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A7457 - Nightly Hypoxemia in the Elderly Inpatient Population and Its Link to Dementia - Further Study Group Results
Author Block: S. WImmer1, S. Pramsohler1, L. Rausch1, N. Hasanagic1, N. C. Netzer2; 1Hermann-Buhl-Institute, University of Innsbruck, Bad Aibling, Germany, 2Psychology and Sports Science, Hermann Buhl Institute for Hypoxia and Sleep Medicine Research University Innsbruck, Bad Aibling, Germany.
Rationale: As causes and types of dementia are various, nightly hypoxemia could be a common ground. There is evidence from several studies that hypoxemia caused by SRBD or COPD can lead to cognitive impairment (Blackwell et al, JAGS 2015; Yaffe et al, JAMA 2011). A Norwegian study showed that roughly 26 % of the average elderly population has nightly hypoxemia (Hjalmarsen and Hykkerud, Age and Aging 2008). There is still a lack of epidemiological data referring to hypoxemia in the elderly. The aim of our still ongoing study is to examine a large number of (N=4000) subjects concerning nightly hypoxemia and its effect on cognitive impairment and dementia. Furthermore this study investigates, if additional supplied O2 for hypoxemic patients results in cognitive improvement. Methods: n=270 consecutive subjects (187 f, 83 m) of the inpatient population of the geriatric rehabilitation clinic in Bad Aibling, Germany, independent of referral reasons and diagnoses with a mean age of 83,9 years were included. Cognitive functioning was assessed first and after a period of ten days with the number connection test (NCT), a concentration test (AKT) and the MMSE (degree of dementia). The SaO2 during sleep was measured for at least 4 hours. T90 >30% was used as a cutoff to distinguish between hypoxic and non-hypoxic patients. Data is expressed descriptively and with Pearson correlation coefficient for correlations between cognitive function test and t90 results. Patients who fulfilled the t90 criteria were given a nightly 2l/O2 supply over a period of 10 days. Results: 63 of n=270 patients (23,3%) had a t90 for more than 30% of the time. There were no significant correlations between the t90 and the cognitive functional testing except the MMSE which correlated with the t90 scores with r = -0.224. Sex correlates significantly with t90 (p=.000), AKT (p=.033) and meanO2 (p= .000). 12 out of 63 Patients agreed to an additional O2 supply. We didn´t see significant improvement of cognitive functioning due to oxygen supply. Conclusion: We found similar epidemiologic data as the Norwegian group. In this preliminary sample of our study we could see a correlation between the MMSE and the t90 scores, but not for the cognitive functioning tests. Additional oxygen provided for the hypoxemic subgroup did not lead to an improvement in cognitive functioning assessed by the mentioned tests. This might change with a larger sample size.