Relationship between inflammation and cognitive function in obstructive sleep apnea.

OBJECTIVES: Obstructive sleep apnea (OSA) can have adverse effects on cognitive functioning, mood, and cardiovascular functioning. OSA brings with it disturbances in sleep architecture, oxygenation, sympathetic nervous system function, and inflammatory processes. It is not clear which of these mechanisms is linked to the decrease in cognitive functioning. This study examined the effect of inflammatory parameters on cognitive dysfunction. MATERIALS AND METHODS: Thirty-nine patients with untreated sleep apnea were evaluated by polysomnography and completed a battery of neuropsychological tests. After the first night of evaluation in the sleep laboratory, blood samples were taken for analysis of interleukin 6, tumor necrosis factor-alpha (TNF-alpha), and soluble TNF receptor 1 (sTNF-R1). RESULTS: sTNF-R1 significantly correlated with cognitive dysfunction. In hierarchical linear regression analysis, measures of obstructive sleep apnea severity explained 5.5% of the variance in cognitive dysfunction (n.s.). After including sTNF-R1, percentage of variance explained by the full model increased more than threefold to 19.6% (F = 2.84, df = 3, 36, p = 0.05). Only sTNF-R1 had a significant individual relationship with cognitive dysfunction (beta = 0.376 t = 2.48, p = 0.02). CONCLUSIONS: sTNF-R1 as a marker of chronic inflammation may be associated with diminished neuropsychological functioning in patients with OSA.

The relationship between heart rate variability and inflammatory markers in cardiovascular diseases.

INTRODUCTION: Recent evidence implicates a cholinergic anti-inflammatory pathway. Because vagus nerve activity mediates some heart rate variability (HRV), this qualitative review examines the literature concerning circulating cytokines and HRV in cardiovascular function in humans. This qualitative review examines the literature concerning circulating cytokines and HRV in cardiovascular function in humans. METHODS: Thirteen studies on HRV, inflammation, and cardiovascular function were located by electronic library search and descriptively reviewed. RESULTS: The relationship between HRV and inflammation was studied in healthy controls, patients with acute or stable coronary heart disease (CHD), patients with metabolic syndrome or impaired glucose tolerance and patients with kidney failure. Investigations focused mainly on Interleukin-6 (IL-6) and C-reactive peptide (CRP). The majority of reviewed studies reported that parasympathetic nervous system tone as inferred from heart rate variability is inversely related to inflammatory markers (r values between -0.2 and -0.4). The relationships with inflammatory markers were similar whether derived from ECG signals as short as 5-30min or from 24-h ECG readings for HRV analyses. While inflammatory markers appear to be related to HRV, it is a mistake to assume that the traditional "vagal measures" of HRV (such as high frequency heart rate variability) are the driving factors. Indeed, low frequency heart rate variability, a complex measure reflecting both parasympathetic and sympathetic activity, is the more commonly associated measure linked to inflammatory markers. DISCUSSION: Heart rate variability is inversely correlated with inflammatory markers in healthy individuals as well as in those with cardiovascular diseases.

Effect of a 2 week CPAP treatment on mood states in patients with obstructive sleep apnea: a double-blind trial.

Obstructive sleep apnea (OSA) is a common disease with significant medical and psychiatric comorbidities. The literature documenting the effects of continuous positive airway pressure (CPAP) treatment on mood in OSA patients is mixed. We previously observed that 1 week of CPAP treatment did not result in improvements in mood beyond those observed in a group treated with placebo-CPAP. This study examined the effect of a 2 week CPAP treatment on mood in a placebo-controlled design in OSA patients. Fifty patients with untreated sleep apnea were evaluated by polysomnography and completed the Profile of Mood States (POMS) pre-/post-treatment. The patients were randomized for 2 weeks to either therapeutic CPAP or placebo-CPAP (at insufficient pressure). Both the therapeutic CPAP and the placebo-CPAP groups showed significant improvements in POMS total score, tension, fatigue, and confusion. No significant time x treatment effect was observed for either group. We could not show a specific beneficial impact of CPAP treatment on mood in OSA patients.

Abnormalities of body fat distribution in HIV-infected persons treated with antiretroviral drugs: The Swiss HIV Cohort Study.

We prospectively assessed the 1-month prevalence of abnormal body fat distribution in HIV-infected individuals. Of 1,359 patients treated with antiretroviral drugs, 578 (43%) had signs of abnormal fat distribution. Peripheral fat loss was observed in 382 patients (28%), whereas 412 (30%) had signs of fat accumulation. The presence of lipodystrophy (peripheral fat loss with or without fat accumulation) was found to be independently associated with increasing age (less than 35 years of age as a reference group: 35 to 41 years of age, OR = 1.5 [95% CI, 1.1-2.3]; and older than 41 years of age, OR = 2.4 [95% CI, 1.7-3.5]), current use of stavudine (OR = 2.4 [95% CI, 1.8-3.3]), current use of abacavir (OR = 2.1 [95% CI, 1.3-3.4]), and elevated lactate level (OR = 1.6 [95% CI, 1.1-2.4]). The prevalence of lipodystrophy was higher among patients who had received stavudine for a longer period (no stavudine in the current combination as a reference group: <6 months, OR = 1.1 [95% CI, 0.6-1.8]; 6-24 months, OR = 2.4 [95% CI, 1.7-3.5]; and >24 months, OR = 3.2 [95% CI, 2.4-4.3]). This study confirms the association between the use of stavudine and lipodystrophy.