Apnea–hypopnea index
The Apnea–Hypopnea Index or Apnoea–Hypopnoea Index (AHI) is an index used to indicate the severity of sleep apnea. It is represented by the number of apnea and hypopnea events per hour of sleep. The apneas (pauses in breathing) must last for at least 10 seconds and be associated with a decrease in blood oxygenation. Combining AHI and oxygen desaturation gives an overall sleep apnea severity score that evaluates both the number of sleep disruptions and the degree of oxygen desaturation (low oxygen level in the blood).
The AHI is calculated by dividing the number of apnea events by the number of hours of sleep. The AHI values for adults are categorized as:[1][2]
- Normal: 0-4
- Mild sleep apnea: 5-14
- Moderate sleep apnea: 15-29
- Severe sleep apnea: 30 or more
For children, because of their different physiology, an AHI in excess of 1 is considered abnormal.[3]
Risks associated with a high AHI
Research shows that individuals suffering from obstructive sleep apnea are at a higher risk of other health comorbidities, including:
- Acute myocardial infarction/heart attack: Obstructive sleep apnea (OSA) presents in 70% of heart attack patients if OSA considered as AHI ≥5 (or in 52% of heart attack patients when OSA considered as AHI ≥10).[4]
- Stroke: In patients with AHI ≥30 macroangiopathic etiology of stroke were significantly higher than in patients with AHI <10.[5]
See also
References
- ↑ "Understanding the Results: Sleep Apnea". Retrieved 5 September 2014.
- ↑ Ruehland WR, Rochford PD, O'Donoghue FJ, Pierce RJ, Singh P, Thornton AT (1 February 2009). "The new AASM criteria for scoring hypopneas: impact on the apnea hypopnea index". Sleep. 32 (2): 150–7. PMC 2635578
. PMID 19238801. - ↑ "Obstructive Sleep Apnea in Children". Retrieved 11 October 2016.
- ↑ Kuniyoshi; et al. (July 2008). "Day–Night Variation of Acute Myocardial Infarction in Obstructive Sleep Apnea". Journal of the American College of Cardiology. 52 (5): 343–346. doi:10.1016/j.jacc.2008.04.027.
- ↑ Claudio L. Bassetti; Milena Milanova; Matthias Gugger (6 March 2006). "Sleep-Disordered Breathing and Acute Ischemic Stroke: Diagnosis, Risk Factors, Treatment, Evolution, and Long-Term Clinical Outcome". Stroke. 37: 967–972. doi:10.1161/01.STR.0000208215.49243.c3.