Article Text
Abstract
Introduction There is an association between Coeliac disease (CD) and Type 1 diabetes however the effect of CD on important diabetes related outcomes is unknown. We previously identified 14 new cases of CD from a prospective study of patients with Type 1 diabetes (n=1000). We aimed to assess the effect of newly diagnosed CD on glycaemic control, lipid profile, renal function, retinopathy and peripheral neural function.
Methods The CDDM patients (n=14) were age, sex, gender, weight and duration matched in a 2:1 ratio with patients having Type 1 diabetes alone (controls from the initial 1000 cohort). HbA1c, total cholesterol, HDL cholesterol, cholesterol:HDL ratio, triglycerides, eGFR and urinary albumin/creatinine ratio (aCR) were measured. Retinopathy was assessed through the annual eye screening programme. Peripheral nerve function was assessed by electrophysiological testing of 2 sensory and 2 motor nerves. Baseline values were recorded for both cases and controls and measurements repeated at 1 year in both groups. The CDDM group had been started on a gluten free diet.
Results At baseline, there were no differences in age, duration, weight or average insulin dose (all p>0.1). Those with CDDM had higher HbA1c (8.2% vs 7.5%, p=0.05), lower total cholesterol (4.1 vs 4.9, p=0.014) and lower HDL cholesterol (1.1 vs 1.6, p=0.017) compared to controls. More patients with CDDM had abnormal urinary aCR (45.5% vs 4.8%, p=0.009) and higher nephropathy stage (p=0.009) compared to controls. There was no difference in the prevalence of retinopathy overall but higher grades of retinal damage were more common in CDDM (58.3% vs 25%, p=0.02). The prevalence of peripheral neuropathy was 42.9% in CDDM and 15% in controls (p=0.11). At 1 year follow-up, HbA1c levels and lipid profile were not significantly different between cases and controls. There were no differences in renal profile between cases and controls however eGFR dropped in those with CDDM (95.5 to 84.0, p=0.003) reflecting two patients having renal deterioration (one started dialysis). There were no differences in the prevalence of retinopathy from baseline but one patient with CDDM underwent retinal laser therapy. There were also no changes in the prevalence of neuropathy.
Conclusion CD has an adverse effect on glycaemic control, HDL cholesterol, renal function and retinal status but not peripheral neuropathy. Following a GFD, glycaemic control and lipid profile improved but renal and retinal changes were still significantly worse compared to controls. This is the first study to observe these microvascular effects. Further research is required to determine whether earlier detection and treatment of CD limits these effects.