Trends in glycemic control in patients with insulin therapy compared with non-insulin or no drugs in type 2 diabetes in Japan: a long-term view of real-world treatment between 2002 and 2018 (JDDM 66)

Abstract

Introduction: We investigated trends in the proportion of diabetes treatment and glycemic control, which may be altered by recent advances in insulin and non-insulin drugs, in Japanese patients with type 2 diabetes.

Research design and methods: A serial cross-sectional study was performed using a multicenter large-population database from the Japan Diabetes Clinical Data Management study group. Patients with type 2 diabetes who attended clinics belonging to the study group between 2002 and 2018 were included to examine trends in glycated hemoglobin A1c (HbA1c) by treatment group using multivariable non-linear regression model.

Results: The proportion of patients with insulin only decreased from 15.0% to 3.6%, patients with insulin+non-insulin drugs increased from 8.1% to 15.1%, patients with non-insulin drugs increased from 50.8% to 67.0%, and those with no drugs decreased from 26.1% to 14.4% from 2002 to 2018, respectively. The HbA1c levels of each group, except for no drugs, continued to decrease until 2014 (unadjusted mean HbA1c (%) from 2002 to 2014: from 7.89 to 7.45 for insulin only, from 8.09 to 7.63 for insulin+non-insulin, and from 7.51 to 6.98 for non-insulin) and remained unchanged thereafter. Among insulin-treated patients, use of human insulin decreased, use of long-acting analog insulin increased, and concomitant use of non-insulin drugs increased (from 35.1% in 2002 to 80.9% in 2018), which included increased use of dipeptidyl peptidase 4 inhibitors, sodium-glucose cotransporter 2 inhibitors, and glucagon-like peptide 1 receptor agonists, and the persistently high use of metformin.

Conclusions: During the past two decades, combined use of insulin and non-insulin drugs increased and glycemic control improved and leveled off after 2014 in Japanese patients with type 2 diabetes. Further studies of the trend in association with age and factors related to metabolic syndrome are necessary to investigate strategies aiming at personalized medicine in diabetes care.

Keywords: diabetes mellitus, type 2; drug therapy; insulin.

Figure 1

Trends in HbA1c level by treatment group: insulin only, insulin+non-insulin, non-insulin, and no drugs, shown as adjusted slopes from 2002 to 2018. HbA1c, glycated hemoglobin A1c; IFCC, International Federation of Clinical Chemistry; NGSP, National Glycohemoglobin Standardization Program.

Figure 2

Proportion of HbA1c categories (from the bottom: <6.0%, 6%–<7%, 7%–<8%, 8%–<9%, and ≥9%) from 2002 to 2018: (A) insulin only, (B) insulin+non-insulin, (C) non-insulin, and (D) no drugs. HbA1c, glycated hemoglobin A1c.

Figure 3

Trends in HbA1c level by insulin regimen in insulin-treated patients using non-insulin drugs, shown as adjusted slopes from 2002 to 2018. HbA1c, glycated hemoglobin A1c; IFCC, International Federation of Clinical Chemistry; NGSP, National Glycohemoglobin Standardization Program.

Figure 4

Changes in the proportion of concomitantly used non-insulin drugs in insulin-treated patients with type 2 diabetes from 2002 to 2018. αGI, α-glucosidase inhibitors; DPP-4i, dipeptidyl peptidase 4 inhibitors; GLP-1RA, glucagon-like peptide 1 receptor agonists; Met, metformin; Pio, pioglitazone; SGLT2i, sodium-glucose cotransporter 2 inhibitors; SU, sulfonylureas.