Influence of obesity on blood glucose control using continuous glucose monitoring data among patients with type 1 diabetes

Introduction

The global increase in the prevalence rates of overweight or obesity has also affected patients with type 1 diabetes (T1D), where this disease had traditionally been associated with a lean phenotype. On the other hand, the effect of obesity on new glycemic control metrics obtained from continuous glucose monitoring (CGM) in T1D is poorly understood. We wanted to assess whether there is any relationship between BMI (body mass index) and the different CGM metrics or HbA1c.

Methods

Two hundred and twenty-five patients with T1D (47.1% ♀, mean age 42.9 ± 14.7 years) with a CGM for a minimum of 6 months were analysed by downloading their CGM and collecting clinical and anthropometric variables.

Results

35.1% (79/225) of the T1D patients had overweight and 17.3% (39/225) lived with obesity, while the remaining 47.6% had a normal weight. A negative correlation was found between GMI (glucose management indicator) and BMI (−0.2; p = 0.008) and HbA1c (−0.2; p = 0.01). In contrast, a positive correlation was observed between the total dose of insulin and the BMI (0.3; p < 0.0001). No significant correlations were found between BMI and other CGM metrics.

Conclusions

Overweight or obesity do not imply worse glycemic control in patients with T1D or less use of CGM. Possibly, and in order to achieve a good glycemic control, more units of insulin are necessary in these patients which, in turn, makes weight control more difficult.