# Sleep-Disordered Breathing Risk with Comorbid Insomnia Is Associated with Mild Cognitive Impairment
## 4 Discussion  
In this cross-sectional analysis of baseline ADNI data, among older adults with normal cognition and MCI, high risk for SDB with comorbid insomnia was associated with greater odds of MCI when compared to each other sleep disorder group. Neither low risk for SDB with insomnia nor high risk for SDB alone was significantly associated with greater odds of MCI when compared to low risk for SDB alone. Existing research in the relationship between SDB and cognitive impairment has rarely considered the concurrent influence of insomnia. Similarly, few studies concerning the relationship between insomnia and cognitive impairment have examined the comorbidity of SDB. Our study highlights the importance of examining these two common sleep \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{2}{c}{**Mild Cognitive Impairment**} & \\  & **Model 1** & **Model 2** & **Model 3** \\  & **OR (95\% CI)** & **OR (95\% CI)** & **OR (95\% CI)** \\ \hline Low risk for SDB & 0.95 (0.69–1.32) & 0.99 (0.71–1.38) & 0.98 (0.70–1.38) \\ with insomnia & 1.43 (0.94–2.18) & 1.42 (0.92–2.18) & 1.40 (0.89–2.21) \\ with insomnia & 2.88 ** (1.43–5.8) & 3.14 ** (1.55–6.36) & 3.22 *** (1.57–6.60) \\ \hline \hline \end{tabular} The results of logistic regression used to evaluate the associations of sleep disorder groups (low risk for SDB alone, with insomnia, high risk for SDB alone, and high risk for SDB with insomnia, each relative to low risk for SDB alone) with the odds of MCI (versus normal cognition). Model 1 adjusted for sociodemographic (age and sex), anthropometric (BMI), and genetic (APOE4 allele number) variables. Model 2 further adjusted for social variables (race, ethnicity, education, and marital status). Model 3 further adjusted for clinical (hypertension, cardiovascular disease, and stroke) and behavioral (alcohol abuse and smoking) variables. * \(p<0.01\); *** \(p<0.001\).  
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Table 2: Associations between sleep disorder groups and MCI with low risk for SDB alone as reference. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{2}{c}{**Mild Cognitive Impairment**} & \\  & **Model 1** & **Model 2** & **Model 3** \\  & **OR (95\% CI)** & **OR (95\% CI)** & **OR (95\% CI)** \\ \hline Low risk for SDB alone & 0.35 ** (0.17–0.70) & 0.32 ** (0.16–0.65) & 0.31 ** (0.15–0.64) \\ Low risk for SDB & 0.33 ** (0.16–0.7) & 0.32 ** (0.15–0.67) & 0.31 ** (0.14–0.66) \\ with insomnia & 0.5 (0.23–1.07) & 0.45 * (0.21–0.98) & 0.43 * (0.20–0.95) \\ \hline \hline \end{tabular} The results of logistic regression used to evaluate the association of sleep disorder groups (low risk for SDB alone, low risk for SDB with insomnia, and high risk for SDB alone, each relative to high risk for SDB with insomnia with insomnia) with the odds of MCI (versus normal cognition). Model 1 adjusted for sociodemographic (age and sex), anthropometric (BMI), and genetic (APOE4 allele number) variables. Model 2 further adjusted for social variables (race, ethnicity, education, and marital status). Model 3 further adjusted for clinical (hypertension, cardiovascular disease, and stroke) and behavioral (alcohol abuse and smoking) variables. * \(p<0.05\); *** \(p<0.01\).  
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Table 3: Associations between sleep disorder groups and MCI with high risk for SDB with insomnia as reference. disorders concurrently. In prior studies of SDB that did not adjust for comorbid insomnia, SDB was prospectively associated with incident cognitive decline at 4-year follow-up among community-dwelling older women [32], and with incident Alzheimer's dementia (RR = 1.20, 95% CI: 1.03-1.41) and vascular dementia (RR = 1.23, 95% CI: 1.04-1.46) in a meta-analysis of three studies [2].