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OBJECTIVE-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. RESEARCH DESIGN AND METHODS-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. RESULTS-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 ofHbA1c 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. CONCLUSIONS-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. [ABSTRACT FROM AUTHOR]

OBJECTIVE--Blood pressure control can reduce the risk of coronary heart disease (CHD) among diabetic patients; however, it is not known whether the lowest risk of CHD is among diabetic patients with the lowest blood pressure level. RESEARCH DESIGN AND METHODS--We performed a prospective cohort study (2000-2009) on diabetic patients including 17,536 African Americans and 12,618 whites. Cox proportional hazards regression models were used to estimate the association of blood pressure with CHD risk. RESULTS--During a mean follow-up of 6.0 years, 7,260 CHD incident cases were identified. The multivariable-adjusted hazard ratios of CHD associated with different levels of systolic/diastolic blood pressure at baseline (<110/65, 110-119/65-69, 120-129/70-80, and 130-139/ 80-90 mmHg [reference group]; 140-159/90-100; and ≥160/100 mmHg) were 1.73, 1.16, 1.04, 1.00, 1.06, and 1.11 (P trend <0.001), respectively, for African American diabetic patients, and 1.60, 1.27, 1.08, 1.00, 0.95, and 0.99 (P trend <0.001) for white diabetic patients, respectively. A U-shaped association of isolated systolic and diastolic blood pressure at baseline as well as blood pressure during follow-up with CHD risk was observed among both African American and white diabetic patients (all P trend <0.001). The U-shaped association was present in the younger age-group (30-49 years), and this U-shaped association changed to an inverse association in the older age-group (≥60 years). CONCLUSIONS--Our study suggests that there is a U-shaped or inverse association between d blood pressure and the risk of CHD, and aggressive blood pressure control (blood pressure <120/70 mmHg) is associated with an increased risk of CHD among both African American and white patients with diabetes. [ABSTRACT FROM AUTHOR]