Weight Change in Patients with Type 2 Diabetes Starting Basal Insulin Therapy: Correlates and Impact on Outcomes

Abstract

Background: An increase in body weight is a commonly perceived effect of insulin therapy for type 2 diabetes mellitus, and this may serve as a barrier to insulin initiation and usage. Objective: To investigate the baseline clinical and demographic factors associated with weight gain during insulin glargine therapy, and the implications of weight change on clinical outcomes. Methods: This was a retrospective analysis of patient-level data from phase 3 or 4 randomized controlled, treat-to-target (fasting plasma glucose [FPG] ≤ 100 mg/dL) trials evaluating basal insulin glargine for ≥ 24 weeks. The Pearson correlation coefficient and Cochran-Armitage trend statistic were used to calculate the existence of a trend between absolute and relative weight change, and relative glycated hemoglobin (HbA_1c) change from baseline; likelihood of achieving target HbA_1c < 7.0%; change from baseline FPG; insulin dose requirements; incidence of hypoglycemia; and adverse events. Results: Eleven studies were included, encompassing a total of 2140 patients. Patients starting insulin glargine treatment gained a mean ± standard deviation 1.8 ± 3.7 kg (4.0 ± 8.2 lb). Most patients had limited weight change (± 2.5 kg or 5.5 lb). Younger age, higher baseline HbA_1c, and higher baseline FPG were predictive of greater weight gain (P < 0.0001). Those who gained more weight experienced the largest decrease from baseline in HbA_1c and FPG. More weight gain was associated with higher insulin dose requirements, an increased risk of experiencing either symptomatic or glucose-confirmed (< 70 mg/dL) hypoglycemia, and more adverse events. Older patients (> 65 years) were less likely to gain weight or to experience glucose-confirmed hypoglycemia, but more likely to experience severe hypoglycemia. Conclusions: In this retrospective analysis of patient-level data, most patients had a stable weight (defined as ± 2.5 kg) after 24 weeks of insulin glargine, and weight gain varied with patient demographics. Therefore, insulin glargine can be used in these patient groups with type 2 diabetes without expectation of significant weight gain.

Keywords:

• body weight
• insulin
• type 2 diabetes mellitus
• glycated hemoglobin