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Abnormal ventilatory responses to hypoxia in Type 2 diabetes
Author(s) -
Weisbrod C. J.,
Eastwood P. R.,
O'Driscoll G.,
Green D. J.
Publication year - 2005
Publication title -
diabetic medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.474
H-Index - 145
eISSN - 1464-5491
pISSN - 0742-3071
DOI - 10.1111/j.1464-5491.2005.01458.x
Subject(s) - medicine , hypoxia (environmental) , type 1 diabetes , diabetes mellitus , type 2 diabetes , endocrinology , hyperoxia , hypoxic ventilatory response , cardiology , respiratory system , lung , oxygen , chemistry , organic chemistry
Aims The incidence of Type 2 diabetes is increasing, along with its associated micro‐ and macrovascular disease manifestations. Previous studies indicate that patients with Type 2 diabetes exhibit abnormal cardiopulmonary reflex responses to various stimuli, although the impact of hypoxia, a common physiological stimulus, on ventilatory responses has not previously been studied in humans with Type 2 diabetes. Methods Minute ventilation (V̇ E ) breathing pattern responses (total breath time, T TOT ; expiratory time, T E ; inspiratory time, T I ; inspiratory duty cycle, T I / T TOT ) were measured during 5 min each of normoxia and isocapnic hypoxia (arterial O 2 saturation ∼85%) in eight subjects with Type 2 diabetes and seven age‐ and body mass index‐matched healthy subjects. Results During normoxia, V̇ E was similar in control and diabetic subjects (6.4 ± 1.2, 6.4 ± 1.1 l/min, respectively). In response to hypoxia, V̇ E significantly increased in both groups (to 17.0 ± 5.0 and 9.5 ± 2.0 l/min, respectively, P < 0.05), but the magnitude of increase in V̇ E was significantly less in diabetic than in control subjects ( P < 0.05). In addition, the breathing pattern response to hypoxia differed between groups in terms of T I / T TOT and T TOT ( P < 0.05), with control subjects significantly decreasing T TOT and T E ( P < 0.05) while diabetic subjects tended to increase both. Conclusions Relative to matched control subjects, Type 2 diabetic subjects exhibit blunted V̇ E responses to acute isocapnic hypoxia, suggesting that this group of diabetic subjects possesses a chemoreflex ill‐equipped to respond homeostatically to hypoxic challenge.