To investigate the relationship between ambulatory blood pressure rhythm and islet α-cells function in patients with type 2 diabetes suffered from sleep disorder.

Four hundred and six patients with type 2 diabetes treated from January 2012 to July 2014 in Metabolic Disease Hospital of Tianjin Medical University were divided into two groups according to Pittsburgh Sleep Quality Index(PSQI): patients without sleep disorder (242 cases) and patients with sleep disorder (164 cases). Oral glucose tolerance test (OGTT), insulin releasing test, glucagon releasing test and 24 h ambulatory blood pressure monitoring were performed in those patients. The differences of α-cells function after fasting and glucose-load, as well as the circadian rhythm of blood pressure and blood pressure variation were compared between the two groups. The correlation analysis was performed between PSQI score and other indicators, and Logistic regression analysis was performed between blood pressure circadian rhythm and influence indicators.

The level of glucagon and glucagon/insulin ratio at each time point as well as area under curve of glucagon and 0, 30, 60, 180 min glucagon/glucose ratio were significantly higher in patients with sleep disorder than those in patients without sleep disorder(t=2.109-14.188, all P<0.05). The levels of 24 h systolic and diastolic blood pressure, nocturnal systolic and diastolic blood pressure and systolic blood pressure of daytime were all significantly higher in diabetic patients with sleep disorder than those in patients without sleep disorder((135±8) vs (130±7) mmHg(1 mmHg=0.133 kPa), (74±6) vs (72±6) mmHg, (131±7) vs (126±6) mmHg, (72±5) vs (68±5) mmHg, (138±8) vs (133±8) mmHg, respectively, t=6.162, 2.254, 8.432, 5.940, 5.585, all P<0.05). The percentage of decreased systolic blood pressure at night and percentage of decreased diastolic blood pressure at night were lower, whereas 24 h systolic and diastolic blood pressure standard deviation as well as variation coefficient were higher in patients with sleep disorder those in patients without sleep disorder(t=2.232-10.065, all P<0.05). Logistic regression analysis showed that blood pressure circadian rhythm was positively related to the percentage of decreased systolic blood pressure at night(OR:2.014-3.006), and negatively related to area under curve of glucagon (OR:0.652-0.975) and PSQI score (OR:0.623-0.818) (all P<0.05).

Circadian rhythm of blood pressure may be related to islet α-cells dysfunction in patients with type 2 diabetes suffered from sleep disorder.

Diabetes mellitus, type 2; Sleep disorders; Ambulatory blood pressure; Circadian rhythm; Islet α-cell