Insulin glargine improves glycaemic control in T2D patients in India

Findings from the prospective PRIMARY-INDIA study presented at ATTD-Asia 2025 show clinically meaningful improvements in glycaemic control with insulin glargine in individuals with type 2 diabetes (T2D) in primary care settings, with a consistent safety profile.

“Real-world studies evaluating insulin glargine in Indian settings are limited. Thus, there is a need for evidence on the usage patterns and clinical outcomes in this setting,” the investigators said.

This observational study was conducted across 45 primary care settings in India. A total of 415 individuals (mean age 56.41 years, 48.9 percent women, mean body weight 68.87 kg) with uncontrolled HbA_1c who were insulin-naïve were included. Of these, 269 received insulin glargine 100 U/mL (Gla-100) and 146 received insulin glargine 300 U/mL (Gla-300). Two-thirds of participants belonged to the urban population, while the remainder were from the semi-urban subgroup. Participants had received at least one oral antidiabetic drug (mean treatment duration 27.28 months). [ATTD-Asia 2025, abstract SOP025]

By month 6, the mean HbA_1c dropped from a baseline level of 10.08 percent to 7.62 percent, yielding a mean difference of 2.46 percent. The mean HbA_1c levels with Gla-100 and Gla-300 were similar (7.6 percent and 7.64 percent).

Month 6 also saw meaningful reductions in fasting plasma glucose (126.49 mg/dL) and postprandial glucose (185.70 mg/dL).

There were also meaningful glycaemic reductions with both insulin glargine doses in both the urban and semi-urban subgroups at 6 months, the researchers noted.

At 6 months, the overall change in insulin dose was 6.8 units/day (least-squares mean). The mean body weight increased from baseline with both Gla-100 (1.29 kg) and Gla-300 (0.64 kg).

Safety profile, Tx satisfaction

More adverse events (AEs) were reported with Gla-100 than with Gla-300 (n=21 and 6, respectively), but these were all mild in severity and unrelated to the study drug, the researchers noted. There were no hypoglycaemia events, serious AEs, or deaths reported.

Moreover, both physicians and patients reported treatment satisfaction with insulin glargine, with scores ranging from 4.42 to 4.54 on the 5-point Likert scale.

Basal insulin remains indispensable

In India, the burden of diabetes among adults aged 20–79 years has increased from 61.3 million in 2011 to approximately 90 million in 2024. [https://idf.org/about-diabetes/diabetes-facts-figures, accessed December 19, 2025] The American Diabetes Association recommends insulin as first-line therapy, even for individuals with uncontrolled T2D despite treatment with oral antihyperglycaemic agents or glucagon-like peptide-1 receptor agonists. [Diabetes Care 2025;48:S181-S206; Diabetes Care 2022;45:2753-2786]

“First-generation basal insulin such as Gla-100 has a well-established mode of action, efficacy, and safety profile … Second-generation basal insulin such as Gla-300 has a steady and prolonged duration of action, with a favourable safety profile and fewer hypoglycaemic events,” the researchers said.

The current results reinforce evidence reflecting the meaningful glycaemic control provided by both Gla-100 and Gla-300, with a lower risk of hypoglycaemia in individuals with T2D. [Diabetes Obes Metab 2015;17:859-867; Diabetes Care 2018;41:1672-1680; Diabetes Ther 2022;13:1187-1202; Diabetes Obes Metab 2019;21:1596-1605]

Despite the emergence of modern glucose-lowering agents with cardiometabolic benefits, basal insulin remains essential, especially for T2D patients with advanced β-cell failure, symptomatic hyperglycaemia, or contraindications to newer antidiabetic agents. [Expert Rev Endocrinol Metab 2025;20:471-474]