In Reply

Abstract

We thank Dr Blaivas for his letter.1Blaivas A.J. Timing antihypertensives to reduce nocturnal blood pressure in CKD: the importance of choosing the right dip.Am J Kidney Dis. 2008; 51: 1069Abstract Full Text Full Text PDF PubMed Scopus (2) Google Scholar The potential role of obstructive sleep apnea (OSA) in the “nondipping” phenomenon is an intriguing question to be evaluated, especially when considering the increasing prevalence of overweight and obese subjects in the western world. We did not address this problem in our paper2Minutolo R. Gabbai F.B. Borrelli S. et al.Changing the timing of antihypertensive therapy to reduce nocturnal blood pressure in CKD: an 8 week uncontrolled trial.Am J Kidney Dis. 2007; 50: 908-917Abstract Full Text Full Text PDF PubMed Scopus (109) Google Scholar because chronic kidney disease (CKD) has widely been proven to be associated with nondipping status due to the typically high sodium sensitivity of patients.3Minutolo R. Borrelli S. Scigliano R. et al.Prevalence and clinical correlates of white coat hypertension in chronic kidney disease.Nephrol Dial Transplant. 2007; 22: 2217-2223Crossref PubMed Scopus (44) Google Scholar, 4Farmer C.K. Goldsmith D.J. Cox J. Dallyn P. Kingswood J.C. Sharpstone P. An investigation of the effect of advancing uraemia, renal replacement therapy and after renal transplantation on blood pressure diurnal variability.Nephrol Dial Transplant. 1997; 12: 2301-2307Crossref PubMed Scopus (164) Google Scholar, 5Sachdeva A. Weder A.B. Nocturnal sodium excretion, blood pressure dipping and sodium sensitivity.Hypertension. 2006; 48: 527-533Crossref PubMed Scopus (118) Google Scholar Furthermore, mean body mass index (BMI) of our small cohort was 28.8 ± 6.9 kg/m2 with 9/32 obese patients (BMI > 30 kg/m2). The mean value is definitely lower than that reported by Campos-Rodriguez et al (35 kg/m2) in the patients of the studies where continuous positive airway pressure (CPAP) therapy re-established dipper status.6Campos-Rodriguez F. Perez-Ronchel J. Grilo-Reina A. et al.Long-term effect of continuous positive airway pressure on BP in patients with hypertension and sleep apnea.Chest. 2007; 132: 1847-1852Crossref PubMed Scopus (93) Google Scholar On the other hand, on the basis of the letter commenting on our study, we have evaluated whether BMI modified response to antihypertensive drug shift. We found no difference in BMI between responders (29.5 ± 6.9 kg/m2) and nonresponders (23.6 ± 4.3 kg/m2). Nevertheless, we believe that this issue should be the object of ad hoc studies in the CKD population. Support: None. Financial Disclosure: None. Changing the Timing of Antihypertensive Therapy to Reduce Nocturnal Blood Pressure in CKD: An 8-Week Uncontrolled TrialAmerican Journal of Kidney DiseasesVol. 50Issue 6PreviewNondipping status is associated with greater cardiovascular morbidity and mortality and faster progression of chronic kidney disease (CKD). We examined whether shifting 1 antihypertensive drug from morning to evening restores the circadian rhythm of blood pressure in nondipper patients with CKD. Full-Text PDF Timing Antihypertensives to Reduce Nocturnal Blood Pressure in CKD: The Importance of Choosing the Right DipAmerican Journal of Kidney DiseasesVol. 51Issue 6PreviewWe read with great interest the article in the December issue of AJKD by Minutolo et al.1 While the report showed noteworthy results with a simple manipulation in the timing of therapy, there was little mention of a frequent cause of “nondipping,” namely obstructive sleep apnea (OSA). The authors reported the body weight, but failed to mention the more meaningful body mass index (BMI), so it is difficult to discern how many of the nondippers might actually have untreated OSA. A recent trial by Campos-Rodriquez2 found that after 24 months of continuous positive airway pressure (CPAP) therapy, 24-hour mean arterial pressure was significantly reduced in those with incompletely controlled hypertension and those who demonstrated adequate CPAP adherence. Full-Text PDF