High frequency of nocturnal hypertension in lupus nephritis: should ABPM be implemented in usual practice?

Hypertension management in lupus nephritis (LN) is guided by in-office blood pressure (BP); however, recent studies demonstrate that lupus patients frequently have nocturnal hypertension and reduced BP dipping. The aim of the study was to evaluate 24-h blood pressure in patients with active LN and after response to treatment.

Seventy active LN patients were evaluated during a LN flare by ambulatory blood pressure monitoring (ABPM). Later, 10 patients with complete response were re-evaluated after 12 months along with 20 matched controls. Overall, daytime and nightime BP, day-to-night dipping, BP load and variability, and the incidence of abnormal BP patterns were assessed. Blood pressure levels were correlated with clinical and histologic parameters and independent associations evaluated by linear regression.

Overall systolic hypertension occurred in 25 (36%) patients and diastolic hypertension in 28 (40%). Nighttime systolic and diastolic hypertension occurred in 35 (50%) and 44 (63%) of patients, respectively. Nocturnal systolic day-to-night BP decrease was abnormal in 59 (84%) patients. Only 18 (26%) were diagnosed with HT by in-office evaluation while 29 (41%) had masked hypertension (MH)/masked uncontrolled hypertension (MUCH), and 3 (4%) had white coat hypertension. Patients with MH had lower eGFR, complement C3, hemoglobin, and higher systolic variability compared with patients with normal BP. Systolic and diastolic BP levels were associated with the years under corticosteroid treatment, activity biomarkers (proteinuria, complement C3), and the degree of interstitial inflammation in the kidney biopsy. A re-evaluation at 12 months showed that although 9 out of 10 patients had normal in-office BP and BP loads improved, still 5 patients remained with MH due to nocturnal hypertension, and 7 remained with abnormal day-to-night dipping. These numbers were higher than those of matched controls.

Due to the high frequency of nocturnal hypertension and abnormal day-to-night dipping, office BP measurements alone may not be sufficient to guide hypertension management in patients with LN.Key Points• Nocturnal hypertension and abnormal BP patterns are frequent and not detectable by the standard in-office BP evaluation in LN patients.• BP abnormalities may not be fully corrected after a complete clinical response to treatment in lupus nephritis and are only detectable by ABPM.• The degree of interstitial inflammation in the kidney biopsy in LN patients is associated to BP levels. This supports the hypotheses underlining the role of interstitial inflammation in salt sensitivity and hypertension.