The Upper Airway Resistance Syndrome: Snoring index

The Upper Airway Resistance Syndrome: Snoring indexThe authors hypothesized that a partial upper airway obstruction may have varying effects depending on age, with patients at the extremes of age having the least ability to compensate. They stated that middle-aged patients may partially compensate by increased work of breathing during sleep, the so-called “athletic snorers.” Unpublished data on chronic heavy snorers with intermittently increased negative Pes leading to arousals and mild sleep disruption were also quoted. The authors postulated that if early treatment were not instituted in these individuals, upper airway obstruction would likely worsen, eventually leading to decompensation with apneas and oxyhemoglobin desaturation. anti allergy

In 1991 Hoffstein and colleagues examined the relationship of snoring intensity and frequency with sleep architecture. All 15 of their subjects snored, but only 2 had an apnea/hypopnea index (AHI) of > 10, and their average body mass index (BMI) was only about 25 kg/m2. The researchers found a correlation between the snoring index (the number of snores per hour) and both sleep efficiency and wakefulness time after sleep onset, but they found no significant effect of snoring on sleep architecture. Although their analysis and discussion focused primarily on snoring itself, the tabular data showed that most of the subjects had a significant number of arousals per night (mean, 57; range, 14 to 178), less than half of which were associated with identifiable respiratory events. Therefore, it is possible that many of these subjects had UARS, although no assessment of daytime somnolence was included. That same year, Guilleminault et al published data on 15 heavy snorers without sleep apnea, most of whom had mild daytime somnolence. Most of these subjects had many brief arousals ranging from 2 to 10 s that were likely related to IUAR, as demonstrated by Pes measurements and pneumotachography. Furthermore, the subjects showed a significant improvement in MSLT scores after treatment with nasal continuous positive airway pressure (nCPAP), despite relatively minor pretreatment complaints of daytime sleepiness that were revealed, typically, only after direct questioning. Interestingly, three of the subjects had low arousal indexes (one to three arous-als/h) and had no improvement in MSLT scores after nCPAP therapy, implying that not all regular heavy snorers have this syndrome. Conversely, Guillemi-nault and colleagues in 1992 proposed that not all of the patients with this clinical syndrome snored.


So Many Advances in Medicine, So Many Yet to Come