[show abstract][hide abstract] ABSTRACT: Glycated hemoglobin was recently recommended for use as a diagnostic test for diabetes. We examined the association between 2010 American Diabetes Association diagnostic cut points for glycated hemoglobin and microvascular outcomes (chronic kidney disease, end-stage renal disease [ESRD], and retinopathy) and formally tested for the presence of risk thresholds in the relationships of glycated hemoglobin with these outcomes.
Prospective cohort and cross-sectional analyses of 11,357 participants (773 with a history of diagnosed diabetes) from the Atherosclerosis Risk in Communities (ARIC) Study.
During a median of 14 years of follow-up of individuals without diagnosed diabetes at baseline, clinical categories of glycated hemoglobin were associated with risk of chronic kidney disease, with adjusted hazard ratios (HRs) of 1.12 (0.94-1.34) and 1.39 (1.04-1.85) for glycated hemoglobin 5.7-6.4% and ≥6.5%, respectively, as compared with <5.7% (P trend = 0.002). The corresponding HRs for ESRD were 1.51 (0.82-2.76) and 1.98 (0.83-4.73), respectively (P trend = 0.047). In the absence of diagnosed diabetes, glycated hemoglobin was cross sectionally associated with the presence of moderate/severe retinopathy, with adjusted odds ratios of 1.42 (0.69-2.92) and 2.91 (1.19-7.11) for glycated hemoglobin 5.7-<6.5% and ≥6.5%, respectively, compared with <5.7% (P trend = 0.011). Risk associations were stronger among individuals with a history of diabetes. We did not observe significant thresholds in the associations of glycated hemoglobin with kidney disease risk or retinopathy.
These data from a community-based, biracial population support the use of new 2010 American Diabetes Association glycated hemoglobin cut points for the diagnosis of diabetes.
[show abstract][hide abstract] ABSTRACT: Serum potassium levels affect insulin secretion by pancreatic β-cells, and hypokalemia associated with diuretic use has been associated with dysglycemia. We hypothesized that adults with lower serum potassium levels and lower dietary potassium intake are at higher risk for incident diabetes mellitus (DM), independent of diuretic use.
We analyzed data from 12 209 participants from the Atherosclerosis Risk in Communities (ARIC) Study, an ongoing prospective cohort study, beginning in 1986, with 9 years of in-person follow-up and 17 years of telephone follow-up. Using multivariate Cox proportional hazard models, we estimated the hazard ratio (HR) of incident DM associated with baseline serum potassium levels.
During 9 years of in-person follow-up, 1475 participants developed incident DM. In multivariate analyses, we found an inverse association between serum potassium and risk of incident DM. Compared with those with a high-normal serum potassium level (5.0-5.5 mEq/L), adults with serum potassium levels lower than 4.0 mEq/L, 4.0 to lower than 4.5 mEq/L, and 4.5 to lower than 5.0 mEq/L had an adjusted HR (95% confidence interval [CI]) of incident DM of 1.64 (95% CI, 1.29-2.08), 1.64 (95% CI, 1.34-2.01), and 1.39 (95% CI, 1.14-1.71), respectively. An increased risk persisted during an additional 8 years of telephone follow-up based on self-report with HRs of 1.2 to 1.3 for those with a serum potassium level lower than 5.0 mEq/L. Dietary potassium intake was significantly associated with risk of incident DM in unadjusted models but not in multivariate models.
Serum potassium level is an independent predictor of incident DM in this cohort. Further study is needed to determine if modification of serum potassium could reduce the subsequent risk of DM.
Archives of internal medicine 10/2010; 170(19):1745-51. · 11.46 Impact Factor
[show abstract][hide abstract] ABSTRACT: A substantial portion of the public health burden of heart failure is due to hospitalizations, many of which are for causes other than cardiovascular disease. We assessed whether left ventricular (LV) systolic dysfunction was associated with increased risk of both cardiovascular and noncardiovascular hospitalizations in a community sample of African Americans.
African American participants from the Jackson, MS, site of the Atherosclerosis Risk in Communities (ARIC) study who underwent echocardiography were followed for 12 years. Hospitalization rates among individuals with and without LV systolic dysfunction were compared using negative binomial regression.
Among 2,416 participants with echocardiograms, LV systolic dysfunction was found in 61 (2.5%). Participants with LV dysfunction experienced 366 hospitalizations, a rate of 1.27 per person-year, compared with 0.25 per person-year among individuals without LV dysfunction. The incidence rate ratio adjusted for demographics, comorbidities, and other risk factors was 3.11 (95% CI 2.22-4.35). The adjusted rate ratios were 4.76 (95% CI 2.90-7.20) for cardiovascular and 2.67 (95% CI 1.82-3.90) for noncardiovascular diagnoses, with similar findings in the subset of individuals with asymptomatic LV dysfunction. The percentage attributable risks for hospitalizations were 87% and 74% for cardiovascular and noncardiovascular causes (79% and 63% after adjustment).
African American individuals with LV dysfunction are at an increased risk of hospitalization due to a wide range of causes, with noncardiovascular hospitalizations accounting for nearly half the increased risk. To the extent that estimates of risk focus on cardiovascular morbidity, they may underestimate the true health burden of LV dysfunction.
American heart journal 09/2010; 160(3):488-95. · 4.65 Impact Factor
[show abstract][hide abstract] ABSTRACT: Although variants in the transcription factor 7-like 2 (TCF7L2) gene are consistently associated with impaired fasting glucose (IFG) in Caucasians, data from large population-based studies of African Americans are lacking. Moreover, few studies have investigated the effects of TCF7L2 on IFG in the context of metabolic risk factors for diabetes.
We investigated the association between the TCF7L2 rs7903146 polymorphism and incident IFG defined as fasting serum glucose levels of 100-125 mg/dL (5.6-6.9 mmol/L) in 1377 African American and 5152 Caucasian participants without diabetes and IFG at intake who participated in the Atherosclerosis Risk in Communities (ARIC) Study from 1987 to 1989 and were followed for 9 years.
Incident IFG was identified in 810 (58.8%) African American and 2652 (51.5%) Caucasian participants. Compared to homozygous CC Caucasian individuals, heterozygous CT [hazard ratio (HR) = 1.09 (95% CI = 1.03-1.15)] and homozygous TT [1.18 (1.05-1.33)] individuals had significantly higher risk of developing IFG over 9-year follow-up. The association between rs7903146 and IFG risk was stronger in Caucasians with obesity [HR(CTvs.CC) = 1.28 (1.12, 1.47); HR(TTvs.CC) = 1.65 (1.25, 2.17)] or high triglycerides [HR(CTvs.CC) = 1.31(1.10, 1.56); HR(TTvs.CC) = 1.72 (1.21, 2.43)]. No association of the TCF7L2 rs7903146 polymorphism and incident IFG was noted in African Americans.
Our study replicates the association between rs7903146 and IFG risk in a population-based, longitudinal cohort of Caucasians but not in African Americans. For the first time, our study provides evidence for interactions between TCF7L2 and metabolic risk factors on the occurrence of IFG in Caucasians.
Diabetes/Metabolism Research and Reviews 07/2010; 26(5):371-7. · 2.97 Impact Factor
[show abstract][hide abstract] ABSTRACT: Diabetes appears to increase risk for some cancers, but the association between preexisting diabetes and postoperative mortality in cancer patients is less clear. Our objective was to systematically review postoperative mortality in cancer patients with and without preexisting diabetes and summarize results using meta-analysis. RSEARCH DESIGN AND METHODS: We searched the Medical Literature Analysis and Retrieval System Online (MEDLINE) and Excerpta Medica Database (EMBASE) for articles published on or before 1 July 2009, including references of qualifying articles. We included English language investigations of short-term postoperative mortality after initial cancer treatment. Titles, abstracts, and articles were reviewed by at least two independent readers. Study population and design, results, and quality components were abstracted with standard protocols by one reviewer and checked for accuracy by additional reviewers.
Of 8,828 titles identified in our original search, 20 articles met inclusion criteria for qualitative systematic review. Of these, 15 reported sufficient information to be combined in meta-analysis. Preexisting diabetes was associated with increased odds of postoperative mortality across all cancer types (OR = 1.85 [95% CI 1.40-2.45]). The risk associated with preexisting diabetes was attenuated but remained significant when we restricted the meta-analysis to models that controlled for confounders (1.51 [1.13-2.02]) or when we accounted for publication bias using the trim and fill method (1.52 [1.13-2.04]).
Compared with their nondiabetic counterparts, cancer patients with preexisting diabetes are approximately 50% more likely to die after surgery. Future research should investigate physiologic pathways to mortality risk and determine whether improvements in perioperative diabetes care can reduce postoperative mortality.
Diabetes care 04/2010; 33(4):931-9. · 7.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: To measure relative and absolute educational disparities in mortality among U.S. adults with diabetes and to compare their magnitude with disparities observed within the nondiabetic population.
A total of 85,867 individuals (5,007 with diabetes), aged 35-84 years, who participated in the National Health Interview Survey from 1986 to 1996 were followed for mortality through 31 December 2002. Relative and absolute educational disparities in all-cause, cardiovascular disease (CVD), and non-CVD mortality were measured.
In relative terms, the risk of all-cause mortality was 28% higher in diabetic adults with the lowest versus the highest position on the educational scale (relative index of inequality 1.28 [95% CI 1.08-1.53]). This inverse relationship reflected marked disparities in CVD mortality and was found in all age, sex, and race/ethnicity groups except Hispanics. Although substantial, this relative educational gradient in mortality among adults with diabetes was smaller than in the nondiabetic population. In absolute terms, diabetic adults with the lowest position on the educational scale suffered 503 excess deaths per 10,000 person-years of follow-up compared with those with the highest position. These absolute disparities were stronger than in the nondiabetic population. The results were even more striking for CVD mortality.
The risk of mortality differs substantially according to educational level among individuals with diabetes in the U.S. Although relative educational disparities in mortality are weaker in adults with versus without diabetes, their absolute impact is greater and translates into a major mortality burden.
Diabetes care 03/2010; 33(6):1200-5. · 7.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: Earlier studies have shown an association between high-normal glucose and increasing glycosylated hemoglobin (HbA1c) levels and cardiovascular events. The objective of this investigation was to study the association between increasing levels of HbA1c in asymptomatic individuals without diabetes mellitus (DM) and coronary plaque characteristics.
The study population consisted of 1043 asymptomatic Korean individuals without DM who underwent 64-slice cardiac computed tomography angiography as part of a health screening evaluation. We excluded 147 individuals with known history of DM and/or fasting glucose of at least 126 mg/dl, no HbA1c data, or missing risk factor information. The associations between coronary atherosclerosis and plaque subtype burden with increasing HbA1c levels were assessed using multivariable regression analyses.
The final study population consisted of 906 individuals without DM (mean age: 49+/-9 years, 62% males); 19 and 9% of the population had any and two or more segments with coronary plaque, respectively. Unadjusted analysis showed a positive association between increasing levels of HbA1c and the number of coronary segments with any (P<0.001) and with mixed coronary plaques (P<0.0001). The association persisted even when traditional risk factors were taken into account. No significant relationship was found between increasing HbA1c levels and the burden of noncalcified or calcified plaque.
Increasing levels of HbA1c in asymptomatic individuals without DM are associated with the presence of coronary atherosclerosis, but more specifically with the presence and burden of mixed coronary plaques. Elements of plaque instability have been associated with mixed coronary plaques.
[show abstract][hide abstract] ABSTRACT: Fasting glucose is the standard measure used to diagnose diabetes in the United States. Recently, glycated hemoglobin was also recommended for this purpose.
We compared the prognostic value of glycated hemoglobin and fasting glucose for identifying adults at risk for diabetes or cardiovascular disease. We measured glycated hemoglobin in whole-blood samples from 11,092 black or white adults who did not have a history of diabetes or cardiovascular disease and who attended the second visit (occurring in the 1990-1992 period) of the Atherosclerosis Risk in Communities (ARIC) study.
The glycated hemoglobin value at baseline was associated with newly diagnosed diabetes and cardiovascular outcomes. For glycated hemoglobin values of less than 5.0%, 5.0 to less than 5.5%, 5.5 to less than 6.0%, 6.0 to less than 6.5%, and 6.5% or greater, the multivariable-adjusted hazard ratios (with 95% confidence intervals) for diagnosed diabetes were 0.52 (0.40 to 0.69), 1.00 (reference), 1.86 (1.67 to 2.08), 4.48 (3.92 to 5.13), and 16.47 (14.22 to 19.08), respectively. For coronary heart disease, the hazard ratios were 0.96 (0.74 to 1.24), 1.00 (reference), 1.23 (1.07 to 1.41), 1.78 (1.48 to 2.15), and 1.95 (1.53 to 2.48), respectively. The hazard ratios for stroke were similar. In contrast, glycated hemoglobin and death from any cause were found to have a J-shaped association curve. All these associations remained significant after adjustment for the baseline fasting glucose level. The association between the fasting glucose levels and the risk of cardiovascular disease or death from any cause was not significant in models with adjustment for all covariates as well as glycated hemoglobin. For coronary heart disease, measures of risk discrimination showed significant improvement when glycated hemoglobin was added to models including fasting glucose.
In this community-based population of nondiabetic adults, glycated hemoglobin was similarly associated with a risk of diabetes and more strongly associated with risks of cardiovascular disease and death from any cause as compared with fasting glucose. These data add to the evidence supporting the use of glycated hemoglobin as a diagnostic test for diabetes.
New England Journal of Medicine 03/2010; 362(9):800-11. · 51.66 Impact Factor
[show abstract][hide abstract] ABSTRACT: To summarize the influence of pre-existing diabetes on mortality and morbidity in men with prostate cancer. We searched MEDLINE and EMBASE from inception through 1 October 2008. Search terms were related to diabetes, cancer and prognosis. Studies were included if they reported an original data analysis of prostate cancer prognosis, compared outcomes between men with and without diabetes and were in English. Titles, abstracts and articles were reviewed independently by two authors. Conflicts were settled by consensus or third review. We abstracted data on study design, analytic methods, outcomes and quality. We summarized mortality and morbidity outcomes qualitatively and conducted a preliminary meta-analysis to quantify the risk of long-term (>3 months), overall mortality. In total, 11 articles were included in the review. Overall, one of four studies found increased prostate cancer mortality, one of two studies found increased nonprostate cancer mortality and one study found increased 30-day mortality. Data from four studies could be included in a preliminary meta-analysis for long-term, overall mortality and produced a pooled hazard ratio of 1.57 (95% CI: 1.12-2.20). Diabetes was also associated with receiving radiation therapy, complication rates, recurrence and treatment failure. Our analysis suggests that pre-existing diabetes affects the treatment and outcomes of men with prostate cancer.
Prostate cancer and prostatic diseases 03/2010; 13(1):58-64. · 2.10 Impact Factor
[show abstract][hide abstract] ABSTRACT: Studies have suggested differences in the association between obesity and ischemic stroke in black versus white populations. In this study, we explored ischemic stroke risk in relation to a variety of obesity measures by sex and race.
Using data from the Atherosclerosis Risk in Communities Study, we obtained information on body mass index, waist circumference, and waist-to-hip ratio from 13 549 black and white participants who were aged 45 to 65 years between 1987 and 1989. All were free of cardiovascular disease and cancer at baseline. Incident strokes over a median follow-up of 16.9 years were ascertained from hospital records.
Although crude incidence rates of ischemic stroke varied more than 3-fold by race and sex, the relationship between higher measures of obesity and ischemic stroke risk was positive and linear across all groups. The crude incidence of ischemic stroke was 1.2 per 1000 person-years for white women with the lowest body mass index, ranging up to 8.0 per 1000 person-years for black men with the highest body mass index. Hazard ratios for the highest versus lowest quintile of body mass index, waist circumference, and waist-to-hip ratio ranged from 1.43 to 3.19, indicating increased stroke risk associated with obesity, however it was measured, even after adjustment for potential confounders. Additional adjustment for factors that may mediate the relationship, such as diabetes and hypertension, significantly attenuated the associations, suggesting that these factors may explain much of the stroke risk associated with obesity.
Degree of obesity, defined by body mass index, waist circumference, or waist-to-hip ratio, was a significant risk factor for ischemic stroke regardless of sex or race.
[show abstract][hide abstract] ABSTRACT: Nonalcoholic fatty liver disease (NAFLD) is associated with obesity, insulin resistance, and impaired glucose tolerance. We investigated whether metformin or changes in metabolic measurements (weight, fasting plasma glucose (FPG), or fasting insulin (FI)) improved serum alanine aminotransferase (ALT) activity, as a marker for NAFLD, in the Diabetes Prevention Program (DPP). From 1996 to 1999, 2,153 participants without marked elevations of serum ALT at baseline were randomized (1,081 to placebo, 1,072 to metformin) and treated for an average of 3.2 years. ALT increased during the first 2 years of the study, and was slightly but significantly lower in the participants randomized to metformin. In regression models adjusted for sex, baseline age, FPG, and FI, these differences remained significant, but disappeared after adjustment for weight, FPG, and FI changes at each examination. The 3-year cumulative incidence for development of abnormal ALT concentrations was not significantly different ((mean +/- s.e.) 21.4 +/- 1.4% and 24.6 +/- 1.4%, P = 0.11) in the metformin vs. placebo groups but was lower in individuals in both groups that lost more weight by the end of year 1 (metformin: 19.4 +/- 2.4% vs. 27.5 +/- 3.7%, for highest vs. lowest quartile of weight loss; placebo: 18.7 +/- 3.4% vs. 28.8 +/- 2.6%). Over 3 years of follow-up in persons at high risk for development of diabetes, serum ALT was consistently lower in those treated with metformin compared with placebo. This effect was mediated by weight loss, indicating that the effects of metformin therapy on ALT is via its effects on weight.
[show abstract][hide abstract] ABSTRACT: To examine the relationship of diabetes and functional disability in older adults and the possible mediating roles of comorbidities and A1C.
We analyzed data from a nationally representative sample of 6,097 participants aged >or=60 years in the National Health and Nutrition Examination Survey, 1999-2006. Diabetes was defined by self-report. Disability was defined as difficulty performing a physical task. We evaluated disability by grouping 19 physical tasks into five functional groups: lower-extremity mobility (LEM), general physical activities (GPA), activities of daily living (ADL), instrumental activities of daily living (IADL), and leisure and social activities (LSA).
Older U.S. adults with diabetes had the greatest disability in GPA (prevalence 73.6% [95% CI 70.2-76.9]), followed by LEM (52.2% [48.5-55.9]), IADL (43.6% [40.1-47.2]), ADL (37.2% [33.1-41.3]), and LSA groups (33.8% [30.8-36.9]). Diabetes was associated with two to three times increased odds of disability across functional groups (all P < 0.05). Comorbidities, mostly cardiovascular disease and obesity, and poor glycemic control (A1C >or=8%) together explained up to 85% of the excess odds of disability associated with diabetes, whereas poor glycemic control alone explained only approximately 10% of the excess odds. Adjustment for comorbidities, A1C, and diabetes duration fully attenuated the associations of diabetes with disability in all functional groups (all P > 0.05).
Older adults with diabetes have a high prevalence of disabilities with variable associations attributable to comorbidities and A1C. Aggressive management of cardiovascular risk factors and obesity may significantly reduce the burden of disability in this population.
Diabetes care 02/2010; 33(5):1055-60. · 7.74 Impact Factor
[show abstract][hide abstract] ABSTRACT: Cigarette smoking is an established predictor of incident type 2 diabetes mellitus, but the effects of smoking cessation on diabetes risk are unknown.
To test the hypothesis that smoking cessation increases diabetes risk in the short term, possibly owing to cessation-related weight gain.
Prospective cohort study.
The ARIC (Atherosclerosis Risk in Communities) Study.
10,892 middle-aged adults who initially did not have diabetes in 1987 to 1989.
Smoking was assessed by interview at baseline and at subsequent follow-up. Incident diabetes was ascertained by fasting glucose assays through 1998 and self-report of physician diagnosis or use of diabetes medications through 2004.
During 9 years of follow-up, 1254 adults developed type 2 diabetes. Compared with adults who never smoked, the adjusted hazard ratio of incident diabetes in the highest tertile of pack-years was 1.42 (95% CI, 1.20 to 1.67). In the first 3 years of follow-up, 380 adults quit smoking. After adjustment for age, race, sex, education, adiposity, physical activity, lipid levels, blood pressure, and ARIC Study center, compared with adults who never smoked, the hazard ratios of diabetes among former smokers, new quitters, and continuing smokers were 1.22 (CI, 0.99 to 1.50), 1.73 (CI, 1.19 to 2.53), and 1.31 (CI, 1.04 to 1.65), respectively. Further adjustment for weight change and leukocyte count attenuated these risks substantially. In an analysis of long-term risk after quitting, the highest risk occurred in the first 3 years (hazard ratio, 1.91 [CI, 1.19 to 3.05]), then gradually decreased to 0 at 12 years.
Residual confounding is possible even with meticulous adjustment for established diabetes risk factors.
Cigarette smoking predicts incident type 2 diabetes, but smoking cessation leads to higher short-term risk. For smokers at risk for diabetes, smoking cessation should be coupled with strategies for diabetes prevention and early detection.
Annals of internal medicine 01/2010; 152(1):10-7. · 13.98 Impact Factor
[show abstract][hide abstract] ABSTRACT: Associations between obesity and lacunar, nonlacunar thrombotic, and cardioembolic stroke are not firmly established.
Body mass index (BMI), waist circumference, and waist-to-hip ratio (WHR) were recorded at baseline between 1987 and 1989 in the Atherosclerosis Risk in Communities (ARIC) Study for 13 549 black and white adults who were aged from 45 to 64 years and had no history of cardiovascular disease or cancer. The incidence of ischemic stroke subtypes was ascertained from surveillance of hospital records over a median follow-up of 16.9 years. Cox proportional hazards regression analyses adjusted for age, sex, race, education, smoking status and cigarette years, usual ethanol intake, and leisure time sports index were used to estimate hazard ratios (HRs).
The ARIC sample at baseline was 43.8% men and 27.3% blacks; mean age was 53.9 years. Mean BMI, waist circumference, and WHR were 27.7 kg/m(2), 96.8 cm, and 0.92, respectively. The associations of lacunar (n = 138), nonlacunar (n = 338), and cardioembolic (n = 122) ischemic stroke incidence with obesity measures were all generally positive and linear. The HRs for the highest versus lowest quintile of the 3 obesity measures ranged from 1.43-2.21 for lacunar stroke, 1.90-2.16 for nonlacunar stroke, and 2.37-2.91 for cardioembolic stroke.
Although different pathophysiological mechanisms may exist, the incidences of lacunar, nonlacunar, and cardioembolic stroke were all significantly positively associated with the degree of obesity, regardless of the measure used.
Journal of Epidemiology 01/2010; 20(5):347-54. · 2.11 Impact Factor
[show abstract][hide abstract] ABSTRACT: Transcription factor 7-like 2 (TCF7L2) has emerged as a consistently replicated susceptibility gene for type 2 diabetes, however, whether the TCF7L2 gene also has similar effects on the retinal microvasculature is less clear. We therefore aimed to investigate the association between the transcription factor 7-like 2 (TCF7L2) rs7903146 polymorphism and retinal microvascular phenotypes in the Atherosclerosis Risk in Communities (ARIC) Study (1993-1995).
This was a population-based, cross-sectional study of 10,320 middle-aged African American (n = 2,199) and Caucasian (n = 8,121) men and women selected from four United States communities to examine the association between TCF7L2 rs7903146 polymorphism and retinal microvascular signs (retinopathy, focal arteriolar narrowing, arteriovenous nicking, arteriolar and venular calibers). Photographs on one randomly selected eye were graded for presence of retinal microvascular signs and used to measure retinal vessel calibres.
After adjusting for age, sex, study center, mean arterial blood pressure, total serum cholesterol, triglycerides, and other covariates, few associations of TCF7L2 rs7903146 and retinal microvascular signs were noted. TCF7L2 rs7903146 T risk allele was significantly associated with focal arteriolar narrowing in Caucasians with hypertension [odds ratio (OR)CT vs. CC (95% CI) = 1.25 (1.09-1.44); ORTT vs. CC = 1.56 (1.18-2.06); P = 0.002] and in Caucasians without diabetes [OR CT vs. CC = 1.18 (1.06-1.32); OR TT vs. CC = 1.40 (1.12, 1.75); P = 0.003]. No significant association of the TCF7L2 rs7903146 polymorphism and retinal vascular signs was noted among African American individuals.
TCF7L2 rs7903146 is not consistently associated with retinal microvascular signs. However, we report an association between the TCF7L2 rs7903146 polymorphism and focal arteriolar narrowing in Caucasians with hypertension or without diabetes. Further research in other large, population-based studies is needed to replicate these findings.
[show abstract][hide abstract] ABSTRACT: Previous studies have shown that neighborhood factors are associated with obesity, but few studies have evaluated the association with weight control behaviors. This study aims to conduct a multi-level analysis to examine the relationship between neighborhood SES and weight-related health behaviors.
In this ancillary study to Look AHEAD (Action for Health in Diabetes) a trial of long-term weight loss among individuals with type 2 diabetes, individual-level data on 1219 participants from 4 clinic sites at baseline were linked to neighborhood-level data at the tract level from the 2000 US Census and other databases. Neighborhood variables included SES (% living below the federal poverty level) and the availability of food stores, convenience stores, and restaurants. Dependent variables included BMI, eating patterns, weight control behaviors and resource use related to food and physical activity. Multi-level models were used to account for individual-level SES and potential confounders.
The availability of restaurants was related to several eating and weight control behaviors. Compared to their counterparts in neighborhoods with fewer restaurants, participants in neighborhoods with more restaurants were more likely to eat breakfast (prevalence Ratio [PR] 1.29 95% CI: 1.01-1.62) and lunch (PR = 1.19, 1.04-1.36) at non-fast food restaurants. They were less likely to be attempting weight loss (OR = 0.93, 0.89-0.97) but more likely to engage in weight control behaviors for food and physical activity, respectively, than those who lived in neighborhoods with fewer restaurants. In contrast, neighborhood SES had little association with weight control behaviors.
In this selected group of weight loss trial participants, restaurant availability was associated with some weight control practices, but neighborhood SES was not. Future studies should give attention to other populations and to evaluating various aspects of the physical and social environment with weight control practices.
BMC Public Health 01/2010; 10:312. · 2.08 Impact Factor
[show abstract][hide abstract] ABSTRACT: Diabetes mellitus increases the risk of incident colorectal cancer, but it is less clear if pre-existing diabetes mellitus influences mortality outcomes, recurrence risk, and/or treatment-related complications in persons with colorectal cancer.
We performed a systematic review and meta-analysis comparing colorectal cancer mortality outcomes, cancer recurrence, and treatment-related complications in persons with and without diabetes mellitus. We searched MEDLINE and EMBASE through October 1, 2008, including hand-searching references of qualifying articles. We included studies in English that evaluated diabetes mellitus and cancer treatment outcomes, prognosis, and/or mortality. The initial search identified 8,208 titles, of which 15 articles met inclusion criteria. Each article was abstracted by one author using a standardized form and re-reviewed by another author for accuracy. Authors graded quality based on pre-determined criteria.
We found significantly increased short-term perioperative mortality in persons with diabetes mellitus. In the meta-analysis of long-term mortality, persons with diabetes mellitus had a 32% increase in all-cause mortality compared to those without diabetes mellitus (95% CI: 1.24, 1.41). Although data on other outcomes are limited, available studies suggest that pre-existing diabetes mellitus predicts increased risk of some post-operative complications as well as 5-year cancer recurrence. In contrast, there is little evidence that diabetes confers increased risk for long-term cancer-specific mortality.
Patients with colorectal cancer and pre-existing diabetes mellitus have an increased risk of short- and long-term mortality. Future research should determine whether improvements in prevention and treatment of diabetes mellitus will improve outcomes for colorectal cancer patients.
Digestive Diseases and Sciences 10/2009; 55(7):1839-51. · 2.26 Impact Factor
[show abstract][hide abstract] ABSTRACT: Although African American adults bear a disproportionate burden from diabetes mellitus (DM), few randomized controlled trials have tested culturally appropriate interventions to improve DM care.
We randomly assigned 542 African Americans with type 2 DM enrolled in an urban managed care organization to either an intensive or minimal intervention group. The intensive intervention group consisted of all components of the minimal intervention plus individualized, culturally tailored care provided by a nurse case manager (NCM) and a community health worker (CHW), using evidence-based clinical algorithms with feedback to primary care providers (eg, physicians, nurse practitioners, or physician assistants). The minimal intervention consisted of mailings and telephone calls every 6 months to remind participants about preventive screenings. Data on diabetic control were collected at baseline and at 24 months by blind observers; data emergency department (ER) visits and hospitalizations were assessed using administrative data.
At baseline, participants had a mean age of 58 years, 73% were women, and 50% were living in poverty. At 24 months, compared with the minimal intervention group, those in the intensive intervention group were 23% less likely to have ER visits (rate difference [RD], -14.5; adjusted rate ratio [RR], 0.77; 95% confidence interval [CI], 0.59-1.00). In on-treatment analyses, the rate reduction was strongest for patients who received the most NCM and CHW visits (RD, -31.0; adjusted RR, 0.66; 95% CI, 0.43-1.00; rate reduction downward arrow 34%).
These data suggest that a culturally tailored intervention conducted by an NCM/CHW team reduced ER visits in urban African Americans with type 2 DM.
clinicaltrials.gov Identifier: NCT00022750.
Archives of internal medicine 10/2009; 169(19):1788-94. · 11.46 Impact Factor
[show abstract][hide abstract] ABSTRACT: The intestinal flora may promote colon tumor formation. Here we explore immunologic mechanisms of colonic carcinogenesis by a human colonic bacterium, enterotoxigenic Bacteroides fragilis (ETBF). ETBF that secretes B. fragilis toxin (BFT) causes human inflammatory diarrhea but also asymptomatically colonizes a proportion of the human population. Our results indicate that whereas both ETBF and nontoxigenic B. fragilis (NTBF) chronically colonize mice, only ETBF triggers colitis and strongly induces colonic tumors in multiple intestinal neoplasia (Min) mice. ETBF induces robust, selective colonic signal transducer and activator of transcription-3 (Stat3) activation with colitis characterized by a selective T helper type 17 (T(H)17) response distributed between CD4+ T cell receptor-alphabeta (TCRalphabeta)+ and CD4-8-TCRgammadelta+ T cells. Antibody-mediated blockade of interleukin-17 (IL-17) as well as the receptor for IL-23, a key cytokine amplifying T(H)17 responses, inhibits ETBF-induced colitis, colonic hyperplasia and tumor formation. These results show a Stat3- and T(H)17-dependent pathway for inflammation-induced cancer by a common human commensal bacterium, providing new mechanistic insight into human colon carcinogenesis.
Nature medicine 09/2009; 15(9):1016-22. · 27.14 Impact Factor