Economic implications of weight change in patients with type 2 diabetes mellitus.

OBJECTIVE

Assess the impact of weight change on costs, resource use, and treatment discontinuation among metformin-treated patients with type 2 diabetes mellitus (T2DM).

STUDY DESIGN

Observational, retrospective cohort.

METHODS

Adults with T2DM who were pre existing metformin-treated patients were included. Insulin users were excluded. Administrative data from January 1, 2000, to December 31, 2010, were linked to clinical data, and patients were placed into cohorts based on relative change in body weight. Three cohorts were created: weight loss (decrease >3%), and weight neutral (change ≤3%), weight gain (increase > 3%). Inter-cohort differences in resource utilization, costs (2010 US$), and treatment discontinuation were evaluated using statistical models that adjusted for baseline characteristics.

RESULTS

A total of 2110 patients (weight loss = 967; weight neutral = 970; weight gain = 173) were included; mean age was 59.6 years, 52.2% were women, 64.1% were Caucasian, and average baseline weight was 98.7 kg. The weight-loss cohort incurred significantly lower costs per year compared with the weight-neutral cohort, driven mainly by lower medical costs from reduced utilization. Weight reduction was associated with approximately $2200 and approximately $440 lower annual all-cause and T2DM-specific costs (P < .05), respectively. Patients who lost weight were 21% less likely to discontinue therapy. Weight gain was associated with a significant increase in all-cause costs of $3400 per year compared with the weight-neutral cohort; however, differences in T2DM-specific costs and discontinuation rates did not reach significance levels.

CONCLUSIONS

Weight loss (> 3%) among patients with T2DM was associated with decreased costs and lower rates of treatment discontinuation. Hence weight-focused treatment approaches can help reduce the economic burden for patients with T2DM.