No abstract

Rapid eye movement (REM)-related obstructive sleep apnea (OSA), a polysomnographic phenotype that affects 12–36% of OSA patients, is defined by apnea and hypopnea events that predominantly or exclusively occur during REM sleep. Recent studies indicated that REM-related OSA was associated with the development of nocturnal non-dipping of systolic and diastolic blood pressure, metabolic syndrome, diabetes, and depressive symptoms. However, to date, the association between REM-related OSA and insomnia still remains unclear. We investigated whether there was a difference between REM- and non-REM-related OSA in terms of insomnia-related sleep disturbance as measured by the Pittsburgh Sleep Quality Index (PSQI) in 1736 patients with OSA. REM-related OSA showed a significant association with increased PSQI in all adjusted models. In the subgroup analysis, the coefficients of all models were higher in female than in male patients with REM-related OSA. Insomnia should be considered an important complaint in patients with REM-related OSA, and its indicators, such as the PSQI, should be included in routine diagnostic testing.

To determine the potential role of autocrine growth factor production in regulating primitive human hematopoietic cell development, we examined highly purified CD34+, c-Kit+ marrow mononuclear cells for expression of c-Kit ligand (KL) and stem cell tyrosine kinase 1 (stk1) ligand (STK1-L). Normal marrow mononuclear cells coexpressing CD34 and c-Kit were isolated by a combination of immunomagnetic bead isolation and fluorescence-activated cell sorting. Purified cells were then screened for expression of KL and stk1-L mRNA using a sensitive reverse transcription-polymerase chain reaction method. Using this approach, expression of both cytokine genes at the mRNA level was found in this highly enriched cell population. We then examined the functional significance of these mRNAs by inhibiting their expression with antisense (AS) oligodeoxynucleotides (ODN). In comparison to untreated or control ODN treated cells, inhibition of KL led to a 70% and 89% inhibition in burst-forming unit-erythroid (BFU-E) and colony-forming unit-Mix (CFU-Mix) colonies but had no significant effect on CFU- granulocyte-macrophage (CFU-GM) cloning efficiency. In contrast, inhibition of STK1-L alone had no effect on colony formation. However, when STK1-L AS ODN was combined with KL AS ODN, additive inhibition of CFU-GM and CFU-MIX but not of BFU-E colonies was observed. These findings, along with those of our previous studies showing inhibition of primitive hematopoietic cell growth with antisense ODN directed towards the stk1 receptor, suggest the possibility that both receptor/ligand axes regulate primitive hematopoietic cell growth via an autocrine growth loop.

Polysomnography (PSG) is considered the gold standard in obstructive sleep apnea-hypopnea syndrome (OSAS) diagnostics, but its availability is still limited. Thus, it seems useful to assess patients pre-diagnostic risk for OSAS to prioritize the use of this examination. The purpose of this study was to assess positive (PPV) and negative (NPV) predictive values of the STOP BANG questionnaire (SBQ) in patients with presumptive diagnosis of OSAS. From a database of 1,171 (880 men) patients of a university based sleep center, 1,123 (847 men) met eligibility criteria and their SBQ scores were subject to the Bayesian analysis. The analysis of PPV and NPV was conducted at all values of SBQ for all subjects, but also separately for males and females, and for total sleep time (TS) and for sleep in the lateral position (LP). The probability of OSAS (AHI ≥ 5) and at least moderate OSAS (AHI ≥ 15) for TS was 0.766 and 0.516, while for LP the values were 0.432 and 0.289, respectively. Overall, due to low specificity, SBQ had low PPV for TS and LP. Negative test result (SBQ < 3) revealed NPV of 0.620 at AHI < 5 and 0.859 at AHI < 15 for TS, while in LP NPV values were 0.935 at AHI < 5 and 1.0 at AHI < 15, (n = 31), while SBQ < 4 generated NPV of 0.943 in LP (n = 105). SBQ did not change probabilities of OSAS to confirm or rebut diagnosis for TS. However, it is highly probable that SQB can rule out OSAS diagnosis at AHI ≥ 15 for LP.

Study Objectives: The aim of the study is to verify a possible association between arterial blood pressure and obstructive sleep apnea (OSA) severity in a group of non-hypertensive patients. Methods: This is a retrospective study of 1,171 consecutive patients referred to the sleep laboratory with complaints suggestive of OSA who underwent standard diagnostic polysomnography. In total, 454 patients with no history of arterial hypertension nor had received any such treatment were selected from this group. Results: Patients with severe OSA (apnea-hypopnea index [AHI] ≥ 30 events/h) presented with higher diastolic blood pressure (DBP) in the morning than healthy subjects (AHI < 5 events/h) or those suffering from mild (15 < AHI ≥ 5 events/h) or moderate OSA (30 < AHI ≥ 15 events/h): 86.2 ± 11.3 versus 79.2 ± 8.5, 80.3 ± 10.2 and 81.4 ± 9.6 mmHg, P < .01, respectively. In a linear regression model, a rise in morning DBP was predicted by AHI (ß = 0.14, P < .001) and body mass index (BMI) (ß = 0.22, P < .01), but not by age (ß = 0.01, P = .92), male sex (ß = −0.06, P = .19), or smoking (ß = 0.01, P = .86). In contrast, no association existed between morning systolic blood pressure (SBP) and AHI independently of BMI, sex, age, or smoking. High blood pressure (ie, SBP ≥ 140 mmHg or DBP ≥ 90 mmHg on each of three measurements on different occasions) was predicted by age of 42 years or older, BMI of at least 29 kg/m 2 , and severe OSA. Conclusions: High AHI, independent of obesity, age and sex, was associated with elevated DBP in the morning. Thus, elevated morning DBP may be one of the symptoms related to OSA that warrants specific diagnostics. Commentary: A commentary on this article appears in this issue on page 861. Keywords: apnea-hypopnea index, body mass index, morning blood pressure Citation: Mokros Ł, Kuczyński W, Franczak Ł, Białasiewicz P. Morning diastolic blood pressure may be independently associated with severity of obstructive sleep apnea in non-hypertensive patients: a cross-sectional study. J Clin Sleep Med. 2017;13(7):905-910.