Background: Type 1 diabetes mellitus (T1DM) and coeliac disease (CD) have been independently associated with reduced bone mineral density (BMD) and increased fracture risk in adults1,2. Whilst poorer glycaemic control and increased microvascular complications3,4 have been described in patients with concomitant CD and T1DM (T1+CD), the literature examining bone health and its determinants in this cohort is limited.
Objective: To evaluate associations of T1+CD with glycaemic control, microvascular disease and fractures, compared with T1DM alone.
Methods: We conducted a retrospective cross-sectional study of young adults with T1DM, who attended outpatient diabetes clinics at a tertiary referral centre between August 2016 to February 2017. Clinical information, radiological and biochemistry results were extracted from medical records. Patients with comorbid chronic kidney disease, glucocorticoid use, malignancy, hypogonadism and untreated hyperthyroidism were excluded.
Results: 346 patients with T1DM only (median age 22 years) and 49 patients with T1+CD (median age 24 years) were included. Median age, gender distribution, BMI, glycated haemoglobin, total daily insulin dose, presence of microvascular complications and serum vitamin D levels were similar between groups. Subjects with T1+CD had a longer median duration of diabetes (14.0 vs 11.0 years; p=0.01) and median duration of CD was 8 years. The adjusted risk of hypoglycaemia (>2 per week) was significantly greater for T1+CD (55.1% vs. 27.7%, OR 3.28, p=0.001, 95%CI 1.61–6.69). Vitamin D sufficiency was associated with a reduced risk of hypoglycaemia (OR 0.48, 95%CI 0.29-0.80; p=0.005), but not fractures. Despite patients with T1+CD having a higher adjusted risk of fracture compared with T1DM alone(12.2% vs. 3.5%; p<0.05, OR 3.50, 95%CI 1.01–12.12), BMD was measured in only 6.1%.
Conclusions: Young adults with T1+CD have significantly more hypoglycaemia and fractures. Recurrent hypoglycaemia may contribute to greater risks for falls and fracture. Longitudinal studies are needed to determine the long-term impact of CD on bone health and glyco-metabolic control in adults with T1DM.