Personalized Obstructive Sleep Apnea Treatment and Effects on Alzheimer's Disease Biomarkers and Cognition Among Blacks

Molecular biomarkers assessed include C₂N, homocysteine, neurofilament light (NfL), glial fibrillary acidic protein (GFAP), tau, and amyloid-beta peptides, along with inflammatory cytokines interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-α). All biomarkers will be measured in picograms per milliliter from blood samples collected at each assessment time point. Higher values indicate greater circulating concentrations of the respective biomarker.

Red Blood Cell Count, White Blood Cell Count, and Platelet Count will be measured. All will be measured in Cells/L.

Total Cholesterol, HDL, LDL, Triglycerides, Bilirubin, Blood Urea Nitrogen (BUN), Calcium, Creatinine, and Glucose. Measured in milligrams/deciliter (mg/dl) assessed with blood analyses.

Hemoglobin, Albumin, and Total Protein. Measured in grams per deciliter assessed with blood analyses.

Glucose/HbA1C, Chloride, Potassium, Sodium, Homocysteine. Measured in mmol/mol assessed with blood analyses

Platelet Count. Measured per microliter of Blood.

Blood Pressure. Measured per microliter of Blood.

Thyroid-stimulating hormone. Measured in milli-international units per litre.

C-reactive protein Highly Sensitive. Measured milligrams per liter.

Folate. Measured microgram.

Vitamin B12. Measured picograms per milliliter.

An assessment of reading decoding skills and crystalized abilities. Participants are asked to read aloud letters and words, pronouncing the words as accurately as possible. Performance will be reported using the NIH Toolbox standardized score. Higher scores indicate better reading decoding and crystallized cognitive ability. Standard scores are norm-referenced, with a mean of 100 and standard deviation of 15. The test also contributes to the NIH Toolbox Crystallized Cognition Composite.

An assessment of receptive vocabulary administered in a computer-adaptive test (CAT) format. Participants must choose which of four pictures best represents a word presented via audio. Performance will be reported using the NIH Toolbox standardized score, with higher scores indicating better receptive vocabulary and crystallized cognitive ability. Standard scores are norm-referenced, with a mean of 100 and standard deviation of 15. The test also contributes to the NIH Toolbox Crystallized Cognition Composite.

An assessment of inhibitory control and attention. Participants will be asked to focus on a particular stimulus while inhibiting attention to the stimuli flanking it. This outcome will be reported as a composite score. Performance will be reported using the NIH Toolbox standardized score, which incorporates accuracy and reaction time. Higher scores indicate better inhibitory control and attention. This measure contributes to the NIH Toolbox Fluid Cognition Composite.

Executive function. An assessment of cognitive flexibility and attention. Participants will be asked to match a series of picture pairs to a target picture. Performance will be reported using the NIH Toolbox standardized score, which incorporates accuracy and reaction time. Higher scores indicate better cognitive flexibility and executive functioning. This measure contributes to the NIH Toolbox Fluid Cognition Composite.

Episodic memory, An assessment of episodic memory. Participants are shown a number of activities, and then asked to reproduce the sequence of pictures as it was presented. Performance will be reported using the NIH Toolbox standardized score, with higher scores indicating better episodic memory performance. This measure contributes to the NIH Toolbox Fluid Cognition Composite.

Participants are given three trials to recall as many words as possible from a list of fifteen unrelated words. After a 5-25 minute delay, participants are asked to freely recall as many of the 15 words as possible. Performance will be reported as the number of words correctly recalled, including immediate learning/recall across the three trials and delayed recall. Higher scores indicate better verbal learning and memory.

An assessment of working memory. Participants will be asked to recall and sequence different stimuli that are presented visually and via audio. Performance will be reported using the NIH Toolbox standardized score, with higher scores indicating better working memory performance.

An assessment of processing speed. Participants are asked to quickly determine whether two stimuli are the same or not the same. Performance will be reported using the NIH Toolbox standardized score, with higher scores indicating faster and better processing-speed performance. This measure contributes to the NIH Toolbox Fluid Cognition Composite.

In this test, participants will be asked to recall a series of numbers in reverse order. The correctly recalled series are scored as 1, and the test contains 14 sequences of numbers. The range of working memory score is from 0 to 14, with higher values representing better outcome.

Health-related quality of life will be assessed using the Patient-Reported Outcomes Measurement Information System Short Form v1.1 - Global Health (5. Excellent, 4. Very good, 3. Good, 2. Fair, 1. Poor). Higher score indicate better self-reported health-related quality of life

Change in Daytime functioning will be assessed using the Patient-Reported Outcomes Measurement Information System Short Form v1.0-Sleep-Related Impairment 8a (1. Not at all 2. A little bit 3.Somewhat 4. Quite a bit 5. Very much). A lower score indicates better daytime functioning

Change in Sleep Quality will be assessed using the Patient-Reported Outcomes Measurement Information System Short Form v1.0- Sleep Disturbance 4a (1. Not at all 2. A little bit 3.Somewhat 4. Quite a bit 5. Very much). Item responses are summed up to produce a raw score ranging from 4 to 20 and converted into a standardized PROMIS T-score. The T-score metric has a population mean of 50 and standard deviation of 10. Higher scores indicate greater sleep disturbance/poorer perceived sleep quality, while lower scores indicate less sleep disturbance/better perceived sleep quality. For this form, raw scores of 4-20 correspond to T-scores of approximately 32.0-73.3.

Sleep quality will be measured by the number of minutes by FitBit Sleep Stages.

Sleep quality as assessed by the Fitbit Sleep Score. Scores range from 1 to 100, with higher scores indicating better sleep quality. Sleep Score categories are interpreted as follows: Excellent (90-100), Good (80-89), Fair (60-79), and Poor (<60).

Hematocrit is the percentage of whole blood volume occupied by red blood cells and will be measured from a blood sample. Measured as a percentage.

Number of calories burned measured by FitBit

Number of floors climbed measured by Fitbit

Distance traveled measured in Miles by Fitbit

Number of steps taken measured by Fitbit

Sleep Awakening measured (Insert how it will be reported) by Fitbit. The outcome will be reported as the number of minutes spent awake during the nightly sleep period, as recorded by Fitbit. Nightly values will be collected during the Fitbit monitoring period, with higher values indicating more time awake during the sleep period and greater sleep disruption. Fitbit records time in minutes spent awake, REM, deep sleep, and light sleep, as well as a nightly sleep score from 0-100.