Israel Medical Association Journal

Background: The DES-obstructive sleep apnea (DES-OSA) score uses morphological characteristics to predict the presence and severity of obstructive sleep apnea syndrome (OSAS).

Objectives: To validate DES-OSA scores on the Israeli population. To identify patients requiring treatment for OSAS. To evaluate whether additional parameters could improve the diagnostic value of DES-OSA scores.

Methods: We performed a prospective cohort study on patients attending a sleep clinic. Polysomnography results were examined independently by two physicians. DES-OSA scores were calculated. STOP and Epworth questionnaires were administered, and data on cardiovascular risk was extracted.

Results: We recruited 106 patients, median age 64 years, 58% male. DES-OSA scores were positively correlated with apnea-hypopnea index (AHI) (P < 0.001) and were significantly different between the OSAS severity groups. Interobserver agreement for calculating DES-OSA was very high between the two physicians (intraclass correlation coefficient 0.86). DES-OSA scores ≤ 5 were associated with high sensitivity and low specificity (0.90 and 0.27, respectively) for moderate to severe OSAS. In univariate analysis, only age was significantly correlated with the presence of OSAS (OR 1.26, P = 0.01). Age older than 66 years as a single point in the DES-OSA score slightly improved the sensitivity of the test.

Conclusions: DES-OSA is a valid score based solely on physical examination, which may be useful for excluding OSAS requiring therapy. DES-OSA score ≤ 5 effectively ruled out moderate to severe OSAS. Age older than 66 years as an extra point improved the sensitivity of the test.

Objectives: To investigate the effect of hypoxemia and nocturnal glucose homeosatsis in non-diabetic patients with sleep apnea.

Methods: Seven non-diabetic patients with moderate to severe sleep apnea were connected to a continuous glucose-monitoring sensor while undergoing overnight polysomnography. Mean SpO₂ and percentage of time spent at SpO₂ < 90% were recorded. The correlation between mean glucose levels, the difference between consecutive mean glucose measurements (glucose variability) and the corresponding oxygen saturation variables were determined in each patient during REM[1] and non-REM sleep.

Results: No consistent correlation was found for the individual patient between oxygen saturation variables and glucose levels during sleep. However, a lower mean SpO₂ correlated with decreased glucose variability during sleep (r = 0.79, P = 0.034). This effect was primarily evident during REM sleep in patients with significant, compared to those with mild, oxygen desaturations during sleep (> 30% vs. < 10% of sleeping time spent with SpO₂ < 90%) (P = 0.03).

Conclusions: Severe nocturnal hypoxemia in non-diabetic patients with moderate to severe sleep apnea might affect glucose regulation primarily during REM sleep.

Methods: We assessed 25 patients with insomnia who were enrolled in a hypnotic study but prior to the study were asked to undergo two full nights in lab polysomnography studies: with and without a placebo. Although they were not explicitly told that they were receiving a placebo, the participants knew that the results of these studies would determine whether they met the criteria to participate in the pharmaceutical study.

Results: Although the participants acknowledged that they were given a placebo, almost all measures of their sleep improved. With placebo, sleep latency was shortened from 55.8 ± 43.5 to 39.8 ± 58.5 minutes (P < 0.05); total sleep time was extended from 283 ± 72.5 to 362.9 ± 56.3 minutes, and sleep efficiency improved from 59.57 ± 14.78 to 75.5 ± 11.70% (P < 0.05). Interestingly, placebo had no effect on the relative sleep stage distribution (percentage of total sleep time), except for a trend toward increased percentage of REM[1] sleep.

Conclusions: Our findings how a clear and significant beneficial effect of placebo on insomnia, despite participants' understanding that they were receiving placebo. These results emphasize the importance of the patients' perception and belief in insomnia treatment, and suggest that in some cases placebo may serve as a treatment.

Obstructive sleep apnea syndrome is a major public health hazard affecting 2–4% of the adult population; only 10% of these patients are recognized by healthcare providers. In the last decade the number of referrals for polysomnography increased threefold in Israel, compared to 12-fold worldwide, and is expected to increase even more in the coming years. This constant demand for PSG[1] studies is beyond the current capacity of sleep laboratories, thus preventing diagnosis for most patients with suspected OSAS[2]. In the current review, we examine problems facing decision-makers on how to treat the increasing flood of patients presenting with symptoms suggestive of sleep-disordered breathing. We evaluate the cost-effectiveness of current technologies for OSA diagnosis, i.e., laboratory versus at-home technologies. We conclude that no current alternative exists to the use of PSG for OSA diagnosis. When at-home technologies are suggested for OSAS diagnosis, data should be provided on factors influencing its cost-effectiveness, e.g., accuracy rates of diagnosis, relative cost of human resources, and case-mix of patients tested. Since PSG remains the gold standard for diagnosis of OSAS, in Israel resources should be allocated to increasing the volume of beds for PSG studies in order to increase access to diagnosis and treatment, which in turn provides better quality of life, saves scarce resources of the healthcare system, prevents unnecessary accidents and increases workers’ productivity.