Background: There is growing evidence of increased cardiovascular risk including hypertension in patients with periodic limb movements during sleep (PLMS). In a multiethnic cohort study, the association between prevalent hypertension and PLMS varied according to ethnicity. We evaluated whether PLMS are associated with hypertension in Koreans.
Methods: We enrolled 1,163 subjects who had polysomnography (PSG) from 2 tertiary hospitals. All subjects completed a sleep questionnaire before the PSG study. Coincidental hypertension was recorded according to past medical history. We analyzed the association between periodic limb movement index (PLMI), periodic limb movement associated with arousal index (PLMAI), and coincidental hypertension. Covariates were age, sex, body mass index (BMI), restless legs syndrome, apnea-hypopnea index (AHI), arousal index, and average oxygen saturation.
Results: A total of 304 subjects (26.1%) had hypertension. The proportion of subjects with hypertension in the PLMI ≥ 15 category was higher than that in the PLMI < 15 category (32.4% vs. 25.0%; P = 0.04). The proportion of subjects with hypertension in the PLMAI ≥ 1 category was 32.6%, which was higher than that in the PLMAI < 1 category (24.6%; P = 0.02). In a multivariate regression model, neither PLMI (odds ratio [OR], 1.12; 95% confidence interval [CI] 0.75-1.68) nor PLMAI (OR, 1.21; 95% CI 0.83-1.76) were associated with hypertension. Statistical significance was found between coincidental hypertension and the following variables: age, smoking history, BMI, and AHI.
Conclusions: In a retrospective hospital-based study, there was no association between coincidental hypertension and PLMI/PLMAI in Koreans.