ORBIT: Elucidating Patient Characteristics and Six-month Basal Insulin Dose for Achieving HbA1C<7%

Background

The efficacy of basal insulin (BI) for achieving adequate glycemic control in patients with type-2 diabetes mellitus (T2DM) is already well established. Appropriate insulin dosage, and timely and adequate dose titration are crucial to achieve target glycemic control while keeping the risk of hypoglycemia minimum. Stepwise insulin titration to reach glycemic target is a lengthy process especially in patients displaying therapeutic inertia. Predicting insulin dose based on patients’ characteristics may allow efficient dose titration in real clinical practice. 

Aim

To explore the six-month dose of BI used in insulin-na?ve T2DM patients achieving glycated hemoglobin (HbA1c) target (<7%) and to determine the patient characteristics that influence the six-month dose of BI in a real-world setting in China.

Patient Profile

Inclusion Criteria

• Adult T2DM patients (age 18-80 years) with inadequately controlled hyperglycemia and treated with oral antidiabetic drugs (OADs) (n=12309)

Main Exclusion Criteria

• History of any type of insulin treatment in past two years

Methods

Study Design

• Post-hoc analysis of the ORBIT (Observational Registry for Basal Insulin Treatment) trial
• ORBIT is a prospective multicenter observational registry in China

Treatment

• Three types of BI namely; neutral protamine Hagedorn (NPH), glargine and detemir were available during the study

Follow-up Visits

• At three and six months

Outcomes

• Six-month dose of BI required for effective glycemic control in T2DM patients (n=12309)
• Clinical characteristics of patients who achieved the HbA1C target (<7%) after six months (n=5191)

Results

• Mean age of patients achieving HbA1c target in BI alone group was 55.30 years, and that in BI plus other insulin subgroups was 54.87 years.
• Three-quarters of the patients in the BI alone group (75.68%) and almost half of the patients (49.01%) in the BI plus other insulin group were on insulin glargine
• Usage of BI plus other insulin regimen was greater in patients with higher baseline HbA1c or FPG and longer duration of diabetes or OAD treatment
• At six months, patients initiated on BI achieved adequate glycemic control (HbA1c<7%) at dose of 0.20 U/kg/day. The six-month doses of different BI types required for adequate HbA1c control in both the study groups were as mentioned in table 1.

• Patients in the BI plus other insulin subgroups required a higher dose of BI to achieve the combined clinical goal of HbA1c <7% and FPG <126 mg/dL as compared with FPG <126 mg/dL alone without hypoglycemia (Table 2).

• The mean dose of initial BI of 0.18 U/kg/day was increased by only 0.03 U/kg/day at six months reflecting insufficient dose titration of insulin.
• Patients with higher baseline HbA1c or FPG, longer duration of diabetes or OAD treatment and more types of OAD were more likely to use the BI plus other insulin regimen as against BI alone.
• A higher proportion of patients in the BI alone group rather than BI plus other insulin subgroup achieved HbA1c target.
• Lower baseline HbA1c or FPG, shorter duration of diabetes or OAD treatment and smaller number of OAD types predicted the glucose control in both the study groups.
• Age, BMI, duration of diabetes, duration of OAD treatment, number of OADs at baseline, and BI type after six months independently and significantly contributed towards the six-month BI dose.

Conclusions

• A six-month dose of 0.20 U/kg/day of BI resulted in effective glycemic control in T2DM patients in real clinical practice in China.
• High body mass index, high FPG, young age, longer duration of diabetes or OAD treatment, a greater number of OADs at baseline, and allocation to glargine and detemir independently and significantly predicted high dose of BI at six months.

J Diabetes.  Apr 23, 2020 (Published Ahead of Print); doi: 10.1111/1753-0407.13046