Obesity is known to be a major risk factor for diabetes, but the magnitude of risk and variation between blacks and whites are less well documented in populations heavily affected by obesity. Herein ...we assess rates and risks of incident diabetes in a diverse southern population where obesity is common.
A total of 24,000 black and 14,064 white adults aged 40-79 in the Southern Community Cohort Study with no self-reported diabetes at study enrollment during 2002-2009 was followed for up to 10 (median 4.5) years. Incidence rates, odds ratios (OR) and accompanying 95% confidence intervals (CI) for medication-treated incident diabetes were determined according to body mass index (BMI) and other characteristics, including tobacco and alcohol consumption, healthy eating and physical activity indices, and socioeconomic status (SES).
Risk of incident diabetes rose monotonically with increasing BMI, but the trends differed between blacks and whites (pinteraction < .0001). Adjusted ORs (CIs) for diabetes among those with BMI≥40 vs 20-25 kg/m2 were 11.9 (8.4-16.8) for whites and 4.0 (3.3-4.8) for blacks. Diabetes incidence was more than twice as high among blacks than whites of normal BMI, but the racial difference became attenuated as BMI rose, with estimated 5-year probabilities of developing diabetes approaching 20% for both blacks and whites with BMI≥40 kg/m2. Diabetes risk was also associated with low SES, significantly (pinteraction≤.02) more so for whites, current cigarette smoking, and lower healthy eating and physical activity indices, although high BMI remained the predominant risk factor among both blacks and whites. From baseline prevalence and 20-year projections of the incidence trends, we estimate that the large majority of surviving cohort participants with BMI≥40 kg/m2 will be diagnosed with diabetes.
Even using conservative criteria to ascertain diabetes incidence (i.e., requiring diabetes medication use and ignoring undiagnosed cases), rates of obesity-associated diabetes were exceptionally high in this low-income adult population. The findings indicate that effective strategies to halt the rising prevalence of obesity are needed to avoid substantial increases in diabetes in coming years.
We present a comprehensive assessment of genomic diversity in the African-American population by studying three genotyped cohorts comprising 3,726 African-Americans from across the United States that ...provide a representative description of the population across all US states and socioeconomic status. An estimated 82.1% of ancestors to African-Americans lived in Africa prior to the advent of transatlantic travel, 16.7% in Europe, and 1.2% in the Americas, with increased African ancestry in the southern United States compared to the North and West. Combining demographic models of ancestry and those of relatedness suggests that admixture occurred predominantly in the South prior to the Civil War and that ancestry-biased migration is responsible for regional differences in ancestry. We find that recent migrations also caused a strong increase in genetic relatedness among geographically distant African-Americans. Long-range relatedness among African-Americans and between African-Americans and European-Americans thus track north- and west-bound migration routes followed during the Great Migration of the twentieth century. By contrast, short-range relatedness patterns suggest comparable mobility of ∼15-16km per generation for African-Americans and European-Americans, as estimated using a novel analytical model of isolation-by-distance.
Oral microbiome may play an important role in cancer pathogenesis. However, no study has prospectively investigated the association of the oral microbiome with subsequent risk of developing ...colorectal cancer (CRC). We conducted a nested case–control study including 231 incident CRC cases and 462 controls within the Southern Community Cohort Study with 75% of the subjects being African‐Americans. The controls were individually matched to cases based on age, ethnic group, smoking, season‐of‐study enrollment and recruitment method. Oral microbiota were assessed using 16S rRNA gene sequencing in pre‐diagnostic mouth rinse samples. Multiple bacterial taxa showed an association with CRC risk at p <0.05. Oral pathogens Treponema denticola and Prevotella intermedia were associated with an increased risk of CRC, with odds ratios (ORs) and 95% confidence intervals (CIs) of 1.76(1.19–2.60) and 1.55(1.08–2.22), respectively, for the individuals carrying these bacteria compared to non‐carriers. In the phylum Actinobacteria, Bifidobacteriaceae was more abundant among CRC patients than among controls. In the phylum Bacteroidetes, Prevotella denticola and Prevotella sp. oral taxon 300 were associated with an increased CRC risk, while Prevotella melaninogenica was associated with a decreased risk of CRC. In the phylum Firmicutes, Carnobacteriaceae, Streptococcaceae, Erysipelotrichaceae, Streptococcus, Solobacterium, Streptococcus sp. oral taxon 058 and Solobacterium moorei showed associations with a decreased risk of CRC. Most of these associations were observed among both African‐ and European‐Americans. Most of the associations were not significant after Bonferroni correction for multiple testing, which may be conservative. Our study suggests that the oral microbiome may play a significant role in CRC etiology.
What's new?
Oral microbiome composition is of special interest in research on colorectal cancer risk, owing in part to evidence that certain oral microbes cause chronic inflammation. In this prospective investigation of participants in the Southern Community Cohort Study in the United States, multiple oral bacterial taxa were associated with risk of developing colorectal cancer. Among the taxa, two species, Treponema denticola and Prevotella intermedia, previously were described as pathogenic in the oral cavity. The findings suggest that oral microbiome composition influences colorectal cancer risk, warranting further investigation for the possible use of oral microbiota in colorectal cancer detection and prevention.
A healthy diet, as defined by the US Dietary Guidelines for Americans (DGA), has been associated with lower morbidity and mortality from major chronic diseases in studies conducted in predominantly ...non-Hispanic white individuals. It is unknown whether this association can be extrapolated to African-Americans and low-income populations.
We examined the associations of adherence to the DGA with total and cause-specific mortality in the Southern Community Cohort Study, a prospective study that recruited 84,735 American adults, aged 40-79 y, from 12 southeastern US states during 2002-2009, mostly through community health centers that serve low-income populations. The present analysis included 50,434 African-Americans, 24,054 white individuals, and 3,084 individuals of other racial/ethnic groups, among whom 42,759 participants had an annual household income less than US$15,000. Usual dietary intakes were assessed using a validated food frequency questionnaire at baseline. Adherence to the DGA was measured by the Healthy Eating Index (HEI), 2010 and 2005 editions (HEI-2010 and HEI-2005, respectively). During a mean follow-up of 6.2 y, 6,906 deaths were identified, including 2,244 from cardiovascular disease, 1,794 from cancer, and 2,550 from other diseases. A higher HEI-2010 score was associated with lower risks of disease death, with adjusted hazard ratios (HRs) of 0.80 (95% CI, 0.73-0.86) for all-disease mortality, 0.81 (95% CI, 0.70-0.94) for cardiovascular disease mortality, 0.81 (95% CI, 0.69-0.95) for cancer mortality, and 0.77 (95% CI, 0.67-0.88) for other disease mortality, when comparing the highest quintile with the lowest (all p-values for trend < 0.05). Similar inverse associations between HEI-2010 score and mortality were observed regardless of sex, race, and income (all p-values for interaction > 0.50). Several component scores in the HEI-2010, including whole grains, dairy, seafood and plant proteins, and ratio of unsaturated to saturated fatty acids, showed significant inverse associations with total mortality. HEI-2005 score was also associated with lower disease mortality, with a HR of 0.86 (95% CI, 0.79-0.93) when comparing extreme quintiles. Given the observational study design, however, residual confounding cannot be completely ruled out. In addition, future studies are needed to evaluate the generalizability of these findings to African-Americans of other socioeconomic status.
Our results showed, to our knowledge for the first time, that adherence to the DGA was associated with lower total and cause-specific mortality in a low-income population, including a large proportion of African-Americans, living in the southeastern US.
In the Shandong Intervention Trial, 2 weeks of antibiotic treatment for Helicobacter pylori reduced the prevalence of precancerous gastric lesions, whereas 7.3 years of oral supplementation with ...garlic extract and oil (garlic treatment) or vitamin C, vitamin E, and selenium (vitamin treatment) did not. Here we report 14.7-year follow-up for gastric cancer incidence and cause-specific mortality among 3365 randomly assigned subjects in this masked factorial placebo-controlled trial. Conditional logistic regression was used to estimate the odds of gastric cancer incidence, and the Cox proportional hazards model was used to estimate the relative hazard of cause-specific mortality. All statistical tests were two-sided. Gastric cancer was diagnosed in 3.0% of subjects who received H pylori treatment and in 4.6% of those who received placebo (odds ratio = 0.61, 95% confidence interval = 0.38 to 0.96, P = .032). Gastric cancer deaths occurred among 1.5% of subjects assigned H pylori treatment and among 2.1% of those assigned placebo (hazard ratio HR of death = 0.67, 95% CI = 0.36 to 1.28). Garlic and vitamin treatments were associated with non-statistically significant reductions in gastric cancer incidence and mortality. Vitamin treatment was associated with statistically significantly fewer deaths from gastric or esophageal cancer, a secondary endpoint (HR = 0.51, 95% CI = 0.30 to 0.87; P = .014).
Purpose
Physical activity (PA) is associated with many health benefits. While PA has been associated with reduced mortality after breast cancer diagnosis in many studies, few studies have examined ...the role of PA in breast cancer survival among underserved and minority populations, including Black women. We investigated PA in association with mortality among Black predominantly low-income breast cancer survivors in the Southern Community Cohort Study (SCCS).
Methods
Study participants were women diagnosed with incident breast cancer (
n
= 949) in the SCCS, which is a prospective cohort study of predominantly low-income adults aged 40–79 years recruited from 12 Southeastern states between 2002 and 2009. Participants completed a detailed baseline questionnaire, with annual follow-up for mortality via registry linkages. Cox regression models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for associations of pre-diagnosis PA (measured via a validated questionnaire) with all-cause and breast cancer-specific mortality.
Results
Breast cancer survivors had a mean age of 61.1 years and most (79.3%) had a household income of < $25,000. In adjusted models, higher levels of total PA (MET-hours/day) were inversely associated with all-cause mortality with HRs (95% CIs): 0.79 (0.59–1.06), 0.66 (0.49–0.90), and 0.60 (0.43–0.84), for Q2, Q3, and Q4 (reference: Q1), respectively,
p
trend
≤ 0.01. A similar inverse association was found for breast cancer-specific mortality.
Conclusion
Higher levels of pre-diagnosis PA were associated with improved survival among low-income Black breast cancer survivors. Resources to reduce barriers to PA participation and increase support for education and intervention efforts to promote PA among Black women are needed.
Persons with low socioeconomic status and nonwhite persons in the United States have high rates of cardiovascular disease. The use of combination pills (also called "polypills") containing low doses ...of medications with proven benefits for the prevention of cardiovascular disease may be beneficial in such persons. However, few data are available regarding the use of polypill therapy in underserved communities in the United States, in which adherence to guideline-based care is generally low.
We conducted a randomized, controlled trial involving adults without cardiovascular disease. Participants were assigned to the polypill group or the usual-care group at a federally qualified community health center in Alabama. Components of the polypill were atorvastatin (at a dose of 10 mg), amlodipine (2.5 mg), losartan (25 mg), and hydrochlorothiazide (12.5 mg). The two primary outcomes were the changes from baseline in systolic blood pressure and low-density lipoprotein (LDL) cholesterol level at 12 months.
The trial enrolled 303 adults, of whom 96% were black. Three quarters of the participants had an annual income below $15,000. The mean estimated 10-year cardiovascular risk was 12.7%, the baseline blood pressure was 140/83 mm Hg, and the baseline LDL cholesterol level was 113 mg per deciliter. The monthly cost of the polypill was $26. At 12 months, adherence to the polypill regimen, as assessed on the basis of pill counts, was 86%. The mean systolic blood pressure decreased by 9 mm Hg in the polypill group, as compared with 2 mm Hg in the usual-care group (difference, -7 mm Hg; 95% confidence interval CI, -12 to -2; P = 0.003). The mean LDL cholesterol level decreased by 15 mg per deciliter in the polypill group, as compared with 4 mg per deciliter in the usual-care group (difference, -11 mg per deciliter; 95% CI, -18 to -5; P<0.001).
A polypill-based strategy led to greater reductions in systolic blood pressure and LDL cholesterol level than were observed with usual care in a socioeconomically vulnerable minority population. (Funded by the American Heart Association Strategically Focused Prevention Research Network and the National Institutes of Health; ClinicalTrials.gov number, NCT02278471.).
Vitamin D is implicated in a wide range of health outcomes, and although environmental predictors of vitamin D levels are known, the genetic drivers of vitamin D status remain to be clarified. ...African Americans are a group at particularly high risk for vitamin D insufficiency but to date have been virtually absent from studies of genetic predictors of circulating vitamin D levels. Within the Southern Community Cohort Study, we investigated the association between 94 single nucleotide polymorphisms (SNPs) in five vitamin D pathway genes (GC, VDR, CYP2R1, CYP24A1, CYP27B1) and serum 25-hydroxyvitamin D (25(OH)D) levels among 379 African American and 379 Caucasian participants. We found statistically significant associations with three SNPs (rs2298849 and rs2282679 in the GC gene, and rs10877012 in the CYP27B1 gene), although only for African Americans. A genotype score, representing the number of risk alleles across the three SNPs, alone accounted for 4.6% of the variation in serum vitamin D among African Americans. A genotype score of 5 (vs. 1) was also associated with a 7.1 ng/mL reduction in serum 25(OH)D levels and a six-fold risk of vitamin D insufficiency (<20 ng/mL) (odds ratio 6.0, p = 0.01) among African Americans. With African ancestry determined from a panel of 276 ancestry informative SNPs, we found that high risk genotypes did not cluster among those with higher African ancestry. This study is one of the first to investigate common genetic variation in relation to vitamin D levels in African Americans, and the first to evaluate how vitamin D-associated genotypes vary in relation to African ancestry. These results suggest that further evaluation of genetic contributors to vitamin D status among African Americans may help provide insights regarding racial health disparities or enable the identification of subgroups especially in need of vitamin D-related interventions.
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