Association of Impaired Diurnal Blood Pressure Variation With a Subsequent Decline in Glomerular Filtration Rate

Abstract

Background: Most healthy people exhibit a decrease in systolic blood pressure (SBP) at night. A drop of less than 10% from mean daytime values (nondipping) is associated with chronic kidney disease, insulin resistance, and cardiovascular events. Whether nondipping precedes a decline in renal function remains unclear. We hypothesized that nondipping would predict a decline in the glomerular filtration rate (GFR) over time.Methods: Consecutive patients referred for ambulatory blood pressure monitoring were included in our retrospective cohort if they had a serum creatinine level noted at the time of their ambulatory blood pressure recording and a follow-up creatinine level recorded at least 1 year later. Mean day and night SBPs were compared (daytime SBP-nighttime SBP ratio). We defined nondipping as a daytime SBP-nighttime SBP ratio higher than 0.90. The GFR was calculated using the Modification of Diet in Renal Disease 4-variable equation.Results: Of 322 patients included, 137 were dippers and 185 were nondippers; their mean baseline GFRs were 80.5 mL/min per 1.73 m 2 and 76.4 mL/min per 1.73 m 2 , respectively. During a median follow-up of 3.2 years, the GFRs remained stable among dippers (mean change, 1.3%) but declined among nondippers (mean change, −15.9%) (PϽ.001). The creatinine levels increased by more than 50% in 2 dippers (1.5%) and in 32 nondippers (17.3%) (PϽ.001). These findings persisted after adjustment for other predictors of GFR decline. Conclusion:Blunted diurnal blood pressure variation is associated with a subsequent deterioration in renal function that is independent of SBP load and other risk factors for renal impairment.

Ausência de descenso noturno se associa a acidente vascular cerebral e infarto do miocárdio

“…However, when the 24-hour period was assessed, this behavior pattern was not observed. These findings, in general, differ from those found in literature [14][15][16]18,19 .…”

“…After the biochemical dosages, we found that, except for the higher levels of HDL-c in ND patients, the remaining variables did not present statistical significance, findings that are similar to those observed in other studies 15,16 . Despite the lower HDL-c in non-dipper patients, there was no correlation to higher risk of lesions in target-organs.…”

“…ND attenuation was associated with the presence of other cardiovascular risk factors (obesity and lower HDL-c) and also with a higher frequency of lesion in target-organ. Studies on the prevalence of cardiovascular and cerebral events varies greatly in the specific literature (Table 5), reaching a frequency of 37.5 to 64.2% [11][12][13][14][15][16][17][18][19][20][21] under several factors' influence, like the definition of sleep and vigil periods 22 .…”

“…These authors showed a direct relation between higher BMI and higher mean pressure for ABMP, and 55% of the individuals with normal weight (normal BMI) presented ND, while only 35% of the obese individuals presented the same condition (p<0.05). Others, however, did not find such association 12,[14][15][16]19 . In our sample, after the logistic regression model, we observed that BMI was not correlated to a higher risk for stroke or MI in ND patients.…”

“…Other authors observed that individuals without ND were older 16,18,19 and that this condition occurs preferentially in non-white people 19 . In the current study, BMI was higher in individuals without ND (30.9 ± 5.7 x 29.2 ± 5.0, p=0.0377), fact also observed by Kotsis et al 27 in 3,216 patients without previous anti-hypertensive treatment.…”