Electronic health record reveals community-level cardiometabolic health benefits associated with 10 years of community-based participatory research

BACKGROUND

While a major goal of community-based participatory research (CBPR) is to improve community health; it is unclear how to measure longstanding success of CBPR.

OBJECTIVE

We sought to determine the impact of ongoing CBPR on cardiometabolic health of participating communities, including in people not directly participating in research.

METHODS

We used linear mixed-effects modelling with electronic medical records from 2002 to 2012 from the Yukon-Kuskokwim Health Corporation, which provides health care to all Alaska Native people in southwestern Alaska, to compare rates of change in cardiometabolic risk factors between communities that did and did not participate in ongoing CBPR beginning in 2003.

RESULTS

We analysed 1,262,035 medical records from 12,402 individuals from 10 study and 38 control communities. Blood pressure declined faster in study than in control communities: systolic blood pressure (0.04 mmHg/year; 95% confidence interval [CI]: 0.01, 0.08); diastolic blood pressure (DBP) (0.07 mmHg/year; 95% CI: 0.04, 0.09). Body mass index increased 0.04 units/year faster in study communities than in control communities (95% CI: 0.03, 0.05). More study visits were associated with faster reduction of DBP and triglyceride levels in study communities.

CONCLUSIONS

Ongoing CBPR may improve overall cardiometabolic health in communities, perhaps by increasing engagement in health and advocacy.

Microaxial circulatory support for percutaneous coronary intervention: A systematic review and meta-analysis

BACKGROUND

Microaxial circulatory support devices have been used to support patients treated with percutaneous coronary intervention (PCI) for acute myocardial infarction complicated by cardiogenic shock (AMICS). The purpose of this systematic review and meta-analysis was to pool and analyze the existing evidence on the baseline characteristics, periprocedural data, and outcomes of microaxial support before and after PCI in AMICS.

METHODS

An electronic database search was performed to identify all cohort studies on Impella and PCI for cardiogenic shock in the English language. A total of five articles comprising 543 patients were included. These patients received microaxial support either before (pre-PCI) or after (post-PCI) undergoing PCI. Comparative analyses were done between both groups.

RESULTS

The mean patient age was 66 years [95% Confidence Interval (58-74)], and 22% (89/396) of patients were female. ST-elevation myocardial infarctions (MI) comprised 64% (44-80) of MIs and 50% (44-56) of MIs involved the left anterior descending artery. The mean number of diseased vessels was 2.21 (1.62-2.80). The mean left ventricular ejection fraction was 31% (23.4-38.6). The mean arterial pressure was 66.3 mm Hg (54.1-78.5). Mean serum lactate [6.1 mmol/L (3.3-8.9)] and serum creatinine [1.4 mg/dl (1.0-1.7)] were similar between groups. 30-day mortality was lower in the pre-PCI group [41% (34%-49%)] compared to the post-PCI group [61% (42%-77%), p < 0.01]. Pooled Kaplan-Meier analysis showed better early survival in the pre-PCI group (p < 0.001).

CONCLUSION

Patients presenting with AMICS were similar at baseline in both pre-PCI and post-PCI groups. Nevertheless, pre-PCI group showed better early survival compared to post-PCI group.

Tricuspid regurgitation associated with implantable electrical device insertion: A systematic review and meta-analysis

BACKGROUND

Implantable cardioverter defibrillator (ICD) and permanent pacemaker (PPM) lead placement may worsen or result in tricuspid regurgitation (TR). While the association between lead placement and the incidence of TR has been established, current understanding of this problem remains incomplete. This systematic review and meta-analysis sought to pool the existing evidence to better understand the occurrence and severity of TR associated with cardiac implantable electrical device (CIED) insertion.

METHODS

An electronic search was performed to identify all relevant studies published from 2000 to 2018. Overall, 15 studies were selected for the analysis comprising 4019 patients with data reported on TR development following ICD or PPM lead placement. Demographic information, perioperative clinical variables, and clinical outcome measures, including pre and postoperative echocardiographic TR grade changes, were extracted and pooled for systematic review.

RESULTS

Mean patient age was 69 years [95% CI: 64.62-73.59], and 63% [95% CI: 57-68] were male. Devices implanted included ICD in 57% [95%CI: 43-70] and PPM in 41% [95%CI: 31-52]. The most common indications for pacemaker implantation were sick sinus syndrome in 22% [95% CI: 22-37] and AV block in 21% [95%CI:12-34. The commonest indications for ICD implantation were primary and secondary prevention of sudden cardiac death. Atrial fibrillation was present in 37% [95%CI: 28-46] and congestive heart failure in 15% [95%CI: 2-57]. Baseline distribution of TR grades were as follows: grade 0/1 TR in 89% [95%CI: 82-93], grade 2 TR in 8% [95%CI: 5-13], grade 3 TR in 2% [95%CI: 0-7] and grade 4 TR in 2% [95%CI: 1-4]. Post-procedure, grade 0/ 1 TR decreased to 68% [95% CI: 51-81] (p < 0.01), grade 2 TR increased to 21% [15-28] (p < 0.01), grade 3 TR increased to 13% [95%CI: 5-32] (p = 0.02), and grade 4 TR increased to 7% [95%CI: 5-9] (p < 0.01).

CONCLUSION

ICD and PPM lead placement is associated with increased TR post-procedure. Further studies are warranted to evaluate changes in TR grade in the long term.

Computational sentiment analysis of an online left ventricular assist device support forum: positivity predominates

Background

The impact of left ventricular assist device (LVAD) complications on the individual patient, overall sentiment, and its effect on referral patterns, is not fully understood. We sought to better understand patient attitudes towards LVAD therapy using a computational sentiment analysis approach.

Methods

Posts, comments, and titles were parsed from MyLVAD.com's HTML as a text file using custom Python scripts (version 3.6). Individual word frequency was computed with word classification as 'positive', 'negative', or 'neutral'. Data transformation and cleaning, sentiment determination, and analysis was performed with a binary dictionary package using R software (version 3.6).

Results

Sixty-six thousand eight hundred and twenty-one unique words were noted, including 4,623 (6.9%) with positive sentiment and 3,248 (4.8%) with negative sentiment. Net sentiment ratio [(number of positive words - number of negative words)/(number of total words)] was 2.1%. Positive sentiment dominated the 20 most commonly used words. Odds ratio of non-neutral words [(number of positive words/number of negative words)] was 1.42, indicating a less obvious disparity in sentiment when expanding analysis beyond the top 20 words. Word cloud analysis of positive and negative sentiments was performed, indicating common use of "infection" (208 mentions) compared to other complications such as "stroke" (29 mentions), "bleeding" (30 mentions), and "thrombosis" or "clot" (32 mentions).

Conclusions

Positive sentiment dominates the most frequently used words, yet this disparity decreases when considering the totality of words. "Infection" is mentioned a disproportionate number of times compared to other LVAD complications. Further research is required to address analysis limitations, including selection bias.

Continuous-flow LVAD exchange to a different pump model: Systematic review and meta-analysis of the outcomes

Despite improved outcomes of modern continuous-flow left ventricular assist devices (CF-LVADs), device exchange is still needed for various indications. While the majority of CF-LVADs are exchanged to the same model, exchange to a different pump model is occasionally warranted. In this meta-analysis, we sought to consolidate the existing evidence to better elucidate the indications and outcomes in these cases. A comprehensive systematic search of adult patient cohorts who underwent CF-LVAD exchange to a different CF-LVAD model was performed. Study-level data from 10 studies comprising 98 patients were extracted and pooled for analysis. Mean patient age was 58 (95% CI: 48-65) and 81% were male. Indication for initial CF-LVAD was ischemic cardiomyopathy in 45% (34-57). Initial device was HeartMate II LVAD (HMII) in 93 (94.9%) and HeartWare HVAD (HW) in 5 (5.1%) patients. After mean CF-LVAD support time of 18.8 (15.2-22.4) months, exchange indications included thrombosis in 71% (43-89), infection in 21% (8-47) and device malfunction in 12% (7-21). HMII to HW exchange occurred in 53 (54.1%) patients, HMII to HeartMate III (HM3) in 32 (32.7%), and HM II to either HW or HM3 in 13 (13.2%) patients. Postoperatively, right ventricular assist device was required in 16% (8-32). Overall, 20% (8-40) of patients experienced a stroke, while HW patients had a significantly higher stroke incidence than HM3 patients (HW: 21% (8-47) vs. HM3: 5% (1-24), P < .01). Overall 30-day mortality was 10% (6-17), while HW had a significantly worse 30-day mortality than HM3 (HW: 13% (7-24) vs. HM3: 5% (1-24), P = .03). Following device exchange from a different CF-LVAD model, HM3 is associated with lower stroke and higher survival when compared to HW.

Utilization of extracorporeal life support for diffuse alveolar damage and diffuse alveolar hemorrhage: A systematic review

Modern extracorporeal life-support (ECLS) technology has been successfully utilized to treat patients with diffuse alveolar damage (DAD) and diffuse alveolar hemorrhage (DAH); however, reports in the literature remain scarce. We sought to pool existing evidence to better characterize ECLS use in these patients. An electronic search was conducted to identify all studies in the English literature reporting the use of ECLS for DAD/DAH. Thirty-two articles consisting of 38 patients were selected, and patient-level data were extracted and pooled for analysis. Median patient age was 36 [IQR: 27, 48] years, and the majority (63.2%) were female. Most common etiological factors included granulomatosis with polyangiitis (8/38, 21.1%), systemic lupus erythematosus (8/38, 21.1%), Goodpasture's syndrome (4/38, 10.5%), and microscopic polyangiitis (4/38, 10.5%). Immunologic markers included anti-neutrophil cytoplasmic antibody (ANCA) in 15/38 (39.5%), anti-nuclear antibody (ANA) in 6/38 (15.8%), and anti-glomerular basement membrane (anti-GBM) antibodies in 4/38 (10.5%). DAH was present in 32/38 (84.2%) of cases and DAD without evidence of DAH was present in 6/38 (15.8%) of cases. ECLS strategies included extracorporeal membrane oxygenation of veno-venous type (VV-ECMO) in 28/38 (73.7%), veno-arterial type (VA-ECMO) in 5/38 (13.2%), and one case of right ventricular assist device with oxygenator (RVAD-ECMO). Heparin was utilized in 18/38 (47.4%) of cases with no difference in use between DAH versus no DAH (P = .46) or VA- versus VV-ECLS (P = 1). Median duration of ECLS was 10 [5, 14] days. Pre- versus post-ECLS comparison of blood gases showed improvement in median PaO₂ (49 [45, 59] mm Hg vs. 80 [70, 99] mm Hg, P < .001), PaO2:FiO₂ ratio (48.2 [41.4, 54.8] vs. 182.0 [149.4, 212.2], P < .01), and pulse oximetry values (76% [72, 80] vs. 96% [94, 97], P = .086). Overall, 94.7% (36/38) of patients survived to decannulation while 30-day mortality was 10.5% (4/38) with no differences between VA- and VV-ECMO (P = 1 and P = .94, respectively). DAD/DAH occurs in a younger, predominantly female population, and tends to be associated with systemic autoimmune processes. ECLS, independent of its type, appears to result in favorable short-term survival.

Outcomes of Extracorporeal Life Support Use in Accidental Hypothermia: A Systematic Review

BACKGROUND

Extracorporeal life support (ECLS) has been used in the treatment of accidental hypothermia with hemodynamic instability, with promising outcomes. This systematic review examines ECLS treatment of accidental hypothermia to assess outcomes.

METHODS

An electronic search was performed to identify articles reporting ECLS use for treatment of accidental hypothermia. Only reports describing patients aged more than 16 years after January 1, 2005, were included. Nineteen studies were identified comprising 47 patients. Demographic information, perioperative variables, and outcomes were extracted for analysis.

RESULTS

Median patient age was 48 years (interquartile range (IQR), 29 to 56), and 72.3% (34 of 47) were male. On presentation, median body temperature was 24.6°C (IQR, 22.2° to 26°C), median potassium level 4.3 mmol/L (IQR, 3.4 to 4.6 mmol/L), and median Glasgow Coma Scale score 3 (IQR, 3 to 7). Cardiac arrest occurred in 35 of 47 patients (74.5%). Median time to ECLS initiation from scene was 155 minutes (IQR, 113 to 245). Median ECLS duration was 18 hours (IQR, 4 to 27), with median rewarming rate of 2°C per hour (IQR, 1.5° to 4°). Median intensive care unit stay and hospital length of stay were 8 days (IQR, 2 to 16) and 17 days (IQR, 10 to 36), respectively. Inhospital mortality was 19.1% (9 of 47). Median discharge Glasgow Coma Scale score was 15 (IQR, 15 to 15) with minor long-term cognitive impairments noted in 6 of 47 patients (19.4%). Survival was significantly associated with potassium on presentation (P < .001), initial body temperature (P < .001), and ECLS rewarming rate (P < .001).

CONCLUSIONS

Extracorporeal life support is a viable cardiac support option for rewarming patients with accidental hypothermia, and initial potassium level, initial body temperature, and ECLS rewarming rate appear to be significantly associated with survival.

Outcomes of percutaneous temporary biventricular mechanical support: a systematic review

Percutaneous biventricular assist devices (BiVAD) are a recently developed treatment option for severe cardiogenic shock. This systematic review sought to identify indications and outcomes of patients placed on percutaneous BiVAD support. An electronic search was performed to identify all appropriate studies utilizing a percutaneous BiVAD configuration. Fifteen studies comprising of 20 patients were identified. Individual patient survival and outcomes data were combined for statistical analysis. All 20 patients were supported with a microaxial LVAD, 12/20 (60%) of those patients were supported with a microaxial (RMA) right ventricular assist device (RVAD), and the remaining 8/20 (40%) patients were supported with a centrifugal extracorporeal RVAD (RCF). All patients presented with cardiogenic shock, and of these, 12/20 (60%) presented with a non-ischemic etiology vs 8/20 (40%) with ischemic disease. For the RMA group, RVAD support was significantly longer [RMA 5 (IQR 4-7) days vs RCF 1 (IQR 1-2) days, p = 0.03]. Intravascular hemolysis post-BiVAD occurred in three patients (27.3%) [RMA 3 (33.3%) vs RCF 0 (0%), p = 0.94]. Five patients received a durable left ventricular assist device, one patient received a total artificial heart, and one patient underwent a heart transplantation. Estimated 30-day mortality was 15.0%, and 78.6% were discharged alive. Both strategies for percutaneous BiVAD support appear to be viable options for severe cardiogenic shock.

Domino heart transplant following heart-lung transplantation: a systematic review and meta-analysis

Background

The domino-donor operation occurs when a "conditioned" heart from the heart-lung transplant (HLT) recipient is transplanted into a separate heart transplant (HT) recipient. The purpose of this systematic review was to investigate the indications and outcomes associated with the domino procedure.

Methods

An electronic search was performed to identify all prospective and retrospective studies on the domino procedure in the English literature. Eight studies reported 183 HLT recipients and 263 HT recipients who were included in the final analysis.

Results

HLT indications included cystic fibrosis in 58% (95% CI: 27-84%) of recipients, primary pulmonary hypertension (PPH) in 17% (95% CI: 12-24%), bronchiectasis in 5% (95% CI: 3-10%), emphysema in 5% (95% CI: 0-45%), and Eisenmenger's syndrome in 4% (95% CI: 2-8%). HT indications included ischemic heart disease in 40% (95% CI: 33-47%), non-ischemic disease in 39% (95% CI: 25-56%), and re-transplantation in 10% (95% CI: 1-59%). The pooled mean pulmonary vascular resistance (PVR) in HT recipients was 3.05 Woods units (95% CI: 0.14-5.95). The overall mortality in the HLT group was 28% (95% CI: 18-41%) at an average follow-up of 15.68 months (95% CI: 0.82-30.54), and 35% (95% CI: 17-58%) in the HT group at an average follow-up of 37.26 months (95% CI: 6.68-67.84). Freedom from rejection in HT was 94% (95% CI: 75-99%) at 1 month, 77% (95% CI: 30-96%) at 6 months, and 41% (95% CI: 33-50%) at 1 year.

Conclusions

The domino procedure appears to be a viable option in properly selected patients that can be performed safely with acceptable outcomes.

Association between iq'mik smokeless tobacco use and cardiometabolic risk profile among Yup'ik Alaska Native people

OBJECTIVE

The traditional lifestyle of Yup'ik Alaska Native people, including a diet abundant in marine-based foods and physical activity, may be cardio-protective. However, iq'mik, a traditional form of smokeless tobacco used by >50% of Yup'ik adults, could increase cardiometabolic (CM) risk. Our objective was to characterize the associations between iq'mik use and biomarkers of CM status (low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], triglycerides [TG], systolic blood pressure [SBP] and diastolic blood pressure [DBP], glycated hemoglobin [HbA1c], fasting blood glucose [FBG], waist circumference [WC], and body mass index [BMI]).

DESIGN

We assessed these associations using data from a cross-sectional sample of Yup'ik adults (n = 874). Current iq'mik use, demographic, and lifestyle data were collected through interviews. Fasting blood samples were collected to measure LDL-C, HDL-C, TG, HbA1c, and FBG. SBP, DBP, WC, and BMI were obtained by physical examination. We characterized the association between current iq'mik use and continuous biomarkers of CM status using multiple approaches, including adjustment for measures of Yup'ik lifestyle and a propensity score.

RESULTS

Based on either adjustment method, current iq'mik use was significantly and positively associated with at least 5% higher HDL-C, and significantly associated but in an inverse direction with multiple biomarkers of CM status including 7% lower TG, 0.05% lower HbA1c, 2% lower FBG, 4% lower WC, and 4% lower BMI. Observed associations for LDL-C, SBP, and DBP varied by adjustment method.

CONCLUSIONS

This inverse association between iq'mik use and cardiometabolic risk status has not been previously reported. Additional research is needed to replicate these findings and explore physiological mechanisms and/or confounding factors.

Dietary Vitamin K and Association with Hepatic Vitamin K Status in a Yup'ik Study Population from Southwestern Alaska

SCOPE

The relationship between dietary vitamin K and plasma PIVKA-II concentration, a biomarker of hepatic vitamin K status, in a Yup'ik study population in southwestern Alaska is investigated.

METHODS AND RESULTS

A total of 659 male and female, self-reported Yup'ik people, ≥14 years of age, were enrolled. Blood is collected for genotyping and plasma PIVKA-II biomarker analysis. A Yup'ik-specific dietary food frequency questionnaire is used to assess vitamin K intake. Among the participants, 22% report not consuming foods rich in vitamin K during the past year and 36% have a PIVKA-II concentration ≥ 2 ng mL-1 , indicating vitamin K insufficiency. The odds of an elevated PIVKA-II concentration are 33% lower in individuals reporting any versus no consumption of vitamin-K-rich foods. The association is significant after adjusting for CYP4F2*3 genotype. Tundra greens are high in vitamin K1 content, but an exploratory analysis suggests that subsistence meat sources have a greater effect on vitamin K status.

CONCLUSIONS

A substantial proportion of the Yup'ik population exhibits vitamin K insufficiency, which is associated with low consumption of vitamin K rich foods and which might affect an individual's response to anticoagulant drugs such as warfarin that target the vitamin K cycle.

Bi-cultural dynamics for risk and protective factors for cardiometabolic health in an Alaska Native (Yup'ik) population

Alaska Native people experience disparities in mortality from heart disease and stroke. This work attempts to better understand the relationships between socioeconomic, behavioral, and cardiometabolic risk factors among Yup'ik people of southwestern Alaska, with a focus on the role of the socioeconomic, and cultural components. Using a cross-sectional sample of 486 Yup'ik adults, we fitted a Partial Least Squares Path Model (PLS-PM) to assess the associations between components, including demographic factors [age and gender], socioeconomic factors [education, economic status, Yup'ik culture, and Western culture], behavioral factors [diet, cigarette smoking and smokeless tobacco use, and physical activity], and cardiometabolic risk factors [adiposity, triglyceride-HDL and LDL lipids, glycemia, and blood pressure]. We found relatively mild associations of education and economic status with cardiometabolic risk factors, in contrast with studies in other populations. The socioeconomic factor and participation in Yup'ik culture had potentially protective associations with adiposity, triglyceride-HDL lipids, and blood pressure, whereas participation in Western culture had a protective association with blood pressure. We also found a moderating effect of participation in Western culture on the relationships between Yup'ik culture participation and both blood pressure and LDL lipids, indicating a potentially beneficial additional effect of bi-culturalism. Our results suggest that reinforcing protective effects of both Yup'ik and Western cultures could be useful for interventions aimed at reducing cardiometabolic health disparities.

Dietary and genetic influences on hemostasis in a Yup'ik Alaska Native population

Fish and marine animals are important components of the subsistence diet of Alaska Native people, resulting in a high ω3 PUFA intake. The historical record for circumpolar populations highlights a tendency for facile bleeding, possibly related to ω3 PUFA effects on platelet activation and/or vitamin K-dependent clotting factors. To evaluate these two scenarios in Yup'ik people of southwestern Alaska, we examined the association between dietary ω3 PUFA intake and activities of clotting factor II, V, fibrinogen, PT, INR, PTT, and sP-selectin in 733 study participants, using the nitrogen isotope ratio of red blood cells as a biomarker of ω3 PUFA consumption. sP-selectin alone correlated strongly and inversely with ω3 PUFA consumption. Approximately 36% of study participants exhibited PIVKA-II values above the threshold of 2 ng/ml, indicative of low vitamin K status. To assess genetic influences on vitamin K status, study participants were genotyped for common vitamin K cycle polymorphisms in VKORC1, GGCX and CYP4F2. Only CYP4F2*3 associated significantly with vitamin K status, for both acute (plasma vitamin K) and long-term (PIVKA-II) measures. These findings suggest: (i) a primary association of ω3 PUFAs on platelet activation, as opposed to vitamin K-dependent clotting factor activity, (ii) that reduced CYP4F2 enzyme activity associates with vitamin K status. We conclude that high ω3 PUFA intake promotes an anti-platelet effect and speculate that the high frequency of the CYP4F2*3 allele in Yup'ik people (~45%) evolved in response to a need to conserve body stores of vitamin K due to environmental limitations on its availability.

High tobacco use prevalence with significant regional and sex differences in smokeless tobacco use among Western Alaska Native people: the WATCH study

Tobacco use prevalence among Alaska Native (AN) people living in Alaska is greater than the general population prevalence statewide and nationally. Better understanding of regional tobacco use is needed to improve cessation efforts and reduce prevalence. Using self-reported baseline data from the Western Alaska Tribal Collaborative for Health study, we describe tobacco use patterns among AN people in two western Alaska regions. Data were stratified by age group and sex. Dual- and multi-product use in the Yukon-Kuskokwim (Y-K) region was stratified by concurrent vs sequential use. Overall, 87% of the cohort reported having used tobacco. In Norton Sound, cigarette (98%) was the predominant tobacco type. In Y-K 71% smoked, 76% used smokeless tobacco (ST), with 47% reporting use of both products. ST use in Y-K consisted of commercial ST and homemade iqmik. Y-K women reported more ST product use, while men reported more cigarette use. Among dual- and multi-product users, the majority reported concurrent use, with no significant differences between men and women. Distinct regional differences include high smoking prevalence in Norton Sound and frequent use of smoking and ST products in Y-K. Findings support modification of cessation programmes to address regional variations in tobacco use patterns.

Outcomes of a Pilot Intervention Study for Young Adults at Risk for Cardiovascular Disease Based on Their Family History

BACKGROUND

Lifestyle choices have a significant impact on cardiovascular disease (CVD) risk. Interventions to promote a heart-healthy lifestyle in young adults at long-term high risk for CVD are needed to decrease the burden of CVD. However, few interventions with this purpose have been developed.

OBJECTIVE

The objective of this study was to examine the effect of a pilot intervention on young adults with a family history of CVD that used 3-generation pedigrees, risk factor information, and counseling on heart disease knowledge, perceived CVD risk, and intention to engage in a heart-healthy lifestyle.

METHODS

A pretest-posttest design, with within-group analysis, was used to examine the effect of the intervention. Paired t test and Wilcoxon signed rank tests were used to examine the changes in heart disease knowledge, perceived risk, and behavioral intention from baseline to postintervention. The Cohen d was calculated to examine the effect of the intervention on study measures. In addition, Spearman ρ was used to examine the associations between postintervention perceived risk, postintervention behavioral intention, and family history.

RESULTS

The sample for the pilot study included 15 mostly white and mostly female healthy young adults between the ages of 18 and 25 years. The intervention was effective at increasing CVD knowledge (P = .02) and had a medium effect on perceived risk and intention to engage in a heart-healthy lifestyle (Cohen d, 0.48-0.58). There were significant associations between postintervention perceived risk and postintervention intention to exercise and the participants' family history of coronary heart disease (r = 0.62, P = .014 and r = 0.55, P = .035, respectively).

CONCLUSIONS

Interventions are needed to increase individuals' awareness of their long-term CVD risk and to improve their ability to make lifestyle changes. Although this intervention was only tested in a small sample, it shows promise to improve heart disease knowledge and perceived lifetime CVD risk and may effect longer-term risk for CVD.

Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for Thirteen Cancer Types

BACKGROUND

Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites.

METHODS

Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers.

RESULTS

GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, hl (2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (ρ = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (ρ = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (ρ = 0.51, SE =0.18), and bladder and lung (ρ = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures.

CONCLUSION

Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.

Associations between diet and cardiometabolic risk among Yup'ik Alaska Native people using food frequency questionnaire dietary patterns

BACKGROUND AND AIMS

In previous analyses, we identified three dietary patterns from food frequency questionnaire data among a sample of Yup'ik Alaska Native people living in Southwest Alaska: a "subsistence foods" dietary pattern and two market-based dietary patterns "processed foods" and "fruits and vegetables". In this analysis, we aimed to characterize the association between the dietary patterns and cardiometabolic (CM) risk factors (lipids, blood pressure, glucose, adiposity).

METHODS AND RESULTS

We used multilevel linear regression to estimate the mean of each CM risk factor, comparing participants in the 4th to the 1st quartile of each dietary pattern (n = 637). Models were adjusted for age, sex, past smoking, current smoking, and physical activity. Mean log triglyceride levels were significantly higher among participants in the 4th compared to the 1st quartile of the processed foods dietary pattern (β = 0.11). Mean HbA1c percent was significantly lower (β = -0.08) and mean diastolic blood pressure (DBP) mm Hg was significantly higher (β = 2.87) among participants in the 4th compared to the 1st quartile of the fruits and vegetables dietary pattern. Finally, mean log triglyceride levels and mean DBP mm Hg were significantly lower among participants in the 4th compared to the 1st quartile of the subsistence foods dietary pattern (β = -0.10 and β = -3.99 respectively).

CONCLUSIONS

We found increased CM risk, as reflected by increased triglycerides, associated with eating a greater frequency of processed foods, and reduced CM risk, as reflected by lower triglycerides and DBP, associated with eating a greater frequency of subsistence foods.

TERT gene harbors multiple variants associated with pancreatic cancer susceptibility

A small number of common susceptibility loci have been identified for pancreatic cancer, one of which is marked by rs401681 in the TERT-CLPTM1L gene region on chromosome 5p15.33. Because this region is characterized by low linkage disequilibrium, we sought to identify whether additional single nucleotide polymorphisms (SNPs) could be related to pancreatic cancer risk, independently of rs401681. We performed an in-depth analysis of genetic variability of the telomerase reverse transcriptase (TERT) and the telomerase RNA component (TERC) genes, in 5,550 subjects with pancreatic cancer and 7,585 controls from the PANcreatic Disease ReseArch (PANDoRA) and the PanScan consortia. We identified a significant association between a variant in TERT and pancreatic cancer risk (rs2853677, odds ratio = 0.85; 95% confidence interval = 0.80-0.90, p = 8.3 × 10(-8)). Additional analysis adjusting rs2853677 for rs401681 indicated that the two SNPs are independently associated with pancreatic cancer risk, as suggested by the low linkage disequilibrium between them (r(2) = 0.07, D' = 0.28). Three additional SNPs in TERT reached statistical significance after correction for multiple testing: rs2736100 (p = 3.0 × 10(-5) ), rs4583925 (p = 4.0 × 10(-5) ) and rs2735948 (p = 5.0 × 10(-5) ). In conclusion, we confirmed that the TERT locus is associated with pancreatic cancer risk, possibly through several independent variants.

Cardiometabolic correlates of low type 2 diabetes incidence in western Alaska Native people - The WATCH study

AIMS

Previously rare among Alaska Native (AN) people, type 2 diabetes (DM2) prevalence as indicated by registry data has increased by as much as 300% in some western Alaska regions. We sought to determine prevalence and incidence of DM2 and analyze associated cardiometabolic risk factors in western AN people.

METHODS

DM2 and prediabetes prevalence and incidence were determined by the Western Alaska Tribal Collaborative for Health using consolidated data from cohort studies conducted during 2000-2010. Crude and age-adjusted incidence for DM2 and prediabetes were calculated using 2010 American Diabetes Association criteria. Effects of covariates on DM2 and prediabetes were determined using univariate and multivariate Cox proportional hazards analyses, adjusted for age and sex.

RESULTS

Excluding baseline diabetes (n=124, 4.5%), 53 cases of new DM2 were identified among 2630 participants. Age- and sex-adjusted DM2 incidence was 4.3/1000 (95% CI 2.9, 5.0) person-years over an average 5.9-year follow up. After excluding baseline prediabetes, 387 new cases of prediabetes were identified among 1841 participants; adjusted prediabetes incidence was 44.5/1000 (95% CI 39.5, 49.5) person years. Independent predictors for DM2 included age, impaired fasting glucose, and metabolic syndrome; family history of diabetes and obesity were additional independent predictors for prediabetes.

CONCLUSIONS

DM2 incidence in western AN people is substantially lower than that for U.S. whites; however, incidence of prediabetes is more than 10-fold higher than western AN DM2 incidence and more closely aligned with U.S. rates. Interventions aimed at achieving healthy lifestyles are needed to minimize risk factors and maximize protective factors for DM2 in this population.

Sex differences in obesity prevalence and cardiometabolic factors among Western Alaska Native people

BACKGROUND AND AIMS

Obesity is associated with increased risks of cardiovascular disease, type 2 diabetes, and other chronic diseases. Prevalence estimates for metabolic disorders are well documented in many populations, but Alaska Native groups are understudied. The Western Alaska Tribal Collaborative for Health Study combines data from three Alaska Native study cohorts to assess differences in obesity prevalence and associations with cardiometabolic risk factors by sex.

METHODS AND RESULTS

Analyses were based upon a sample of 3985 adult Yup'ik and Inupiat participants with a mean age of 40 years. Prevalence of obesity and metabolic risk factors was assessed according to nationally recognized guidelines. Regression analysis was used to evaluate the association between obesity and cardiometabolic risk factors, including lipids, blood pressure and glucose. The prevalence of obesity (BMI ≥ 30) was significantly higher in women (40%) than men (20%). Only 18.6% of men had a waist circumference (WC) > 102 cm, while 58% of women had a WC > 88 cm (p < 0.001). Women had higher mean HDL-C and triglyceride levels compared to men, while systolic and diastolic blood pressure, LDL-C, and glucose means were higher in men than in women. In multivariate analyses, BMI and WC were significantly associated with all of the cardiometabolic risk factors, although these associations were more pronounced in men than women.

CONCLUSION

The high prevalence of obesity and central adiposity among AN women is an important public health concern. Differences in associations between obesity and cardiometabolic risk factors by sex warrants further investigation to develop effective intervention programs.

Prevalence of Hypertension and Associated Risk Factors in Western Alaska Native People: The Western Alaska Tribal Collaborative for Health (WATCH) Study

Hypertension is a common chronic disease and a key risk factor in the development of cardiovascular disease. The Western Alaska Tribal Collaborative for Health study consolidates baseline data from four major cohorts residing in the Norton Sound and Yukon-Kuskokwim regions of western Alaska. This consolidated cohort affords an opportunity for a systematic analysis of high blood pressure and its correlates in a unique population with high stroke rates over a wide age range. While the prevalence of hypertension among western Alaska Native people (30%, age-standardized) is slightly less than that of the US general population (33%), cardiovascular disease is a leading cause of mortality in this rural population. The authors found that improvement is needed in hypertension awareness as about two thirds (64%) of patients reported awareness and only 39% with hypertension were controlled on medication. Future analyses assessing risk and protective factors for incident hypertension in this population are indicated.

Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33

Genome-wide association studies (GWAS) have mapped risk alleles for at least 10 distinct cancers to a small region of 63 000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (association analysis based on subsets) across six distinct cancers in 34 248 cases and 45 036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single-nucleotide polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 × 10(-39); Region 3: rs2853677, P = 3.30 × 10(-36) and PConditional = 2.36 × 10(-8); Region 4: rs2736098, P = 3.87 × 10(-12) and PConditional = 5.19 × 10(-6), Region 5: rs13172201, P = 0.041 and PConditional = 2.04 × 10(-6); and Region 6: rs10069690, P = 7.49 × 10(-15) and PConditional = 5.35 × 10(-7)) and one in the neighboring CLPTM1L gene (Region 2: rs451360; P = 1.90 × 10(-18) and PConditional = 7.06 × 10(-16)). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele-specific effects on DNA methylation were seen for a subset of risk loci, indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci.

Genome-wide association study identifies multiple susceptibility loci for pancreatic cancer

We performed a multistage genome-wide association study including 7,683 individuals with pancreatic cancer and 14,397 controls of European descent. Four new loci reached genome-wide significance: rs6971499 at 7q32.3 (LINC-PINT, per-allele odds ratio (OR) = 0.79, 95% confidence interval (CI) 0.74-0.84, P = 3.0 × 10(-12)), rs7190458 at 16q23.1 (BCAR1/CTRB1/CTRB2, OR = 1.46, 95% CI 1.30-1.65, P = 1.1 × 10(-10)), rs9581943 at 13q12.2 (PDX1, OR = 1.15, 95% CI 1.10-1.20, P = 2.4 × 10(-9)) and rs16986825 at 22q12.1 (ZNRF3, OR = 1.18, 95% CI 1.12-1.25, P = 1.2 × 10(-8)). We identified an independent signal in exon 2 of TERT at the established region 5p15.33 (rs2736098, OR = 0.80, 95% CI 0.76-0.85, P = 9.8 × 10(-14)). We also identified a locus at 8q24.21 (rs1561927, P = 1.3 × 10(-7)) that approached genome-wide significance located 455 kb telomeric of PVT1. Our study identified multiple new susceptibility alleles for pancreatic cancer that are worthy of follow-up studies.

My family medical history and me: feasibility results of a cardiovascular risk reduction intervention

OBJECTIVE

Evaluate the feasibility and acceptability of a behaviorally focused intervention designed to increase perceived cardiovascular disease (CVD) and coronary heart disease (CHD) risk in young adults with a family history (FH) of CVD/CHD.

DESIGN AND SAMPLE

Single group, pre-post-test design. Fifteen, mostly female (n = 13, 86.7%), White, young adults (mean age 20.8 years) with a minimum of a high school education with a FH of CVD/CHD.

MEASURES

Feasibility examined the recruitment strategy, study procedures, appropriateness and quality of the study instruments, and problems that occurred during delivery of the intervention. Acceptability examined participants' engagement in the in person sessions and at home exercises and their feedback about the intervention.

INTERVENTION

Two, in person sessions provided personalized, tailored messages about 10-year and lifetime CHD risk based on risk factors, FH from a three-generation pedigree, lipid levels, blood pressure, and smoking status, and brief counseling about how to engage in a healthy lifestyle to decrease CVD/CHD risk.

RESULTS

The intervention was feasible and acceptable. Participants requested more information on healthy food choices, including which foods to avoid and which exercises most improve cardiovascular health.

CONCLUSIONS

Although requiring refinement, the intervention has potential public health implications and deserves further testing.

All-cause, cardiovascular, and cancer mortality in western Alaska Native people: western Alaska Tribal Collaborative for Health (WATCH)

OBJECTIVES

We determined all-cause, cardiovascular disease (CVD), and cancer mortality in western Alaska Native people and examined agreement between death certificate information and adjudicated cause of deaths.

METHODS

Data from 4 cohort studies were consolidated. Death certificates and medical records were reviewed and adjudicated according to standard criteria. We compared adjudicated CVD and cancer deaths with death certificates by calculating sensitivity, specificity, predictive values, and κ statistics.

RESULTS

Men (n = 2116) and women (n = 2453), aged 18 to 95 years, were followed an average of 6.7 years. The major cause of death in men was trauma (25%), followed by CVD (19%) and cancer (13%). The major cause of death in women was CVD (24%), followed by cancer (19%) and trauma (8%). Stroke rates in both genders were higher than those of US Whites. Only 56% of deaths classified as CVD by death certificate were classified as CVD by standard criteria; discordance was higher among men (55%) than women (32%; κs = 0.4 and 0.7).

CONCLUSIONS

We found lower rates for coronary heart disease death but high rates of stroke mortality. Death certificates overestimated CVD mortality; concordance between the 2 methods is better for cancer mortality. The results point to the importance of cohort studies in this population in providing data to assist in health care planning.

Family history of diabetes and pancreatic cancer as risk factors for pancreatic cancer: the PACIFIC study

Genetic association studies have identified more than a dozen genes associated with risk of pancreatic cancer. Given this genetic heterogeneity, family history can be useful for identifying individuals at high risk for this disease. The goal of this analysis was to evaluate associations of family history of diabetes and family history of pancreatic cancer with risk of pancreatic cancer. PACIFIC is a case-control study based on two large health plans. Cases were diagnosed with pancreatic ductal adenocarcinoma (PDA) and controls were selected from the health plan enrollment databases and frequency matched to cases. Family history data were collected using an interviewer-administered questionnaire and were available on 654 cases and 697 controls. Logistic regression was used for the association analyses. First-degree relative history of diabetes was statistically significantly associated with increased risk of PDA [OR, 1.37; 95% confidence interval (CI), 1.10-1.71]. The highest risk of PDA was observed for an offspring with diabetes (OR, 1.95; 95% CI, 1.23-3.09). In addition, history of pancreatic cancer increased risk for PDA with an OR of 2.79 (95% CI, 1.44-4.08) for any first-degree relative history of pancreatic cancer. This population-based analysis showed that family history of diabetes was associated with increased risk of PDA and confirmed previous studies showing that first-degree family history of pancreatic cancer is associated with PDA. These results support the need for ongoing studies of genetic influences on pancreatic cancer in large samples and investigations of possible pleiotropic genetic effects on diabetes and pancreatic cancer.

Utilizing harmonization and common surveillance methods to consolidate 4 cohorts: the Western Alaska Tribal Collaborative for Health (WATCH) study

BACKGROUND

According to health status reports, chronic disease prevalence appears to be rising in western Alaska Native (AN) people, and accurate population-based data are needed. Four cohort studies of western AN people were conducted in the Norton Sound and Yukon-Kuskokwim regions, but none have been large enough to allow reliable estimates of rates of chronic diseases and evaluate their risk factors.

OBJECTIVE

In this article, the methods used to combine 4 major cohort studies of rural western AN people are described and the benefits and challenges encountered in combining data and standardizing surveillance methods for these studies are discussed.

DESIGN

Tribal permission was obtained for each cohort study and the consolidated study. Data from baseline exams were directly combined or harmonized into new variables. Common surveillance methods were developed and implemented to identify incidence and risk factors for cardiovascular disease (CVD) events and type 2 diabetes.

RESULTS

A cohort of 4,569 western AN participants (2,116 men and 2,453 women), aged 18-95 years, was established to study CVD and diabetes prevalence. Prospective surveillance data over an average 6.7-year follow-up can now be used to study CVD and diabetes incidence and associated risk factors in a subset of 2,754 western AN participants (1,218 men and 1,536 women) who consented to initial surveillance.

CONCLUSIONS

The combined cohort provides statistical power to examine incidence rates and risk factors for CVD and diabetes and allows for analyses by geographic region. The data can be used to develop intervention programmes in these populations and others.

Research guidelines in the era of large-scale collaborations: an analysis of Genome-wide Association Study Consortia

Scientific research has shifted from studies conducted by single investigators to the creation of large consortia. Genetic epidemiologists, for example, now collaborate extensively for genome-wide association studies (GWAS). The effect has been a stream of confirmed disease-gene associations. However, effects on human subjects oversight, data-sharing, publication and authorship practices, research organization and productivity, and intellectual property remain to be examined. The aim of this analysis was to identify all research consortia that had published the results of a GWAS analysis since 2005, characterize them, determine which have publicly accessible guidelines for research practices, and summarize the policies in these guidelines. A review of the National Human Genome Research Institute's Catalog of Published Genome-Wide Association Studies identified 55 GWAS consortia as of April 1, 2011. These consortia were comprised of individual investigators, research centers, studies, or other consortia and studied 48 different diseases or traits. Only 14 (25%) were found to have publicly accessible research guidelines on consortia websites. The available guidelines provide information on organization, governance, and research protocols; half address institutional review board approval. Details of publication, authorship, data-sharing, and intellectual property vary considerably. Wider access to consortia guidelines is needed to establish appropriate research standards with broad applicability to emerging forms of large-scale collaboration.

Low-density lipoprotein cholesterol, apolipoprotein B, and risk of coronary heart disease: from familial hyperlipidemia to genomics

Coronary heart disease (CHD) affects 17 million people in the United States and accounts for over a million hospital stays each year. Technological advances, especially in genetics and genomics, have changed our understanding of the risk factors for developing CHD. The purpose of this article is to review low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (apo B), and risk of CHD. The article focuses on five topics: (1) a description of lipoprotein classes, normal lipoprotein metabolism, and the biological mechanism of atherosclerosis; (2) a review of selected epidemiologic and clinical trial studies examining the associations between elevated LDL-C and apo B with CHD; (3) a brief review of the familial forms of hyperlipidemia; (4) a description of variants in genes that have been associated with higher LDL-C levels in candidate gene studies and genome-wide association studies (GWAS); and (5) nursing implications, including a discussion on how genetic tests are evaluated and the current clinical utility and validity of genetic tests for CHD.

A meta-analysis and genome-wide association study of platelet count and mean platelet volume in african americans

Several genetic variants associated with platelet count and mean platelet volume (MPV) were recently reported in people of European ancestry. In this meta-analysis of 7 genome-wide association studies (GWAS) enrolling African Americans, our aim was to identify novel genetic variants associated with platelet count and MPV. For all cohorts, GWAS analysis was performed using additive models after adjusting for age, sex, and population stratification. For both platelet phenotypes, meta-analyses were conducted using inverse-variance weighted fixed-effect models. Platelet aggregation assays in whole blood were performed in the participants of the GeneSTAR cohort. Genetic variants in ten independent regions were associated with platelet count (N = 16,388) with p<5×10⁻⁸ of which 5 have not been associated with platelet count in previous GWAS. The novel genetic variants associated with platelet count were in the following regions (the most significant SNP, closest gene, and p-value): 6p22 (rs12526480, LRRC16A, p = 9.1×10⁻⁹), 7q11 (rs13236689, CD36, p = 2.8×10⁻⁹), 10q21 (rs7896518, JMJD1C, p = 2.3×10⁻¹²), 11q13 (rs477895, BAD, p = 4.9×10⁻⁸), and 20q13 (rs151361, SLMO2, p = 9.4×10⁻⁹). Three of these loci (10q21, 11q13, and 20q13) were replicated in European Americans (N = 14,909) and one (11q13) in Hispanic Americans (N = 3,462). For MPV (N = 4,531), genetic variants in 3 regions were significant at p<5×10⁻⁸, two of which were also associated with platelet count. Previously reported regions that were also significant in this study were 6p21, 6q23, 7q22, 12q24, and 19p13 for platelet count and 7q22, 17q11, and 19p13 for MPV. The most significant SNP in 1 region was also associated with ADP-induced maximal platelet aggregation in whole blood (12q24). Thus through a meta-analysis of GWAS enrolling African Americans, we have identified 5 novel regions associated with platelet count of which 3 were replicated in other ethnic groups. In addition, we also found one region associated with platelet aggregation that may play a potential role in atherothrombosis.

The majority of the variation in platelet count and mean platelet volume between individuals is heritable. We performed genome-wide association studies in more than 16,000 African American participants from seven population-based cohorts to identify genetic variants that correlate with variation in platelet count and mean platelet volume. We observed statistically significant evidence (p-value<5×10⁻⁸) that 10 genomic regions were associated with platelet count and 3 were associated with mean platelet volume. Of the regions that were significantly associated, we found 5 novel regions that were not reported previously in other populations. Three of these 5 regions were also associated with platelet count in European Americans and Hispanic Americans. All these regions contain genes that are either known to have or potentially may have a role in determining platelet count and/or mean platelet volume. We further found that one of these regions was also associated with agonist-induced platelet aggregation. Further studies will determine the exact role played by these genomic regions in platelet biology. The knowledge generated by this and other studies will not only help us better understand platelet biology but can also lead us to the discovery of new anti-platelet drugs.

Genome-wide association study of white blood cell count in 16,388 African Americans: the continental origins and genetic epidemiology network (COGENT)

Total white blood cell (WBC) and neutrophil counts are lower among individuals of African descent due to the common African-derived “null” variant of the Duffy Antigen Receptor for Chemokines (DARC) gene. Additional common genetic polymorphisms were recently associated with total WBC and WBC sub-type levels in European and Japanese populations. No additional loci that account for WBC variability have been identified in African Americans. In order to address this, we performed a large genome-wide association study (GWAS) of total WBC and cell subtype counts in 16,388 African-American participants from 7 population-based cohorts available in the Continental Origins and Genetic Epidemiology Network. In addition to the DARC locus on chromosome 1q23, we identified two other regions (chromosomes 4q13 and 16q22) associated with WBC in African Americans (P<2.5×10⁻⁸). The lead SNP (rs9131) on chromosome 4q13 is located in the CXCL2 gene, which encodes a chemotactic cytokine for polymorphonuclear leukocytes. Independent evidence of the novel CXCL2 association with WBC was present in 3,551 Hispanic Americans, 14,767 Japanese, and 19,509 European Americans. The index SNP (rs12149261) on chromosome 16q22 associated with WBC count is located in a large inter-chromosomal segmental duplication encompassing part of the hydrocephalus inducing homolog (HYDIN) gene. We demonstrate that the chromosome 16q22 association finding is most likely due to a genotyping artifact as a consequence of sequence similarity between duplicated regions on chromosomes 16q22 and 1q21. Among the WBC loci recently identified in European or Japanese populations, replication was observed in our African-American meta-analysis for rs445 of CDK6 on chromosome 7q21 and rs4065321 of PSMD3-CSF3 region on chromosome 17q21. In summary, the CXCL2, CDK6, and PSMD3-CSF3 regions are associated with WBC count in African American and other populations. We also demonstrate that large inter-chromosomal duplications can result in false positive associations in GWAS.

Although recent genome-wide association studies have identified common genetic variants associated with total white blood cell (WBC) and WBC sub-type counts in European and Japanese ancestry populations, whether these or other loci account for differences in WBC count among African Americans is unknown. By examining >16,000 African Americans, we show that, in addition to the previously identified Duffy Antigen Receptor for Chemokines (DARC) locus on chromosome 1, another variant, rs9131, and other nearby variants on human chromosome 4 are associated with total WBC count in African Americans. The variants span the CXCL2 gene, which encodes an inflammatory mediator involved in WBC production and migration. We show that the association is not restricted to African Americans but is also present in independent samples of European Americans, Hispanic Americans, and Japanese. This finding is potentially important because WBC mediate or have altered counts in a variety of acute and chronic disorders.

Association study of type 2 diabetes genetic susceptibility variants and risk of pancreatic cancer: an analysis of PanScan-I data

OBJECTIVE

To examine associations between recently identified common type 2 diabetes (T2D) susceptibility genetic variants and pancreatic cancer risk.

METHODS

Using data on individuals of European ancestry from the Cancer Genetic Markers of Susceptibility PanScan-I study (1,763 pancreatic cancer cases and 1,802 controls), we tested associations for 37 T2D susceptibility variants with pancreatic cancer risk. Associations with pancreatic cancer were also tested for three composite T2D susceptibility measures, incorporating data on all 37 variants, and for ten additional variants related to T2D-related phenotypes, including fasting glucose and beta-cell function.

RESULTS

Of the 37 T2D risk alleles, two showed nominally significant positive associations with pancreatic cancer risk (FTO rs8050136 per-allele OR = 1.12; CI: 1.02-1.23; MTNR1B rs1387153 OR = 1.11; CI: 1.00-1.23) and one showed an inverse association (BCL11A rs243021 OR = 0.88; CI: 0.80-0.97). The composite T2D susceptibility measures were not associated with pancreatic cancer. The glucose-raising allele of MADD rs11039149 was associated with increased risk of pancreatic cancer (OR = 1.14; CI: 1.03-1.27).

CONCLUSIONS

Overall, these results do not provide strong evidence that common variants underling T2D or related phenotypes also affect pancreatic cancer risk; however, associations for FTO, MTNR1B, BCL11A, and MADD variants warrant further investigation in larger studies. Hypothesis-driven analyses of existing genome-wide genetic data can be cost-efficient and promising approaches for investigating genetic susceptibility to complex diseases.

Association of diabetes susceptibility gene calpain-10 with pancreatic cancer among smokers

OBJECTIVE

The objective of this study was to test the association between calpain-10 (CAPN10), a diabetes susceptibility gene, with risk of pancreatic cancer (PC).

METHODS

DNA samples from 83 incident exocrine PC cases and 166 controls, all of whom were smokers, were genotyped for four markers of CAPN10 in a nested case-control study based on the Beta-Carotene and Retinol Efficacy Trial (CARET), a randomized chemoprevention trial of subjects at high risk of lung cancer. Controls were matched on sex, race, age, CARET intervention arm, duration of exposure to asbestos, and smoking history. Conditional logistic regression was used for statistical analyses.

RESULTS

The minor allele of SNP-43 (rs3792267) in intron 3 was associated with increased risk of PC with an odds ratio of 1.57 (95%CI 1.03-2.38, p = 0.035) per allele. The three markers of the highest risk haplotype had an odds ratio of 1.98 (95%CI 1.12-3.49, p = 0.019) for risk of PC compared to the most common haplotype. There was no evidence of interaction between either of these associations by diabetes status.

CONCLUSION

These results suggest that variation in CAPN10 may be associated with increased risk of PC among smokers. Thus, studies of genes associated with diabetes risk in PC are warranted in a larger population.

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.

Association between the peroxisome proliferator-activated receptor gamma Pro12Ala variant and haplotype and pancreatic cancer in a high-risk cohort of smokers: a pilot study

OBJECTIVES

The Pro12Ala variant in the peroxisome proliferator-activated receptor gamma (PPARG) gene has been associated with diabetes and several cancers. This pilot study tested for the association between Pro12Ala and pancreatic cancer risk in a high-risk sample of smokers.

METHODS

A nested case-control study was conducted in 83 incident cases of pancreatic cancer and 166 matched controls originally recruited into a cohort chemoprevention study of lung cancer. Associations between Pro12Ala and pancreatic cancer risk were measured using conditional logistic regression.

RESULTS

Carriers of the G allele (Ala) of the Pro12Ala variant had a borderline increased relative risk of pancreatic cancer compared with homozygous carriers of the C allele (Pro), with an odds ratio of 1.79 (95% confidence interval [CI], 0.96-3.33; P=0.06). Among subjects randomized to high-dose vitamin A, the odds ratio was 2.80 (95% CI, 1.16-6.74; P=0.02) versus 1.20 (95% CI, 0.45-3.23; P=0.71) in the placebo group. A haplotype including Pro12Ala was also significantly associated with pancreatic cancer risk in all subjects and in subjects randomized to vitamin A.

CONCLUSIONS

This analysis presents the first evidence that PPARG may be associated with pancreatic cancer risk, and this candidate gene should be investigated in future, larger studies.

Trp64Arg polymorphism of the β3-adrenergic receptor gene, pre-pregnancy obesity and risk of pre-eclampsia

OBJECTIVE

Trp64Arg polymorphism of the beta3-adrenergic receptor (beta3-AR) gene was reported to be associated with increased risk of obesity and insulin resistance. Both traits have been implicated in the epidemiology and pathogenesis of pre-eclampsia. We investigated the relation of the beta3-AR gene to pre-pregnancy obesity and risk of pre-eclampsia. The present study is a case-control study of 87 Caucasian pre-eclampsia cases and 214 controls.

METHODS

Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI), adjusted for maternal age and parity. Normotensive carriers of the variant allele (i.e. Arg64 allele) were 3.6 times more likely to be obese (body mass index (BMI) > or = 30 kg/m2) as compared with women not carrying the variant allele (OR = 3.6, 95% CI 0.8-15.0).

RESULTS

Arg64 allele was more frequent in controls as compared with pre-eclampsia cases (11.7 vs. 5.3%, p < 0.01). After adjusting for age and parity, carriers experienced a 60% reduction in risk of pre-eclampsia (OR = 0.4, 95% CI 0.2, 0.9) as compared with women not carrying this allele. The association between carriage of the variant allele and risk of pre-eclampsia appeared to be modified by maternal BMI. Compared with lean carriers, lean women without the variant allele experienced only a small increase in the risk of pre-eclampsia (OR = 1.5; 95% CI: 0.6, 3.9). The OR for overweight women without the variant allele was 7.3 (95% CI 2.7-19.2).

CONCLUSIONS

Our results suggest a puzzling relationship between the polymorphism and the risk of pre-eclampsia. Future studies are needed to confirm these findings.

Measuring dietary acculturation in Japanese Americans with the use of confirmatory factor analysis of food-frequency data

BACKGROUND

Epidemiologic evidence suggests that dietary changes associated with acculturation to a Western diet may increase the risk of type 2 diabetes in Japanese Americans.

OBJECTIVE

We hypothesized that dietary acculturation patterns could be measured by confirmatory factor analysis (CFA) by using a culturally sensitive food-frequency questionnaire (FFQ). We examined the utility of the estimated factor scores by testing for associations with diabetes and 2 risk factors for diabetes-body mass index (BMI; in kg/m(2)) and C-reactive protein (CRP).

DESIGN

By using cross-sectional data from a sample of 219 Nisei (second-generation Japanese American; mean age 70 y) and 277 Sansei (third-generation Japanese American; mean age 42 y) participants in the Japanese American Family Study, we conducted CFA on 5 items characteristic of a Japanese diet and 4 items characteristic of a Western diet. The resulting factor scores were examined for associations with diabetes by using logistic regression and for associations with BMI and CRP by using linear regression.

RESULTS

CFA confirmed the presence of Japanese and Western food factors. The Nisei had a significantly higher average factor score for the Japanese food factor and significantly lower average factor score for the Western food factor than did the Sansei. In Sansei persons, but not in Nisei persons, the Western food factor score was significantly associated with plasma CRP concentration (P = 0.02), BMI (P = 0.02), and diabetes (P = 0.001).

CONCLUSIONS

In this Japanese American sample, dietary acculturation can be estimated by using CFA on FFQ data. Future studies should investigate the effects of dietary acculturation on disease risk independent of other lifestyle factors.

Genomic scan of 12 hereditary prostate cancer families having an occurrence of pancreas cancer

BACKGROUND

Prostate cancer is a genetically heterogeneous disease. Using the occurrence of other cancers in hereditary prostate cancer (HPC) families is a promising strategy for developing genetically homogeneous data sets that can enhance the ability to identify susceptibility loci using linkage analysis.

METHODS

Twelve HPC families with the co-occurrence of adenocarcinoma of the pancreas were selected from the Prostate Cancer Genetic Research Study (PROGRESS). Non-parametric linkage analysis for a prostate/pancreas cancer susceptibility phenotype was performed using 441 genome-wide microsatellite markers.

RESULTS

No statistically significant linkage signal was detected in this analysis. The strongest linkage signals, as measured by Kong and Cox LOD score (KC LOD), were observed on chromosomes 2q37.2-q37.3 (KC LOD = 1.01; P = 0.02) and 16q23.2 (KC LOC = 1.05; P = 0.01).

CONCLUSIONS

Despite the lack of statistically significant findings, four chromosomal regions, three of which (2q, 16q, 17q) were previously noted as harboring potential susceptibility loci, showed suggestive linkage results in this scan.

Association of gestational diabetes mellitus and low-density lipoprotein (LDL) particle size

A predominance of small, dense low-density lipoproteins (LDL) is characteristic of the dyslipidemic state seen in type 2 diabetes. However, no study has investigated the association in gestational diabetes mellitus (GDM), which is pathophysiologically similar to type 2 diabetes. We hypothesized that LDL particle size is reduced in GDM cases compared with controls. Gradient gel electrophoresis was used to characterize LDL subclass phenotypes in non-fasting intrapartum plasma from 105 GDM cases and 96 controls. All participants were free of pre-existing diabetes or hypertension. The authors used logistic regression to estimate odds ratios (OR) and 95 % confidence intervals (CI) adjusted for confounders. Women with this phenotype had a significant 4.9-fold (95 % CI: 1.1-23.2) increased risk of GDM compared with those with the large, buoyant phenotype. The magnitude of this association was attenuated when plasma triglyceride and other confounders were included in the model (OR=4.2, 95 % CI: 0.5-39.5). Mean LDL particle size in GDM cases was smaller compared with controls (270.1 vs. 272.7A, p=0.003). The OR of GDM risk was 1.8 (95 % CI: 0.9-3.3) for every 10-A reduction in LDL particle size. Large prospective studies are needed to evaluate the association between smaller LDL particle size in early pregnancy with subsequent GDM risk.

Functional variants of the lipoprotein lipase gene and the risk of preeclampsia among non-Hispanic Caucasian women

Hypertriglyceridemia is an important pathophysiologic feature of preeclampsia, a common vascular disorder of pregnancy. Three well-documented functional variants (N291S, S447X, and D9N) of the lipoprotein lipase gene were related to hypertriglyceridemia. Results from the only two studies concerning the relationship between these variants and preeclampsia risk have been inconsistent. We investigated this relationship in a case-control study including 144 preeclamptic and 290 normotensive pregnant women (all non-Hispanic Caucasians). We estimated odds ratios (OR) and 95% confidence intervals (CI) adjusted for maternal age, pre-pregnancy body mass index, and parity. After adjusting for covariates, women with the 291 N/S or S/S genotype had significantly increased risk of preeclampsia (OR 6.9, 95% CI 1.9-25.4) compared with women with the common 291N/N genotype. The 447 S/X or X/X genotype was not significantly associated with preeclampsia risk. The frequency of the 9N variant allele was 1.8% in controls, while this allele was not observed among cases. Haplotype 9D/291S/447S was strongly associated with higher risk of preeclampsia as compared with the most common haplotype 9D/291N/447S (adjusted OR 6.6, 95% CI 1.7-25.0). Results from our study support the thesis that abnormal lipid metabolism is important in the pathogenesis of preeclampsia.

Differences in survival by histologic type of pancreatic cancer

OBJECTIVE

Although pancreatic cancer has an extremely high case fatality rate, little is known about differences in mortality by histologic types. We examined median survival and risk of mortality for endocrine pancreatic tumors and two types of exocrine tumors, adenocarcinomas, and mucinous tumors.

METHOD

This analysis included 35,276 pancreatic cancer cases reported to the nine population-based cancer registries participating in the Surveillance, Epidemiology, and End Results program from 1973 to 2000. Survival among cases with pancreatic adenocarcinomas, mucinous tumors, and endocrine tumors were compared using Kaplan-Meier plots. Comparative risks of mortality were evaluated using multivariate adjusted Cox regression models.

RESULTS

Endocrine pancreatic cancer cases had a median survival of 27 months compared with a median survival of 4 months for adenocarcinoma and mucinous tumor cases. Compared with adenocarcinoma cases, endocrine tumor cases had a 0.28-fold lower risk of mortality [95% confidence interval (95% CI), 0.26-0.30], and mucinous tumor cases had a 0.88-fold lower risk (95% CI, 0.84-0.91). These results were similar for men and women. Within histologic types, advanced tumor stage, older diagnosis age, surgery, and Black race were associated with increased risks of mortality, whereas female sex and more recent year of diagnosis were associated with decreased risks.

CONCLUSION

This study confirms the clinical observation that patients with endocrine pancreatic cancer survive longer than patients with exocrine tumors. A better understanding of these differences could contribute to identifying the underlying causes of pancreatic cancer and to improving survival rates across all histologic types.

Hepatic lipase gene polymorphism, pre-pregnancy overweight status and risk of preeclampsia among Peruvian women

We examined the association between the hepatic lipase (LIPC) gene promoter polymorphism (-514C/T) and risk of preeclampsia among Peruvian women. We also evaluated whether this association is modified by maternal pre-pregnancy overweight status. Using a case control study design, 157 preeclampsia cases and 180 normotensive controls were enrolled in the study. Genotyping was conducted using PCR amplification, NlaIII enzyme digestion and gel electrophoresis. Logistic regression procedures were used to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CI). After adjusting for confounding by maternal age, parity and pre-pregnancy body mass index (BMI), the relative risks of preeclampsia for women with LIPC -514CT and LIPC -514TT genotypes were 1.0 (95% CI 0.5-2.2) and 1.5 (95% CI 0.7-3.3) respectively, using women with LIPC -514CC genotype as a reference. Women who were both overweight and who had the LIPC -514TT genotype had a significant 3-fold increased risk of preeclampsia (Adj. OR:3.0 95% CI 1.3-6.8) as compared to those women who were not overweight and had the LIPC -514CC/CT genotype. In this study, we found that LIPC -514TT genotype and overweight status, when occurring together, were associated with a 3-fold increase in risk of preeclampsia among Peruvian women.