Endocrine Abstracts (2019) 63 P579 | DOI: 10.1530/endoabs.63.P579

Oral glucose tolerance test is recommended for screening for new-onset glucose metabolism impairment during chronic low-dose glucocorticoid therapy

Karolina Nowak1, Monika Rdzanek1, Agnieszka Łebek-Szatańska1, Anna Nowakowska-Płaza2, Agnieszka Zielińska2, Katarzyna Romanowska-Próchnicka3,4, Wojciech Zgliczyński1 & Lucyna Papierska1

1Department of Endocrinology, Centre of Postgraduate Medical Education, Warsaw, Poland; 2Department of Rheumatology, Eleonora Reicher National Institute of Geriatrics, Rheumatology and Rehabilitation, Warsaw, Poland; 3Department of Systemic Connective Tissue Diseases, Eleonora Reicher National Institute of Geriatrics, Rheumatology and Rehabilitation, Warsaw, Poland; 4Department of General and Experimental Pathology, 2nd Faculty of Medicine, Medical University of Warsaw, Warsaw, Poland.

Introduction: Patients with connective tissue diseases are susceptible to the occurrence of side-effects of long term treatment with low-dose glucocorticoids as these medications often cannot be withdrawn due to exacerbation of the underlying disease. The new-onset of glucose metabolism impairment is not considered common in patients treated with low-dose glucocorticoids and the risk factors are thought to be the same as in general population: increasing age, obesity or family history of diabetes. As glucocorticoids cause mainly postprandial hyperglycemia determining fasting plasma glucose to screen patients for diabetes (which is recommended by International Diabetes Federation and American Diabetes Association) can lead to false negative results. Since long-lasting hyperglycemia is a condition that can lead to higher cardiovascular risk it is important to properly diagnose and treat this condition.

Objectives: The aim of the study was to evaluate the prevalence and risk factors of steroid-induced glucose metabolism impairment in patients chronically treated with glucocorticoids.

Material and methods: Oral glucose tolerance test (OGTT) was performed in 107 patients diagnosed with connective tissue disease and treated with ≤ 7.5 mg of prednisone (or metyloprednisolone equivalent) for more than 3 months. All participants underwent clinical and biochemical evaluation: age, sex, time of treatment, current and cumulative dose of steroid, family history of diabetes, BMI, HbA1c, HOMA-IR, fasting insulin concentration. None of the patients had previous history of pre-diabetes/diabetes. Logistic regression analysis was used to evaluate the association between the presence of glucose metabolism impairment (dependent variable) and analyzed risk factors.

Results: Participants were divided into two groups based on results of OGTT. 75 patients had normal OGTT and 32 patients (29.9%) were diagnosed with glucocorticoid-induced glucose metabolism impairment. 18 patients (16.8%) had impaired glucose tolerance and 1 (0.9%) was diagnosed with diabetes without coincide impaired fasting glucose thus the disturbances would not be diagnosed without OGTT. No statistical significance was found for current or cumulative dose of glucocorticoids, time of treatment, waist circumference, family history of diabetes, BMI, HOMA-IR or fasting insulin concentration as the risk factors for developing new-onset glucocorticoid-induced glucose metabolism impairment. Only age (1 year increase) was found to be a significant risk factor (OR 1.05 95%CI1.01–1.08, p=0.02).

Conclusions: 17.7% of patients could be correctly diagnosed with pre-diabetes or diabetes based exclusively on OGTT. This test is the only standardized tool that is able to properly reveal the steroid-induced glucose metabolism impairment. It should be performed in every patients chronically treated with glucocorticoids even without other risk factors of diabetes.