study from four countries: Denmark, Sweden, the UK and the USA. We identified people who were new users of mirabegron or antimuscarinics from 2012 to 2018 using prescription or dispensing records. Occurrences of major cardiac events, heart attack, stroke, death due to cardiac events and death from any cause were evaluated. Overall, we identified 152,026 times when mirabegron or antimuscarinics were each used as new treatments. Most of the people in the study were women (63.1%) and at least 65 years old (72.6%). There were no notable differences between the treatment groups with regard to how often major cardiac events, heart attack or stroke occurred. Further, death due to cardiac events and death from any cause were no higher with mirabegron compared with antimuscarinics. We obtained similar results when the data were assessed for patients who were at high risk for cardiac events or split by age (less than 65 years or at least 65 years) or a history of overactive bladder medication use. In conclusion, this large study involving data from several countries found no higher risk of major cardiac events, heart attack, stroke or death among people prescribed mirabegron compared with antimuscarinics.

A study of cancer occurrence in users of mirabegron and antimuscarinic treatments for overactive bladder.

OBJECTIVE: This post-authorization safety study (EU PAS Register Number: EUPAS16088) was designed to compare the incidence of cancer outcomes in patients treated with mirabegron versus antimuscarinic medications. METHODS: Cohorts of mirabegron initiators during 2012-2018 were propensity-score matched to antimuscarinic medication initiators within real-world data sources (Danish National Registers, Swedish National Registers, Clinical Practice Research Datalink [UK], Optum [US], and Humana [US]). Incident cancer cases were identified during follow-up from direct linkage to cancer registers or validated through medical record review or through physician questionnaires. Comparisons of sex-specific composite cancer outcomes (cancer of the lung/bronchus, colon/rectum, melanoma of skin, urinary bladder, non-Hodgkin lymphoma, kidney/renal pelvis, pancreas, prostate in men and breast and uterus in women) were made overall and for person-time in the first year and after the first year following start of treatment, for all ages and for the subgroup ≥65 years. RESULTS: Among the 80,637 mirabegron initiators matched to 169,885 antimuscarinic medication initiators, 68% were at least 65 years of age and 66% were women. Over 5000 incident cancer cases were observed overall. Incidence rates were higher for men than women for composite and individual cancer outcomes. The pooled fixed effects hazard ratios for composite cancer outcomes (all ages) were 1.05 (95% confidence interval [CI]: 0.98-1.14) for women and 1.06 (95% CI: 0.98-1.14) for men. Results were similar in persons ≥65 years. CONCLUSIONS: The results suggest no association between mirabegron use and risk of cancer, compared with antimuscarinic medications, in either men or women. Registration: EU PAS Register Number: EUPAS16088.

Validation of cardiovascular outcomes and risk factors in the Clinical Practice Research Datalink in the United Kingdom.

PURPOSE: Strategies to identify and validate acute myocardial infarction (AMI) and stroke in primary-care electronic records may impact effect measures, but to an unknown extent. Additionally, the validity of cardiovascular risk factors that could act as confounders in studies on those endpoints has not been thoroughly assessed in the United Kingdom Clinical Practice Research Datalink's (CPRD's) GOLD database. We explored the validity of algorithms to identify cardiovascular outcomes and risk factors and evaluated different outcome-identification strategies using these algorithms for estimation of adjusted incidence rate ratios (IRRs). METHODS: First, we identified AMI, stroke, smoking, obesity, and menopausal status in a cohort treated for overactive bladder by applying computerized algorithms to primary care medical records (2004-2012). We validated these cardiovascular outcomes and risk factors with physician questionnaires (gold standard for this analysis). Second, we estimated IRRs for AMI and stroke using algorithm-identified and questionnaire-confirmed cases, comparing these with IRRs from cases identified through linkage with hospitalization/mortality data (best estimate). RESULTS: For AMI, the algorithm's positive predictive value (PPV) was >90%. Initial algorithms for stroke performed less well because of inclusion of codes for prevalent stroke; algorithm refinement increased PPV to 80% but decreased sensitivity by 20%. Algorithms for smoking and obesity were considered valid. IRRs based on questionnaire-confirmed cases only were closer to IRRs estimated from hospitalization/mortality data than IRRs from algorithm-identified cases. CONCLUSIONS: AMI, stroke, smoking, obesity, and postmenopausal status can be accurately identified in CPRD. Physician questionnaire-validated AMI and stroke cases yield IRRs closest to the best estimate.

Evaluating the Effectiveness of an Additional Risk Minimization Measure to Reduce the Risk of Prescribing Mirabegron to Patients with Severe Uncontrolled Hypertension in Four European Countries.

BACKGROUND: Mirabegron, indicated for the treatment of overactive bladder, is contraindicated in patients with severe uncontrolled hypertension (systolic blood pressure ≥180 mm Hg and/or diastolic blood pressure ≥110 mm Hg). In September 2015, a Direct Healthcare Professional Communication (DHPC) letter was disseminated as an additional risk minimisation measure. PURPOSE: To assess the effectiveness of the DHPC in reducing the proportions of patients with severe or non-severe uncontrolled hypertension at mirabegron initiation. METHODS: An observational multi-database cohort study was undertaken using routinely collected healthcare data (December 2012-December 2016) from the PHARMO Database Network (Netherlands), SIDIAP database (Spain), CPRD (United Kingdom, UK) and national healthcare registers and electronic medical records from Finland. DHPC effectiveness was evaluated using interrupted time series analyses comparing trends and changes in monthly proportions of severe or non-severe uncontrolled hypertensive mirabegron initiations relative to the timing of the DHPC dissemination. RESULTS: The study population comprised 52,078 patients. Prior to DHPC dissemination, across the four databases, 0.3-1.3% had severe uncontrolled hypertension. Estimated absolute changes (EAC) in proportions of severe uncontrolled hypertension post-DHPC indicated a tendency towards a lower proportion in the Netherlands (EAC -0.36%, p=0.053), unchanged proportions in Spain and the UK and a higher proportion in Finland (EAC +0.73%, p=0.016). For non-severe uncontrolled hypertension (13-16% pre-DHPC), post-DHPC proportions tended to be lower in the Netherlands (EAC -2.02%, p=0.038) and Spain (EAC -1.04%, p=0.071), and unchanged in the UK and Finland. CONCLUSION: Severe uncontrolled hypertension prior to mirabegron initiation was uncommon in these four European countries even before DHPC dissemination. This suggests that other risk minimisation communications (prior to the DHPC dissemination) had worked adequately with respect to minimising mirabegron use among patients with severe uncontrolled hypertension. No strong and consistent evidence of further risk minimisation after the DHPC dissemination was observed in this study.

Plasma 25-Hydroxyvitamin D and Mortality in Patients With Suspected Stable Angina Pectoris.

Context and Objective: Vitamin D status may affect cardiovascular disease (CVD) development and survival. We studied the relationship between concentrations of the circulating biomarker 25-hydroxyvitamin D (25OHD) and all-cause and cardiovascular mortality risk. Design, Setting, Participants, and Main Outcome Measures: 25OHD, the sum of 25-hydroxyvitamin D3 and 25-hydroxyvitamin D2, was analyzed in plasma samples from 4114 white patients suspected of having stable angina pectoris and was adjusted for seasonal variation. Hazard ratios (HRs) for all-cause and cardiovascular mortality were estimated by using multivariable Cox models with 25OHD as the main exposure variable, with adjustment for study site, age, sex, smoking, body mass index, estimated glomerular filtration rate, and systolic blood pressure. Results: A total of 895 (21.8%) deaths, including 407 (9.9%) from CVD causes, occurred during a mean ± standard deviation follow-up of 11.9 ± 3.0 years. Compared with the first 25OHD quartile, HRs in the second, third, and fourth quartiles were 0.64 [95% confidence interval (CI), 0.54 to 0.77], 0.56 (95% CI, 0.46 to 0.67), and 0.56 (95% CI, 0.46 to 0.67) for all-cause mortality and 0.70 (95% CI, 0.53 to 0.91), 0.60 (95% CI, 0.45 to 0.79), and 0.57 (95% CI, 0.43 to 0.75) for cardiovascular mortality, respectively. Threshold analysis demonstrated increased all-cause and CVD mortality in patients with 25OHD concentrations below ∼42.5 nmol/L. Moreover, analysis suggested increased all-cause mortality at concentrations >100 nmol/L. Conclusion: Plasma 25OHD concentrations were inversely associated with cardiovascular mortality and nonlinearly (U-shaped) associated with all-cause mortality.

Incidence of Common Cancers in Users of Antimuscarinic Medications for Overactive Bladder: A Danish Nationwide Cohort Study.

The purpose of this study was to estimate the incidence rate (IR) of 10 common cancers in new users of antimuscarinic overactive bladder (OAB) medications. We conducted a cohort study using data recorded in Danish registers for patients newly exposed to the OAB drugs, darifenacin, fesoterodine, oxybutynin, solifenacin, tolterodine or trospium in years 2004-2012, aged ≥18 years and without cancer before treatment initiation. We estimated IRs for each study cancer (bladder, breast, colorectal, lung, melanoma, non-Hodgkin lymphoma, pancreas, prostate, renal and uterine), standardised by age and sex and explored IR trends over time since treatment initiation. For all cancer analyses, only the first incident targeted cancer was considered. Of 72,917 patients (60% women; mean age at treatment start: 66 years), 3475 developed a study cancer during 259,072 person-years of follow-up. The most common study cancers were prostate (48.1% of study cancers in men), breast (40.0% of study cancers in women) and lung (15.4% of all study cancers). The overall standardised study cancer IR was 5.4 per 1000 person-years (95% confidence interval, 5.3-5.6); IRs were similar across individual OAB drugs. The standardised IRs for bladder and prostate cancers, which have symptoms in common with OAB, were highest in the first 6 months of treatment initiation and lower thereafter. In contrast, IRs for other study cancers were nearly constant during follow-up. Cancer IRs did not vary substantially by individual OAB drug. Protopathic bias is a plausible explanation for the higher rates of bladder and prostate cancers observed soon after starting OAB drug treatment.

Validation of Cancer Cases Using Primary Care, Cancer Registry, and Hospitalization Data in the United Kingdom.

BACKGROUND: In the United Kingdom, hospital or cancer registry data can be linked to electronic medical records for a subset of general practices and years. METHODS: We used Clinical Practice Research Datalink data (2004-2012) from patients treated for overactive bladder. We electronically identified provisional cases of 10 common cancers in General Practitioner Online Database data and validated them by medical profile review. In practices with linkage to Hospital Episodes Statistics and National Cancer Data Repository (2004-2010), we validated provisional cancer cases against these data sources. This linkage also let us identify additional cancer diagnoses in individuals without cancer diagnosis records in the General Practitioner Online Database. RESULTS: Among 50,840 patients, 1,486 provisional cancer cases were identified in the General Practitioner Online Database for 2004-2012. Medical profile review confirmed 93% of 661 cases in nonlinked practices (range, 100% of non-Hodgkin lymphomas and uterine cancer to 77% of skin melanomas) and 96% of 825 cases in linked practices (100% of kidney and uterine cancers to 92% of melanomas). In the subset of linked practices, for 2004-2010, 720 cases were confirmed, of which 68% were identifiable in the General Practitioner Online Database (range, 90% of breast to 36% of kidney cancers). CONCLUSIONS: Most cases of cancer identified electronically in the General Practitioner Online Database were confirmed. A substantial proportion of cases, especially of cancer types not typically managed by general practitioners, would be missed without Hospital Episodes Statistics and National Cancer Data Repository data (and are likely missed in nonlinked practices). See video abstract at, http://links.lww.com/EDE/B315. REGISTRATION (BEFORE STUDY CONDUCT): European Union electronic Register of Post-Authorisation Studies (EU PAS Registry) number EUPAS5529, http://www.encepp.eu/encepp/viewResource.htm?id=11107.

Physical activity and risk of prostate and bladder cancer in China: The South and East China case-control study on prostate and bladder cancer.

BACKGROUND: Recent meta-analyses have suggested a modest protective effect of high levels of physical activity on developing both prostate and bladder cancer, but significant heterogeneity between studies included in these meta-analyses existed. To our knowledge, few Chinese studies investigated the association between physical activity and prostate cancer and none between physical activity and bladder cancer. Given the inconsistencies between previous studies and because studies on the relation between physical activity and prostate and bladder cancer in China are scarce, it remains elusive whether there is a relationship between physical activity and prostate and bladder cancer within the Chinese population. METHODS: We investigated the association between physical activity and risk of developing prostate and bladder cancer within a hospital-based case-control study in the East and South of China among 260 and 438 incident prostate and bladder cancer cases, respectively, and 427 controls. A questionnaire was administered to measure physical activity as metabolic equivalents (METs). Random effects logistic regression was used to calculate odds ratios (ORs) of prostate and bladder cancer for different levels of physical activity and for the specific activities of walking and cycling. RESULTS: Increasing overall physical activity was associated with a significant reduction in prostate cancer risk (Ptrend = 0.04) with the highest activity tertile level showing a nearly 50% reduction in prostate cancer risk (OR = 0.53, 95%CI: 0.28-0.98). Overall physical activity was not significantly associated with risk of bladder cancer (Ptrend = 0.61), neither were vigorous (Ptrend = 0.60) or moderate levels of physical activity (Ptrend = 0.21). Walking and cycling were not significantly associated with either prostate (Ptrend> = 0.62) or bladder cancer risk (Ptrend> = 0.25). CONCLUSIONS: The findings of this largest ever case-control study in China investigating the relationship between physical activity and prostate and bladder cancer suggest that overall physical activity is associated with a decreased risk of prostate cancer, but not with bladder cancer.

Circulating Folate and Vitamin B12 and Risk of Prostate Cancer: A Collaborative Analysis of Individual Participant Data from Six Cohorts Including 6875 Cases and 8104 Controls.

BACKGROUND: Folate and vitamin B12 are essential for maintaining DNA integrity and may influence prostate cancer (PCa) risk, but the association with clinically relevant, advanced stage, and high-grade disease is unclear. OBJECTIVE: To investigate the associations between circulating folate and vitamin B12 concentrations and risk of PCa overall and by disease stage and grade. DESIGN, SETTING, AND PARTICIPANTS: A study was performed with a nested case-control design based on individual participant data from six cohort studies including 6875 cases and 8104 controls; blood collection from 1981 to 2008, and an average follow-up of 8.9 yr (standard deviation 7.3). Odds ratios (ORs) of incident PCa by study-specific fifths of circulating folate and vitamin B12 were calculated using multivariable adjusted conditional logistic regression. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Incident PCa and subtype by stage and grade. RESULTS AND LIMITATIONS: Higher folate and vitamin B12 concentrations were associated with a small increase in risk of PCa (ORs for the top vs bottom fifths were 1.13 [95% confidence interval (CI), 1.02-1.26], ptrend=0.018, for folate and 1.12 [95% CI, 1.01-1.25], ptrend=0.017, for vitamin B12), with no evidence of heterogeneity between studies. The association with folate varied by tumour grade (pheterogeneity<0.001); higher folate concentration was associated with an elevated risk of high-grade disease (OR for the top vs bottom fifth: 2.30 [95% CI, 1.28-4.12]; ptrend=0.001), with no association for low-grade disease. There was no evidence of heterogeneity in the association of folate with risk by stage or of vitamin B12 with risk by stage or grade of disease (pheterogeneity>0.05). Use of single blood-sample measurements of folate and B12 concentrations is a limitation. CONCLUSIONS: The association between higher folate concentration and risk of high-grade disease, not evident for low-grade disease, suggests a possible role for folate in the progression of clinically relevant PCa and warrants further investigation. PATIENT SUMMARY: Folate, a vitamin obtained from foods and supplements, is important for maintaining cell health. In this study, however, men with higher blood folate levels were at greater risk of high-grade (more aggressive) prostate cancer compared with men with lower folate levels. Further research is needed to investigate the possible role of folate in the progression of this disease.

Sarcosine and other metabolites along the choline oxidation pathway in relation to prostate cancer--a large nested case-control study within the JANUS cohort in Norway.

Methyl group donors and intermediates of one-carbon metabolism affect DNA synthesis and DNA methylation, and may thereby affect prostate carcinogenesis. Choline, the precursor of betaine, and the one-carbon metabolite sarcosine have been associated with increased prostate cancer risk. Within JANUS, a prospective cohort in Norway (n = 317,000) with baseline serum samples, we conducted a nested case-control study among 3,000 prostate cancer cases and 3,000 controls. Using conditional logistic regression, odds ratios (ORs) and 95% confidence intervals (CIs) for prostate cancer risk were estimated according to quintiles of circulating betaine, dimethylglycine (DMG), sarcosine, glycine and serine. High sarcosine and glycine concentrations were associated with reduced prostate cancer risk of borderline significance (sarcosine: highest vs. lowest quintile OR = 0.86, CI = 0.72-1.01, p(trend) = 0.03; glycine: OR = 0.83, CI = 0.70-1.00, p(trend) = 0.07). Serum betaine, DMG and serine were not associated with prostate cancer risk. However, individuals with a high glycine/serine ratio were at decreased prostate cancer risk (OR = 0.74, CI = 0.69-0.85, p(trend) < 0.001). This population-based study suggested that men with high serum sarcosine or glycine concentrations have modestly reduced prostate cancer risk. Ratios of metabolites reflecting one-carbon balance may be associated with prostate cancer risk, as demonstrated for the glycine/serine ratio, and should be explored in future studies.

Serum folate and vitamin B12 concentrations in relation to prostate cancer risk--a Norwegian population-based nested case-control study of 3000 cases and 3000 controls within the JANUS cohort.

BACKGROUND: Although individual studies have been inconsistent, meta-analyses of epidemiological data suggest that high folate and vitamin B12 levels may be associated with increased prostate cancer risk. METHODS: Within JANUS, a prospective cohort in Norway (n = 317 000) with baseline serum samples, we conducted a nested case-control study among 3000 prostate cancer cases and 3000 controls, matched on age and time at serum sampling, and county of residence. Using conditional logistic regression, odds ratios (OR) and 95% confidence intervals (CI) for prostate cancer risk were estimated according to quintiles of serum folate, vitamin B12, methylmalonic acid (MMA), total homocysteine (tHcy) and methionine, and according to MTHFR 677C→T genotypes. To correct for degradation during sample storage, folate concentration was measured as p-aminobenzoylglutamate (pABG) equivalents following oxidation and acid hydrolysis. RESULTS: We observed a weak positive association between folate concentration and prostate cancer risk [OR highest vs lowest quintile = 1.15 (0.97-1.37), P-trend = 0.04], which was more pronounced among individuals ≥ 50 years at inclusion [OR 1.40 (1.07-1.84), P-trend = 0.02]. tHcy showed an inverse trend with risk [OR 0.92 (0.77-1.10), P-trend = 0.03]. Vitamin B12, MMA and methionine concentrations were not associated with prostate cancer risk. Compared with the MTHFR 677CC genotype, the CT and TT variants, both of which were related to lower folate concentrations, were associated with reduced prostate cancer risk [OR 0.82 (0.72-0.94) and OR 0.78 (0.64-0.94), respectively]. CONCLUSION: This large-scale population-based study suggests that high serum folate concentration may be associated with modestly increased prostate cancer risk. We did not observe an association between vitamin B12 status and prostate cancer risk.

Biomarkers related to one-carbon metabolism as potential risk factors for distal colorectal adenomas.

BACKGROUND: Efficient one-carbon metabolism, which requires adequate supply of methyl group donors and B-vitamins, may protect against colorectal carcinogenesis. However, plasma folate and vitamins B2 and B12 have inconsistently been associated with colorectal cancer risk, and there have been no previous studies relating plasma concentrations of methionine, choline, and betaine to this outcome. METHODS: This study comprised 10,601 individuals, 50 to 64 years of age, participating in the Norwegian Colorectal Cancer Prevention (NORCCAP) screening study. Using logistic regression analyses, we crosssectionally investigated associations between distal colorectal adenoma occurrence-potential precursor lesions of colorectal carcinomas-and plasma concentrations of methyl group donors and B-vitamins, and polymorphisms of genes related to one-carbon metabolism. RESULTS: Screening revealed 1,809 subjects (17.1%) with at least one adenoma. The occurrence of high-risk adenomas (observed in 421 subjects) was inversely associated with plasma concentrations of methionine (highest versus lowest quartile: odds ratio (OR) = 0.61; 95% confidence interval (CI) = 0.45-0.83), betaine: OR = 0.74; 95% CI = 0.54-1.02, the vitamin B2 form flavin-mononucleotide (FMN): OR = 0.65; 95% CI = 0.49-0.88, and the vitamin B6 form pyridoxal 5'-phosphate (PLP): OR = 0.69; 95% CI = 0.51-0.95, but not with folate, choline, vitamin B12 concentrations, or with the studied polymorphisms. High methionine concentration in combination with high vitamin B2 or B6 concentrations was associated with lower occurrence of high-risk adenomas compared with these factors individually. CONCLUSIONS: High plasma concentrations of methionine and betaine, and vitamins B2 and B6 may reduce risk of developing colorectal adenomas. IMPACT: In addition to B-vitamins, methyl group donors such as methionine and betaine may play a role in colorectal carcinogenesis.

Dietary intake of protein is positively associated with percent body fat in middle-aged and older adults.

Data on associations between dietary intake of macronutrients and body composition in the general population are sparse. This population-based, cross-sectional study of 4478 middle-aged (47-49 y) and elderly (71-74 y) men and women from the Hordaland Health Study in western Norway was conducted using a validated FFQ and measurements by dual-energy X-ray absorptiometry. The relation between macronutrient intake [percentage of total energy intake (E%)] and percent body fat was investigated in the total population and in a subgroup with intermediate BMI and stable weight (BMI within the 25th-75th percentile and weight change <5% during the last 6 y; n = 975). In the total population, protein intake (E%) was associated with higher percent body fat (partial r = 0.11; P < 0.001) in multivariate linear regression analysis. In the subgroup with intermediate BMI and stable weight, there was no association between protein intake (E%) and percent body fat. Fat intake (E%) was positively associated (partial r = 0.07) whereas carbohydrate intake (E%) was inversely associated (partial r = -0.07) with percent body fat (P = 0.042 for both) in the subgroup with intermediate BMI and stable weight. Both in the total population and in the stable weight group, physical activity was inversely related to adiposity (partial r = -0.15 and -0.12, respectively; P < 0.001). Our results may explain some of the conflicting data on the effects of macronutrients in different populations and suggest the potential importance of protein intake as a factor in obesity.

Dietary methyl donors, methyl metabolizing enzymes, and epigenetic regulators: diet-gene interactions and promoter CpG island hypermethylation in colorectal cancer.

Dietary methyl donors might influence DNA methylation during carcinogenesis of colorectal cancer (CRC). Among 609 CRC cases and 1,663 subcohort members of the Netherlands Cohort Study on diet and cancer (n = 120,852), we estimated CRC risk according to methyl donor intake across genotypes of folate metabolizing enzymes and methyltransferases.Although diet-gene interactions were not statistically significant, methionine intake was inversely associated with CRC among subjects having both common rs2424913 and rs406193 DNMT3B C > T genotypes (highest versus lowest tertile: RR = 0.44; p (trend) = 0.05). Likewise, vitamin B2 was modestly inversely associated among individuals with the MTHFR c.665CC (rs1801133) genotype (RR = 0.66; p (trend) = 0.08), but with a significant reduced risk when ≤ 1 rare allele occurred in the combination of folate metabolizing enzymes MTHFR, MTRR and MTR (RR = 0.30; p (trend) = 0.005). Folate or vitamin B6 were neither inversely associated with CRC nor was methyl donor intake associated with the CpG island methylator phenotype (CIMP).Despite the absence of heterogeneity across genotypes, might an effect of methyl donors on CRC be more pronounced among individuals carrying common variants of folate metabolizing enzymes or DNA methyltransferases. Combining genotypes may assist to reveal diet associations with CRC, possibly because rare variants of related genes may collectively affect specific metabolic pathways or enzymatic functions.

Genetic variants of methyl metabolizing enzymes and epigenetic regulators: associations with promoter CpG island hypermethylation in colorectal cancer.

Aberrant DNA methylation affects carcinogenesis of colorectal cancer. Folate metabolizing enzymes may influence the bioavailability of methyl groups, whereas DNA and histone methyltransferases are involved in epigenetic regulation of gene expression. We studied associations of genetic variants of folate metabolizing enzymes (MTHFR, MTR, and MTRR), DNA methyltransferase DNMT3b, and histone methyltransferases (EHMT1, EHMT2, and PRDM2), with colorectal cancers, with or without the CpG island methylator phenotype (CIMP), MLH1 hypermethylation, or microsatellite instability. Incidence rate ratios were calculated in case-cohort analyses, with common homozygotes as reference, among 659 cases and 1,736 subcohort members of the Netherlands Cohort Study on diet and cancer (n = 120,852). Men with the MTHFR 677TT genotype were at decreased colorectal cancer risk (incidence rate ratio, 0.49; P = 0.01), but the T allele was associated with increased risk in women (incidence rate ratio, 1.39; P = 0.02). The MTR 2756GG genotype was associated with increased colorectal cancer risk (incidence rate ratio, 1.58; P = 0.04), and inverse associations were observed among women carrying DNMT3b C-->T (rs406193; incidence rate ratio, 0.72; P = 0.04) or EHMT2 G-->A (rs535586; incidence rate ratio, 0.76; P = 0.05) polymorphisms. Although significantly correlated (P < 0.001), only 41.5% and 33.3% of CIMP tumors harbored MLH1 hypermethylation or microsatellite instability, respectively. We observed inverse associations between MTR A2756G and CIMP among men (incidence rate ratio, 0.58; P = 0.04), and between MTRR A66G and MLH1 hypermethylation among women (incidence rate ratio, 0.55; P = 0.02). In conclusion, MTHFR, MTR, DNMT3b, and EHMT2 polymorphisms are associated with colorectal cancer, and rare variants of MTR and MTRR may reduce promoter hypermethylation. The incomplete overlap between CIMP, MLH1 hypermethylation, and microsatellite instability indicates that these related "methylation phenotypes" may not be similar and should be investigated separately.

Alcohol consumption and mutations or promoter hypermethylation of the von Hippel-Lindau gene in renal cell carcinoma.

Alcohol consumption has been associated with a decreased risk for renal cell cancer in several studies. We investigated whether alcohol is associated with (epi)genetic changes of the von Hippel-Lindau (VHL) gene in renal cell cancer. The Netherlands Cohort Study (NLCS) on Diet and Cancer started in 1986 (n = 120,852) and uses the case-cohort method. After 11.3 years of follow-up, 314 renal cell cancer cases and 4,511 subcohort members were available for analysis. DNA was isolated from paraffin-embedded tumor tissue from 235 cases. VHL mutations were analyzed by sequencing, whereas VHL promoter methylation was analyzed using methylation-specific PCR. In multivariate analysis, hazard ratios of renal cell cancer for cohort members who consumed up to 5, 15, 30, and > or = 30 g of alcohol per day were 0.72, 0.64, 0.81, and 0.69, respectively, compared with nondrinkers [95% confidence interval (95% CI) for the > or = 30 category, 0.44-1.07; P for trend, 0.17]. Alcohol intake from beer, wine, and liquor was associated with decreased risks for renal cell cancer, although not statistically significant. Hazard ratios were not different for clear-cell renal cell cancer with and without VHL mutations, except for alcohol from beer, which was associated with an increased risk for clear-cell renal cell cancer without VHL mutations (hazard ratio for > or = 5 g of alcohol from beer compared with nondrinkers, 2.74; 95% CI, 1.35-5.57). Alcohol was associated with a decreased risk for clear-cell renal cell cancer without VHL gene promoter methylation (hazard ratio for >15 g compared with nondrinkers, 0.58; 95% CI, 0.34-0.99). In this study, a not statistically significant inverse association was observed between alcohol and renal cell cancer. There was no statistical significant heterogeneity by VHL mutation or methylation status.

Dietary folate, methionine, riboflavin, and vitamin B-6 and risk of sporadic colorectal cancer.

Adequate intake of folate, methionine, riboflavin, and vitamin B-6 may prevent aberrant DNA methylation and thereby protect against colorectal cancer (CRC). However, previous epidemiological studies investigating associations between dietary intakes of these nutrients and CRC have been inconsistent. We investigated the associations between intakes of folate, methionine, riboflavin, and vitamin B-6 and CRC risk, accounting for the sublocalization of the tumor. Within the Netherlands Cohort Study on diet and cancer (n = 120,852), 2349 cases and 4168 subcohort members were available for data analyses from a follow-up period of 13.3 y after baseline. Gender-specific adjusted incidence rate ratios (RR) were calculated over quintiles of dietary intake in case-cohort analyses. Folate intake was not associated with CRC risk in either men or women. However, methionine was associated with decreased risk of proximal colon cancer among men (RR = 0.57 for highest vs. lowest quintile of intake; P-trend = 0.03) and rectal cancer among women (highest vs. lowest quintile; RR = 0.45; P-trend = 0.05). Riboflavin tended to be associated with decreased proximal colon cancer risk among women (RR = 0.61; P-trend = 0.07). Conversely, there was a strong positive association between vitamin B-6 and rectal cancer among women (RR = 3.57; P-trend = 0.01). Our findings suggest that relatively high methionine intake may protect against proximal colon cancer in men and rectal cancer in women but that folate may not have a protective effect. This is the 2nd prospective cohort study in which vitamin B-6 intake was associated with increased risk of rectal tumors in women, which might suggest that this vitamin enhances rectal cancer in women.