HbA1c and lower-extremity amputation risk in low-income patients with diabetes.
ABSTRACT: Diabetes confers a very high risk of lower-extremity amputation (LEA); however, few studies have assessed whether blood glucose control can reduce LEA risk among patients with diabetes, especially in practice settings where low-income patients predominate.We performed a prospective cohort study (2000-2009) on patients with diabetes that included 19,808 African Americans and 15,560 whites. The cohort was followed though 31 May 2012. Cox proportional hazards regression models were used to estimate the association of HbA1c with LEA risk.During a mean follow-up of 6.83 years, 578 LEA incident cases were identified. The multivariable-adjusted hazard ratios of LEA associated with different levels of HbA1c at baseline (<6.0% [reference group], 6.0-6.9, 7.0-7.9, 8.0-8.9, 9.0-9.9, and ?10.0%) were 1.00, 1.73 (95% CI 1.07-2.80), 1.65 (0.99-2.77), 1.96 (1.14-3.36), 3.02 (1.81-5.04), and 3.30 (2.10-5.20) (P trend <0.001) for African American patients with diabetes and 1.00, 1.16 (0.66-2.02), 2.28 (1.35-3.85), 2.38 (1.36-4.18), 2.99 (1.71-5.22), and 3.25 (1.98-5.33) (P trend <0.001) for white patients with diabetes, respectively. The graded positive association of HbA1c during follow-up with LEA risk was observed among both African American and white patients with diabetes (all P trend <0.001). With stratification by sex, age, smoking status, blood pressure, LDL cholesterol, BMI, use of glucose-lowering agents, and income, this graded association of HbA1c with LEA was still present.The current study conducted in a low-income population suggests a graded association between HbA1c and the risk of LEA among both African American and white patients with type 2 diabetes.
Project description:<h4>Objective</h4>Clinical trials to date have not provided definitive evidence regarding the effects of glucose lowering with coronary heart disease (CHD) risk among diabetic patients.<h4>Research design and methods</h4>We prospectively investigated the association of HbA1c at baseline and during follow-up with CHD risk among 17,510 African American and 12,592 white patients with type 2 diabetes.<h4>Results</h4>During a mean follow-up of 6.0 years, 7,258 incident CHD cases were identified. The multivariable-adjusted hazard ratios of CHD associated with different levels of HbA1c at baseline (<6.0 [reference group], 6.0-6.9, 7.0-7.9, 8.0-8.9, 9.0-9.9, 10.0-10.9, and ?11.0%) were 1.00, 1.07 (95% CI 0.97-1.18), 1.16 (1.04-1.31), 1.15 (1.01-1.32), 1.26 (1.09-1.45), 1.27 (1.09-1.48), and 1.24 (1.10-1.40) (P trend = 0.002) for African Americans and 1.00, 1.04 (0.94-1.14), 1.15 (1.03-1.28), 1.29 (1.13-1.46), 1.41 (1.22-1.62), 1.34 (1.14-1.57), and 1.44 (1.26-1.65) (P trend <0.001) for white patients, respectively. The graded association of HbA1c during follow-up with CHD risk was observed among both African American and white diabetic patients (all P trend <0.001). Each one percentage increase of HbA1c was associated with a greater increase in CHD risk in white versus African American diabetic patients. When stratified by sex, age, smoking status, use of glucose-lowering agents, and income, this graded association of HbA1c with CHD was still present.<h4>Conclusions</h4>The current study in a low-income population suggests a graded positive association between HbA1c at baseline and during follow-up with the risk of CHD among both African American and white diabetic patients with low socioeconomic status.
Project description:To test among diabetes-free urban community-dwelling adults the hypothesis that the proportion of African genetic ancestry is positively associated with glycaemia, after accounting for other continental ancestry proportions, BMI and socioeconomic status (SES).The Boston Area Community Health cohort is a multi-stage 1:1:1 stratified random sample of self-identified African-American, Hispanic and white adults from three Boston inner city areas. We measured 62 ancestry informative markers, fasting glucose (FG), HbA1c, BMI and SES (income, education, occupation and insurance status) and analysed 1,387 eligible individuals (379 African-American, 411 Hispanic, 597 white) without clinical or biochemical evidence of diabetes. We used three-heritage multinomial linear regression models to test the association of FG or HbA1c with genetic ancestry proportion adjusted for: (1) age and sex; (2) age, sex and BMI; and (3) age, sex, BMI and SES.Mean age- and sex-adjusted FG levels were 5.73 and 5.54 mmol/l among those with 100% African or European ancestry, respectively. Using per cent European ancestry as the referent, each 1% increase in African ancestry proportion was associated with an age- and sex-adjusted FG increase of 0.0019 mmol/l (p = 0.01). In the BMI- and SES-adjusted model the slope was 0.0019 (p = 0.02). Analysis of HbA1c gave similar results.A greater proportion of African genetic ancestry is independently associated with higher FG levels in a non-diabetic community-based cohort, even accounting for other ancestry proportions, obesity and SES. The results suggest that differences between African-Americans and whites in type 2 diabetes risk may include genetically mediated differences in glucose homeostasis.
Project description:OBJECTIVES:Targeted Training in Illness Management (TTIM) focuses on enhancing care engagement for people living with serious mental illness and diabetes. This secondary analysis from a 60-week, randomized controlled trial of TTIM versus treatment as usual evaluated racial subgroup outcomes. METHOD:Demographics, clinical characteristics, and diabetes status were evaluated for those self-identifying as non-Hispanic White, African American, and Hispanic. Longitudinal response to TTIM was evaluated using a multiple domain risk index. Due to their small sample size; those identifying as Hispanic were excluded from this analysis. RESULTS:Non-Hispanic White participants had greater baseline socioeconomic advantages. Baseline risk scores, glycosylated hemoglobin (HbA1c) values, and HbA1c differences over time were similar for African American and non-Hispanic White participants. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE:African American participants living with serious mental illness and diabetes receiving TTIM did as well as non-Hispanic White participants. Inclusive approaches that feature peer support and are situated in safety-net health care settings need to be further investigated with respect to potentially impacting health disparities. (PsycINFO Database Record
Project description:To assess whether in people with poorly controlled type 2 diabetes (HbA1c>7.5%) improvement in HbA1c varies by ethnic and social group.Prospective 2-year cohort of type 2 diabetes treated in general practice.All patients with type 2 diabetes in 100 of the 101 general practices in two London boroughs. The sample consisted of an ethnically diverse group with uncontrolled type 2 diabetes aged 37-71 years in 2007 and with HbA1c recording in 2008-2009.Change from baseline HbA1c in 2007 and achievement of HbA1c control in 2008 and 2009 were estimated for each ethnic, social and treatment group using multilevel modelling.The sample consisted of 6104 people; 18% were white, 63% south Asian, 16% black African/Caribbean and 3% other ethnic groups. HbA1c was lower after 1 and 2 years in all ethnic groups but south Asian people received significantly less benefit from each diabetes treatment. After adjustment, south Asian people were found to have 0.14% less reduction in HbA1c compared to white people (95% CI 0.04% to 0.24%) and white people were 1.6 (95% CI 1.2 to 2.0) times more likely to achieve HbA1c controlled to 7.5% or less relative to south Asian people. HbA1c reduction and control in black African/Caribbean and white people did not differ significantly. There was no evidence that social deprivation influenced HbA1c reduction or control in this cohort.In all treatment groups, south Asian people with poorly controlled diabetes are less likely to achieve controlled HbA1c, with less reduction in mean HbA1c than white or black African/Caribbean people.
Project description:AIM:To evaluate the efficacy and safety of the glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide in African-American people with Type 2 diabetes. METHODS:Analyses were performed on patient-level data from individuals self-defined as African-American or non-African-American in seven phase III studies. Endpoints included change in HbA1c level, fasting plasma glucose level and body weight from baseline, proportion of patients reaching HbA1c target [< 53 mmol/mol (< 7.0%)], and incidence of hypoglycaemia and nausea. Analyses used data obtained after 26 weeks. Within-population comparisons of liraglutide were performed vs placebo for African-American and non-African-American patient groups. In addition, between-population comparisons with non-African-American patients were performed for each treatment. RESULTS:In African-American patients (n = 225), HbA1c was significantly reduced at 26 weeks with liraglutide 1.2 and 1.8 mg (-11 and -14 mmol/mol, respectively compared with placebo; P < 0.0001). There were also significant reductions in fasting plasma glucose (-2.4 and -3.1 mmol/l, respectively, compared with placebo; P < 0.0001). Statistically significant reductions in body weight were observed with 1.8 mg liraglutide (-2.1 kg compared with placebo; P = 0.0056), but not with 1.2 mg liraglutide (-0.26 kg; P = 0.7307). The P value for interaction between treatment and race was significant for body weight (P = 0.0355). The incidence of non-severe hypoglycaemia with liraglutide was low (11-15% of patients), and < 25% of patients receiving liraglutide experienced nausea. CONCLUSIONS:This meta-analysis suggests that liraglutide is well tolerated and efficacious for treatment of Type 2 diabetes in African-American patients, with an efficacy that was shown not to differ from that observed in non-African-American patients over 26 weeks.
Project description:Relative to European Americans, African Americans manifest lower levels of computed tomography-based calcified atherosclerotic plaque (CP), a measure of subclinical cardiovascular disease (CVD). Potential relationships between CP and cerebral structure are poorly defined in the African American population. We assessed associations among glycemic control, inflammation, and CP with cerebral structure on MRI and with cognitive performance in 268 high-risk African Americans with type 2 diabetes.Associations among hemoglobin A1c (HbA1c), C-reactive protein (CRP), and CP in coronary arteries, carotid arteries, and the aorta with MRI volumetric analysis (white matter volume, gray matter volume [GMV], cerebrospinal fluid volume, and white matter lesion volume) were assessed using generalized linear models adjusted for age, sex, African ancestry proportion, smoking, BMI, use of statins, HbA1c, hypertension, and prior CVD.Participants were 63.4% female with mean (SD) age of 59.8 years (9.2), diabetes duration of 14.5 years (7.6), HbA1c of 7.95% (1.9), estimated glomerular filtration rate of 86.6 mL/min/1.73 m(2) (24.6), and coronary artery CP mass score of 215 mg (502). In fully adjusted models, GMV was inversely associated with coronary artery CP (parameter estimate [?] -0.47 [SE 0.15], P = 0.002; carotid artery CP (? -1.92 [SE 0.62], P = 0.002; and aorta CP [? -0.10 [SE 0.03] P = 0.002), whereas HbA1c and CRP did not associate with cerebral volumes. Coronary artery CP also associated with poorer global cognitive function on the Montreal Cognitive Assessment.Subclinical atherosclerosis was associated with smaller GMV and poorer cognitive performance in African Americans with diabetes. Cardioprotective strategies could preserve GMV and cognitive function in high-risk African Americans with diabetes.
Project description:HIV patients on HAART are prone to metabolic abnormalities, including insulin resistance, lipodystrophy and diabetes. This study purports to investigate the relationship of ethnicity and CD4+ T cell count attained after stable highly-active antiretroviral treatment (HAART) with glucose metabolism in hyperrtriglyceridemic HIV patients without a history of diabetes.Demographic, anthropometric, clinical, endocrinologic, energy expenditure and metabolic measures were obtained in 199 multiethnic, healthy but hypertriglyceridemic HIV-infected patients [46% Hispanic, 17% African-American, 37% Non-Hispanic White (NHW)] on stable HAART without a history of diabetes. The relationship of glucose and insulin responses to ethnicity, CD4 strata (low (<300/cc) or moderate-to-high (? 300/cc)), and their interaction was determined.African-Americans had significantly greater impairment of glucose tolerance (P?<?0.05) and HbA1c levels (P?<?.001) than either Hispanics or NHWs. In multivariate models, after adjusting for confounders (age, sex, HIV/HAART duration, smoking, obesity, glucose, insulin and lipids), African-Americans and Hispanics had significantly higher HbA1c and 2-hour glucose levels than NHW's. Demonstrating a significant interaction between ethnicity and CD4 count (P?=?0.023), African Americans with CD4 <300/cc and Hispanics with CD4 ?300/cc had the most impaired glucose response following oral glucose challenge.Among hypertriglyceridemic HIV patients on HAART, African-Americans and Hispanics are at increased risk of developing diabetes. Ethnicity also interacts with CD4+ T cell count attained on stable HAART to affect post-challenge glycemic response.
Project description:Several prospective studies have evaluated the association between glycosylated hemoglobin (HbA1c) and death risk among diabetic patients. However, the results have been inconsistent.We performed a prospective study which included 13,334 men and 21,927 women with type 2 diabetes. Cox proportional hazards regression models were used to estimate the association of different levels of HbA1c with all-cause mortality.During a mean follow up of 8.7 years, 4199 (2082 men and 2117 women) patients died. The multivariable-adjusted hazard ratios (HRs) of all-cause mortality associated with different levels of HbA1c at baseline (<6.0%, 6.0-6.9% [reference], 7.0-7.9, 8.0-8.9%, 9.0-9.9%, 10.0-10.9%, and ?11.0%) were 1.06, 1.00, 1.10, 0.93, 1.26, 1.18 and 1.31 (Pnon-linear=0.008) for men, and 1.21, 1.00, 1.01, 1.08, 1.30, 1.30 and 1.74 (Pnon-linear<0.001) for women, respectively. The J-shaped association of HbA1c with all-cause mortality was confirmed among African American and white diabetic patients, patients who were more than 50 years old, never smoked or used insulin. When we used an updated mean value of HbA1c, the J-shaped association of HbA1c with the risk of all-cause mortality did not change.Our study demonstrated a J-shaped association between HbA1c and the risk of all-cause mortality among men and women with type 2 diabetes. Both high and low levels of HbA1c were associated with an increased risk of all-cause mortality.
Project description:Reaching Out and Preventing Increases in Diabetes (RAPID) is a community-based randomized trial evaluating the comparative costs and effectiveness of a group-based adaption of the DPP lifestyle intervention developed and implemented in partnership with the YMCA. RAPID enrolled adult primary care patients, with BMI 24 kg/m(2) or higher and abnormal glucose metabolism (HbA1c 5.7-6.9% or fasting plasma glucose 100-125 mg/dL). 509 participants were enrolled and randomized to one of two groups: standard clinical advice plus free-of-charge access to a group-based adaption of the DPP offered by the Y, versus standard clinical advice alone. Key outcomes for future analysis will include differences in body weight and other cardiovascular risk factors over a 24-month intervention period. At baseline, RAPID participants had a mean (SD) age of 51 ± 12.1 years, weight of 225.1 ± 56.2 lbs, and BMI of 36.9 ± 8.6 kg/m(2). 70.7% were women, 57.2% were African American, 35.4% were non-Hispanic White, and 3.2% were Hispanic. Mean HbA1c was 6.05 ± 0.34%. Additionally, 55.4% of participants had a baseline systolic blood pressure of ?130 mmHg, 33.1% had a total blood cholesterol exceeding 200mg/dL, and 74% reported a household income of <$25,000. The RAPID Study successfully randomized a large cohort of participants with a wide distribution of age, body weight, and race who are at high risk for developing type 2 diabetes.
Project description:African American men have the highest rates of prostate cancer incidence and mortality in the United States. Understanding underlying reasons for this disparity could identify preventive interventions important to African American men.To determine whether the association of obesity with prostate cancer risk differs between African American and non-Hispanic white men and whether obesity modifies the excess risk associated with African American race.Prospective study of 3398 African American and 22,673 non-Hispanic white men who participated in the Selenium and Vitamin E Cancer Prevention Trial (2001-2011) with present analyses completed in 2014.Total, low-grade (Gleason score <7), and high-grade (Gleason score ?7) prostate cancer incidence.With a median (interquartile range) follow-up of 5.6 (1.8) years, there were 270, 148, and 88 cases of total, low-, and high-grade prostate cancers among African American men and a corresponding 1453, 898, and 441 cases in non-Hispanic white men, respectively. Although not associated with risk among non-Hispanic white men, BMI was positively associated with an increase in risk among African American men (BMI, <25 vs ?35: hazard ratio [HR], 1.49 [95% CI, 0.95, 2.34]; P for trend?=?.03). Consequently, the risk associated with African American race increased from 28% (HR, 1.28 [95% CI, 0.91-1.80]) among men with BMI less than 25 to 103% (HR, 2.03 [95% CI, 1.38-2.98]) among African American men with BMI at least 35 (P for trend?=?.03). Body mass index was inversely associated with low-grade prostate cancer risk within non-Hispanic white men (BMI, <25 vs ?35: HR, 0.80 [95% CI, 0.58-1.09]; P for trend?=?.02) but positively associated with risk within African American men (BMI, <25 vs ?35: HR, 2.22 [95% CI, 1.17-4.21]; P for trend?=?.05). Body mass index was positively associated with risk of high-grade prostate cancer in both non-Hispanic white men (BMI, <25 vs ?35: HR, 1.33 [95% CI, 0.90-1.97]; P for trend?=?.01) and African American men, although the increase may be larger within African American men, albeit the racial interaction was not statistically significant (BMI, <25 vs ?35: HR, 1.81 [95% CI, 0.79-4.11]; P for trend?=?.02).Obesity is more strongly associated with increased prostate cancer risk among African American than non-Hispanic white men and reducing obesity among African American men could reduce the racial disparity in cancer incidence. Additional research is needed to elucidate the mechanisms underlying the differential effects of obesity in African American and non-Hispanic white men.