Sleep-disordered breathing in nonobese diabetic subjects with autonomic neuropathy.
To assess the occurrence and nature of sleep-disordered breathing (SDB) in 26 adult, nonobese diabetics (18 with autonomic neuropathy (DAN+) (age 45 (41-50) yrs; body mass index (BMI) 24.1 (22-26) kg x m(-2)) and eight without autonomic neuropathy (DAN-) (age 45 (35-55) yrs; BMI 24.8 (23-26) kg x m(-2))) overnight full sleep studies and measurements of central and peripheral carbon dioxide (CO2) chemosensitivity were performed. DAN+ were divided in two subgroups, according to the presence (DAN+PH+; n=10) or absence (DAN+PH-; n=8) of postural hypotension. Ten normal subjects were studied as controls (age 42 (36-48) yrs; BMI 24.4 (23-25) kg x m(-2)). In contrast to DAN- and controls, who did not show SDB, five DAN+ (four DAN+PH- and one DAN+PH+) had an apnoea/hypopnoea index > or = 10 and four DAN+ (two DAN+PH- and two DAN+PH+) had an apnoea index > or = 5. All the events were obstructive, occurring mainly during rapid eye movement (REM) sleep. Ten DAN+ exhibited a mean lowest oxygen saturation < 90% during REM sleep. No periodic breathing or central sleep apnoeas were found in DAN+PH+, although they had an enhanced central chemoresponsiveness to CO2. Both DAN+ subgroups showed a marked reduction in peripheral CO2 chemosensitivity. In conclusion, adult nonobese diabetics with autonomic neuropathy, independent of the severity of their dysautonomy, have obstructive sleep apnoea/hypopnoea with a frequency > 30%. A decrease in peripheral carbon dioxide chemosensitivity prevents adult nonobese diabetics with autonomic neuropathy and postural hypotension from experiencing posthyperventilatory central sleep apnoea, despite an increased hypercapnic central drive.
Dept of Internal Medicine and Endocrine-Metabolic Sciences, University of Perugia, Perugia, Italy.
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Bottini
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Dottorini
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Cristina Cordoni
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G
Casucci
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Tantucci
D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000150:complications* / Q000503:physiopathology; D015992:Body Mass Index; D003929:Diabetic Neuropathies / Q000150:complications* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007024:Hypotension, Orthostatic / Q000150:complications* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D017286:Polysomnography; D012129:Respiratory Function Tests; D020182:Sleep Apnea, Central / Q000209:etiology* / Q000503:physiopathology