For decades, type 2 diabetes management has followed a familiar pathway: begin with lifestyle modification and metformin, then add medications sequentially if glycemic control remains inadequate.

But evidence from randomized trials is prompting renewed debate about whether the traditional “start low, go slow” approach should give way to earlier dual therapy in some patients. For example, the VERIFY trial, published in 2019 in The Lancet, found that starting patients with newly diagnosed type 2 diabetes on a combination of vildagliptin and metformin significantly prolonged glycemic durability compared with metformin alone.

Other studies have reported similar findings. The EDICT randomized trialpublished in 2015 in Diabetes Obesity and Metabolism, found that patients treated with initial combination therapy using metformin, pioglitazone, and exenatide achieved greater and more durable reductions in A1c than patients treated with sequential add-on therapy.

Guidelines from both the American Diabetes Association (ADA) and the American Association of Clinical Endocrinology already recommend considering combination therapy earlier in the disease course for some patients. The ADA suggests dual therapy when A1c is roughly 1.5%-2% above a patient’s glycemic target, typically below 7%.

Therapeutic Inertia Remains a Challenge

Therapeutic inertia — the failure to intensify therapy when patients do not meet glycemic targets — remains a persistent challenge in diabetes care. A large observational study in Diabetes Care found that many patients with type 2 diabetes remained above recommended A1c thresholds for years before treatment was intensified. Such delays can expose patients to prolonged hyperglycemia and an increased risk for diabetes-related complications.

In everyday clinical practice, therapeutic inertia can arise from several factors, including clinical uncertainty, competing demands during visits, and insurance barriers.

Joseph Barrera, MD, an endocrinologist with Providence Health System in Rancho Mission Viejo, California, said he frequently sees patients referred to endocrinology after spending extended periods on metformin alone despite persistently elevated A1c levels.

“Sometimes they’ve been on metformin alone for quite a while and their A1c is above target,” Barrera said. “You look at it and think they probably should have added something sooner or been referred earlier.”

Which Patients May Benefit Most?

While not every patient requires immediate combination therapy, certain populations may benefit more from earlier intensification.

Patients presenting with high baseline A1c levels are among the most obvious candidates.

“If someone’s A1c is pushing 9%, the chances of getting them below target with metformin alone are pretty low,” Barrera said.

Jason Ling, MD, an endocrinologist in Fullerton, California, also with the Providence Health System, said early dual therapy can also improve long-term glycemic durability.

“Patients are able to attain their A1c goals faster with combination therapy,” Ling said. “Patients who undergo stepwise escalation often reach treatment failure more often.”

He noted that combination therapy may be more effective because different drug classes target distinct physiologic mechanisms involved in type 2 diabetes.

“Using multiple treatments targets different organ defects in the ‘ominous octet’ compared with single treatments alone,” Ling said, adding that earlier therapy may help preserve beta-cell function. The “ominous octet” refers to interconnected organ-driven pathologic defects responsible for the development of hyperglycemia in type 2 diabetes.

Certain cardiometabolic conditions may also strengthen the case for initiating combination therapy earlier.

“Patients with atherosclerotic cardiovascular disease will benefit from combination therapy with SGLT2 inhibitors and GLP-1 receptor agonists,” Ling said. “There are cardiorenal benefits with these drugs beyond just glucose lowering.”

Ling also said that patients with chronic kidney disease or heart failure may also benefit from therapies such as SGLT2 inhibitors.

Weight, Hypoglycemia, and Newer Therapies

Newer drug classes have shifted the balance of risks and benefits associated with early combination therapy. The doctors said that GLP-1 receptor agonists and GLP-1/glucose-dependent insulinotropic polypeptide therapies can promote weight loss and carry a lower risk for hypoglycemia than older therapies such as sulfonylureas or insulin.

“These therapies are better in lowering weight and have less hypoglycemia compared with other treatments,” Ling said. “They also have cardiovascular benefits and favorable kidney and liver outcomes.”

Patient awareness may also be influencing prescribing patterns. Because GLP-1 receptor agonists have received widespread public attention for their weight-loss effects, patients are increasingly asking clinicians about them.

“Patients often come in asking about GLP-1 medications,” Barrera said. “That sometimes becomes the push that leads to adding a second drug earlier.”

Barrera said that wins right off the bat may also reinforce patient engagement.

“When people see early success, whether it’s improved glucose control or weight loss, they often become more motivated to stick with lifestyle changes.”

Barriers to Earlier Combination Therapy

Ling said that despite patient interest in early combination therapy, real-world barriers remain.

“Cost and coverage greatly influence doing a combination approach,” Ling said.

Some clinicians may still prefer a stepwise approach to better evaluate the benefits and side effects of individual medications, Ling said. He said that in the short term, adverse effects can also occur, including gastrointestinal symptoms with GLP-1 receptor agonists and genital infections associated with SGLT2 inhibitors, although both drug classes generally have favorable safety profiles and low risk for hypoglycemia.

A Shift Toward Earlier Intervention

As evidence continues to accumulate, many experts believe diabetes care is gradually shifting toward a more proactive strategy that targets multiple metabolic pathways earlier in the disease course.

“You could almost make the case that more patients than not should be on combination therapy earlier than how we’ve been using it so far,” Barrera said.

Both doctors said that primary care providers should make treatment decisions on an individualized basis, guided by shared decision-making. Clinicians should discuss effectiveness, potential side effects, and cost considerations with patients before selecting a treatment strategy. Some medication combinations should also be avoided, such as GLP-1 receptor agonists with DPP-4 inhibitors or overlapping insulin secretagogues.

For patients with very high glucose level — such as blood glucose above 300 mg/dL or A1c above 10% — insulin therapy may still be appropriate, Ling said.

Ultimately, experts say the goal is not necessarily to abandon stepwise escalation entirely, but to reconsider when earlier combination therapy may provide patients with faster, more durable glycemic control.

No reported disclosures.