Hypertension and risk of death from external causes in the Physicians' Health Study enrollment cohort

OBJECTIVES

To address the recent hypothesis that hypertension increases the risk of death from external causes.

METHODS

We examined blood pressure and death from external causes among 82,037 male physicians who were screened for eligibility to enroll in the Physicians' Health Study.

RESULTS

During up to 6.6 years of mortality follow-up, there were 304 deaths from external causes. No association was found overall, although we observed an increased risk of non-passive external causes of death, particularly death due to falls, which was independent of various lifestyle, medical, and pharmacological risk factors.

CONCLUSIONS

The results of our study support this novel hypothesis. Further studies are needed to explore potential causal mechanisms between elevated BP and the risk of external death.

Dietary ω-3 fatty acid and fish intake and incident age-related macular degeneration in women

OBJECTIVE

To examine whether intake of ω-3 fatty acids and fish affects incidence of age-related macular degeneration (AMD) in women.

DESIGN

A detailed food-frequency questionnaire was administered at baseline among 39 876 female health professionals (mean [SD] age: 54.6 [7.0] years). A total of 38 022 women completed the questionnaire and were free of a diagnosis of AMD. The main outcome measure was incident AMD responsible for a reduction in best-corrected visual acuity to 20/30 or worse based on self-report confirmed by medical record review.

RESULTS

A total of 235 cases of AMD, most characterized by some combination of drusen and retinal pigment epithelial changes, were confirmed during an average of 10 years of follow-up. Women in the highest tertile of intake for docosahexaenoic acid, compared with those in the lowest, had a multivariate-adjusted relative risk of AMD of 0.62 (95% confidence interval, 0.44-0.87). For eicosapentaenoic acid, women in the highest tertile of intake had a relative risk of 0.66 (95% confidence interval, 0.48-0.92). Consistent with the findings for docosahexaenoic acid and eicosapentaenoic acid, women who consumed 1 or more servings of fish per week, compared with those who consumed less than 1 serving per month, had a relative risk of AMD of 0.58 (95% confidence interval, 0.38-0.87).

CONCLUSION

These prospective data from a large cohort of female health professionals without a diagnosis of AMD at baseline indicate that regular consumption of docosahexaenoic acid and eicosapentaenoic acid and fish was associated with a significantly decreased risk of incident AMD and may be of benefit in primary prevention of AMD.

Migraine features, associated symptoms and triggers: a principal component analysis in the Women's Health Study

AIMS

Migraine has a wide clinical spectrum. Our aim was to group information on migraine characteristics into meaningful components and to identify key components of the migraine phenotype.

METHODS

We performed two principal component analyses, one among participants in the Women's Health Study enrollment cohort and one in a sub-cohort with additional migraine-specific information.

RESULTS

Among the 9427 women with migraine attack-related information at enrollment, the three most important components pertained to central nervous system (CNS) sensitization, attack frequency/pain location and aura/visual phenomena. In the subgroup of 1675 women with more detailed information, food triggers and unspecific symptoms constituted two principal components that explain more of the variance of the migraine phenotype than the three attack-related components.

CONCLUSIONS

Our results indicate that information on migraine-associated features, symptoms and triggers is highly correlated, allowing the extraction of principal components. Migraine attack-related symptoms are best summarized by symptoms related to CNS sensitization, attack frequency/pain location and aura/visual phenomena. Taking a more general view, unspecific symptoms and food triggers appear to carry stronger importance in characterizing the migraine phenotype. These components are useful for future research on the pathophysiology and genetics of migraine and may have implications for diagnosing and treating patients.

Meta-analysis of genome-wide association studies in >80 000 subjects identifies multiple loci for C-reactive protein levels

BACKGROUND

C-reactive protein (CRP) is a heritable marker of chronic inflammation that is strongly associated with cardiovascular disease. We sought to identify genetic variants that are associated with CRP levels.

METHODS AND RESULTS

We performed a genome-wide association analysis of CRP in 66 185 participants from 15 population-based studies. We sought replication for the genome-wide significant and suggestive loci in a replication panel comprising 16 540 individuals from 10 independent studies. We found 18 genome-wide significant loci, and we provided evidence of replication for 8 of them. Our results confirm 7 previously known loci and introduce 11 novel loci that are implicated in pathways related to the metabolic syndrome (APOC1, HNF1A, LEPR, GCKR, HNF4A, and PTPN2) or the immune system (CRP, IL6R, NLRP3, IL1F10, and IRF1) or that reside in regions previously not known to play a role in chronic inflammation (PPP1R3B, SALL1, PABPC4, ASCL1, RORA, and BCL7B). We found a significant interaction of body mass index with LEPR (P<2.9×10(-6)). A weighted genetic risk score that was developed to summarize the effect of risk alleles was strongly associated with CRP levels and explained ≈5% of the trait variance; however, there was no evidence for these genetic variants explaining the association of CRP with coronary heart disease.

CONCLUSIONS

We identified 18 loci that were associated with CRP levels. Our study highlights immune response and metabolic regulatory pathways involved in the regulation of chronic inflammation.

Randomised vitamin E supplementation and risk of chronic lung disease in the Women's Health Study

BACKGROUND

The oxidant/antioxidant balance in lung tissue is hypothesised to contribute to the risk of chronic obstructive pulmonary disease (COPD). Observational studies consistently report higher antioxidant status associated with lower COPD risk, but few randomised studies have been reported.

METHODS

A post hoc analysis of 38,597 women without chronic lung disease at baseline was conducted in the Women's Health Study (WHS) to test the effect of vitamin E on the risk of incident chronic lung disease. The WHS is a randomised double-blind placebo-controlled factorial trial of vitamin E (600 IU every other day) and aspirin (100 mg every other day) in female health professionals aged≥45 years. Using Cox proportional hazards models, the effect of randomised vitamin E assignment on self-reported physician-diagnosed chronic lung disease was evaluated.

RESULTS

During 10 years of follow-up (376,710 person-years), 760 first occurrences of chronic lung disease were reported in the vitamin E arm compared with 846 in the placebo arm (HR 0.90; 95% CI 0.81 to 0.99; p=0.029). This 10% reduction in the risk of incident chronic lung disease was not modified by cigarette smoking, age, randomised aspirin assignment, multivitamin use or dietary vitamin E intake (minimum p for interaction=0.19). Current cigarette smoking was a strong predictor of chronic lung disease risk (HR 4.17; 95% CI 3.70 to 4.70; vs. never smokers).

CONCLUSIONS

In this large randomised trial, assignment to 600 IU vitamin E led to a 10% reduction in the risk of chronic lung disease in women.

Physical activity modifies the effect of LPL, LIPC, and CETP polymorphisms on HDL-C levels and the risk of myocardial infarction in women of European ancestry

BACKGROUND

Recent genome-wide association studies have identified common variants associated with high-density lipoprotein cholesterol (HDL-C). Whether these associations are modified by physical activity, which increases HDL-C levels and reduces the risk of cardiovascular disease, is uncertain.

METHODS AND RESULTS

In a prospective cohort study of 22 939 apparently healthy US women of European ancestry, we selected 58 single nucleotide polymorphisms (SNPs) in 9 genes that demonstrated genome-wide association (P<5×10(-8)) with HDL-C levels and sought evidence of effect modification according to levels of physical activity. Physical activity modified the effects on HDL-C of 7 SNPs at 3 loci, and the strongest evidence of effect was observed for rs10096633 at lipoprotein lipase (LPL), rs1800588 at hepatic lipase (LIPC), and rs1532624 at cholesteryl ester transfer protein (CETP) (each P-interaction<0.05). The per-minor-allele increase in HDL-C for rs1800588 at LIPC and rs1532624 at CETP was greater in active than inactive women, whereas the reverse was observed for rs10096633 at LPL. Minor-allele carrier status at the LPL SNP was associated with a reduced risk of myocardial infarction in active (hazard ratio, 0.51; 95% confidence interval 0.30-0.86) but not among inactive women (hazard ratio 1.13; 95% confidence interval 0.79 to 1.61; P-interaction=0.007). By contrast, carrier status at the CETP SNP was associated with a reduced risk of myocardial infarction regardless of activity level (hazard ratio, 0.72; 95% confidence interval, 0.57 to 0.92; P-interaction=0.71). No association between LIPC SNP carrier status and myocardial infarction risk was noted.

CONCLUSIONS

The effects of common variants in the LPL, LIPC, and CETP genes on HDL-C levels are modified by physical activity. For a common variant in LPL, the impact on myocardial infarction varied by activity level, whereas the effects of a common variant in CETP on myocardial infarction risk did not.

Coffee and caffeine consumption in relation to sex hormone-binding globulin and risk of type 2 diabetes in postmenopausal women

OBJECTIVE

Coffee consumption has been inversely associated with type 2 diabetes risk, but its mechanisms are largely unknown. We aimed to examine whether plasma levels of sex hormones and sex hormone-binding globulin (SHBG) may account for the inverse association between coffee consumption and type 2 diabetes risk.

RESEARCH DESIGN AND METHODS

We conducted a case-control study nested in the prospective Women's Health Study (WHS). During a median follow-up of 10 years, 359 postmenopausal women with newly diagnosed type 2 diabetes were matched with 359 control subjects by age, race, duration of follow-up, and time of blood draw.

RESULTS

Caffeinated coffee was positively associated with SHBG but not with sex hormones. Multivariable-adjusted geometric mean levels of SHBG were 26.6 nmol/l among women consuming ≥4 cups/day of caffeinated coffee and 23.0 nmol/l among nondrinkers (P for trend = 0.01). In contrast, neither decaffeinated coffee nor tea was associated with SHBG or sex hormones. The multivariable-adjusted odds ratio (OR) of type 2 diabetes for women consuming ≥4 cups/day of caffeinated coffee compared with nondrinkers was 0.47 (95% CI 0.23-0.94; P for trend = 0.047). The association was largely attenuated after further adjusting for SHBG (OR 0.71 [95% CI 0.31-1.61]; P for trend = 0.47). In addition, carriers of rs6259 minor allele and noncarriers of rs6257 minor allele of SHBG gene consuming ≥2 cups/day of caffeinated coffee had lower risk of type 2 diabetes in directions corresponding to their associated SHBG.

CONCLUSIONS

Our findings suggest that SHBG may account for the inverse association between coffee consumption and type 2 diabetes risk among postmenopausal women.

Dietary omega-3 fatty acids and fish consumption and risk of type 2 diabetes

BACKGROUND

Although dietary omega-3 (n-3) fatty acids may confer some cardiovascular benefits, it is unclear whether these nutrients may also unfavorably affect risk of type 2 diabetes (T2D).

OBJECTIVE

We evaluated whether dietary omega-3 fatty acids and fish consumption were associated with increased risk of T2D.

DESIGN

This was a prospective study of 36,328 women (mean age: 54.6 y) who participated in the Women's Health Study and who were followed from 1992 to 2008. Incident T2D was self-reported and validated primarily through the collection of supplementary information from participants. Information on omega-3 and fish intakes was obtained by using a validated food-frequency questionnaire. We used Cox proportional hazard models to estimate adjusted relative risks.

RESULTS

During an average follow-up of 12.4 y, 2370 women developed T2D. Marine but not plant-based omega-3 fatty acids were positively associated with incident T2D. From the lowest to highest quintiles of marine omega-3 intake, the multivariable-adjusted hazard ratios (95% CIs) for T2D were 1.0 (referent), 1.17 (1.03, 1.33), 1.20 (1.05, 1.38), 1.46 (1.28, 1.66), and 1.44 (1.25, 1.65), respectively (P for trend < 0.0001). A similar association was observed with fish intake, but additional adjustment for docosahexaenoic acid led to the elimination of the association. The relation between marine omega-3 fatty acids and T2D was observed in hypertensive and nonhypertensive subjects and in women who reported infrequent fish consumption.

CONCLUSION

Our data suggest an increased risk of T2D with the intake of long-chain omega-3 fatty acids, especially with higher intakes (≥ 0.20 g omega-3/d or ≥ 2 servings of fish/d). The Women's Health Study was registered at clinicaltrials.gov as NCT00000479.

Migraine and functional outcome from ischemic cerebral events in women

BACKGROUND

Studies have linked migraine with aura to an increased risk of ischemic stroke, particularly among women. Data on the relationship of migraine and functional outcome from ischemic cerebral events are sparse.

METHODS AND RESULTS

This was a prospective cohort study among 27 852 women enrolled in the Women's Health Study for whom we had information on migraine and measured cholesterol values and who had no prior stroke or transient ischemic attack (TIA) at baseline. Migraine was classified into no history of migraine, active migraine with aura, active migraine without aura, and past history of migraine. Possible functional outcomes were no stroke or TIA, TIA, and stroke with modified Rankin Scale (mRS) score 0 to 1, mRS 2 to 3, and mRS 4 to 6. We used multinomial logistic regression to evaluate the relationship of migraine with functional outcomes after ischemic stroke. During a mean of 13.5 years of follow-up, 398 TIAs and 345 ischemic strokes occurred. Compared with women without history of migraine and who did not experience a TIA or stroke, women who reported migraine with aura had adjusted relative risk (95% confidence interval) of 1.56 (1.03 to 2.36) for TIA, 2.33 (1.37 to 3.97) for stroke with mRS 0 to 1, 0.82 (0.30 to 2.24) for mRS 2 to 3, and 1.18 (0.28 to 4.97) for mRS 4 to 6. The risk of any outcome was not significantly elevated for women who experienced migraine without aura or who had a past history of migraine.

CONCLUSIONS

Results of this large prospective cohort suggest that women with migraine with aura are at increased risk of experiencing TIA or ischemic stroke with good functional outcome.

Age-related cataract in a randomized trial of vitamins E and C in men

OBJECTIVE

To test whether supplementation with alternate-day vitamin E or daily vitamin C affects the incidence of age-related cataract in a large cohort of men.

METHODS

In a randomized, double-masked, placebo-controlled trial, 11,545 apparently healthy US male physicians 50 years or older without a diagnosis of cataract at baseline were randomly assigned to receive 400 IU of vitamin E or placebo on alternate days and 500 mg of vitamin C or placebo daily.

MAIN OUTCOME MEASURE

Incident cataract responsible for a reduction in best-corrected visual acuity to 20/30 or worse based on self-report confirmed by medical record review.

APPLICATION TO CLINICAL PRACTICE

Long-term use of vitamin E and C supplements has no appreciable effect on cataract.

RESULTS

After 8 years of treatment and follow-up, 1174 incident cataracts were confirmed. There were 579 cataracts in the vitamin E-treated group and 595 in the vitamin E placebo group (hazard ratio, 0.99; 95% confidence interval, 0.88-1.11). For vitamin C, there were 593 cataracts in the treated group and 581 in the placebo group (hazard ratio, 1.02; 95% confidence interval, 0.91-1.14).

CONCLUSION

Long-term alternate-day use of 400 IU of vitamin E and daily use of 500 mg of vitamin C had no notable beneficial or harmful effect on the risk of cataract.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00270647.

Asthma, chronic obstructive pulmonary disease, and type 2 diabetes in the Women's Health Study

BACKGROUND

Chronic airway inflammation in asthma or chronic obstructive pulmonary disease (COPD) may be involved in the pathogenesis of type 2 diabetes; however, prospective data have been limited.

METHODS

A prospective cohort of 38,570 women who were aged ≥ 45 years, free of cardiovascular disease and cancer at baseline, and free of diabetes at baseline and in the first 12 months were analyzed. We classified all women into three groups according to the presence and absence of self-reported asthma or COPD (including emphysema, chronic bronchitis, and bronchiectasis).

RESULTS

During a median follow-up of 12.2 years, 2472 incident type 2 diabetes events were documented. Women who had ever reported asthma or COPD were associated with an increased diabetes risk; the multivariate RRs were 1.37 (95% CI, 1.20-1.57) for women who had asthma alone and 1.38 (95% CI, 1.14-1.67) for COPD without asthmatic symptoms. Furthermore, these associations were not significantly modified by age, smoking status, physical activity, BMI, alcohol intake, hormone replacement therapy, menopausal status or randomized treatment.

CONCLUSIONS

Asthma and COPD were individually and independently associated with an increased risk of type 2 diabetes in women, indicating that chronic airway inflammation may contribute to diabetes pathogenesis.

Thirty new loci for age at menarche identified by a meta-analysis of genome-wide association studies

To identify loci for age at menarche, we performed a meta-analysis of 32 genome-wide association studies in 87,802 women of European descent, with replication in up to 14,731 women. In addition to the known loci at LIN28B (P = 5.4 × 10⁻⁶⁰) and 9q31.2 (P = 2.2 × 10⁻³³), we identified 30 new menarche loci (all P < 5 × 10⁻⁸) and found suggestive evidence for a further 10 loci (P < 1.9 × 10⁻⁶). The new loci included four previously associated with body mass index (in or near FTO, SEC16B, TRA2B and TMEM18), three in or near other genes implicated in energy homeostasis (BSX, CRTC1 and MCHR2) and three in or near genes implicated in hormonal regulation (INHBA, PCSK2 and RXRG). Ingenuity and gene-set enrichment pathway analyses identified coenzyme A and fatty acid biosynthesis as biological processes related to menarche timing.

Variant ABO blood group alleles, secretor status, and risk of pancreatic cancer: results from the pancreatic cancer cohort consortium

BACKGROUND

Subjects with non-O ABO blood group alleles have increased risk of pancreatic cancer. Glycosyltransferase activity is greater for the A(1) versus A(2) variant, whereas O01 and O02 variants are nonfunctioning. We hypothesized: 1) A(1) allele would confer greater risk than A(2) allele, 2) protective effect of the O allele would be equivalent for O01 and O02 variants, 3) secretor phenotype would modify the association with risk.

METHODS

We determined ABO variants and secretor phenotype from single nucleotide polymorphisms in ABO and FUT2 genes in 1,533 cases and 1,582 controls from 12 prospective cohort studies. Adjusted odds ratios (OR) for pancreatic cancer were calculated using logistic regression.

RESULTS

An increased risk was observed in participants with A(1) but not A(2) alleles. Compared with subjects with genotype O/O, genotypes A(2)/O, A(2)/A(1), A(1)/O, and A(1)/A(1) had ORs of 0.96 (95% CI, 0.72-1.26), 1.46 (95% CI, 0.98-2.17), 1.48 (95% CI, 1.23-1.78), and 1.71 (95% CI, 1.18-2.47). Risk was similar for O01 and O02 variant O alleles. Compared with O01/O01, the ORs for each additional allele of O02, A(1), and A(2) were 1.00 (95% CI, 0.87-1.14), 1.38 (95% CI, 1.20-1.58), and 0.96 (95% CI, 0.77-1.20); P, O01 versus O02 = 0.94, A(1) versus A(2) = 0.004. Secretor phenotype was not an effect modifier (P-interaction = 0.63).

CONCLUSIONS

Among participants in a large prospective cohort consortium, ABO allele subtypes corresponding to increased glycosyltransferase activity were associated with increased pancreatic cancer risk.

IMPACT

These data support the hypothesis that ABO glycosyltransferase activity influences pancreatic cancer risk rather than actions of other nearby genes on chromosome 9q34.

Eighteen insulin-like growth factor pathway genes, circulating levels of IGF-I and its binding protein, and risk of prostate and breast cancer

BACKGROUND

Circulating levels of insulin-like growth factor I (IGF-I) and its main binding protein, IGF binding protein 3 (IGFBP-3), have been associated with risk of several types of cancer. Heritable factors explain up to 60% of the variation in IGF-I and IGFBP-3 in studies of adult twins.

METHODS

We systematically examined common genetic variation in 18 genes in the IGF signaling pathway for associations with circulating levels of IGF-I and IGFBP-3. A total of 302 single nucleotide polymorphisms (SNP) were genotyped in >5,500 Caucasian men and 5,500 Caucasian women from the Breast and Prostate Cancer Cohort Consortium.

RESULTS

After adjusting for multiple testing, SNPs in the IGF1 and SSTR5 genes were significantly associated with circulating IGF-I (P < 2.1 × 10(-4)); SNPs in the IGFBP3 and IGFALS genes were significantly associated with circulating IGFBP-3. Multi-SNP models explained R(2) = 0.62% of the variation in circulating IGF-I and 3.9% of the variation in circulating IGFBP-3. We saw no significant association between these multi-SNP predictors of circulating IGF-I or IGFBP-3 and risk of prostate or breast cancers.

CONCLUSION

Common genetic variation in the IGF1 and SSTR5 genes seems to influence circulating IGF-I levels, and variation in IGFBP3 and IGFALS seems to influence circulating IGFBP-3. However, these variants explain only a small percentage of the variation in circulating IGF-I and IGFBP-3 in Caucasian men and women.

IMPACT

Further studies are needed to explore contributions from other genetic factors such as rare variants in these genes and variation outside of these genes.

Telomere length and genetic analyses in population-based studies of endometrial cancer risk

BACKGROUND

Telomeres are protective structures at the ends of linear chromosomes, regulated by a host of associated proteins. When telomeres become dysfunctional, genomic instability ensues. The vast majority of cells undergo apoptosis, although a rare cell may survive and become tumorigenic.

METHODS

The authors used conditional logistic regression to examine relative telomere length in peripheral blood leukocytes, genetic variants at telomere maintenance gene loci (TERT, TNKS2, POT1, TERF1, TERF2), and endometrial cancer risk in case-control studies nested within the Nurses' Health Study and the Women's Health Study.

RESULTS

Relative telomere length was significantly inversely correlated with body mass index and weight gain since age 18 years. The authors did not observe a relationship between relative telomere length and endometrial cancer risk. Women in the shortest quartile had a multivariate-adjusted odds ratio (OR) of 1.20 (95% confidence interval [95% CI], 0.73-1.96; P for trend = .37) compared with women in the longest quartile. The authors found an elevation in endometrial cancer risk among women carrying at least 1 minor allele of RS2736122 (TERT; OR, 1.18; 95% CI, 1.01-1.38) or RS12412538 (TNKS2; OR, 1.16; 95% CI, 1.00-1.34).

CONCLUSIONS

Relative telomere length was not associated with endometrial cancer risk. Other aspects of telomere maintenance remain to be explored.

Prospective cohort study of breast implants and the risk of connective-tissue diseases

BACKGROUND

A 2000 meta-analysis indicated no overall association between breast implants and risk of connective-tissue diseases (CTDs). However, a large retrospective cohort study we previously conducted suggested, instead, a small increased risk of CTDs. Because of limitations inherent to the retrospective cohort study design, we sought clarification by conducting a prospective cohort study of the association of breast implants with CTD risk.

METHODS

Participants were 23 847 US women (mean age 56.6 years), 3950 of whom had breast implants and 19 897 did not. Women reported their breast implant status at baseline in 2001 and were followed for a median of 3.63 years. During follow-up, women reported incident CTD, confirmed using a CTD screening questionnaire (CSQ) and medical records.

RESULTS

In multivariate analyses, the rate ratios for self-reported CTD (113 vs 377 cases in the implanted and non-implanted group, respectively) were 1.60 [95% confidence interval (CI) 1.28-2.00], for CSQ-confirmed CTD (77 vs 226 cases), 1.80 (1.37-2.38) and for medical record confirmed CTD (21 vs 74 cases), 1.39 (0.82-2.35).

CONCLUSIONS

Although this prospective cohort study represented a stronger design than the retrospective cohort study, the present data should still be viewed cautiously because of remaining methodological limitations, including the potential for differential self-reporting of CTD and CTD symptoms among women with and without breast implants, the difficulty of obtaining medical records for women reporting CTD and the low and possibly differential confirmation of self-reported disease against medical records. A reasonable conclusion is the lack of a large increase in CTD risk (e.g. ≥2-fold) associated with breast implants.

Intakes of vitamins A, C, and E and use of multiple vitamin supplements and risk of colon cancer: a pooled analysis of prospective cohort studies

OBJECTIVE

To evaluate the associations between intakes of vitamins A, C, and E and risk of colon cancer.

METHODS

Using the primary data from 13 cohort studies, we estimated study- and sex-specific relative risks (RR) with Cox proportional hazards models and subsequently pooled RRs using a random effects model.

RESULTS

Among 676,141 men and women, 5,454 colon cancer cases were identified (7-20 years of follow-up across studies). Vitamin A, C, and E intakes from food only were not associated with colon cancer risk. For intakes from food and supplements (total), the pooled multivariate RRs (95% CI) were 0.88 (0.76-1.02, >4,000 vs. ≤ 1,000 μg/day) for vitamin A, 0.81 (0.71-0.92, >600 vs. ≤ 100 mg/day) for vitamin C, and 0.78 (0.66-0.92, > 200 vs. ≤ 6 mg/day) for vitamin E. Adjustment for total folate intake attenuated these associations, but the inverse associations with vitamins C and E remained significant. Multivitamin use was significantly inversely associated with colon cancer risk (RR = 0.88, 95% CI: 0.81-0.96).

CONCLUSIONS

Modest inverse associations with vitamin C and E intakes may be due to high correlations with folate intake, which had a similar inverse association with colon cancer. An inverse association with multivitamin use, a major source of folate and other vitamins, deserves further study.

Family history of cancer and risk of pancreatic cancer: a pooled analysis from the Pancreatic Cancer Cohort Consortium (PanScan)

A family history of pancreatic cancer has consistently been associated with increased risk of pancreatic cancer. However, uncertainty remains about the strength of this association. Results from previous studies suggest a family history of select cancers (i.e., ovarian, breast and colorectal) could also be associated, although not as strongly, with increased risk of pancreatic cancer. We examined the association between a family history of 5 types of cancer (pancreas, prostate, ovarian, breast and colorectal) and risk of pancreatic cancer using data from a collaborative nested case-control study conducted by the Pancreatic Cancer Cohort Consortium. Cases and controls were from cohort studies from the United States, Europe and China, and a case-control study from the Mayo Clinic. Analyses of family history of pancreatic cancer included 1,183 cases and 1,205 controls. A family history of pancreatic cancer in a parent, sibling or child was associated with increased risk of pancreatic cancer [multivariate-adjusted odds ratios (ORs) = 1.76, 95% confidence interval (CI) = 1.19-2.61]. A family history of prostate cancer was also associated with increased risk (OR = 1.45, 95% CI = 1.12-1.89). There were no statistically significant associations with a family history of ovarian cancer (OR = 0.82, 95% CI = 0.52-1.31), breast cancer (OR = 1.21, 95% CI = 0.97-1.51) or colorectal cancer (OR = 1.17, 95% CI = 0.93-1.47). Our results confirm a moderate sized association between a family history of pancreatic cancer and risk of pancreatic cancer and also provide evidence for an association with a family history of prostate cancer worth further study.

Caffeine consumption and incident atrial fibrillation in women

BACKGROUND

It is somewhat controversial whether caffeine consumption is associated with an increased risk of developing atrial fibrillation (AF).

OBJECTIVE

We prospectively assessed the relation between caffeine intake and incident AF.

DESIGN

A total of 33,638 initially healthy women who participated in the Women's Health Study and who were gt 45 y of age and free of cardiovascular disease and AF at baseline were prospectively followed for incident AF from 1993 to 2 March 2009. All women provided information on caffeine intake via food-frequency questionnaires at baseline and in 2004.

RESULTS

During a median follow-up of 14.4 y (interquartile range: 13.8-14.8 y), 945 AF events occurred. Median caffeine intakes across increasing quintiles of caffeine intake were 22, 135, 285, 402, and 656 mg/d, respectively. Age-adjusted incidence rates of AF across increasing quintiles of caffeine intake were 2.15, 1.89, 2.01, 2.24, and 2.04 events, respectively, per 1000 person-years of follow-up. In Cox proportional hazards models updated in 2004 by using time-varying covariates, the corresponding multivariable-adjusted hazard ratios (95% CI) were 1.0, 0.88 (0.72, 1.06), 0.78 (0.64, 0.95), 0.96 (0.79, 1.16), and 0.89 (0.73, 1.09) (P for linear trend: 0.45). None of the individual components of caffeine intake (coffee, tea, cola, and chocolate) were significantly associated with incident AF.

CONCLUSIONS

In this large cohort of initially healthy women, elevated caffeine consumption was not associated with an increased risk of incident AF. Therefore, our data suggest that elevated caffeine consumption does not contribute to the increasing burden of AF in the population. This trial was registered at clinicaltrials.gov as NCT00000479.

Migraine and risk of haemorrhagic stroke in women: prospective cohort study

OBJECTIVES

To examine the association between migraine and migraine aura status with risk of haemorrhagic stroke.

DESIGN

Prospective cohort study.

SETTING

Women's Health Study, United States.

PARTICIPANTS

27,860 women aged >or=45 who were free from stroke or other major disease at baseline and had provided information on self reported migraine, aura status, and lipid values.

MAIN OUTCOME MEASURES

Time to first haemorrhagic stroke and subtypes of haemorrhagic stroke.

RESULTS

At baseline, 5130 (18%) women reported any history of migraine; of the 3612 with active migraine (migraine in the previous year), 1435 (40%) described having aura. During a mean of 13.6 years of follow-up, 85 haemorrhagic strokes were confirmed after review of medical records. Compared with women without a history of migraine, there was no increased risk of haemorrhagic stroke in those who reported any history of migraine (adjusted hazard ratio 0.98, 95% confidence interval 0.56 to 1.71, P=0.93). In contrast, risk was increased in women with active migraine with aura (2.25, 1.11 to 4.54, P=0.024). The age adjusted increased risk was stronger for intracerebral haemorrhage (2.78, 1.09 to 7.07, P=0.032) and for fatal events (3.56, 1.23 to 10.31, P=0.02). Four additional haemorrhagic stroke events were attributable to migraine with aura per 10 000 women per year. Women who reported active migraine without aura had no increased risk for haemorrhagic stroke.

CONCLUSION

Migraine with aura might, in addition to ischaemic events, also be a risk factor for haemorrhagic stroke. The relatively low number of events and attributable risk should caution against definitive conclusions and call for further confirmation of these observations.

Dietary fatty acids and the risk of hypertension in middle-aged and older women

Dietary intake of various fats may have different effects on blood pressure. We conducted a prospective cohort study to examine the association between intake of subtype and individual fatty acids (FAs) and the risk of developing hypertension among 28 100 US women aged ≥39 years and free of cardiovascular disease and cancer. Baseline intake of FAs was assessed using semiquantitative food frequency questionnaires. Incident hypertension was identified from annual follow-up questionnaires based on self-reported physician diagnosis, medication use, and blood pressure levels. A total of 13 633 women developed incident hypertension during 12.9 years of follow-up. After adjusting for demographic, lifestyle, and other dietary factors, intake of saturated FAs, monounsaturated FAs, and trans-unsaturated FAs (trans FAs) was positively associated with the risk of hypertension. The multivariable relative risks and 95% CIs of hypertension in the highest compared with the lowest quintile of intake were 1.12 (1.05 to 1.20) for saturated FAs, 1.11 (1.04 to 1.18) for monounsaturated FAs, and 1.15 (1.08 to 1.22) for trans FAs. After additional adjustment for body mass index and history of diabetes mellitus and hypercholesterolemia, these associations were attenuated and remained statistically significant only for trans FAs (relative risk in the highest quintile: 1.08; 95% CI: 1.01 to 1.15). Intake of polyunsaturated FAs, including ω3 and ω6 polyunsaturated FAs, was not significantly associated with the risk of hypertension. In conclusion, higher intake of saturated FAs, monounsaturated FAs, and trans FAs was each associated with increased risk of hypertension among middle-aged and older women, whereas only association for trans FAs remained statistically significant after adjustment for obesity-related factors.

Birth weight is a significant risk factor for incident atrial fibrillation

BACKGROUND

Few if any studies have assessed the relationship between birth weight and incident atrial fibrillation (AF).

METHODS AND RESULTS

From 1993 to 2009, we prospectively followed 27 982 women who were >45 years of age and free of cardiovascular disease and AF at baseline. Information on birth weight was categorized into 5 different categories: <2.5, 2.5 to 3.2, 3.2 to 3.9, 3.9 to 4.5, and >4.5 kg. The primary outcome was time to incident AF. During 14.5 years of follow-up, 735 AF events occurred. Age-adjusted incidence rates for incident AF from the lowest to the highest birth weight category were 1.45, 1.82, 1.88, 2.57, and 2.55 events per 1000 person-years of follow-up. After multivariable adjustment, hazard ratios for incident AF across increasing birth weight categories were 1.0, 1.30 (95% confidence interval [CI], 0.96 to 1.75), 1.28 (95% CI, 0.96 to 1.69), 1.70 (95% CI, 1.23 to 2.37), and 1.71 (95% CI, 1.12 to 2.61) (P for linear trend=0.002). Adding body mass index, blood pressure, and diabetes mellitus at study entry did not have a large effect on these estimates (P for linear trend=0.004). In contrast, including height in the multivariable model substantially attenuated the relationship between birth weight and AF (P for linear trend=0.17), and additional adjustment for maximum weight in young adulthood further attenuated this association (multivariable-adjusted hazard ratio across birth weight categories, 1.0, 1.27 [95% CI, 0.94 to 1.71], 1.10 [95% CI, 0.83 to 1.46], 1.41 [95% CI, 1.01 to 1.96], and 1.29 [95% CI, 0.84 to 1.98]; P for linear trend=0.23).

CONCLUSIONS

Birth weight is significantly associated with incident AF among women, suggesting that early life determinants may play an important role in the pathogenesis of AF.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000479.

Alcohol intake and pancreatic cancer: a pooled analysis from the pancreatic cancer cohort consortium (PanScan)

The literature has consistently reported no association between low to moderate alcohol consumption and pancreatic cancer; however, a few studies have shown that high levels of intake may increase risk. Most single studies have limited power to detect associations even in the highest alcohol intake categories or to examine associations by alcohol type. We analyzed these associations using 1,530 pancreatic cancer cases and 1,530 controls from the Pancreatic Cancer Cohort Consortium (PanScan) nested case-control study. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using unconditional logistic regression, adjusting for potential confounders. We observed no significant overall association between total alcohol (ethanol) intake and pancreatic cancer risk (OR = 1.38, 95% CI = 0.86-2.23, for 60 or more g/day vs. >0 to <5 g/day). A statistically significant increase in risk was observed among men consuming 45 or more grams of alcohol from liquor per day (OR = 2.23, 95% CI = 1.02-4.87, compared to 0 g/day of alcohol from liquor, P-trend = 0.12), but not among women (OR = 1.35, 95% CI = 0.63-2.87, for 30 or more g/day of alcohol from liquor, compared to none). No associations were noted for wine or beer intake. Overall, no significant increase in risk was observed, but a small effect among heavy drinkers cannot be ruled out.

Risk of colon cancer and coffee, tea, and sugar-sweetened soft drink intake: pooled analysis of prospective cohort studies

BACKGROUND

The relationships between coffee, tea, and sugar-sweetened carbonated soft drink consumption and colon cancer risk remain unresolved.

METHODS

We investigated prospectively the association between coffee, tea, and sugar-sweetened carbonated soft drink consumption and colon cancer risk in a pooled analysis of primary data from 13 cohort studies. Among 731 441 participants followed for up to 6-20 years, 5604 incident colon cancer case patients were identified. Study-specific relative risks (RRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models and then pooled using a random-effects model. All statistical tests were two-sided.

RESULTS

Compared with nonconsumers, the pooled multivariable relative risks were 1.07 (95% CI = 0.89 to 1.30, P(trend) = .68) for coffee consumption greater than 1400 g/d (about six 8-oz cups) and 1.28 (95% CI = 1.02 to 1.61, P(trend) = .01) for tea consumption greater than 900 g/d (about four 8-oz cups). For sugar-sweetened carbonated soft drink consumption, the pooled multivariable relative risk comparing consumption greater than 550 g/d (about 18 oz) to nonconsumers was 0.94 (95% CI = 0.66 to 1.32, P(trend) = .91). No statistically significant between-studies heterogeneity was observed for the highest category of each beverage consumed (P > .20). The observed associations did not differ by sex, smoking status, alcohol consumption, body mass index, physical activity, or tumor site (P > .05).

CONCLUSIONS

Drinking coffee or sugar-sweetened carbonated soft drinks was not associated with colon cancer risk. However, a modest positive association with higher tea consumption is possible and requires further study.

Genetic variation in sex-steroid receptors and synthesizing enzymes and colorectal cancer risk in women

OBJECTIVES

Several lines of evidence have suggested that female hormones may lower the risk for developing colorectal cancer. However, the mechanisms by which sex hormones affect colorectal cancer development remain unknown. We sought to determine whether the association may be under genetic control by evaluating genetic variation in estrogen receptors (ESR1 and ESR2), progesterone receptor (PGR), aromatase cytochrome 450 enzyme (CYP19A1), and 17 beta-hydroxysteroid dehydrogenase type 2 gene (HSD17B2).

METHODS

We included 158 incident cases of colorectal cancer and 563 randomly chosen control subjects from 28,345 women in the Women's Health Study aged 45 or older who provided blood samples and had no history of cancer or cardiovascular disease at baseline in 1993. All cases and controls were Caucasians of European descent. A total of 63 tagging and putative functional SNPs in the 5 genes were included for analysis. Unconditional logistic regression was used to estimate odds ratio (ORs) and 95% confidence intervals (CIs).

RESULTS

There was no association between variation in ESR1, ESR2, PGR, CYP19A1 and HSD17B2 and colorectal cancer risk after correction for multiple comparisons (p values after correction > or =0.25). There was also no association with any of the haplotypes examined (p > or = 0.15) and no evidence of joint effects of variants in the 5 genes (p > or = 0.51).

CONCLUSION

Our data offer insufficient support for an association between variation in ESR1, ESR2, PGR, CYP19A1, and HSD17B2 and risk for developing colorectal cancer.