OSA severity tied to interarm SBP difference

Moderate to severe obstructive sleep apnoea (OSA) shows an independent association with the interarm systolic blood pressure (SBP) difference (IAD), but not with interankle SBP difference (IAND) and ankle-brachial index (ABI), suggests a study.

The investigators carried out this cross-sectional study in a large sleep cohort from the Tokyo Sleep Heart Study to examine the relationship between OSA and four-limb blood pressure differences. Some 2,643 consecutive patients who visited the sleep clinic for polysomnography between 2005 and 2017 underwent BP measurement simultaneously in all four limbs by oscillometric methods.

IAD ≥10 mm Hg showed a significantly higher prevalence in the moderate OSA (15 ≤ apnoea-hypopnoea index [AHI] <30) and severe OSA (AHI ≥30) groups than the no/mild (AHI <15) group (4.2 percent and 4.6 percent vs 1.4 percent).

In multivariate logistic regression analysis, moderate to severe OSA was also significantly associated with IAD ≥10 mm Hg, even after adjustments for confounding variables (moderate OSA: odds ratio [OR], 4.869, 95 percent confidence interval [CI], 1.080‒21.956; p=0.039; severe OSA: OR, 5.301, 95 percent CI, 1.226‒22.924; p=0.026).

On the other hand, no significant associations were observed between OSA severity and IAND ≥15 mm Hg or ABI <0.9.

“OSA is recognized as an independent risk factor for cardiovascular disease,” the investigators said, noting that IAD, IAND, and ABI are all known predictors of cardiovascular events.