Endocrine

, Volume 41, Issue 3, pp 518–525

The relation of serum 25-hydroxyvitamin-D levels with severity of obstructive sleep apnea and glucose metabolism abnormalities

Authors

    • Department of Endocrinology and MetabolismAnkara Diskapi Yildirim Beyazit Training and Research Hospital
  • E. Cakal
    • Department of Endocrinology and MetabolismAnkara Diskapi Yildirim Beyazit Training and Research Hospital
  • M. Sahin
    • Department of Endocrinology and MetabolismAnkara Diskapi Yildirim Beyazit Training and Research Hospital
  • E. Cakir Ozkaya
    • Department of Endocrinology and MetabolismAnkara Diskapi Yildirim Beyazit Training and Research Hospital
  • H. Firat
    • Division of Sleep Disorders, Department of Chest MedicineAnkara Diskapi Yildirim Beyazit Training and Research Hospital
  • T. Delibasi
    • Department of Endocrinology and MetabolismAnkara Diskapi Yildirim Beyazit Training and Research Hospital
Original Article

DOI: 10.1007/s12020-012-9595-1

Cite this article as:
Bozkurt, N.C., Cakal, E., Sahin, M. et al. Endocrine (2012) 41: 518. doi:10.1007/s12020-012-9595-1

Abstract

Obstructive sleep apnea (OSA) and 25-hydroxyvitamin-D3 (25-OH-D) deficiency are two separate disorders associating with obesity, inflammation, and impaired glucose metabolism. We aimed to investigate the vitamin D status of OSA patients regarding to potential links between lower vitamin D levels and abnormal glucose metabolism, which is one of the main adverse outcomes of OSA. Study group is composed of 190 non-diabetic subjects who were suspected of having OSA. Subjects undergone polysomnography and were grouped due to apnea−hypopnea indices (AHI) as controls (AHI < 5, n = 47), mild OSA (5 ≤ AHI < 15, n = 46), moderate OSA (15 ≤ AHI < 30, n = 47), and severe OSA (AHI ≥ 30, n = 50). Serum 25-OH-D, HbA1c, insulin levels were measured and 75-g oral glucose tolerance test was performed. Serum 25-OH-D level (ng/ml) of OSA patients were lower than control subjects (17.4 ± 6.9 vs. 19.9 ± 7.8), and decrement was parallel to severity of OSA; as 18.2 ± 6.4 (5 ≤ AHI < 15), 17.5 ± 7.4 (15 ≤ AHI < 30), and 16.3 ± 6.9 (AHI > 30), respectively (P = 0.097, r = −0.13). However, severe female OSA patients had significantly lower 25-OH-D levels (11.55 ng/ml), while control males had the highest mean value (21.7 ng/ml) (P < 0.001). Frequency of insulin resistance (IR) was 48%, prediabetes 41%, diabetes 16% in OSA patients. Mean 25-OH-D level of insulin resistant subjects (HOMA-IR ≥ 2.7, n = 77, AHI = 35.5) was lower than non-insulin resistant subjects (HOMA-IR < 2.7, n = 113, AHI = 19.8) as 16.18 ± 7.81 versus 19.2 ± 6.6, respectively (P = 0.004). 25-OH-D level of 91 non-diabetic subjects (n = 91, AHI = 19.7) was 19.5 ± 7.4, prediabetics (n = 75, AHI = 28.7) was 17.45 ± 6.9, and diabetics (n = 24, AHI = 46.3) was 13.8 ± 5.3 (P = 0.02). We showed that subjects with more severe OSA indices (AHI ≥ 15) tended to present lower vitamin D levels correlated to increased prevalence of IR, prediabetes, and diabetes. Vitamin D deficiency may play a role and/or worsen OSA’s adverse outcomes on glucose metabolism. OSA patients may be considered for supplementation treatment which was shown to ameliorate abnormal glucose metabolism and inflammation.

Keywords

Vitamin DObstructive sleep apneaPrediabetesInsulin resistance

Copyright information

© Springer Science+Business Media, LLC 2012