UNDIAGNOSED SLEEP-DISORDERED BREATHING AMONG MALE NONDIPPERS WITH ESSENTIAL-HYPERTENSION

Objective A blunting of the nocturnal fall in arterial blood pressure is found in a minority of patients (nondippers) with essential hyperte nsion, We tested whether sleep-disordered breathing (snoring and apnea or hypopnea) might explain such a finding for male patients, among wh om its prevalence is much higher, Setting and patients We studied 100 new cases of hypertension in men, observed consecutively by a local gr oup of general practitioners and diagnosed essential hypertensives in a referral clinic, By using 24 h ambulatory blood pressure monitoring with a SpaceLabs 90207 device, 15 patients were classified initially n ondippers (daytime ambulatory blood pressure greater than or equal to 136/87 mmHg; night-time decrease by <10% of the daytime mean), but onl y 11 were confirmed to be nondippers by continuous blood pressure moni toring with a Finapres device. Ten dippers matched by age, body mass i ndex and mean 24 h blood pressure were used as controls. Main outcome measures Parameters of nocturnal polysomnography. Results During polys omnography, the nondippers exhibited a blunting of the sleep-related f all in blood pressure and an increased variability in blood pressure a ssociated with sleep-disordered breathing (heavy snoring for all, with an apnea or hypopnea index >10 in 10 cases), Six of the control patie nts breathed normally and four snored nonapneically, There was a norma l fall in nocturnal blood pressure in all 10 cases, Conclusions The no ndipper condition appears to be associated with undiagnosed apneic sno ring for an unselected population of previously untreated male subject s with a diagnosis of essential hypertension, Ambulatory blood pressur e monitoring of such patients is of limited diagnostic value.