Patients’ insulin needs depend on their age, BMI

Age and body mass index (BMI) affect the basal insulin needs of type 1 diabetes (T1D) patients, a new study has found.

Sixty-seven inpatients with T1D participated in the study. While hospitalized, they received diabetic-friendly meals and underwent basal insulin adjustments to maintain stable blood glucose levels. Bolus insulin doses before meals were likewise adjusted to manage blood glucose. The total daily insulin dose (TDD) and the percent of total daily basal insulin (TBD) to TDD (%TBD/TDD) were calculated.

Assessment of 3-day insulin requirements revealed that the TDD was 33.0 units, while TBD was 7.0 units. The total bolus dose needed was 26.0 units. The resulting %TBD/TDD was 24.1±9.8 percent.

The researchers then performed Pearson’s and Spearman’s rank correlation analyses to determine factors linked to %TBD/TDD. They found that BMI was directly and significantly associated with %TBD/TDD (r, 0.489; p<0.001), while age at examination (r, –0.270; p=0.027) and at diabetes onset (r, –0.370; p=0.002) showed inverse correlations.

Multiple regression analysis subsequently confirmed the significant and independent roles of BMI (β, 0.340; p=0.004) and age at examination (β, –0.288; p=0.012) in affecting %TBD/TDD. Diabetes duration and serum levels of C-peptide had no such impacts.

Study limitations included its retrospective and observational design, small study size, single-centre data source, and limited generalizability.

“It is important to set the %TBD/TDD on an individual basis while considering patient background characteristics, such as the BMI and age,” the researchers said.