After adjustment , a weak but significant association was found between cumulative time spent with SaO2 below 90 % ( CT90 % ) and baseline PAC ( P < 0.047 , R 0.019 ) , and between changes in PAC and changes in office DBP ( P < 0.020 , R 0.083 ) CONCLUSIONS : : Night-time hypoxemia and changes in DBP showed an association with baseline and changes in PAC , respectively .