SBP variability linked to higher risk of POAG
Systolic blood pressure (SBP) variability appears to be a significant predictor of primary open angle glaucoma (POAG) even after controlling for confounders and other risk factors, a new study reveals.
Data of 80,021 participants from the Korean National Health Insurance Service were retrieved. Those with only one BP measurement, below the age of 40 and had POAG before December 2006 were excluded.
Patients were then stratified into quartiles according to their variabilities in diastolic blood pressure (DBP), SBP and the difference between the two.
Of the participants, 910 had POAG while 79,111 did not. Compared with the healthy cohort, those with POAG were generally older (p<0.0001), were nondrinkers (p=0.0365), engaged in regular exercise (p=0.0126) and nonsmokers (p=0.0141). After adjusting for age, the significant effects of alcohol consumption, exercise and smoking disappeared.
Similarly, after adjusting for age, the visit-to-visit variability in SBP and DBP remained significantly different between the two groups. Multivariate Cox’s regression showed that those in the highest quartile of SBP variability were at a higher risk of developing POAG (SD: hazard ratio [HR], 1.261; 95 percent CI, 1.035 to 1.536; CV: HR, 1.233; 1.012 to 1.502).
On the other hand, DBP showed only mild predictive value. Those in the third SD quartiles of DBP were at a higher risk of POAG, but no CV quartile showed such relationship.
Finally, compared with those in the first three quartiles, individuals in the fourth quartile of SBP SD were more likely to be female (p<0.0001), older (p<0.0001), nondrinkers (p<0.0001) and nonsmokers (p<0.0001), and less likely to engage in exercise regularly (p<0.0001).
The authors thus recommend that patients who exhibit greater visit-to-visit variability in SBP should be closely monitored for potential development of POAG.