A multi-stage genome-wide association study of bladder cancer identifies multiple susceptibility loci

We conducted a multi-stage, genome-wide association study of bladder cancer with a primary scan of 591,637 SNPs in 3,532 affected individuals (cases) and 5,120 controls of European descent from five studies followed by a replication strategy, which included 8,382 cases and 48,275 controls from 16 studies. In a combined analysis, we identified three new regions associated with bladder cancer on chromosomes 22q13.1, 19q12 and 2q37.1: rs1014971, (P = 8 × 10⁻¹²) maps to a non-genic region of chromosome 22q13.1, rs8102137 (P = 2 × 10⁻¹¹) on 19q12 maps to CCNE1 and rs11892031 (P = 1 × 10⁻⁷) maps to the UGT1A cluster on 2q37.1. We confirmed four previously identified genome-wide associations on chromosomes 3q28, 4p16.3, 8q24.21 and 8q24.3, validated previous candidate associations for the GSTM1 deletion (P = 4 × 10⁻¹¹) and a tag SNP for NAT2 acetylation status (P = 4 × 10⁻¹¹), and found interactions with smoking in both regions. Our findings on common variants associated with bladder cancer risk should provide new insights into the mechanisms of carcinogenesis.

Change in physical activity and colon cancer incidence and mortality

BACKGROUND

Although data on the association of physical activity and colon cancer risk is convincing, little research has examined whether change in physical activity alters risk of cancer incidence and mortality.

METHODS

We examined the association of 10- and 15-year change in physical activity with risk of colon cancer incidence and mortality in the Cancer Prevention Study II. Endpoints were verified through medical record abstraction or registry or National Death Index linkage. Ten-year physical activity analysis included 1,863 incident and 826 fatal cases, whereas the longer-term exposure analysis included 1,386 incident and 602 fatal colon cancer cases. Age and multivariable-adjusted hazard ratios were estimated using Cox proportional hazards models.

RESULTS

Neither measure of physical activity change was associated with colon cancer incidence. Fifteen-year change was not associated with colon cancer mortality. However, consistently high physical activity over 10 years was associated with a decreased risk of colon cancer mortality as compared with those with consistently low activity. The association attenuated to borderline significance with adjustment for body mass index. Those consistently at or above sample median physical activity levels over 15 years had half the risk of colon cancer death as those consistently below the median.

CONCLUSIONS

Regular long-term physical activity was associated with a lower risk of colon cancer mortality.

IMPACT

This study suggests that long-term participation in physical activity provides the greatest reduction in risk of colon cancer death.

Prospective study reveals associations between colorectal cancer and type 2 diabetes mellitus or insulin use in men

BACKGROUND & AIMS

Type 2 diabetes mellitus (DM) is associated with an increased risk of colorectal cancer (CRC); it is not clear if this association varies by sex or other factors. Insulin use might also be associated with CRC risk. We investigated associations of type 2 DM and insulin use with CRC risk.

METHODS

The Cancer Prevention Study II Nutrition Cohort is a prospective study of cancer incidence. In 1992 or 1993, adult participants (n = 184,194) completed a detailed, self-administered questionnaire. Follow-up questionnaires were sent in 1997 and every 2 years thereafter. Cox proportional hazards regression analysis was used to calculate relative risks (RR) and 95% confidence intervals (CI), adjusting for covariates.

RESULTS

After exclusions, 73,312 men and 81,663 women remained in the final analytic cohort; 1567 men (227 with type 2 DM) and 1242 women (108 with type 2 DM) were diagnosed with colon or rectal cancer by 2007. Among men, type 2 DM was associated with increased risk of incident CRC compared to not having type 2 DM (RR: 1.24; 95% CI: 1.08-1.44); risk was higher for participants with type 2 DM using insulin (RR: 1.36; 95% CI: 1.05-1.78), and participants with type 2 DM not using insulin (RR: 1.22, 95% CI: 1.04-1.45). Among women, type 2 DM and insulin use were not associated with risk of incident CRC (RR: 1.01; 95% CI: 0.82-1.23 and RR: 0.95; 95% CI: 0.64-1.41, respectively).

CONCLUSIONS

There is a modest association between type 2 DM and CRC among men, but not women. Insulin use is not associated with a substantially increased risk of CRC.

Leisure time spent sitting in relation to total mortality in a prospective cohort of US adults

The obesity epidemic is attributed in part to reduced physical activity. Evidence supports that reducing time spent sitting, regardless of activity, may improve the metabolic consequences of obesity. Analyses were conducted in a large prospective study of US adults enrolled by the American Cancer Society to examine leisure time spent sitting and physical activity in relation to mortality. Time spent sitting and physical activity were queried by questionnaire on 53,440 men and 69,776 women who were disease free at enrollment. The authors identified 11,307 deaths in men and 7,923 deaths in women during the 14-year follow-up. After adjustment for smoking, body mass index, and other factors, time spent sitting (> or = 6 vs. <3 hours/day) was associated with mortality in both women (relative risk = 1.34, 95% confidence interval (CI): 1.25, 1.44) and men (relative risk = 1.17, 95% CI: 1.11, 1.24). Relative risks for sitting (> or = 6 hours/day) and physical activity (<24.5 metabolic equivalent (MET)-hours/week) combined were 1.94 (95% CI: 1.70, 2.20) for women and 1.48 (95% CI: 1.33, 1.65) for men, compared with those with the least time sitting and most activity. Associations were strongest for cardiovascular disease mortality. The time spent sitting was independently associated with total mortality, regardless of physical activity level. Public health messages should include both being physically active and reducing time spent sitting.

Waist circumference and all-cause mortality in a large US cohort

BACKGROUND

Waist circumference (WC), a measure of abdominal obesity, is associated with higher mortality independent of body mass index (BMI). Less is known about the association between WC and mortality within categories of BMI or for the very high levels of WC that are now common.

METHODS

We examined the association between WC and mortality among 48,500 men and 56,343 women, 50 years or older, in the Cancer Prevention Study II Nutrition Cohort. A total of 9315 men and 5332 women died between 1997 and the end of follow-up in 2006.

RESULTS

After adjustment for BMI and other risk factors, very high levels of WC were associated with an approximately 2-fold higher risk of mortality in men and women (among men, relative risk [RR]=2.02; 95% confidence interval [CI], 1.71-2.39 for WC>or=120 cm compared with <90 cm; among women, RR=2.36; 95% CI, 1.98-2.82 for WC>or=110 cm compared with <75 cm). The WC was positively associated with mortality within all categories of BMI. In men, a 10-cm increase in WC was associated with RRs of 1.16 (95% CI, 1.09-1.23), 1.18 (95% CI, 1.12-1.24), and 1.21 (95% CI, 1.13-1.30) within normal (18.5 to <25), overweight (25 to <30), and obese (>or=30) BMI categories, respectively. In women, corresponding RRs were 1.25 (95% CI, 1.18-1.32), 1.15 (95% CI, 1.08-1.22), and 1.13 (95% CI, 1.06-1.20).

CONCLUSION

These results emphasize the importance of WC as a risk factor for mortality in older adults, regardless of BMI.

Multiple independent loci at chromosome 15q25.1 affect smoking quantity: a meta-analysis and comparison with lung cancer and COPD

Recently, genetic association findings for nicotine dependence, smoking behavior, and smoking-related diseases converged to implicate the chromosome 15q25.1 region, which includes the CHRNA5-CHRNA3-CHRNB4 cholinergic nicotinic receptor subunit genes. In particular, association with the nonsynonymous CHRNA5 SNP rs16969968 and correlates has been replicated in several independent studies. Extensive genotyping of this region has suggested additional statistically distinct signals for nicotine dependence, tagged by rs578776 and rs588765. One goal of the Consortium for the Genetic Analysis of Smoking Phenotypes (CGASP) is to elucidate the associations among these markers and dichotomous smoking quantity (heavy versus light smoking), lung cancer, and chronic obstructive pulmonary disease (COPD). We performed a meta-analysis across 34 datasets of European-ancestry subjects, including 38,617 smokers who were assessed for cigarettes-per-day, 7,700 lung cancer cases and 5,914 lung-cancer-free controls (all smokers), and 2,614 COPD cases and 3,568 COPD-free controls (all smokers). We demonstrate statistically independent associations of rs16969968 and rs588765 with smoking (mutually adjusted p-values<10(-35) and <10(-8) respectively). Because the risk alleles at these loci are negatively correlated, their association with smoking is stronger in the joint model than when each SNP is analyzed alone. Rs578776 also demonstrates association with smoking after adjustment for rs16969968 (p<10(-6)). In models adjusting for cigarettes-per-day, we confirm the association between rs16969968 and lung cancer (p<10(-20)) and observe a nominally significant association with COPD (p = 0.01); the other loci are not significantly associated with either lung cancer or COPD after adjusting for rs16969968. This study provides strong evidence that multiple statistically distinct loci in this region affect smoking behavior. This study is also the first report of association between rs588765 (and correlates) and smoking that achieves genome-wide significance; these SNPs have previously been associated with mRNA levels of CHRNA5 in brain and lung tissue.

Diabetes and cancer: a consensus report

Epidemiologic evidence suggests that cancer incidence is associated with diabetes as well as certain diabetes risk factors and treatments. This consensus statement of experts assembled jointly by the American Diabetes Association and the American Cancer Society reviews the state of science concerning 1) the association between diabetes and cancer incidence or prognosis; 2) risk factors common to both diabetes and cancer; 3) possible biologic links between diabetes and cancer risk; and 4) whether diabetes treatments influence the risk of cancer or cancer prognosis. In addition, key unanswered questions for future research are posed.

Circulating 25-hydroxyvitamin D and risk of non-hodgkin lymphoma: Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

Case-control studies generally suggesting an inverse association between sun exposure and non-Hodgkin lymphoma (NHL) have led to speculation that vitamin D may protect against lymphomagenesis. To examine this hypothesis, the authors conducted a pooled investigation of circulating 25-hydroxyvitamin D (25(OH)D) and subsequent NHL risk within 10 cohorts participating in the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers. The authors analyzed measurements from 1,353 cases and 1,778 controls using conditional logistic regression and other methods to estimate the association of 25(OH)D with NHL. No clear evidence of association between categories of 25(OH)D concentration and NHL was observed overall (P(trend) = 0.68) or by sex (men, P(trend) = 0.50; women, P(trend) = 0.16). Findings for other measures (continuous log(25(OH)D), categories of 25(OH)D using sex-/cohort-/season-specific quartiles as cutpoints, categories of season-adjusted residuals of predicted 25(OH)D using quartiles as cutpoints) were generally null, although some measures of increasing 25(OH)D were suggestive of an increased risk for women. Results from stratified analyses and investigations of histologic subtypes of NHL were also null. These findings do not support the hypothesis that elevated circulating 25(OH)D concentration is associated with a reduced risk of NHL. Future research investigating the biologic basis for the sunlight-NHL association should consider alternative mechanisms, such as immunologic effects.

Diabetes and cancer: a consensus report

Epidemiologic evidence suggests that cancer incidence is associated with diabetes as well as certain diabetes risk factors and diabetes treatments. This consensus statement of experts assembled jointly by the American Diabetes Association and the American Cancer Society reviews the state of science concerning 1) the association between diabetes and cancer incidence or prognosis, 2) risk factors common to both diabetes and cancer, 3) possible biologic links between diabetes and cancer risk, and 4) whether diabetes treatments influence risk of cancer or cancer prognosis. In addition, key unanswered questions for future research are posed.

Abstract 5740: Alcoholic beverage consumption and the incidence of non-Hodgkin lymphoma in the Cancer Prevention Study-II (CPS-II) Nutrition Cohort

Results of several case-control studies suggest an inverse association between alcohol consumption and risk of NHL, and potential differences in the strength of association across histologic subtypes. However, this relationship has been examined in few prospective cohort studies and of these, two included only women. Furthermore, most cohort studies had too few cases to explore potential differences in association according to histologic subtypes, gender and other factors. Using data from the large American Cancer Society CPS-II Nutrition Cohort, we examined the association of self-reported alcohol intake with the incidence of NHL in men and in women, and in ever and never smokers. We also examined associations according to specific NHL subtypes. Among the 70,424 men and 78,019 women included in this analysis, 1,120 male and 865 female incident cases of lymphoma were identified during the follow-up period (1992-2007). Multivariable-adjusted relative risks (RR) and 95% confidence intervals (CI) were computed using Cox proportional hazards regression controlling for age, race/ethnicity, smoking status, family history of hematopoietic cancer, education, body mass index, height and physical activity (METS). For men, the RR (95% CI) estimates for all NHL subtypes combined associated with consumption of &gt;0-&lt;1, 1-2, and &gt;2 drinks per day compared to non-drinkers were 0.94 (0.82-1.08), 0.90 (0.74-1.08), and 0.80 (0.66-0.98) (p-trend=0.04). The corresponding RR (95% CI) estimates were similar for women (i.e., 0.92 (0.80-1.07), 0.87 (0.66-1.15) and 0.68 (0.47-0.99) (p-trend=0.04)). There was no effect modification of this association by gender (p for interaction=0.93). In addition, there was no effect modification by smoking status (p for interaction=0.76). In analyses of specific NHL subtypes, a statistically significant inverse association was observed for B-cell lymphomas, which comprised the majority of NHL neoplasms (i.e., &gt;90%). For men and women combined, the RRs (95% CIs) for B-cell lymphoma associated with consumption of &gt;0-&lt;1, 1-2, and &gt;2 drinks per day compared to non-drinkers were 0.96 (0.86-1.06), 0.91 (0.77-1.07) and 0.76 (0.64-0.92) (p-trend=0.004). However, we also observed non-significant inverse associations of alcohol intake with nearly all NHL subtypes. In summary, results from this large prospective cohort study support previous reports from other studies showing an inverse association between alcohol intake and the incidence of lymphoma in men and in women. They also suggest no meaningful differences in the nature of the association of alcohol intake with the incidence of specific histologic subtypes of lymphoma, or by smoking status.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5740.

Abstract 1823: The association between cigarette smoking and lymphoid neoplasms in a large US cohort study

Few modifiable risk factors for lymphoid neoplasms have been identified. Cigarette smoking has been hypothesized to influence risk through direct carcinogenic effects, immunosuppression, and increased leukocyte production. However, prior studies of cigarette smoking and lymphoid neoplasms have been notably inconsistent. Often, this is attributed to the heterogeneous nature of the disease. Among the few studies that examined this association across lymphoma subtypes, some showed positive associations with follicular lymphoma and with Hodgkin disease. To further clarify these relationships, we examined cigarette smoking status, intensity, and duration in relation to the risk of non-Hodgkin lymphomas (NHL), subtypes of NHL (diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), multiple myeloma (MM), and T-cell lymphomas), and Hodgkin disease in the American Cancer Society Cancer Prevention Study II (CPS-II) Nutrition Cohort, a prospective study of cancer incidence and mortality in US men and women. From 1992-2007, 2,034 incident NHL cases and 57 Hodgkin cases were identified among 152,989 men and women who were cancer-free at enrollment. Cox proportional hazards modeling was used to compute hazard rate ratios (RR) while adjusting for potential confounders. When compared with never smokers there was an association with NHL among former smokers (RR=1.13, 95% CI (1.03-1.24)), but not current smokers (RR=1.03, 95% CI (0.86-1.23)), and not with smoking intensity or duration. Among NHL sub-types, ever smoking was significantly associated with CLL/SLL (RR=1.37) and T-cell lymphomas (RR=1.55). No association was seen with other sub-types of NHL, or Hodgkin disease. When associations with NHL were examined by gender there were significant differences in men and women by current smoking status (interaction p=0.015). A strong dose response relationship with the number of years smoked was noted in current female smokers (p-trend=0.005) resulting in a 2-fold higher risk of NHL among women smoking for 50 years or more compared with never smokers (RR=2.27, 95% CI 1.32-3.89). Associations also differed by gender for some subgroups of NHL. Specifically, current smoking was significantly associated with CLL/SLL and FL in women, but associations were null or inverse in men. However, T-cell lymphomas were associated with similarly increased risk in both men and women. In conclusion, this study supports an association of cigarette smoking with T-cell lymphomas, and associations with smoking among women especially for the CLL/SLL and follicular sub-types. It also provides further evidence that the etiology of lymphoid neoplasms may vary by lymphoma sub-type and gender, and that studies of these neoplasms should carefully consider this disease heterogeneity.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1823.

Abstract 2805: A pooled investigation of circulating 25-hydroxyvitamin D and non-Hodgkin lymphoma: The Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

Findings from several epidemiologic studies suggest that exposure to solar ultraviolet radiation may be associated with a reduced risk of non-Hodgkin lymphoma (NHL). These observations have led to speculation that vitamin D may protect against lymphomagenesis. To investigate this hypothesis, the authors conducted a pooled investigation of circulating 25-hydroxyvitamin D [25(OH)D] and subsequent NHL risk within ten cohorts participating in the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers. Prediagnostic samples of serum or plasma from 1,353 cases and 1,778 controls were assayed for 25(OH)D by immunoassay at a single laboratory. Odds ratios (ORs) and 95% confidence intervals (CIs) relating categories of 25(OH)D concentration with NHL risk were calculated using conditional logistic regression models, with 50-&lt;75 nmol/L used as the reference category. Analyses of common NHL histologic subtypes were performed using polytomous regression modeling.

Overall, no evidence of association with NHL risk was observed for either low 25(OH)D concentration (&lt;25 nmol/L: OR 1.08, 95% CI 0.78-1.50) or high concentration (≥100 nmol/L: OR 0.86, 95% CI 0.57-1.27), and a test for trend was not statistically significant (P = 0.68).

Analyses of other measures of 25(OH)D {continuous log[25(OH)D], categories of 25(OH)D using sex/cohort/season-specific cutpoints, categories of season-adjusted residuals of predicted 25(OH)D} were similarly null, as were results from stratified analyses and investigations of histologic subtypes of NHL. These findings do not support the hypothesis that elevated circulating 25(OH)D levels are associated with reduced NHL risk. Future research investigating the biologic basis for the sunlight-NHL association should consider alternative mechanisms, such as immunologic effects.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2805.

Abstract 1841: Diabetes, insulin-use and risk of colorectal cancer in a U.S. cohort study

Background: Diabetes is associated with a modest increased risk of colorectal cancer (CRC). Evidence also indicates that high endogenous insulin and glucose levels are associated with increased risk of CRC. However, few studies have evaluated whether exogenous insulin, used to treat diabetes, is associated with risk of CRC, and one of these studies reported strongly increased risk among diabetics who had used insulin. Further, few studies have examined the association between diabetes and risk of CRC by gender, tumor phenotype (e.g., sub-site, stage) and other factors, that may be relevant to the etiology of CRC.

Methods: The CPS II Nutrition Cohort is a prospective study of cancer incidence including approximately 184,000 U.S. adults aged 50 to 75 at enrollment in 1992-93. At enrollment, participants completed a detailed self-administered questionnaire that included information on demographic, medical, lifestyle, and dietary factors. The questionnaire asked if a participant had been diagnosed by a physician with diabetes mellitus and if the participant was taking insulin to treat the disease. Follow-up questionnaires were sent to cohort members in 1997, and every two years thereafter to update exposure information, including diabetes and insulin-use, and to learn of incident cancers. Colorectal cancer cases in the current study were identified by linkage with the National Death Index (NDI) or by self-reports, subsequently verified by medical record abstraction or linkage with state cancer registries.

Results: After exclusions, 73,328 men and 81,670 women remained in the final analytic cohort, of whom 1,444 men and 1,154 women were diagnosed with colon or rectal cancer between enrollment and the end of follow-up in 2007. Among female participants, diabetes and insulin-use were not associated with incident colorectal cancer overall (Relative Risk (RR): 0.98; 95% Confidence Interval (CI): 0.79-1.22 and RR: 0.92; 95% CI: 0.61-1.40, respectively) or when stratified by tumor sub-site in the colon or rectum, stage of disease, or fatality. Among male participants, both diabetes and insulin-use were associated with modestly increased risk of incident colorectal cancer (RR: 1.25; 95% CI: 1.08-1.46 and RR: 1.35; 95% CI: 1.02-1.78, respectively). There were no clear differences in associations with diabetes by subsite or stage. Duration of diabetes was linearly associated with CRC risk among men (p-trend: 0.0002), but not women. Duration of insulin-use was not linearly associated with CRC risk in men or women.

Conclusions: Our results from a large U.S. prospective study confirm a modest association between diabetes and colorectal cancer risk among men but not among women. Reasons for these differences are unclear but might be due to sex-differences in hormones or better glucose control among women than men. Our results also suggest that exogenous insulin-use is unlikely to substantially increase risk of colorectal cancer among diabetics.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1841.

Abstract 1826: Anthropometric characteristics, physical activity and risk of lymphoid neoplasms in a large US cohort

Body size, height, and physical inactivity are known to alter immune function and have been hypothesized to increase risk of non-Hodgkin lymphoma (NHL). However, results of other studies are inconsistent and whether these relationships vary by histologic subtypes of NHL is not well-documented. Therefore, we examined measures of body size (BMI, adult weight gain, and BMI at age 18), height, physical activity, and sitting time in relation to risk of NHL overall and within the major subtypes (diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), and B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), and multiple myeloma (MM)) in the American Cancer Society Cancer Prevention Study II (CPS-II) Nutrition Cohort, a prospective study of cancer incidence and mortality, using information obtained at baseline in 1992. From 1992-2007, 2000 incident NHL cases were identified among 150,189 men and women who were cancer-free at enrollment. Cox proportional hazards modeling was used to compute hazard rate ratios (RR) while adjusting for potential confounders. Obese men and women (BMI &gt; 30) had a 20% higher incidence of all NHL (95% confidence interval (CI) 1.05-1.37) compared to normal weight individuals (BMI 18.5-&lt;25). BMI at age 18 and BMI measured 10-years prior to baseline (in 1982) were also associated with NHL risk (trend p=0.008 and p=0.0003, respectively) in men and women, even after adjustment for baseline BMI. Height was positively associated with overall risk (RR=1.25, 95% CI 1.10-1.43 for sex-specific quintile 5 vs. 1). Associations were similar across all subtypes of NHL examined. Measures of physical activity and sitting time were not associated with risk of NHL or within any specific subtype. These findings suggest that obesity throughout adulthood and greater height may play a role in the etiology of NHL. While more recent obesity may impact immune function or levels of various hormones, height and BMI at age 18 may reflect early-life consequences of nutrition or exposure to growth hormones.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1826.

The association of endogenous sex hormones, adiposity, and insulin resistance with incident diabetes in postmenopausal women

CONTEXT

In postmenopausal women, endogenous bioavailable testosterone (T) and estradiol (E2) have been positively associated, and SHBG has been negatively associated, with incident type 2 diabetes (T2DM). Previous studies have not explored possible factors explaining these relationships.

OBJECTIVE

Our objective was to examine the association of endogenous sex hormones with incident T2DM in postmenopausal women and possible explanatory factors.

DESIGN, SETTING, AND PARTICIPANTS

The Multi-Ethnic Study of Atherosclerosis (MESA) is a prospective study that included 1612 postmenopausal women aged 45-84 yr, followed between the years 2000-2006, who were not taking hormone replacement therapy, had no prevalent cardiovascular disease or diabetes, and had complete ascertainment of sex hormones.

MAIN OUTCOME MEASURES

T2DM was defined based on fasting glucose and/or treatment for diabetes.

RESULTS

There were 116 incident cases of diabetes during follow-up. Across higher quartiles of bioavailable T and E2 and lower quartiles of SHBG, we found significantly greater hazards of developing incident T2DM (all P for trend <or=0.001). After adjustment for body mass index and insulin resistance estimated by homeostasis model assessment of insulin resistance, bioavailable T was no longer associated with incident T2DM. The associations of E2 and SHBG with incident T2DM were partially explained by body mass index and insulin resistance but persisted in fully adjusted models (both P for trend <0.02). Dehydroepiandrosterone had no relationship with incident T2DM.

CONCLUSIONS

Adiposity and insulin resistance explained most of the association of bioavailable T but only partially explained the associations of E2 and SHBG with incident T2DM among postmenopausal women.

Colorectal cancer incidence and postmenopausal hormone use by type, recency, and duration in cancer prevention study II

The Women's Health Initiative randomized trials showed a reduction in colorectal cancer risk with the use of estrogen plus progesterone (E + P), but not with estrogen alone (E-only), after intervention periods <7 years. Using data from the Cancer Prevention Study II Nutrition Cohort, we examined associations of colorectal cancer risk with E-only and E + P, including analyses by recency and duration of hormone use. During 13.2 years of follow-up, 776 cases of invasive colorectal cancer occurred among 67,412 postmenopausal women participants. Cox proportional hazards models were used to estimate multivariate-adjusted relative risks (RR) and 95% confidence intervals (95% CI) of colorectal cancer for current and former hormone users according to hormone type and duration of use. Relative to women who never used postmenopausal hormones, current, but not former, use of E-only was associated with a reduced risk of colorectal cancer (RR 0.76; 95% CI, 0.59-0.97). Among current E-only users, duration of use was inversely and linearly associated with risk (P(trend) = 0.01). Use of E-only for <5 years was not associated with reduced risk, whereas use for >or=20 years was associated with a 45% reduction in risk (RR, 0.55; 95% CI, 0.36-0.86). There were no statistically significant associations between E + P and colorectal cancer risk. Our results suggest a strong inverse association of long-term use of E-only with colorectal cancer risk, underscoring the importance of collecting data on duration of hormone use in epidemiologic studies of postmenopausal hormones and risk of disease.

Serum IGF-I and C-reactive protein in healthy black and white young men: the CARDIA male hormone study

OBJECTIVE

Animal and human studies suggest that C-reactive protein (CRP) may be inversely associated with serum insulin-like growth factor-I (IGF-I) concentrations. However, most human studies have not controlled adequately for confounding factors, particularly nutritional intake. This population-based study examined whether CRP is inversely associated with IGF-I and IGFBP-3 concentrations.

METHODS

In cross-sectional analysis, multivariable linear regression with adjustment for age, BMI, smoking status, alcohol intake, and nutritional factors was used to relate log CRP, the independent variable, to IGF-I and IGFBP-3 in a sample of black (n=364) and white men (n=486) separately by race.

RESULTS

Only black men had positive findings: log CRP was significantly associated with IGF-I (beta=-13.1 ng/ml, p=0.02) and the difference in mean IGF-I concentrations between the highest and lowest quartiles of CRP was 26 ng/ml. There was a statistically significant interaction between log CRP and smoking status (p=0.02); the regression coefficient for IGF-I predicted from log CRP was significant in smokers (beta=-39.8 ng/ml, p=0.0001), but not in non-smokers. The difference in mean IGF-I concentrations between highest and lowest quartiles of CRP was 100 ng/ml for black smokers. There were no associations for IGFBP-3.

CONCLUSIONS

In our study, CRP levels are inversely associated with IGF-I concentrations in black male smokers; however, the causal nature of the association is unclear and should be studied further.

Bone mineral density and atherosclerosis: the Multi-Ethnic Study of Atherosclerosis, Abdominal Aortic Calcium Study

CONTEXT

Molecular and cell biology studies have demonstrated an association between bone and arterial wall disease, but the significance of a population-level association is less clear and potentially confounded by inability to account for shared risk factors.

OBJECTIVE

To test population-level associations between atherosclerosis types and bone integrity.

MAIN OUTCOME MEASURES

Volumetric trabecular lumbar bone mineral density (vBMD), ankle-brachial index (ABI), intima-media thickness (IMT) of the common carotid (CCA-IMT) and internal carotid (ICA-IMT) arteries, and carotid plaque echogenicity.

DESIGN, SETTING AND PARTICIPANTS

A random subset of participants from the Multi-Ethnic Study of Atherosclerosis (MESA) assessed between 2002 and 2005.

RESULTS

904 post-menopausal female (62.4 years; 62% non-white; 12% ABI <1; 17% CCA-IMT >1mm; 33% ICA-IMT >1mm) and 929 male (61.4 years; 58% non-white; 6% ABI <1; 25% CCA-IMT >1mm; 40% ICA-IMT >1mm) were included. In serial, sex-specific regression models adjusting for age, ethnicity, body mass index, dyslipidemia, hypertension, smoking, alcohol consumption, diabetes, homocysteine, interleukin-6, sex hormones, and renal function, lower vBMD was associated with lower ABI in men (p for trend <0.01) and greater ICA-IMT in men (p for trend <0.02). CCA-IMT was not associated with vBMD in men or women. Carotid plaque echogenicity was independently associated with lower vBMD in both men (trend p=0.01) and women (trend p<0.04). In all models, adjustment did not materially affect results.

CONCLUSIONS

Lower vBMD is independently associated with structural and functional measures of atherosclerosis in men and with more advanced and calcified carotid atherosclerotic plaques in both sexes.

Serum 25-hydroxyvitamin D concentrations and postmenopausal breast cancer risk: a nested case control study in the Cancer Prevention Study-II Nutrition Cohort

INTRODUCTION

Vitamin D status measured during adulthood has been inversely associated with breast cancer risk in some, but not all, studies. Vitamin D has been hypothesized to prevent breast cancer through genomic and non-genomic actions in cell-cycle regulation.

METHODS

A subset (n = 21,965) of female participants from the prospective Cancer Prevention Study-II (CPS-II) Nutrition Cohort provided a blood sample from 1998-2001 and were followed through 2005. We measured serum 25-hydroxyvitamin D (25(OH)D) in 516 verified incident cases and 516 controls, matched on birth date (+/- 6 months), date of blood draw (+/- 6 months) and race. Information on medical history, risk factors and lifestyle was available from repeated questionnaires. We computed multi-variable odds ratios (OR) and 95% confidence intervals (95% CI) for the association between 25(OH)D quintile and breast cancer risk using unconditional logistic regression, controlling for matching factors and additional confounders.

RESULTS

We observed no association between 25(OH)D and breast cancer (OR = 1.09, 95% CI 0.70-1.68, P = 0.60) for the top vs bottom quintile. Using a priori cut-points, the OR was 0.86 (95% CI 0.59-1.26), for > or =75 vs <50 nmol/L. Results were not different when the first two years of follow-up were excluded, or in analyses stratified by season, latitude, BMI, postmenopausal hormone use, or by tumor grade or estrogen receptor status.

CONCLUSIONS

These results do not support an association between adulthood serum 25(OH)D and postmenopausal breast cancer. We cannot rule out an association with 25(OH)D status earlier in life.

Association of endogenous sex hormones with diabetes and impaired fasting glucose in men: multi-ethnic study of atherosclerosis

OBJECTIVE

To assess associations of sex hormones with impaired fasting glucose (IFG) and type 2 diabetes in men.

RESEARCH DESIGN AND METHODS

A total of 3,156 African American, Non-Hispanic white, Hispanic, and Chinese-American men aged 45-84 years who participated in the baseline visit of the Multi-Ethnic Study of Atherosclerosis (MESA) were included. Odd sratios and 95% CIs for type 2 diabetes and IFG compared with normal fasting glucose for quartiles of hormones were estimated.

RESULTS

After adjusting for age, ethnicity, BMI, and waist circumference, IFG and diabetes were associated inversely with total testosterone and sex hormone-binding globulin (SHBG) and positively with estradiol (E2). Dehydroepiandrosterone was positively associated with IFG but not with diabetes. Associations did not differ across ethnic groups.

CONCLUSIONS

Regardless of obesity, total testosterone and SHBG were associated inversely and E2 was associated positively with IFG and diabetes in men. Further research is warranted to better understand the underlying biological mechanisms.

Ethnic differences in ST height in the multiethnic study of atherosclerosis

BACKGROUND

ST elevation in precordial leads has been associated with genetic syndromes of arrhythmias and sudden death. ST height data in different ethnic groups are limited.

METHODS

ST height was determined in 4612 African-American, Chinese, Hispanic, and non-Hispanic white men and women aged 45-84 years in the Multiethnic Study of Atherosclerosis (MESA). For leads I, II, and V(1) to V(6,) ST height, measured at the J point and 60 ms after the J point, adjusted for covariates were compared between non-Hispanic white and other ethnic groups using analysis of covariance (ANCOVA).

RESULTS

Among men, ST height was significantly different across all ethnic groups at both time points for all leads (P < 0.01), except at the J point for limb lead II (P = 0.2). Among women, differences were also significant at the J point and 60 ms past the J point (P < 0.01). ST height was lowest for non-Hispanic whites in all leads and at both time points. At the J point, Chinese had the highest ST height for leads V(1) and V(2), whereas African Americans had the greatest ST height for leads I and V(3) to V(6). At 60 ms past the J point, Chinese men had the greatest ST height for lead I and V(1) to V(6;) and Chinese women had greatest ST height for leads V(1) to V(3).

CONCLUSIONS

There were significant differences in ST height among ethnic groups in all ECG leads. The physiological mechanisms and clinical significance of these differences and the possible association with arrhythmias require further study.

Association of coronary artery and aortic calcium with lumbar bone density: the MESA Abdominal Aortic Calcium Study

Atherosclerosis and osteoporosis share many risk factors, but their independent association is unclear. The authors investigated the independent associations between volumetric trabecular bone mineral density (vBMD) of the lumbar spine and coronary artery calcium (CAC) and abdominal aortic calcium (AAC). During 2002-2005, they used quantitative computed tomography to assess vBMD and the presence and extent of CAC and AAC among 946 women (mean age = 65.5 years) and 963 men (mean age = 64.1 years) in a substudy of the Multi-Ethnic Study of Atherosclerosis. Prevalences of CAC were 47% and 68% in women and men, respectively, and AAC prevalences were 70% and 73%. Sequential, sex-specific regression models included adjustment for age, ethnicity, body mass index, hypertension, dyslipidemia, diabetes mellitus, smoking, alcohol consumption, physical activity, interleukin-6, C-reactive protein, homocysteine, and sex hormones. After full adjustment, lower vBMD was associated with greater CAC score among women (P < 0.002) and greater AAC score among women (P = 0.004) and men (P < 0.001). After adjustment, vBMD quartile was inversely associated with CAC prevalence (P-trend = 0.05) in women and AAC prevalence (P-trend < 0.01) in men. Partially and fully adjusted models showed similar results. Though modest, these significant, independent associations suggest that atherosclerosis and bone loss may be related.