Background: Obesity and subsequent insulin resistance is becoming more frequent among type 1 diabetes (T1DM) patients, leading to double diabetes and potentially increasing vascular risk. Studies in double diabetes remain limited and this population is not fully characterised.
Aims: To investigate the prevalence of overweight and obese T1DM patients and analyse the effects of increasing weight on cardiovascular risk and microvascular outcomes in this cohort.
Methods: Single centre observational study of 1132 T1DM patients aged 1940. Diagnosis of microvascular disease and cardiovascular risk (lipid profile and blood pressure) were identified using patient notes. Data were analysed using regression models with adjustments for HbA1c, age, gender and duration of diabetes.
Results: Body mass index (BMI) was used to classify individuals into normal weight (NW, BMI 2024.9 kg/m2), overweight (OW, BMI 2529.9 kg/m2) and obese (OB, BMI>30 kg/m2), with a prevalence of 43%, 38% and 17%, respectively.
LDL-cholesterol was increased in OW and OB compared with NW (2.6±0.78, 2.7±0.83 and 2.4± 0.72 mmol/L, respectively; P<0.01) with an inverse picture for HDL-cholesterol, 1.5±0.56, 1.5±0.54 and 1.7±0.48 mmol/L, respectively; P<0.01). Odds ratio for hypertension was 1.91 (CI: 1.582.24, P<0.001) in OW and OB groups compared with NW. Significantly increased rates of retinopathy were observed in OW and OB patients compared with NW, but this difference was lost after adjustment for confounders.
Conclusion: Overweight and obese T1DM patients have pro-atherogenic lipid profile and higher blood pressure compared with normal weight patients, independent of HbA1c. These data suggest that overweight and obese T1DM patients may be at increased risk of micro- and macrovascular complications and future interventional outcome studies are warranted.