Diabetes treatment has advanced because several diabetes organizations united to recommend a “time in range” target of 70-180 mg/dL for glucose levels derived from continuous glucose monitoring (CGM).

Published in 2019, the consensus statement advised a goal of spending more than 70% of time in the 70-180 mg/dL range for most people with type 1 diabetes (T1D) and type 2 diabetes (T2D), with modifications for certain subgroups. The upper limit of 180 mg/dL exceeds the typical 140 mg/dL post-meal threshold for most people who don’t have diabetes, but was chosen for practicality and to minimize hypoglycemia risk.

However, newer devices and medications have enabled people with diabetes who use insulin to achieve completely “normal” glucose levels — ie, 70-140 mg/dL — for longer periods without excess hypoglycemia risk. So should this “time in tight range (TiTR),” also called “time in normal range (TiNR)” or “time in normal glycemia (TiNG),” become the new therapeutic target? 

On March 22, 2025, two endocrinologists debated this question at the Advanced Technologies & Treatments for Diabetes (ATTD) 2025. Anders L. Carlson, MD, medical director of the International Diabetes Center (IDC), Minneapolis, took the positive side, while Jeremy Pettus, MD, assistant professor of medicine at the University of California San Diego, who lives with T1D himself, argued that it’s too soon.

Carlson began by noting that TiTR is achievable with current automated insulin delivery (AID) system technology. In one study published in Diabetes Care of 13,461 real-world users with T1D of the Minimed 780G hybrid closed-loop AID system, TiTR increased from 37.2% at baseline to 57.0% after settings had been optimized, while the time spent between 140 mg/dL and 180 mg/dL didn’t change significantly, about 25% at both time points.

“What that tells us is that [TiTR] behaves differently than overall time in range,” Carlson noted.

The amount of time spent in hypoglycemia didn’t increase with 780G use, dropping slightly from 0.6% to 0.4%. “If you look back where we came from…we’ve been very worried, understandably so, about an individual’s risk for hypoglycemia. In the current studies using AID, we just haven’t seen a clinically significant increase in the time spent in hypoglycemic range,” Carlson noted.

Indeed, another study of 72 adults with T1D who had frequently experienced hypoglycemia in the past showed that those using AID experienced less time below range (TBR) than did those using separate sensor/pump devices.

“I think we can safely say that some of our technologies do increase [TiTR] without increasing [TBR]. That’s not to say there aren’t individuals where that would be a concern, or that hypoglycemia is just an afterthought with these systems…We still need to be mindful of it. But I do think we’re evolving to a point where we can achieve those physiologic levels,” Carlson said.

Early data suggest correlations between TiTR and reductions in long-term diabetes-related complications. One example is a longitudinal study of 71 adults with T1D in whom each 5% decrease in TiTR was associated with a 28% increase in the odds of incident retinopathy. And in a cross sectional study of 808 adults with T1D, each 10% increase in TiTR was associated with lower incidences of retinopathy, nephropathy, peripheral neuropathy, and stroke.

And in a prospective study of 6061 people with T2D, lower TiTR was associated with a significantly higher rate of all-cause mortality at a median 11 years’ follow-up, among both those with A1c above and below 7.0%.

Carlson added that over the past decade there has been a major evolution of drugs including glucagon-like peptide 1 agonists and sodium-glucose cotransporter 2 inhibitors that help normalize glucose levels, along with an “explosion” in commercially available AID systems. A 2024 study of CGM use in 3840 people with T2D not taking insulin suggested at 1-year 17% improved TIR and TiTR, leading the American Diabetes Association’s Standard of Care to advise consideration of CGM in that population.

He acknowledged that there is a potential for increased stress and burden when the goal is TiTR, particularly among those with T1D and their caregivers. There is limited data on this, although one qualitative study of 30 young adults with T1D and their caregivers showed a mixed bag: Some found a TiTR goal burdensome and feared it would increase hypoglycemia, whereas others felt it would help improve their management.

Carlson concluded by noting that more research will be needed on subgroups, as well the development of new tools and CGM visualization standards, and a consensus on the official name of the 70-140 goal. “Our understanding continues to evolve on how to set most appropriately CGM-based glycemic management targets…to assist with shared decision-making and to optimize and personalize glycemic management.”

He added, “I think there will be patients where practicality wins the day. But I do think it’s time we start thinking about what it would be like to restore someone to a physiologic glucose range.”

Pettus said TiTR is a “useful metric and it might motivate patients,” but “it should not be the primary treatment goal.” To merit changing guidelines, TiTR would have to reduce long-term and/or acute complications, improve quality of life, and also be practicable and obtainable, he argued, adding “Establishing TiTR as a primary treatment goal accomplishes none of these.” 

In the landmark Diabetes Control and Complications Trial (DCCT), in T1D, the risk for retinopathy and other microvascular complications declined as A1c levels were brought down from an average of 9% to about 7% with intensive insulin therapy compared with participants receiving standard of care. But at levels below 7%, the benefits became less pronounced and the hypoglycemia risk increased.

Of course, the DCCT took place prior to the availability of diabetes technology. But, a study published in February 2025 demonstrated that when the DCCT results were converted to CGM metrics, the TIR, TiTR, and A1c in the intensive treatment group were 63%, 42%, and 7.3%, respectively, compared with 37%, 21%, and 9.1% in the standard of care group. The adjusted hazard ratio for retinopathy for every 0.5 SD change in TiTR was 1.66, virtually identical to those of TIR, 1.63; and A1c, 1.54. Results were similar for microalbuminuria.

The authors concluded, “This analysis does not support a switch from TIR to TiTR as the preferred outcome metric for clinical trials or glycemic management.” 

Pettus said that this isn’t surprising because TIR and TiTR are highly correlated, as was shown in another recent paper of 1901 young adults with T1D. “If you increase your TIR you’re also going to increase your TiTR, so…honestly, we’re already doing that.” 

And he pointed out that although newer technology certainly reduces the hypoglycemia risk, it hasn’t eliminated it. In a study of more than 2000 adults with T1D, rates of self-reported severe hypoglycemia in the past year among those using CGM with multiple daily injections, CGM with an insulin pump, or an AID were 23.0%, 19.0%, and 16.6%, respectively. Moreover, there was no improvement in hypoglycemic unawareness.

“Technology helps…but it doesn’t solve the problem…If you tell people to tighten their target to 70-140, the only possible outcome is an increase in hypoglycemia. And for what benefit, I don’t know,” Pettus said. 

Regarding quality of life, 80% of people with diabetes feel “constrained” by their condition, based on the recently-published “Diabetes Constraints Scale.” It consists of six items assessing time spent thinking about diabetes more than desired, feeling pressure to eat snacks to avoid low blood sugar, feeling restricted around exercising and limited in eating, feeling spontaneous, and feeling “free to live my life the way I want.” 

“Will changing our metrics from TIR to TiTR make people feel better about any of these? Absolutely not,” Pettus emphasized.

And as for practicability/obtainability, Pettus pointed to his own real-world study of claims data published in 2019, showing that TiTR values calculated from A1c levels of individuals aged 20 years, 40 years, and 65 years were just 15% (A1c, 9.4%), 28% (A1c, 8.3%), and 38% (A1c, 7.8%). Thus, establishing TiTR as the goal “would be alienating even more the haves and have nots of where we are and where we need to be,” he said.

Pettus concluded with a slide of a quote from a commentary he and a colleague published in 2024 in Diabetes Care: “The final question we are left with is this: Is TiTR an interesting new metric or is it the new standard? For us, it’s too early to make TiTR a new recommendation for the masses. It may come with time, but not yet.” 

Pettus reported consulting fees from Diasome, Eli Lilly, MannKind, Novo Nordisk, and Sanofi. Carlson had no personal financial disclosures. His employer, the nonprofit IDC/HealthPartners Institute, contracts for his services and he receives no personal income from the following activities: Participation in clinical research, member of a scientific board, and/or served as a consultant for Abbott Diabetes Care, Dexcom, Eli Lilly, Insulet, Mannkind, Medtronic, Novo Nordisk, Sanofi, Luna, and Zealand.

Miriam E. Tucker is a freelance journalist based in the Washington DC area. She is a regular contributor to Medscape, with other work appearing in the Washington Post, NPR’s Shots blog, and Diatribe. She is on X (formerly Twitter) @MiriamETucker and BlueSky @miriametucker.bsky.social.