Effects of basal insulin glargine and omega-3 fatty acid on cognitive decline and probable cognitive impairment in people with dysglycaemia: a substudy of the ORIGIN trial.

BACKGROUND: Diabetes and non-diabetic dysglycaemia are risk factors for accelerated cognitive decline. In this planned substudy of the Outcome Reduction with Initial Glargine Intervention (ORIGIN) trial, we assessed whether normalising glucose with insulin glargine or administering omega-3 fatty acids in this population may slow this process or affect the development of cognitive impairment. METHODS: The ORIGIN trial recruited participants older than 50 years with dysglycaemia who were taking either no or one oral glucose-lowering drug, who had additional risk factors for cardiovascular events, whose HbA1c was less than 9%, and who were not taking insulin. Participants were recruited from 573 sites in 40 countries. Participants were randomly assigned to either titrated basal insulin glargine targeting a fasting plasma glucose concentration of 5.3 mmol/L or lower or standard care and to either omega-3 fatty acid (1 g) or placebo by a factorial design. Outcome adjudicators and data analysts were masked to treatment allocation. Cognitive function was assessed by the Mini-Mental State Examination (MMS) and Digit Symbol Substitution (DSS). The effect of insulin glargine or omega-3 fatty * acid on cognitive function over time, the annualised change in test scores, and the development of probable cognitive impairment were measured. All analyses were restricted to those participants who had a cognitive measurement at both baseline and at least one follow-up visit. The ORIGIN trial is registered with ClinicalTrials.gov, NCT00069784. FINDINGS: Participants were randomly assigned between Sept 1, 2003, and Dec 15, 2005. MMSE and DSS were assessed in 11,685 and 3392 ORIGIN participants (mean age 63.4 years [SD 7.7]), who were followed up for a median of 6.2 years (IQR 5.8-6.7). There was no difference in the rate of change of cognitive test scores between the insulin glargine and standard care groups (for the MMSE 0.0046, 95% CI -0.0132 to 0.0224, p=0.39; and for the DSS -0.0362, -0.2180 to 0.1455, p=0.34) or between the omega-3 fatty acid and placebo groups (for the MMSE 0.0013, 95% CI -0.0165 to 0.0191, p=0.21; and for the DSS -0.0605, -0.2422 to 0.1212, p=0.72). Similarly, the incidence of probable cognitive impairment did not differ between the insulin glargine and standard care groups (p=0.065) or the omega-3 fatty acid and placebo groups (p=0.070). In a subgroup analysis, allocation to insulin glargine versus standard care seemed to reduce the decline in the MMSE (but not the DSS) in participants with dysglycaemia but without evidence of diabetes (pinteraction=0.024). INTERPRETATION: In this relatively young cohort of people with dysglycaemia, insulin mediated normoglycaemia and omega-3 fatty acid for over 6 years had a neutral effect on the rate of cognitive decline and on incident cognitive impairment. Future studies should assess the effect of these interventions in an older cohort or the effect of other glucometabolic interventions on cognitive decline. FUNDING: Sanofi.

Effect of insulin glargine and n-3FA on carotid intima-media thickness in people with dysglycemia at high risk for cardiovascular events: the glucose reduction and atherosclerosis continuing evaluation study (ORIGIN-GRACE).

OBJECTIVE: To evaluate the effects of insulin glargine and n-3 polyunsaturated fatty acid (n-3FA) supplements on carotid intima-media thickness (CIMT). RESEARCH DESIGN AND METHODS: We enrolled 1,184 people with cardiovascular (CV) disease and/or CV risk factors plus impaired fasting glucose, impaired glucose tolerance, or early type 2 diabetes in a randomized multicenter 2 × 2 factorial design trial. Participants received open-label insulin glargine (targeting fasting glucose levels ≤ 5.3 mmol/L [95 mg/dL]) or standard glycemic care and double-blind therapy with a 1-g capsule of n-3FA or placebo. The primary trial outcome was the annualized rate of change in maximum CIMT for the common carotid, bifurcation, and internal carotid artery segments. Secondary outcomes were the annualized rates of change in maximum CIMT for the common carotid and the common carotid plus bifurcation, respectively. Baseline followed by annual ultrasounds were obtained during a median follow-up of 4.9 years. RESULTS: Compared with standard care, insulin glargine reduced the primary CIMT outcome, but the difference was not statistically significant (difference = 0.0030 ± 0.0021 mm/year; P = 0.145) and significantly reduced the secondary CIMT outcomes (differences of 0.0033 ± 0.0017 mm/year [P = 0.049] and 0.0045 ± 0.0021 mm/year [P = 0.032], respectively). There were no differences in the primary and secondary outcomes between the n-3FA supplement and placebo groups. CONCLUSIONS: In people with CV disease and/or CV risk factors and dysglycemia, insulin glargine used to target normoglycemia modestly reduced CIMT progression, whereas daily supplementation with n-3FA had no effect on CIMT progression.