Co-morbid insomnia and sleep apnoea is associated with increased hypertension risk in a middle-aged population

<bold>Background:</bold> Emerging evidence suggests co-morbid insomnia and sleep apnoea (COMISA) is associated with increased risk of all-cause mortality. We studied the association between COMISA and hypertension in the Swedish CArdioPulmonary bioImaging Study (SCAPIS). <bold>Methods:</bold> Participants aged 50-64 years were randomly recruited from the general population. Information on anthropometrics, lifestyle, sleep, and comorbidities, was collected. Obstructive sleep apnoea (OSA) was assessed using a polygraphic device in a sub-cohort of SCAPIS (n=4286, 46% males, age 57.5±4.3 years, body mass index 26.6±4.3 kg/m²). COMISA was defined as apnoea-hypopnea index (AHI) >10 events/h and insomnia severity index score ≥15. Hypertension was defined as hypertension diagnosis with antihypertensive treatment. <bold>Results:</bold> COMISA was found in 12.8% of males and 19.8% of females with OSA (<bold>P=0.004</bold>). AHI was comparable between COMISA and OSA/no-insomnia groups (19±9 vs. 18±9 events/h, P=0.62). Difficulty initiating sleep, difficulty maintaining sleep, and early morning awakening ≥3 times/week was reported in 42.4, 84.3, and 51.1% of COMISA patients, respectively. Compared with non-OSA, OSA/no-insomnia and COMISA was associated with an increased risk of hypertension in a dose-dependent manner after controlling for confounders (odds ratio [95%CI]: <bold>1.37 [1.10-1.69]</bold>, <bold>2.06 [1.37-3.10]</bold>, <bold>P=0.004, <0.001</bold>, respectively). <bold>Conclusions:</bold> In this large population based study, we demonstrated the synergic effect of insomnia on cardiovascular complications in OSA. Adequate insomnia management should be considered for precision treatment of COMISA.