Estudi de la prevalença d'hipòxia intermitent en pacients estables amb diabetis de tipus 2 mal controlada i de l'evolució del control de la glucèmia amb el tractament amb pressió positiva contínua a la via aèria

Student thesis: Doctoral thesis

Abstract

Rationale and objectives. Numerous studies suggest that obstructive sleep apnea (OSA) affects glucose metabolism and point to intermittent hypoxia (IH) as a potential intermediate mechanism in this relationship. The present study examined the prevalence of IH secondary to OSA in patients with poorly controlled type 2 diabetes, the association between IH and glycaemic control and the impact of OSA treatment on glycaemic control and on other secondary variables. Subjects and methods. The study included 145 consecutive patients, aged 18 to 70 years, with type 2 diabetes on stable treatment and glycosylated haemoglobin level (HbA1c) ≥7% (53 mmol/mol) who attended an outpatient Endocrinology clinic and were not on treatment with continuous positive pressure airway pressure (CPAP). Patients underwent overnight pulse oximetry and respiratory poligraphy in case IH (desaturation index [DI] ≥15) was found. After a 14-week run-in period, the 50 patients with OSA and apnoea plus hypopnoea index (AHI) >20 were treated with CPAP with assessment of HbA1c among other variables at 14, 28 and 56 weeks of treatment. The change in HbA1c level was compared with that experienced by a group of 32 patients without significant nocturnal hypoxia (DI <5 and <20% of time with oxyhaemoglobin saturation <90%). Results. IH was observed in 54 (37%) patients, of whom 52 had OSA, and was associated with worse glycaemic control (HbA1c level > median), independently of potential confounders. IH was associated with an adjusted odds ratio (OR) for having a level of HbA1c >8,5% of 2,31 (95% CI: 1,06 to 5,04) in a model adjusted for body mass index and of 2,46 (95% CI: 1,13 to 5,34) in a model adjusted for waist to height ratio. CPAP treatment did not change HbA1c levels, which evolved similarly to those of control patients. OSA treatment improved sleep quality, but not the lipid profile, blood pressure or albuminuria. An analysis of the subgroup of patients with treatment compliance ≥4 h/day showed similar results. Conclusions. Patients with poorly controlled type 2 diabetes have a high prevalence of IH secondary to undiagnosed OSA that is independently associated with worse glycaemic control. However, in these patients the treatment of OSA does not improve glycaemic control.

Palabras clave
Date of Award1 Jul 2016
Original languageCatalan
SupervisorFerran Morell Brotad (Tutor) & Gabriel Sampol Rubio (Director)

Keywords

  • Sleep apnea
  • Type 2 diabetes
  • Continuos positive airway pressure

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