Obstructive sleep apnea and type 2 diabetes

Abstract

Type 2 diabetes and obstructive sleep apnea (OSA) are diseases with high prevalence and major public health impact. There is evidence that regular snoring and OSA are independently associated with alterations in glucose metabolism. Thus, OSA might be a risk factor for the development of type 2 diabetes. Possible causes might be intermittent hypoxia and sleep fragmentation, which are typical features of OSA. OSA might also be a reason of ineffective treatment of type 2 diabetes. There is further evidence that the treatment of OSA by continuous positive airway pressure (CPAP) therapy might correct metabolic abnormalities in glucose metabolism. It is assumed that this depends on therapy compliance to CPAP. On the other hand, there are also hints in the literature that type 2 diabetes per se might induce sleep apnea, especially in patients with autonomic neuropathy. Pathophysiological considerations open up new insights into that problem. Based on the current scientific data, clinicians have to be aware of the relations between the two diseases, both from the sleep medical and the diabetological point of view. The paper summarizes the most important issues concerning the different associations of OSA and type 2 diabetes.

Figure 1

Minute ventilation (V_E) responses to acute hypoxia (11% O₂ in N₂) in diabetic (streptozotocin-induced) and healthy adult Wistar rats (n = 6 in both groups). Symbols are means ± SE of percentage increases in ventilation at sequential 30 s time points of hypoxic tests from the baseline level taken as 100% in each animal. Inset: difference in mean percentage increases from baseline to peak hypoxic hyperventilation between diabetic and healthy rats. *P < 0.03 for all (Mann-Whitney U test).

Figure 2

Possible interactions between obstructive sleep apnea and Type 2 diabetes. OSA - obstructive sleep apnea, CPAP - continuous positive airway pressure, AN - autonomic neuropathy [adopted from Tasali and Ip 2008].