The age-dependent association of risk factors with pancreatic cancer.

BACKGROUND: Pancreatic cancer presents as advanced disease in >80% of patients; yet, appropriate ages to consider prevention and early detection strategies are poorly defined. We investigated age-specific associations and attributable risks of pancreatic cancer for established modifiable and non-modifiable risk factors. PATIENTS AND METHODS: We included 167 483 participants from two prospective US cohort studies with 1190 incident cases of pancreatic cancer during >30 years of follow-up; 5107 pancreatic cancer cases and 8845 control participants of European ancestry from a completed multicenter genome-wide association study (GWAS); and 248 893 pancreatic cancer cases documented in the US Surveillance, Epidemiology, and End Results (SEER) Program. Across different age categories, we investigated cigarette smoking, obesity, diabetes, height, and non-O blood group in the prospective cohorts; weighted polygenic risk score of 22 previously identified single nucleotide polymorphisms in the GWAS; and male sex and black race in the SEER Program. RESULTS: In the prospective cohorts, all five risk factors were more strongly associated with pancreatic cancer risk among younger participants, with associations attenuated among those aged >70 years. The hazard ratios comparing participants with three to five risk factors with those with no risk factors were 9.24 [95% confidence interval (CI) 4.11-20.77] among those aged ≤60 years, 3.00 (95% CI 1.85-4.86) among those aged 61-70 years, and 1.46 (95% CI 1.10-1.94) among those aged >70 years (Pheterogeneity = 3×10-5). These factors together were related to 65.6%, 49.7%, and 17.2% of incident pancreatic cancers in these age groups, respectively. In the GWAS and the SEER Program, the associations with the polygenic risk score, male sex, and black race were all stronger among younger individuals (Pheterogeneity ≤0.01). CONCLUSIONS: Established risk factors are more strongly associated with earlier-onset pancreatic cancer, emphasizing the importance of age at initiation for cancer prevention and control programs targeting this highly lethal malignancy.

Vitamin B6 catabolism and lung cancer risk: results from the Lung Cancer Cohort Consortium (LC3).

BACKGROUND: Increased vitamin B6 catabolism related to inflammation, as measured by the PAr index (the ratio of 4-pyridoxic acid over the sum of pyridoxal and pyridoxal-5'-phosphate), has been positively associated with lung cancer risk in two prospective European studies. However, the extent to which this association translates to more diverse populations is not known. MATERIALS AND METHODS: For this study, we included 5323 incident lung cancer cases and 5323 controls individually matched by age, sex, and smoking status within each of 20 prospective cohorts from the Lung Cancer Cohort Consortium. Cohort-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between PAr and lung cancer risk were calculated using conditional logistic regression and pooled using random-effects models. RESULTS: PAr was positively associated with lung cancer risk in a dose-response fashion. Comparing the fourth versus first quartiles of PAr resulted in an OR of 1.38 (95% CI: 1.19-1.59) for overall lung cancer risk. The association between PAr and lung cancer risk was most prominent in former smokers (OR: 1.69, 95% CI: 1.36-2.10), men (OR: 1.60, 95% CI: 1.28-2.00), and for cancers diagnosed within 3 years of blood draw (OR: 1.73, 95% CI: 1.34-2.23). CONCLUSION: Based on pre-diagnostic data from 20 cohorts across 4 continents, this study confirms that increased vitamin B6 catabolism related to inflammation and immune activation is associated with a higher risk of developing lung cancer. Moreover, PAr may be a pre-diagnostic marker of lung cancer rather than a causal factor.

Associations of early life and adulthood adiposity with risk of epithelial ovarian cancer.

BACKGROUND: Few studies have evaluated the association between early life adiposity and ovarian cancer risk. Adiposity during different periods of life may be differentially associated with the risk. PATIENTS AND METHODS: We prospectively followed 133 526 women in the Nurses' Health Study (NHS; 1980-2012) and NHSII (1989-2013). Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident ovarian cancer (N = 788) according to validated measures for early life adiposity [body mass index (BMI) at age 10 imputed from somatotype and recalled BMI at age 18) as well as BMI change between age 10 and 18 and after age 18 (current weight assessed on every biennial questionnaire since baseline). RESULTS: After mutual adjustment for BMI at age 10, BMI at age 18 and current BMI, the HR (95% CI) for ovarian cancer risk per 5 kg/m2 was 0.84 (0.74-0.96) for BMI at age 10 (P-trend = 0.01), 1.17 (1.03-1.33) for BMI at age 18 (P-trend = 0.02), and 1.06 (0.99-1.14) for current BMI (P-trend = 0.08). However, the inverse association with BMI at age 10 was attenuated after adjusting for BMI change between age 10 and 18 and BMI change after age 18 (HR per 5 kg/m2: 1.04; 95% CI 0.91-1.20; P-trend = 0.55). By contrast, BMI change between age 10 and 18 was strongly positively associated with ovarian cancer risk (HR per 5 kg/m2 increase: 1.24; 95% CI 1.11-1.39; P-trend = 0.0002), whereas BMI change since age 18 was only slightly associated with risk (HR per 5 kg/m2 increase: 1.06; 95% CI 0.99-1.14; P-trend = 0.10). These associations were in general stronger for premenopausal cases or non-serous tumors. CONCLUSION: Early life changes in adiposity were more strongly associated with ovarian cancer risk than adulthood changes. The specific mechanisms underlying the associations with adiposity changes during early life warrant further investigation.

No association between circulating concentrations of vitamin D and risk of lung cancer: an analysis in 20 prospective studies in the Lung Cancer Cohort Consortium (LC3).

Background: There is observational evidence suggesting that high vitamin D concentrations may protect against lung cancer. To investigate this hypothesis in detail, we measured circulating vitamin D concentrations in prediagnostic blood from 20 cohorts participating in the Lung Cancer Cohort Consortium (LC3). Patients and methods: The study included 5313 lung cancer cases and 5313 controls. Blood samples for the cases were collected, on average, 5 years before lung cancer diagnosis. Controls were individually matched to the cases by cohort, sex, age, race/ethnicity, date of blood collection, and smoking status in five categories. Liquid chromatography coupled with tandem mass spectrometry was used to separately analyze 25-hydroxyvitamin D2 [25(OH)D2] and 25-hydroxyvitamin D3 [25(OH)D3] and their concentrations were combined to give an overall measure of 25(OH)D. We used conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for 25(OH)D as both continuous and categorical variables. Results: Overall, no apparent association between 25(OH)D and risk of lung cancer was observed (multivariable adjusted OR for a doubling in concentration: 0.98, 95% CI: 0.91, 1.06). Similarly, we found no clear evidence of interaction by cohort, sex, age, smoking status, or histology. Conclusion: This study did not support an association between vitamin D concentrations and lung cancer risk.

Germline variants in IL4, MGMT and AKT1 are associated with prostate cancer-specific mortality: An analysis of 12,082 prostate cancer cases.

BACKGROUND: Prostate cancer (PCa) is a leading cause of mortality and genetic factors can influence tumour aggressiveness. Several germline variants have been associated with PCa-specific mortality (PCSM), but further replication evidence is needed. METHODS: Twenty-two previously identified PCSM-associated genetic variants were genotyped in seven PCa cohorts (12,082 patients; 1544 PCa deaths). For each cohort, Cox proportional hazards models were used to calculate hazard ratios and 95% confidence intervals for risk of PCSM associated with each variant. Data were then combined using a meta-analysis approach. RESULTS: Fifteen SNPs were associated with PCSM in at least one of the seven cohorts. In the meta-analysis, after adjustment for clinicopathological factors, variants in the MGMT (rs2308327; HR 0.90; p-value = 3.5 × 10-2) and IL4 (rs2070874; HR 1.22; p-value = 1.1 × 10-3) genes were confirmed to be associated with risk of PCSM. In analyses limited to men diagnosed with local or regional stage disease, a variant in AKT1, rs2494750, was also confirmed to be associated with PCSM risk (HR 0.81; p-value = 3.6 × 10-2). CONCLUSIONS: This meta-analysis confirms the association of three genetic variants with risk of PCSM, providing further evidence that genetic background plays a role in PCa-specific survival. While these variants alone are not sufficient as prognostic biomarkers, these results may provide insights into the biological pathways modulating tumour aggressiveness.

Epigenetic regulation of RNA polymerase III transcription in early breast tumorigenesis.

RNA polymerase III (Pol III) transcribes medium-sized non-coding RNAs (collectively termed Pol III genes). Emerging diverse roles of Pol III genes suggest that individual Pol III genes are exquisitely regulated by transcription and epigenetic factors. Here we report global Pol III expression/methylation profiles and molecular mechanisms of Pol III regulation that have not been as extensively studied, using nc886 as a representative Pol III gene. In a human mammary epithelial cell system that recapitulates early breast tumorigenesis, the fraction of actively transcribed Pol III genes increases reaching a plateau during immortalization. Hyper-methylation of Pol III genes inhibits Pol III binding to DNA via inducing repressed chromatin and is a determinant for the Pol III repertoire. When Pol III genes are hypo-methylated, MYC amplifies their transcription, regardless of its recognition DNA motif. Thus, Pol III expression during tumorigenesis is delineated by methylation and magnified by MYC.

Multivitamin use and risk of stroke incidence and mortality amongst women.

BACKGROUND AND PURPOSE: Few studies have examined the association between multivitamin use and the risk of stroke incidence and mortality, and the results remain inconclusive as to whether multivitamins are beneficial. METHODS: The associations between multivitamin use and the risk of incident stroke and stroke mortality were prospectively examined in 86 142 women in the Nurses' Health Study, aged 34-59 years and free of diagnosed cardiovascular disease at baseline. Multivitamin use and covariates were updated every 2 years and strokes were documented by review of medical records. Hazard ratios of total, ischaemic and hemorrhagic strokes were calculated across categories of multivitamin use (non-user, past, current user) and duration (years), using Cox proportional hazards models. RESULTS: During 32 years of follow-up from 1980 to 2012, 3615 incident strokes were documented, including 758 deaths from stroke. In multivariate analyses, women who were current multivitamin users did not have a lower risk of incident total stroke compared to non-users [relative risk (RR) 1.02, 95% confidence interval (CI) 0.93-1.11], even those with longer durations of 15 or more years of use (RR 1.08, 95% CI 0.97-1.20) or those with a lower quality diet (RR 0.96, 95% CI 0.80-1.15). There was also no indication of benefit from multivitamin use for incident ischaemic or hemorrhagic strokes or for total stroke mortality. CONCLUSIONS: Long-term multivitamin use was not associated with reduced risk of stroke incidence or mortality amongst women in the study population, even amongst those with a lower diet quality. An effect in a less well-nourished population cannot be ruled out.

Common variation in BRCA1 may have a role in progression to lethal prostate cancer after radiation treatment.

BACKGROUND: To evaluate whether single-nucleotide polymorphisms (SNPs) reflecting common variation in the tumor suppressor BRCA1 affect prostate cancer outcomes. Because radiation therapy (RT) induces DNA damage, we hypothesized that common variation in BRCA1 has a role in progression to lethal prostate cancer, particularly in patients receiving RT. METHODS: We followed 802 men diagnosed with localized prostate cancer (cT1-T3/N0/M0) who were treated with RT in the US Health Professionals Follow-up Study (HPFS) and Physicians' Health Study (PHS), for progression to lethal prostate cancer. Six SNPs (rs3737559, rs1799950, rs799923, rs915945, rs4474733 and rs8176305) were genotyped in HPFS to capture common variation across BRCA1. rs4474733 and rs8176305 were also evaluated in the PHS cohort. Cox proportional hazards models were used to estimate per-allele hazard ratios (HR) and 95% confidence intervals (CI) stratified by primary treatment. RESULTS: In the RT group (n=802), 71 men progressed to lethal disease during a mean follow-up of 12 years. We found that two SNPs, rs4473733 (HR: 0.65; 95% CI 0.42-0.99) and rs8176305 (HR: 2.03; 95% CI 1.33-3.10), were associated with lethal prostate cancer in men receiving RT. CONCLUSIONS: Common variation in BRCA1 may influence clinical outcomes in patients receiving RT for localized prostate cancer by modifying the response to RT. Our findings merit further follow-up studies to validate these SNPs and better understand their functional and biological significance.

Nut consumption and risk of colorectal cancer in women.

BACKGROUND/OBJECTIVES: Increasing nut consumption has been associated with reduced risk of obesity and type II diabetes, the risk factors for colorectal cancer. However, the association between nut consumption and colorectal cancer risk is unclear. We aimed to examine the association of long-term nut consumption with risk of colorectal cancer. SUBJECTS/METHODS: We prospectively followed 75,680 women who were free of cancer at baseline in the Nurses' Health Study, and examined the association between nut consumption and colorectal cancer risk. Nut consumption was assessed at baseline and updated every 2-4 years. Relative risks (RRs) and 95% confidence intervals (95% CIs) were estimated using Cox proportional hazards models. RESULTS: During 2,103,037 person-years of follow-up, we identified 1503 colorectal cancer cases. After adjustment for other known or suspected risk factors, women who consumed nuts 2 or more times per week (that is, ⩾ 56 g per week) had a 13% lower risk of colorectal cancer compared with those who rarely consumed nuts, but the association was not statistically significant (RR: 0.87; 95% CI: 0.72-1.05; P-trend: 0.06). No association was observed for peanut butter. CONCLUSIONS: In this large prospective cohort of women, frequent nut consumption was not significantly associated with colorectal cancer risk after adjusting for other risk factors.

Replication of a genetic variant for prostate cancer-specific mortality.

BACKGROUND: Few genetic variants have been confirmed as being associated with prostate cancer-specific mortality (PCSM). A recent study identified 22 candidate single-nucleotide polymorphisms (SNPs) associated with PCSM in a Seattle-based patient cohort. Five of these associations were replicated in an independent Swedish cohort. METHODS: We genotyped these 22 SNPs in Physicians' Health Study (PHS) participants diagnosed with prostate cancer (PCa). Using the same model that was found to be most significant in the Seattle cohort, we examined the association of these SNPs with lethal disease with Cox proportional hazards models. RESULTS: One SNP, rs5993891 in the ARVCF gene on chromosome 22q11, which had also replicated in the Swedish cohort, was also significantly associated with PCSM in the PHS cohort (hazard ratio (HR)=0.32; P=0.01). When we tested this SNP in an additional cohort (Health Professionals Follow-up Study, HPFS), the association was null (HR=0.95, P=0.90); however, a meta-analysis across all studies showed a statistically significant association with a HR of 0.52 (0.29-0.93, P=0.03). CONCLUSIONS: The association of rs5993891 with PCSM was further replicated in PHS and remains significant in a meta-analysis, though there was no association in HPFS. This SNP may contribute to a genetic panel of SNPs to determine at diagnosis whether a patient is more likely to exhibit an indolent or aggressive form of PCa. This study also emphasizes the importance of multiple rounds of replication.

Fruit and vegetable consumption and hypertriglyceridemia: Korean National Health and Nutrition Examination Surveys (KNHANES) 2007-2009.

BACKGROUND: Limited research has been conducted on the association between intake of fruits and vegetables and hypertriglyceridemia, especially in Asian populations. This study aimed to investigate the association between total fruit and vegetable intake, as well as subgroups of fruit and vegetable intake, with hypertriglyceridemia among Korean adults. METHODS: We conducted a cross-sectional study of 7934 adults aged 19-64 years from the fourth Korean Health and Nutrition Examination Survey. Fruit and vegetable intake was estimated from a food frequency questionnaire. Subgroups of fruits and vegetables included citrus, non-citrus and carotene-rich fruits and cruciferous, green leafy and carotene-rich vegetables. Hypertriglyceridemia (plasma triglyceride ⩾150 mg/dl) was diagnosed using a blood sample drawn after 12+ hours of fasting. RESULTS: There were 2001 (25.2%) cases of hypertriglyceridemia among the participants. Total fruit intake was significantly inversely associated with the prevalence of hypertriglyceridemia; the multivariate odds ratios (95% confidence intervals) of hypertriglyceridemia across increasing quintiles were 1.00 (ref), 0.76 (0.62, 0.92), 0.72 (0.58, 0.90), 0.68 (0.54, 0.85) and 0.64 (0.49, 0.82; Ptrend=0.001) after controlling for survey year, body mass index, waist circumference, smoking, alcohol drinking, physical activity, education and income. Similar inverse associations were found for all fruit subgroups. However, we found no significant association between intakes of total or subgroups of vegetable and hypertriglyceridemia; the odds ratio for top vs bottom quintile was 1.00 (0.81-1.24) for total vegetable intake. CONCLUSIONS: Our findings support a potential beneficial role of fruit consumption to reduce blood triglyceride levels in Asian populations.

TRIM24 links glucose metabolism with transformation of human mammary epithelial cells.

Tripartite motif 24 protein (TRIM24) is a plant homeodomain/bromodomain histone reader, recently associated with poor overall survival of breast-cancer patients. At a molecular level, TRIM24 is a negative regulator of p53 levels and a co-activator of estrogen receptor. However, the role of TRIM24 in breast tumorigenesis remains largely unknown. We used an isogenic human mammary epithelial cell (HMEC) culture model, derived from reduction mammoplasty tissue, and found that ectopic expression of TRIM24 in immortalized HMECs (TRIM24 iHMECs) greatly increased cellular proliferation and induced malignant transformation. Subcutaneous injection of TRIM24 iHMECs in nude mice led to growth of intermediate to high-grade tumors in 60-70% of mice. Molecular analysis of TRIM24 iHMECs revealed a glycolytic and tricarboxylic acid cycle gene signature, alongside increased glucose uptake and activated aerobic glycolysis. Collectively, these results identify a role for TRIM24 in breast tumorigenesis through reprogramming of glucose metabolism in HMECs, further supporting TRIM24 as a viable therapeutic target in breast cancer.

Involvement of polypyrimidine tract-binding protein (PTBP1) in maintaining breast cancer cell growth and malignant properties.

We have investigated some roles of splicing factor polypyrimidine tract-binding protein (PTBP1) in human breast cancer. We found that PTBP1 was upregulated in progressively transformed human mammary epithelial cells (HMECs), as well as in breast tumor cell lines compared with HMECs with finite growth potential and found that the level of PTBP1 correlated with the transformation state of HMECs. Knockdown of PTBP1 expression substantially inhibited tumor cell growth, colony formation in soft agar and in vitro invasiveness of breast cancer cell lines, a result similar to what we have reported in ovarian cancer. However, ectopic expression of PTBP1 (as a PTBP1-EGFP fusion protein) did not enhance the proliferation of immortalized HMEC. Rather, PTBP1 expression promoted anchorage-independent growth of an immortalized HMEC as assessed by increased colony formation in soft agar. In addition, we found that knockdown of PTBP1 expression led to upregulation of the expression of the M1 isoform of pyruvate kinase (PKM1) and increase of the ratio of PKM1 vs PKM2. PKM1 has been reported to promote oxidative phosphorylation and reduce tumorigenesis. Correspondingly, we observed increased oxygen consumption in PTBP1-knockdown breast cancer cells. Together, these results suggest that PTBP1 is associated with breast tumorigenesis and appears to be required for tumor cell growth and maintenance of transformed properties. PTBP1 exerts these effects, in part, by regulating the splicing of pyruvate kinase, and consequently alters glucose metabolism and contributes to the Warburg effect.

Nut consumption and risk of pancreatic cancer in women.

BACKGROUND: Increasing nut intake has been associated with reduced risk of diabetes mellitus, which is a risk factor for pancreatic cancer. METHODS: We prospectively followed 75 680 women in the Nurses' Health Study, and examined the association between nut consumption and pancreatic cancer risk. Participants with a previous history of cancer were excluded. Nut consumption was assessed at baseline and updated every 2 to 4 years. Relative risks (RRs) and 95% confidence intervals (95% CIs) were estimated using Cox proportional hazards models. RESULTS: We documented 466 incident cases of pancreatic cancer. After adjusting for age, height, smoking, physical activity, and total energy intake, women who consumed a 28-g (1 oz) serving size of nuts ≥2 times per week experienced a significantly lower risk of pancreatic cancer (RR, 0.65; 95% CI, 0.47-0.92; P for trend=0.007) when compared with those who largely abstained from nuts. The results did not appreciably change after further adjustment for body mass index (BMI) and history of diabetes mellitus (RR, 0.68; 95% CI, 0.48-0.95; P for trend=0.01). The inverse association persisted within strata defined by BMI, physical activity, smoking, and intakes of red meat, fruits, and vegetables. CONCLUSION: Frequent nut consumption is inversely associated with risk of pancreatic cancer in this large prospective cohort of women, independent of other potential risk factors for pancreatic cancer.

Overall and abdominal adiposity and hypertriglyceridemia among Korean adults: the Korea National Health and Nutrition Examination Survey 2007-2008.

BACKGROUND/OBJECTIVES: Obesity is associated with increased triglyceride levels. We examined whether overall obesity (body mass index (BMI)) and abdominal obesity (waist circumference (WC)) are independently associated with hypertriglyceridemia among the Korean population. SUBJECTS/METHODS: A national sample of 5036 Koreans aged 19-64 was examined with cross-sectional surveys, the Korea National Health and Nutrition Examination Survey, in 2007 and 2008. BMI, WC and other lifestyle information were assessed. RESULTS: We documented 1344 cases (26.7%) of hypertriglyceridemia (fasting triglycerides of >150 mg/dl). Both BMI and WC were each independently associated with hypertriglyceridemia. Multivariate odds ratios (ORs) of increasing categories of BMI (<18.5, 18.5≤ - <23, 23≤ - <25, 25≤ - <28, ≥28 kg/m²), were 0.49, 1.00 (reference), 1.26, 1.63 and 1.84, respectively (P=0.0007) adjusting for WC. There was a positive association between WC and hypertriglyceridemia across increasing quintiles of WC (multivariate-adjusted ORs: 1.00 (reference), 1.54, 2.54, 2.21 and 2.36; P<0.0001), adjusting for BMI. WC was positively related to hypertriglyceridemia in both gender. However, only women's BMI was independently associated with hypertriglyceridemia after adjusting for WC. The joint relation between BMI and WC and hypertriglyceridemia showed that within each BMI category, higher WC predicted a greater prevalence of hypertriglyceridemia and vice versa. The receiver operating characteristic curves indicated that BMI (0.69) and WC (0.72) were similar in predicting hypertriglyceridemia. CONCLUSIONS: Both BMI and WC were strongly independently associated with hypertriglyceridemia among the population. Both measurements should be considered for use in assessing health risk at clinical settings and epidemiologic research among Asian population.

Dietary glycemic index, glycemic load, insulin index, fiber and whole-grain intake in relation to risk of prostate cancer.

OBJECTIVE: Insulin may play a role in prostate cancer tumorigenesis. Postprandial blood glucose and insulin responses of foods depend importantly on the carbohydrate quality and quantity, represented by glycemic index (GI), glycemic load (GL), fiber and whole-grain content, but are also influenced by intake of protein and other characteristics. The recently developed insulin index (II) quantifies the postprandial insulin secretion, also taking into account these additional characteristics. METHODS: We investigated the association between dietary GI, GL, II, fiber, and whole grains and risk of total prostate cancer (n = 5,112) and subgroups of prostate cancer as defined by stage or grade in 49,934 male participants of the Health Professionals Follow-up Study. Multivariate adjusted hazard ratios (HR) and 95% confidence intervals (95% CI) were estimated using Cox proportional hazards regression. RESULTS: Dietary GI, GL, II, or fiber was not associated with risk of total or subgroups of prostate cancer. We observed a positive association between dietary intake of whole grains and total prostate cancer (HR highest versus lowest quintile 1.13, 95% CI 1.03-1.24), which was attenuated after restriction to PSA-screened participants (HR 1.03, 95% CI 0.91-1.17). CONCLUSIONS: These results suggest that long-term exposure to a diet with a high insulin response does not affect prostate cancer incidence.

Diabetes mellitus, fasting blood glucose concentration, and risk of vascular disease: a collaborative meta-analysis of 102 prospective studies.

BACKGROUND: Uncertainties persist about the magnitude of associations of diabetes mellitus and fasting glucose concentration with risk of coronary heart disease and major stroke subtypes. We aimed to quantify these associations for a wide range of circumstances. METHODS: We undertook a meta-analysis of individual records of diabetes, fasting blood glucose concentration, and other risk factors in people without initial vascular disease from studies in the Emerging Risk Factors Collaboration. We combined within-study regressions that were adjusted for age, sex, smoking, systolic blood pressure, and body-mass index to calculate hazard ratios (HRs) for vascular disease. FINDINGS: Analyses included data for 698 782 people (52 765 non-fatal or fatal vascular outcomes; 8.49 million person-years at risk) from 102 prospective studies. Adjusted HRs with diabetes were: 2.00 (95% CI 1.83-2.19) for coronary heart disease; 2.27 (1.95-2.65) for ischaemic stroke; 1.56 (1.19-2.05) for haemorrhagic stroke; 1.84 (1.59-2.13) for unclassified stroke; and 1.73 (1.51-1.98) for the aggregate of other vascular deaths. HRs did not change appreciably after further adjustment for lipid, inflammatory, or renal markers. HRs for coronary heart disease were higher in women than in men, at 40-59 years than at 70 years and older, and with fatal than with non-fatal disease. At an adult population-wide prevalence of 10%, diabetes was estimated to account for 11% (10-12%) of vascular deaths. Fasting blood glucose concentration was non-linearly related to vascular risk, with no significant associations between 3.90 mmol/L and 5.59 mmol/L. Compared with fasting blood glucose concentrations of 3.90-5.59 mmol/L, HRs for coronary heart disease were: 1.07 (0.97-1.18) for lower than 3.90 mmol/L; 1.11 (1.04-1.18) for 5.60-6.09 mmol/L; and 1.17 (1.08-1.26) for 6.10-6.99 mmol/L. In people without a history of diabetes, information about fasting blood glucose concentration or impaired fasting glucose status did not significantly improve metrics of vascular disease prediction when added to information about several conventional risk factors. INTERPRETATION: Diabetes confers about a two-fold excess risk for a wide range of vascular diseases, independently from other conventional risk factors. In people without diabetes, fasting blood glucose concentration is modestly and non-linearly associated with risk of vascular disease. FUNDING: British Heart Foundation, UK Medical Research Council, and Pfizer.

Prospective study of predictors of vitamin D status and survival in patients with colorectal cancer.

BACKGROUND: In an earlier study, a 25-hydroxyvitamin D(3) (25(OH)D) score calculated from known predictors of vitamin D status significantly predicted plasma levels of 25(OH)D and the risk of colorectal cancer, but the influence of the 25(OH)D score on survival after diagnosis is unknown. MATERIALS AND METHODS: We prospectively examined the influence of post-diagnosis predicted 25(OH)D levels on mortality among 1017 participants in the Nurses' Health Study and Health Professionals Follow-Up Study who were diagnosed with colorectal cancer from 1986 to 2004. Colorectal cancer-specific and overall mortality according to quintiles of predicted 25(OH)D levels were assessed. Cox proportional hazards models were used to calculate hazard ratios (HRs) adjusted for other risk factors of survival. RESULTS: Higher predicted 25(OH)D levels were associated with a significant reduction in colorectal cancer-specific (P trend=0.02) and overall mortality (P trend=0.002). Compared with levels in the lowest quintile, participants with predicted 25(OH)D levels in the highest quintile had an adjusted HR of 0.50 (95% CI, 0.26-0.95) for cancer-specific mortality and 0.62 (95% CI, 0.42-0.93) for overall mortality. CONCLUSION: Higher predicted 25(OH)D levels after a diagnosis of colorectal cancer may be associated with improved survival. Further study of the vitamin D pathway in colorectal cancer is warranted.

Plasma Abeta, homocysteine, and cognition: the Vitamin Intervention for Stroke Prevention (VISP) trial.

BACKGROUND: Amyloid-beta protein (Abeta) plays a key role in Alzheimer disease (AD) and is also implicated in cerebral small vessel disease. Serum total homocysteine (tHcy) is a risk factor for small vessel disease and cognitive impairment and correlates with plasma Abeta levels. To determine whether this association results from a common pathophysiologic mechanism, we investigated whether vitamin supplementation-induced reduction of tHcy influences plasma Abeta levels in the Vitamin Intervention in Stroke Prevention (VISP) study. METHODS: Two groups of 150 patients treated with either the high-dose or low-dose formulation of pyridoxine, cobalamin, and folic acid in a randomized, double-blind fashion were selected among the participants in the VISP study without recurrent stroke during follow-up and in the highest 10% of the distribution for baseline tHcy levels. Concentrations of plasma Abeta with 40 (Abeta40) and 42 (Abeta42) amino acids were measured at baseline and at the 2-year visit. RESULTS: tHcy levels significantly decreased with vitamin supplementation in both groups. tHcy were strongly correlated with Abeta40 but not Abeta42 concentrations. There was no difference in the change in Abeta40, Abeta42 (p = 0.40, p = 0.35), or the Abeta42/Abeta40 ratio over time (p = 0.86) between treatment groups. Abeta measures were not associated with cognitive change. CONCLUSIONS: This double-blind randomized controlled trial of vitamin therapy demonstrates a strong correlation between serum tHcy and plasma Abeta40 concentrations in subjects with ischemic stroke. Treatment with high dose vitamins does not, however, influence plasma levels of Abeta, despite their effect on lowering tHcy. Our results suggest that although tHcy is associated with plasma Abeta40, they may be regulated by independent mechanisms.

Effects of G/A polymorphism, rs266882, in the androgen response element 1 of the PSA gene on prostate cancer risk, survival and circulating PSA levels.

Prostate-specific antigen (PSA) is a protease produced in the prostate that cleaves insulin-like growth factor binding protein-3 and other proteins. Production is mediated by the androgen receptor (AR) binding to the androgen response elements (ARE) in the promoter region of the PSA gene. Studies of a single nucleotide polymorphism (PSA -158 G/A, rs266882) in ARE1 of the PSA gene have been conflicting for risk of prostate cancer and effect on plasma PSA levels. In this nested case-control analysis of 500 white cases and 676 age- and smoking-matched white controls in the Physicians' Health Study we evaluated the association of rs266882 with risk and survival of prostate cancer and prediagnostic total and free PSA plasma levels, alone or in combination with AR CAG repeats. We used conditional logistic regression, linear regression and Cox regression, and found no significant associations between rs266882 (GG allele vs AA allele) and overall prostate cancer risk (RR=1.21, 95% confidence intervals (CI): 0.88-1.67) or prostate cancer-specific survival (RR=0.94, 95%CI: 0.56-1.58). Similarly, no associations were found among high grade or advanced stage tumours, or by calendar year of diagnosis. There was no significant association between rs266882 and baseline total or free PSA levels or the AR CAG repeats, nor any interaction associated with prostate cancer risk. Meta-analysis of 12 studies of rs266882 and overall prostate cancer risk was null.