Endocrine Abstracts

Introduction: The autoimmune process is currently the most common cause ofthe primary adrenal insufficiency cases in developed countries. The complexity of this process consists of genetic, immunological and environmental factors. It has been proven that vitamin D (VD) inhibits the production of inflammatory cytokines and can modulate immune-regulatory mechanisms.

Purpose: The aim of our study was to evaluate the prevalence of VD insufficiencyin patients with Addison’s disease (AD), as well as to evaluate associations between vitamin D levels and the various clinical and laboratory parameters of the disease.

Methods: We retrospectively analysed medical records of 31 patients adults with the diagnosis of autoimmune Addison’s disease and with measured serum VD levels. We analysed correlations between serum VD and various laboratory parameters as well as AD patients symptoms collected from structured medical interviews.

Results: 90.3% of the subjects had inadequate VD level – 54.8% below 20 ng/ml and 35.5% between 20 to 30 ng/ml, respectively. Furthermore, 19.3% of patients have been found to be severely deficient in VD (< 10 ng/ml). There were no significant associations of serum VD level with sex, age and smoking status. There was a significant difference in VD level between patients previously supplementing and non-supplementing VD (23.91 ± 3.6 vs 15.29 ± 1.77 ng/ml, P = 0.02). In 70% of patients who supplemented 2000 IU vitamin D prior to the admission to the hospital, supplementation did not provide adequate vitamin D level. Among various laboratory variables, only serum calcium levels significantly correlated with VD status (r = 0.53, P = 0.006). We observed that mean level of serum VD was significantly lower in patients with severe fatigue (15.17 ± 8.41 vs 26.83 ± 12.29 ng/ml, P = 0.011) and limited exercise capacity (12.38 ± 6.9 vs 21.63 ± 10.87 ng/ml, P = 0.016).No associations have been found between serum VD and other clinical features (fainting, loss of appetite, weight loss, nausea, vomiting, diarrhoea, musculoskeletal pain, abdominal pain).

Conclusion: This study demonstrates a high incidence of vitamin D deficiency and a significant correlation between low levels of VD and severe fatigue as well as limited exercise capacityin AD patients. Further studies are needed to clarify if impaired vitamin D level is a causal factor in the pathogenesis of AD andto assess if VD supplementation improves the quality of life of the AD patients.