Jardiance vs Lantus: Real-World Evidence Comparison

How Each Drug Lowers Blood Sugar

Empagliflozin and insulin glargine reduce glucose through opposite ends of the metabolic axis. Empagliflozin blocks renal SGLT2 transporters to dump roughly 70 to 90 g of glucose per day into the urine, independent of insulin secretion. Insulin glargine supplies exogenous basal insulin to suppress hepatic glucose output and drive peripheral glucose uptake for 24 hours.

Empagliflozin: Insulin-Independent Glycosuria

Because Jardiance does not require functioning beta cells, it works even in patients with significant insulin deficiency, as long as the kidneys are filtering adequately. The FDA-approved label requires an eGFR of at least 30 mL/min/1.73 m² for glycemic benefit, though the drug is approved for heart failure and CKD at lower eGFR thresholds. A 2014 phase III trial (N=986) published in Diabetes Care showed empagliflozin 25 mg reduced HbA1c by 0.77% versus placebo at 24 weeks when added to metformin (Häring et al., Diabetes Care 2014).

Real-world pharmacy claims data from the CVD-REAL Nordic study (N=22,589 new SGLT2i users matched to comparators) confirmed the HbA1c signal and showed a 53% lower rate of hospitalization for heart failure (Birkeland et al., Lancet Diabetes Endocrinol 2017).

Insulin Glargine: Titrated Basal Coverage

Lantus provides a peakless 24-hour insulin profile. Its glycemic potency scales with dose, which is why patients with very high HbA1c (above 10%) typically achieve larger absolute reductions than they would with any oral or injectable non-insulin agent. The EDITION I trial (N=807 insulin-experienced type 2 patients) showed glargine 300 U/mL (Toujeo, a next-generation formulation) reduced HbA1c by 0.83% at 6 months, though glargine 100 U/mL (Lantus) carries the longest real-world dataset (Riddle et al., Diabetes Care 2014).

The ORIGIN trial (N=12,537) tested whether early basal insulin initiation would reduce cardiovascular events in people with dysglycemia. It did not. The primary MACE outcome HR was 1.02 (95% CI 0.87 to 1.19, P<0.001 for non-inferiority), establishing that insulin glargine is cardiovascularly safe but not cardioprotective (Gerstein et al., NEJM 2012).

Landmark Trial Evidence

The most reliable tier of evidence comes from cardiovascular outcome trials (CVOTs) and large randomized studies.

EMPA-REG OUTCOME (2015): Cardiovascular Mortality Signal

EMPA-REG OUTCOME enrolled 7,020 adults with type 2 diabetes and established cardiovascular disease, randomized to empagliflozin 10 mg, empagliflozin 25 mg, or placebo on top of standard care. At a median follow-up of 3.1 years, empagliflozin reduced the primary MACE outcome by 14% (HR 0.86, 95% CI 0.74 to 0.99, P<0.001 for non-inferiority; P=0.04 for superiority). Cardiovascular death specifically fell by 38% (HR 0.62, 95% CI 0.49 to 0.77). Hospitalization for heart failure dropped 35% (Zinman et al., NEJM 2015).

These numbers were so striking that the FDA updated the Jardiance label to include a cardiovascular mortality indication in 2016, a label expansion insulin glargine has never received. The American Diabetes Association 2024 Standards of Care now recommend SGLT2 inhibitors with proven CV benefit as the preferred add-on for patients with atherosclerotic CVD, heart failure, or CKD, independent of HbA1c (ADA Standards of Care 2024).

ORIGIN (2012): Insulin Glargine's Cardiovascular Neutrality

ORIGIN remains the definitive cardiovascular safety dataset for Lantus. Over a median 6.2 years, glargine did not increase or decrease MACE. The trial also documented a median weight gain of 1.6 kg in the glargine group versus a 0.5 kg loss in the standard-care group. Confirmed hypoglycemia occurred in 28.1% of glargine-treated patients versus 6.6% of controls (Gerstein et al., NEJM 2012).

A secondary ORIGIN analysis published in Diabetes Care found no increase in cancer incidence with glargine, resolving an earlier concern about the IGF-1 receptor (Gerstein et al., Diabetes Care 2013).

Real-World Evidence: What Claims Data and Registries Show

CVD-REAL Studies

The CVD-REAL program analyzed de-identified administrative claims across six countries (N over 300,000 matched patients). Patients initiating any SGLT2 inhibitor (predominantly empagliflozin in Europe) showed a 39% lower all-cause death rate and a 36% lower heart-failure hospitalization rate than matched initiators of other glucose-lowering drugs, which included insulin (Kosiborod et al., Circulation 2017).

The CVD-REAL 2 extension (N=235,064 across 6 countries outside Europe) replicated the heart-failure finding (OR 0.64, 95% CI 0.50 to 0.82) and added a significant reduction in all-cause mortality (Kosiborod et al., Lancet Diabetes Endocrinol 2018).

Empa-Reg in Routine Practice: The EMPRISE Study

EMPRISE is an ongoing FDA-mandated real-world study comparing empagliflozin to sitagliptin in US commercial and Medicare claims. The first interim report (N=16,443 matched pairs) confirmed a 50% lower rate of hospitalization for heart failure with empagliflozin (HR 0.50, 95% CI 0.28 to 0.91) with no increase in lower-extremity amputations or diabetic ketoacidosis beyond background rates (Patorno et al., Circulation 2019).

Insulin Glargine Real-World Effectiveness

Real-world titration of Lantus often underperforms clinical trials. A 2019 analysis of 14,684 US patients newly started on basal insulin found only 38.5% achieved HbA1c <7% within 12 months, despite insulin being the most potent glycemic agent available. Clinical inertia, fear of hypoglycemia, and suboptimal dose titration drove this gap (Blonde et al., Diabetes Obes Metab 2019).

Safety Profiles Compared

Hypoglycemia

This is the single biggest practical difference between the two drugs. Empagliflozin carries essentially no intrinsic hypoglycemia risk, glucose excretion slows automatically as plasma glucose falls below roughly 180 mg/dL, providing a physiologic safety floor. The EMPA-REG OUTCOME data showed confirmed hypoglycemia in 8.3% of the empagliflozin group versus 7.9% of placebo, with excess events attributable to concomitant sulfonylurea or insulin use (Zinman et al., NEJM 2015).

Insulin glargine carries an absolute hypoglycemia risk that scales with dose, renal function, irregular meals, and exercise. In ORIGIN, nocturnal confirmed hypoglycemia affected 10.0% of glargine patients annually versus 4.2% in the control group (Gerstein et al., NEJM 2012). Patients over age 65 are at particular risk for severe episodes requiring assistance, which the ADA flags as a reason to use agents with lower hypoglycemia risk in older adults (ADA Standards of Care 2024, Section 13).

Diabetic Ketoacidosis

Empagliflozin carries a small but real risk of euglycemic DKA (eDKA), especially in patients with unrecognized type 1 diabetes, prolonged fasting, or significant insulin deficiency. The FDA issued a safety communication on SGLT2i-associated DKA in 2015 (FDA Drug Safety Communication 2015). Real-world incidence in type 2 diabetes is low, approximately 0.16 to 0.76 events per 1,000 patient-years in large claims datasets, but the condition is potentially life-threatening and frequently missed because glucose may be only mildly elevated (Blau et al., Diabetes Care 2021).

Insulin glargine does not cause DKA on its own; if anything, adequate basal insulin is protective against ketosis in patients with insulin deficiency.

Genitourinary Infections

SGLT2 inhibitors increase urinary glucose concentration, raising the risk of genital mycotic infections. In clinical trials, approximately 10% of women and 3 to 4% of men on empagliflozin developed a genital mycotic infection versus 2 to 3% and 0.5 to 1% on placebo, respectively (Zinman et al., NEJM 2015). Urinary tract infection rates were not meaningfully different from placebo in most large trials.

Insulin injections carry no infection risk beyond rare injection-site reactions or lipohypertrophy with repeated needle use at the same site.

Body Weight and Blood Pressure

Empagliflozin produces consistent 2 to 3 kg weight loss and reduces systolic blood pressure by 3 to 4 mmHg in clinical trials, benefits with downstream cardiovascular implications. Insulin glargine typically causes 1 to 4 kg weight gain proportional to dose and glucose-lowering achieved, and does not lower blood pressure.

Kidney Protection: Empagliflozin's Expanding Indication

The EMPA-KIDNEY trial (N=6,609) enrolled adults with CKD (eGFR 20 to 45 or eGFR 45 to 90 with albuminuria) and showed empagliflozin 10 mg reduced the composite of kidney disease progression or CV death by 28% (HR 0.72, 95% CI 0.64 to 0.82, P<0.001) over a median 2 years (Herrington et al., NEJM 2023). The FDA approved empagliflozin for CKD in March 2024 based largely on this data.

Insulin glargine is safe in CKD but requires dose reduction as eGFR falls because of reduced insulin clearance and increased hypoglycemia risk. No trial has shown a renoprotective signal for basal insulin beyond glycemic control.

Glycemic Effectiveness: When Lantus Wins

For patients with HbA1c above 10% or with symptomatic hyperglycemia (polyuria, polydipsia, weight loss), insulin glargine provides faster and deeper glucose reduction than any oral or once-weekly injectable agent. The UKPDS study showed that intensive glycemic control with any agent reduces microvascular complications, a benefit that requires actually reaching target glucose levels (UKPDS Group, Lancet 1998).

Empagliflozin's HbA1c-lowering ceiling of approximately 0.8 to 1.0% means it cannot rescue severely uncontrolled patients without concurrent dose increases of other agents. A practical clinical decision framework:

Use empagliflozin (Jardiance) preferentially when:

• Established atherosclerotic CVD, heart failure with reduced or preserved ejection fraction, or CKD is present
• HbA1c is 7.0 to 9.0% and the patient is already on metformin
• Weight loss and blood pressure reduction are treatment goals
• Hypoglycemia avoidance is a priority (older adults, people who drive or operate machinery)

Use insulin glargine (Lantus) preferentially when:

• HbA1c exceeds 10% or symptomatic hyperglycemia is present
• Beta-cell failure is significant and oral agents have failed or are contraindicated
• eGFR is below 30 mL/min/1.73 m² (below threshold for Jardiance glycemic benefit)
• Pregnancy or pre-conception planning is a factor (insulin remains the standard)
• Cost is prohibitive for newer agents (biosimilar glargine is available under $30/vial through some pharmacy programs)

Should You Switch from Jardiance to Lantus?

Switching from Jardiance to Lantus is sometimes appropriate and sometimes a step backward. The clinical trigger that most often prompts this switch is rising HbA1c despite empagliflozin, reflecting progressive beta-cell failure, the natural history of type 2 diabetes in many patients. When that happens, adding basal insulin to empagliflozin (rather than replacing it) is the combination most supported by evidence and current ADA/EASD guidelines (Davies et al., Diabetes Care 2022).

When Stopping Empagliflozin Is Necessary Before Starting Insulin

If a patient is admitted to hospital, facing surgery, or undergoing prolonged fasting, empagliflozin should be held 3 to 4 days before the procedure because of eDKA risk under perioperative metabolic stress. The patient will need bridging glucose management during that period, which may include insulin glargine initiation. The ADA's 2024 perioperative guidance specifies holding SGLT2 inhibitors at least 3 days before surgery (ADA Standards 2024, Section 16).

Combination Therapy: Adding Lantus to Jardiance

Multiple trials support running both drugs simultaneously. A 2015 randomized trial (N=1,162) published in Diabetes Care showed adding empagliflozin to basal insulin reduced HbA1c by an additional 0.57% versus placebo while cutting insulin dose by 0.5 units/kg/day and reducing hypoglycemia frequency by 14% (Rosenstock et al., Diabetes Care 2015). Patients also lost 1.8 kg versus gaining 0.3 kg on insulin-plus-placebo.

This combination has real-world durability. A German registry analysis of 2,407 patients on basal insulin plus an SGLT2 inhibitor showed mean HbA1c fell from 8.4% to 7.6% over 12 months, with no significant increase in DKA events compared with insulin monotherapy (Fadini et al., Nutr Metab Cardiovasc Dis 2020).

Cost and Access

Branded Jardiance (empagliflozin) has a list price around $600, $650/month in the US. Eli Lilly's authorized generic and Boehringer Ingelheim patient programs can reduce out-of-pocket costs significantly for commercially insured patients. As of 2025, no FDA-approved generic empagliflozin tablet is available.

Lantus list price is approximately $300, $400/vial, but biosimilar insulin glargine products (Basaglar, Semglee, Rezvoglar) are available at 15 to 30% lower cost. Semglee was designated an interchangeable biosimilar by the FDA in 2021 (FDA Biosimilar Approval 2021), meaning pharmacists can substitute it without a new prescription in states that permit automatic substitution.

For uninsured patients, Civica Rx and Mark Cuban's Cost Plus Drugs list biosimilar glargine products at under $50/vial, making Lantus-class therapy far more accessible than branded empagliflozin.

Guideline Positions in 2024 to 2025

The ADA 2024 Standards of Care place SGLT2 inhibitors with proven cardiovascular benefit (empagliflozin, canagliflozin, dapagliflozin) as preferred second-line agents for patients with established CVD, heart failure, or CKD, a recommendation independent of HbA1c level (ADA Standards 2024, Section 9). The guidance reads: "For patients with type 2 diabetes and established CVD, multiple ASCVD risk factors, heart failure, or CKD, a GLP-1 receptor agonist or SGLT2 inhibitor with demonstrated CVD benefit is recommended."

Insulin glargine is recommended when glucose targets cannot be met with non-insulin agents and in patients with severe hyperglycemia at diagnosis. The ADA's stepwise algorithm does not place basal insulin versus SGLT2 inhibitors in direct competition, they occupy different rungs on the glycemic management ladder (ADA Standards 2024, Section 9).

The European Association for the Study of Diabetes (EASD) 2022 consensus report echoes this positioning. Its lead author Dr. Melanie Davies stated that the goal is "to treat the whole patient, not just the glucose number," with cardiorenal risk driving drug selection before HbA1c targets in high-risk individuals (Davies et al., Diabetes Care 2022).

Practical Prescribing Summary

| Feature | Jardiance (Empagliflozin) | Lantus (Insulin Glargine) | |---|---|---| | Route | Oral once daily | Subcutaneous injection once daily | | HbA1c reduction | 0.5 to 0.8% | 1.5 to 2.5% | | CV mortality | Reduced 38% (EMPA-REG) | Neutral (ORIGIN) | | Weight | 2 to 3 kg loss | 1 to 4 kg gain | | Hypoglycemia | Low intrinsic risk | Dose-dependent risk | | eGFR cutoff for glycemia | <30 mL/min/1.73 m² loses efficacy | Reduce dose; use with caution | | CKD protection | Yes (EMPA-KIDNEY, HR 0.72) | No independent evidence | | DKA risk | Rare euglycemic DKA | None if used correctly | | Monthly US list price | ~$630 | ~$350 (biosimilar ~$50, $80) |