Association of Glycemia, Lipids, and Blood Pressure With Cognitive Performance in People With Type 2 Diabetes in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE)

OBJECTIVE Type 2 diabetes is a risk factor for cognitive impairment. We examined the relation of glycemia, lipids, blood pressure (BP), hypertension history, and statin use with cognition in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE). RESEARCH DESIGN AND METHODS Cross-sectional analyses from GRADE at baseline examined the association of glycemia (hemoglobin A1c [HbA1c]), LDL, systolic BP (SBP) and diastolic BP (DBP), hypertension history, and statin use with cognition assessed by the Spanish English Verbal Learning Test, letter and animal fluency tests, and Digit Symbol Substitution Test (DSST). RESULTS Among 5,047 GRADE participants, 5,018 (99.4%) completed cognitive assessments. Their mean age was 56.7 ± 10.0 years, and 36.4% were women. Mean diabetes duration was 4.0 ± 2.7 years. HbA1c was not related to cognition. Higher LDL was related to modestly worse DSST scores, whereas statin use was related to modestly better DSST scores. SBP between 120 and 139 mmHg and DBP between 80 and 89 mmHg were related to modestly better DSST scores. Hypertension history was not related to cognition. CONCLUSIONS In people with type 2 diabetes of a mean duration of &amp;lt;5 years, lower LDL and statin use were related to modestly better executive cognitive function. SBP levels in the range of 120–139 mmHg and DBP levels in the range of 80–89 mmHg, but not lower levels, were related to modestly better executive function. These differences may not be clinically significant. </jats:sec

Baseline Characteristics of Randomized Participants in the Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study (GRADE)

OBJECTIVE GRADE (Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study) is a 36-center unmasked, parallel treatment group, randomized controlled trial evaluating four diabetes medications added to metformin in people with type 2 diabetes (T2DM). We report baseline characteristics and compare GRADE participants to a National Health and Nutrition Examination Survey (NHANES) cohort. RESEARCH DESIGN AND METHODS Participants were age ≥30 years at the time of diagnosis, with duration of T2DM &amp;lt;10 years, HbA1c 6.8–8.5% (51–69 mmol/mol), prescribed metformin monotherapy, and randomized to glimepiride, sitagliptin, liraglutide, or insulin glargine. RESULTS At baseline, GRADE’s 5,047 randomized participants were 57.2 ± 10.0 years of age, 63.6% male, with racial/ethnic breakdown of 65.7% white, 19.8% African American, 3.6% Asian, 2.7% Native American, 7.6% other or unknown, and 18.4% Hispanic/Latino. Duration of diabetes was 4.2 ± 2.8 years, with mean HbA1c of 7.5 ± 0.5% (58 ± 5.3 mmol/mol), BMI of 34.3 ± 6.8 kg/m2, and metformin dose of 1,944 ± 204 mg/day. Among the cohort, 67% reported a history of hypertension, 72% a history of hyperlipidemia, and 6.5% a history of heart attack or stroke. Applying GRADE inclusion criteria to NHANES indicates enrollment of a representative cohort with T2DM on metformin monotherapy (NHANES cohort average age, 57.9 years; mean HbA1c, 7.4% [57 mmol/mol]; BMI, 33.2 kg/m2; duration, 4.2 ± 2.5 years; and 7.2% with a history of cardiovascular disease). CONCLUSIONS The GRADE cohort represents patients with T2DM treated with metformin requiring a second diabetes medication. GRADE will inform decisions about the clinical effectiveness of the addition of four classes of diabetes medications to metformin. </jats:sec