Adrenal Insufficiency: Investigating Prevalence and Healthcare Utilization Using Administrative Data

Context

Adrenal insufficiency (AI) is an uncommon, life-threatening disorder requiring lifelong treatment with steroid therapy and special attention to prevent adrenal crisis. Little is known about the prevalence of AI in Canada or healthcare utilization rates by these patients.

Objective

We aimed to assess the prevalence and healthcare burden of AI in Alberta, Canada.

Methods

This study used a population-based, retrospective administrative health data approach to identify patients with a diagnosis of AI over a 5-year period and evaluated emergency and outpatient healthcare utilization rates, steroid dispense records, and visit reasons.

Results

The period prevalence of AI was 839 per million adults. Patients made an average of 2.3 and 17.8 visits per year in the emergency department and outpatient settings, respectively. This was 3 to 4 times as frequent as the average Albertan, and only 5% were coded as visits for AI. The majority of patients were dispensed glucocorticoid medications only.

Conclusion

The prevalence of AI in Alberta is higher than published data in other locations. The frequency of visits suggests a significant healthcare burden and emphasizes the need for a strong understanding of this condition across all clinical settings. Our most concerning finding is that 94.3% of visits were not labeled with AI, even though many of the top presenting complaints were consistent with adrenal crisis. Several data limitations were discovered that suggest improvements in the standardization of data submission and coding can expand the yield of future studies using this method.

Splice variant-dependent regulation of beta-cell sodium-calcium exchange by acyl-coenzyme As

The sodium-calcium exchanger isoform 1 (NCX1) is intimately involved in the regulation of calcium (Ca(2+)) homeostasis in many tissues including excitation-secretion coupling in pancreatic beta-cells. Our group has previously found that intracellular long-chain acyl-coenzyme As (acyl CoAs) are potent regulators of the cardiac NCX1.1 splice variant. Despite this, little is known about the biophysical properties of beta-cell NCX1 splice variants and the effects of intracellular modulators on their important physiological function in health and disease. Here, we show that the forward-mode activity of beta-cell NCX1 splice variants is differentially modulated by acyl-CoAs and is dependent both upon the intrinsic biophysical properties of the particular NCX1 splice variant as well as the side chain length and degree of saturation of the acyl-CoA moiety. Notably, saturated long-chain acyl-CoAs increased both peak and total NCX1 activity, whereas polyunsaturated long-chain acyl-CoAs did not show this effect. Furthermore, we have identified the exon within the alternative splicing region that bestows sensitivity to acyl-CoAs. We conclude that the physiologically relevant forward-mode activity of NCX1 splice variants expressed in the pancreatic beta-cell are sensitive to acyl-CoAs of different saturation and alterations in intracellular acyl-CoA levels may ultimately lead to defects in Ca(2+)-mediated exocytosis and insulin secretion.