Short Sleep Duration Is Associated With a Blood Pressure Nondipping Pattern in Type 1 Diabetes: The DIAPASOM study

OBJECTIVE

To assess whether nocturnal blood pressure dipping status in type 1 diabetes is correlated with specific sleep characteristics and differences in nocturnal glycemic profiles.

RESEARCH DESIGN AND METHODS

Twenty type 1 diabetic adult patients underwent sleep studies with simultaneous 24-h ambulatory blood pressure monitoring and continuous nocturnal glucose monitoring.

RESULTS

Altogether, 55% of patients exhibited blunted blood pressure dipping. They did not differ from the dipper group in age, BMI, or systolic (SBP) and diastolic (DBP) blood pressure. Total sleep period (TSP) was higher in the dipper group (497 ± 30 vs. 407 ± 44 min for dippers and nondippers, respectively, P < 0.001). TSP was correlated with SBP and DBP day-night differences (r = 0.44 and 0.49, respectively). Periods of nocturnal hypoglycemia (i.e., % of TSP with glycemia <70 mg/dl) were longer in the dipper group (8.1 ± 10.7 vs. 0.1 ± 0.4% for dippers and nondippers, respectively, P = 0.02).

CONCLUSIONS

Dipping status in type 1 diabetes was associated with longer sleep duration and with hypoglycemia unawareness.During sleep, ambulatory blood pressure monitoring (ABPM) demonstrates a normal decline of over 10% in blood pressure (BP), corresponding to the so-called dipping status. In type 1 diabetes, nondipping status is more prevalent (1) and is associated with increased risks for sustained hypertension, retinopathy, and nephropathy (1–3). Dipping pattern could be influenced by sleep duration and associated sleep disorders (4). In type 1 diabetes, sleep stability impacts sleep-related hypoglycemia by changing awakening responses to these episodes (5). Our hypothesis was that type 1 diabetic subjects with more stable sleep could exhibit normal BP dip and, because of higher arousal thresholds, could present an increased frequency of nocturnal hypoglycemia.