We aimed to describe the differences between adult patients with cystic fibrosis related diabetes (CFRD) and those with normal glucose tolerance (NGT) in Tasmania from 2007 to 2012. 

We retrospectively identified patients diagnosed with cystic fibrosis (CF) under the care of the Tasmanian Adult Cystic Fibrosis Unit (TACFU). We collected point prevalence data from electronic medical records from 2007 and 2012. For both years we compared age, gender, genotype, body mass index, lung function, pseudomonas colonisation, bone mineral density (BMD), and vitamin D for patients with NGT and those with CFRD. We also compared demographics, lung function, glycosylated haemoglobin (HbA1c), insulin therapy and diabetes related complications for the cohorts with CFRD in 2007 and 2012. 

Of 44 patients with CF in 2007, 20 (45.5%) had CFRD, and in 2012, 25 (49%) out of 51 patients had CFRD. In 2007 the group with CFRD were older compared to those with NGT (30.5±2.0 vs 18.9±1.4 years, p<0.005). The cohort with CFRD also had poorer lung function (% predicted FEV1 58.2±7.2 vs 86.6±7.5%, p<0.05), and worse BMD (T-score femoral neck -1.2±0.3 vs +0.4±0.4, p<0.005). Patients with CFRD in 2012 had poorer femoral neck BMD than those with NGT (T-score -1.2±0.2 vs -0.2±0.3, p<0.002). When comparing the 2012 CFRD cohort with that of 2007, there were no significant differences found; HbA1c (mean 7.67±0.4 vs 6.96±0.4%, p=0.22), urinary ACR (mean 7.2±3.9 vs 6.3±4.0, p=0.87), but increased insulin use (mean 96 vs 72%, p=0.07) identified. No patients were recorded as having retinopathy or neuropathy.   

We found that CFRD was highly prevalent in the TACFU population. Presence of CFRD was associated with increased age, poorer lung function, and worse bone density. There were no significant differences found between the 2007 versus 2012 cohort, although an increased trend in insulin use suggests increasing awareness of its importance.