Sleep and nighttime behavior disorders in older adults: associations with hypercholesterolemia and hypertriglyceridemia at baseline, and a predictive analysis of incident cases at 12 months follow-up.

Introduction: Sleep disorders, particularly insomnia and obstructive sleep apnea, are associated with dyslipidemia in the general population. The study's aim was to explore the association between pathological Cholesterol and Triglyceride levels, and sleep and nighttime behavior disorders (SNBD) in older adults, whether they might predict SNBD onset, and to emphasize the role of body mass index (BMI) in this association.

Methods: Alzheimer's Disease Neuroimaging Initiative (ADNI) population with complete Cholesterol, Triglyceride, SNBD, and neurocognitive data were included. Logistic regression was performed to study the association between hypercholesterolemia, hypertriglyceridemia, and SNBD at baseline and at 12 months. Relevant confounders, particularly BMI, were adjusted for.

Results: Among the 2,216 included cases, 1,045 (47%) were females, and the median age was 73 years (IQR: 68, 78). At baseline, 357 (16%) had SNBD and 327 (18%) at 12 months; 187 of them were incident cases. There were more cases of baseline SNBD in the hypertriglyceridemia group than in those without (19% vs. 14%, P-value = 0.003). Similarly, more follow-up SNBD cases had hypertriglyceridemia at baseline (21% vs. 16%, P-value = 0.025). SNBD cases at baseline had significantly higher serum Triglyceride levels than those without (132 vs. 118mg/dL, P-value < 0.001). Only hypertriglyceridemia was significantly associated with baseline SNBD (crude OR = 1.43, 95%CI: 1.13,1.80, P-value = 0.003), even after adjustment for confounding factors (adj. OR = 1.36, 95%CI: 1.06,1.74, P-value = 0.016) and (BMI-adj. OR = 1.29, 95%CI: 1.00,1.66, P-value = 0.048). None of the dyslipidemia forms did predict incident cases at 12 months.

Conclusions: Hypertriglyceridemia, but not hypercholesterolemia, was associated with higher odds of SNBD. The association was independent of BMI. None of the dyslipidemia forms did predict incident SNBD over 12 months. Sleep disorders should motivate a systematic screening of dyslipidemia in older adults and vice versa.