The New England Journal of Medicine JULY 26, 2012

Basal Insulin and Cardiovascular and Other Outcomes in Dysglycemia (ORIGIN)

The ORIGIN Trial Investigators

Bottom Line

In patients with cardiovascular risk factors and early dysglycemia, adding insulin glargine to target normal fasting glucose levels had a neutral effect on cardiovascular outcomes and cancer, while modestly increasing hypoglycemia and weight.

Key Findings

1. There was no significant difference in the first coprimary outcome (cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke) between insulin glargine and standard care (2.94 vs 2.85 per 100 person-years; HR 1.02, 95% CI 0.94-1.11; P=0.63).

2. There was no significant difference in the second coprimary outcome (first coprimary plus revascularization or hospitalization for heart failure) (5.52 vs 5.28 per 100 person-years; HR 1.04, 95% CI 0.97-1.11; P=0.27).

3. Insulin glargine increased the incidence of severe hypoglycemia (1.00 vs 0.31 per 100 person-years) and caused moderate weight gain (median increase of 1.6 kg vs a 0.5 kg decrease in the standard-care group).

4. Among participants without diabetes at baseline, incident diabetes was reduced by 28% in the glargine group compared to standard care (HR 0.72; 95% CI 0.58-0.91; P=0.006).

Study Design

Design

RCT

Open-Label

Sample

12,537

Patients

Duration

6.2 yr

Median

Setting

40 countries

Population Adults aged 50 years or older with cardiovascular risk factors and either impaired fasting glucose, impaired glucose tolerance, or early type 2 diabetes.

Intervention Insulin glargine (administered via daily injection) titrated to a target fasting blood glucose level of ≤95 mg/dL (5.3 mmol/L).

Comparator Standard glycemic care per local guidelines without the use of insulin glargine.

Outcome Coprimary outcomes: (1) composite of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke; and (2) the first composite plus revascularization or hospitalization for heart failure.

Study Limitations

• The open-label design for the insulin comparison could have influenced concurrent medical management or patient behaviors, though the primary endpoints were objective and robust.

• The standard care group achieved excellent glycemic control (median HbA1c 6.5%), resulting in a very narrow glycemic contrast with the glargine group (median HbA1c 6.2%), potentially obscuring any long-term cardioprotective effect of tighter control.

• The median follow-up of 6.2 years may not have been long enough to evaluate the full potential of early glucose normalization on macrovascular disease pathogenesis in a cohort with early dysglycemia.

Clinical Significance

The ORIGIN trial decisively established that exogenous insulin glargine is safe to use in terms of cardiovascular events and oncogenicity over the long term, laying to rest theoretical concerns regarding the adverse effects of insulin analogs. However, it also showed that initiating basal insulin merely to normalize fasting glucose in prediabetes or early diabetes does not provide macrovascular benefits and instead confers risks of hypoglycemia and weight gain, thus guiding clinicians to use insulin only when indicated for glycemic control rather than cardioprotection.

Historical Context

Prior to ORIGIN, there were epidemiological concerns that exogenous hyperinsulinemia might be atherogenic or promote cancer. Concurrently, a major 'glucocentric' hypothesis suggested that very early initiation of basal insulin to aggressively normalize fasting glucose could preserve beta-cell function and prevent cardiovascular disease in high-risk patients with prediabetes or early type 2 diabetes. ORIGIN was a landmark mega-trial designed to definitively assess both the long-term safety and the potential cardioprotective efficacy of insulin glargine in this population.

Guided Discussion

High-yield insights from every perspective

Med Student

Medical Student

What are the physiological mechanisms by which exogenous basal insulin like glargine contributes to weight gain and hypoglycemia, and why was cancer risk specifically monitored in this trial?

Key Response

Exogenous insulin bypasses the physiological portal-systemic gradient and lacks autoregulation based on ambient glucose, risking hypoglycemia. It acts as an anabolic hormone, promoting lipogenesis and inhibiting lipolysis, leading to weight gain. Glargine's structural modifications increase its affinity for the IGF-1 receptor in vitro, raising theoretical mitogenic concerns, which ORIGIN reassuringly showed were clinically neutral.

Resident

Given the ORIGIN trial findings, how should clinicians weigh the risks and benefits of initiating basal insulin to achieve normoglycemia in early type 2 diabetes with high cardiovascular risk compared to modern alternatives?

Key Response

ORIGIN showed that targeting normal fasting glucose with glargine safely controls glycemia without increasing cardiovascular risk, but it does not offer cardioprotection and causes weight gain and hypoglycemia. Residents should recognize that modern agents like GLP-1 RAs and SGLT2 inhibitors are now preferred as they actively reduce cardiovascular events and promote weight loss, unlike early insulin therapy.

Fellow

The ORIGIN trial reported a modestly lower incidence of newly diagnosed diabetes in the standard care group compared to the insulin group after washout. How should an endocrinologist interpret this: does early basal insulin alter the natural history of beta-cell decline, or is it an artifact?

Key Response

This addresses the debate over whether early insulin provides beta-cell rest or merely masks underlying disease. Although the trial showed a slight delay in incident diabetes, the effect faded during the washout period (seen in the ORIGIN-GRACE follow-up), suggesting exogenous insulin temporarily masks hyperglycemia rather than durably arresting the progressive beta-cell failure characteristic of dysglycemia.

Attending

How does the ORIGIN trial's failure to demonstrate a cardiovascular benefit from aggressive fasting glucose normalization fundamentally shift the paradigm of type 2 diabetes management away from a purely glucocentric model?

Key Response

For decades, dogma suggested that lowering glucose intrinsically reduced macrovascular events. ORIGIN, alongside ACCORD and ADVANCE, proved that simply lowering glucose with insulin does not reduce cardiovascular risk and introduces harms like hypoglycemia. This was pivotal in shifting the paradigm toward using disease-modifying therapies (e.g., SGLT2 inhibitors) that reduce cardiovascular risk independently of glycemic efficacy.

Scholarly Review

Critical appraisal through the lens of expert reviewers and guideline development

PhD

The ORIGIN trial utilized a 2x2 factorial design to evaluate both insulin glargine and omega-3 fatty acids. What are the key methodological assumptions required for interpreting main effects in this design, and how might an interaction between the interventions threaten statistical validity?

Key Response

A 2x2 factorial design assumes the absence of a significant biological or statistical interaction between the treatments, allowing the trial to be powered for both independently. If insulin and omega-3s had synergistic or antagonistic effects on cardiovascular outcomes, the marginal analysis of the main effects would be confounded, necessitating a much larger sample size to analyze the four individual groups accurately.

Journal Editor

Because the insulin glargine intervention in ORIGIN was open-label while the omega-3 arm was blinded, what specific biases are introduced regarding secondary outcomes and event ascertainment, and how do trialists mitigate these threats?

Key Response

An open-label design introduces performance bias, where patients or clinicians might manage other cardiovascular risk factors differently, and reporting bias for self-reported adverse events like hypoglycemia. Reviewers must scrutinize whether the blinded endpoint adjudication committee (using a PROBE design) was rigorously shielded from unmasking clues to ensure the primary composite cardiovascular outcome remained unbiased.

Guideline Committee

Based on the ORIGIN trial demonstrating neutral cardiovascular outcomes but increased weight and hypoglycemia, how should current clinical practice guidelines grade the recommendation for early basal insulin to prevent cardiovascular events in prediabetes or early type 2 diabetes?

Key Response

The ORIGIN data provide strong Level A evidence against using insulin glargine to prevent cardiovascular events in early dysglycemia. Consequently, guidelines from the ADA and EASD do not recommend basal insulin for cardiovascular risk reduction or diabetes prevention, instead strongly recommending lifestyle modifications, metformin for prevention, and organ-protective agents like GLP-1 RAs or SGLT2is for cardiovascular risk reduction in established disease.

Clinical Landscape

Noteworthy Related Trials

2008

ACCORD Trial

n = 10,251 · NEJM

Tested

Intensive glycemic control (target HbA1c < 6.0%)

Population

T2DM patients with high CV risk

Comparator

Standard glycemic control (target HbA1c 7.0-7.9%)

Endpoint

Nonfatal MI, nonfatal stroke, or CV death

Key result: Intensive therapy was halted early due to increased all-cause mortality, with no significant reduction in major CV events.

2008

ADVANCE Trial

n = 11,140 · NEJM

Tested

Intensive glucose control (gliclazide-based, target HbA1c <= 6.5%)

Population

T2DM patients with high CV risk

Comparator

Standard glucose control

Endpoint

Composite of major macrovascular or microvascular events

Key result: Intensive control reduced the incidence of combined major macro- and microvascular events, primarily driven by a reduction in nephropathy, but did not significantly affect macrovascular events or mortality.

2017

DEVOTE Trial

n = 7,637 · NEJM

Tested

Insulin degludec

Population

T2DM patients at high risk for cardiovascular events

Comparator

Insulin glargine U100

Endpoint

Time to first occurrence of a 3-point MACE

Key result: Insulin degludec was non-inferior to insulin glargine for major cardiovascular events and resulted in a significantly lower rate of severe hypoglycemia.

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