Relationship between circadian blood pressure variability and function of islet α and β cell in type 2 diabetes with dyssomnia

Aims: To investigate the relationship between circadian blood pressure (BP) variability and function of islet alpha and beta cell in type 2 diabetes (T2D) with dyssomnia. Methods: Patients with T2D were divided into dyssomnia group and non-dyssomnia group by PSQI. OGTT, insulin and glucagon-releasing test were tested, and ambulatory BP was monitored for 24 hours to compare two groups with alpha and beta cell, circadian BP variability and fasting and post-meal BP variability. The correlation and regression analysis were made between PSQI and other indicators. Results: In dyssomnia group, (1) Glucagon, glucagon/insulin ratio and AUC(G) were significantly higher (P < 0.05). (2) Fasting insulin (13.32 +/- 4.54 mIU/L), AUC(I) (8.51 +/- 0.54) and HOMA-IR (4.62 +/- 1.11) were high (P < 0.05). But ISI (-4.27 +/- 0.77) was low (P < 0.05). (3) Mean 24-hour and nighttime SBP and DBP, as well as their standard deviations and coefficients of variation, were all higher in the dyssomnia group (P < 0.05). Multiple stepwise regression analysis showed that PSQI score was positively related to AUC(G), HOMA-IR, nighttime SBP, and negatively related to ISI and nocturnal BP fall (P < 0.05). Conclusion: Dyssomnia may cause abnormal circadian BP variability through various mechanisms. Improving dyssomnia can help to better function the islet alpha and beta cell and restore normal circadian BP variability. (C) 2015 Elsevier Inc. All rights reserved.