Dataset Information

Cerebral oxygenation in wake and during sleep and its relationship to cognitive function in community-dwelling older adults without sleep disordered breathing.

ABSTRACT:

Background

This descriptive cross-sectional study investigated the relationships between cerebral oxygen reserve and cognitive function in community-dwelling older adults.

Methods

Participants (72 women and 40 men) underwent standard polysomnography, including regional measures of percent oxyhemoglobin saturation (rcSO(2)) determined by cerebral oximetry. Two variables were used to calculate cerebral oxygen reserve: (a) awake rcSO(2) (mean presleep rcSO(2)) and (b) the change in rcSO(2) from before sleep to the end of the first non-rapid-eye movement cycle. General linear models, adjusted for the effects of education and occupation, tested differences in performance on standard tests of memory, attention, and speed of mental processing.

Results

Awake rcSO(2) values were normal (60%-79.9%) in 64 participants, marginal (50%-59.9%) in 41, and low (43%-49.9%) in 7. Participants with normal awake levels had higher cognitive function than those with low levels (p < .05). Changes in rcSO(2) were greatest in participants with marginal awake rcSO(2) values; among whom, those who increased rcSO(2) during sleep (n = 17) had better memory function than the 24 who did not (p < .05).

Conclusions

Low awake rcSO(2) values mark individuals with low cerebral oxygen reserves and generally lower cognitive function; marginal awake rcSO(2) values that fall during sleep may indicate loss of cerebral oxygen reserve and an increased risk for cognitive decline. Further studies may clarify the significance of and mechanisms underlying individual differences in awake rcSO(2) and the changes that occur in rcSO(2) while asleep.

SUBMITTER: Carlson BW

PROVIDER: S-EPMC3011955 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:PurposeWe investigated the association between sleep disordered breathing and erectile dysfunction in older men.Materials and methodsWe performed a cross-sectional analysis of community dwelling men age 67 years or older enrolled in the Osteoporotic Fractures in Men Sleep Study. Participants underwent overnight polysomnography (2003 to 2005) and completed sexual health questionnaires (2005 to 2006). We defined sleep disordered breathing using the apnea-hypopnea index or nocturnal hypoxemia. Erectile dysfunction was defined using the MMAS (Massachusetts Male Aging Study) scale and, in sexually active men, the International Index of Erectile Function. We used logistic regression to examine the association between sleep disordered breathing and erectile dysfunction.ResultsMean participant age was 76±5 years. Of the 2,676 men completing the MMAS, 70% had moderate to complete erectile dysfunction. Among 1,099 sexually active men completing the IIEF-5 (5-item International Index of Erectile Function), 26% had moderate to severe erectile dysfunction. A higher apnea-hypopnea index was associated with greater odds of MMAS defined moderate to complete erectile dysfunction after adjusting for age and study site (OR 1.39, 95% CI 1.00-1.92 for severe sleep disordered breathing vs none, p trend=0.008), but not after further adjustment for body mass index, socioeconomic status and comorbidities (OR 1.05, 95% CI 0.75-1.49, p trend=0.452). Greater nocturnal hypoxemia was associated with increased odds of MMAS defined moderate to complete erectile dysfunction (unadjusted OR 1.36, 95% Cl 1.04-1.80 vs none) but this was attenuated after adjustment for age and study site (OR 1.24, 95% CI 0.92-1.66). Sleep disordered breathing was not associated with erectile dysfunction by 5-item International Index of Erectile Function.ConclusionsIn this cross-sectional analysis in older men sleep disordered breathing was associated with higher odds of erectile dysfunction in unadjusted analyses that was largely explained by higher body mass index and increased comorbidity among men with sleep disordered breathing. Prospective studies accounting for obesity and multimorbidity would further clarify the association of sleep disordered breathing and erectile dysfunction.