Elevated blood pressure is not associated with accelerated glomerular filtration rate decline in the general non-diabetic middle-aged population

Abstract

Although hypertension is a risk factor for end-stage renal disease, this complication develops in only a minority of hypertensive patients. Whether non-malignant hypertension itself is sufficient to cause reduced glomerular filtration rate (GFR) is unclear. We investigated whether elevated blood pressure (BP) was associated with accelerated GFR decline in the general population. The study was based on the Renal Iohexol-clearance Survey in Tromsø 6 (RENIS-T6), which included a representative sample of 1594 subjects aged 50 to 62 years from the general population without baseline diabetes, kidney or cardiovascular disease. GFR was measured as iohexol clearance at baseline and follow-up after a median observation time of 5.6 years. BP was measured according to a standardized procedure. The mean (standard deviation) GFR decline rate was 0.95 (2.23) mL/min/year. In multivariable adjusted linear mixed regressions with either baseline systolic or diastolic BP as the independent variable, there were no statistically significant associations with GFR decline. We conclude that elevated BP is not associated with accelerated mean GFR decline in the general middle-aged population. Additional genetic and environmental factors are probably necessary for elevated BP to develop manifest chronic kidney disease in some individuals.

High Ambulatory Arterial Stiffness Index Is an Independent Risk Factor for Rapid Age-Related Glomerular Filtration Rate Decline in the General Middle-Aged Population

“…6,8,26 This finding suggested that arterial stiffness might be an early stage in the mechanism for accelerated GFR decline. We previously reported that baseline conventional BP per se did not accelerate age-related GFR decline in the RENIS cohort, 19 and the current investigation found the same results for ABP (Table 3).…”

“…38 In the current study, ambulatory PP was not a predictor of GFR decline, which confirmed our previous analyses based on baseline conventional BP. 19 AASI remained a significant predictor of the same magnitude even when adjustments were made for ambulatory PP or other baseline ABP components in sensitivity analyses.…”

“…13 We adjusted for drift in the method between baseline and follow-up by reanalyzing frozen baseline samples, as described previously. 19 The intraindividual variation in the GFR measurements for a random sample of RENIS-FU participants with repeated investigations after 2 weeks and within 2 months was 4.2%.…”

Association of Increasing GFR with Change in Albuminuria in the General Population

“…In the RENIS-FU Study, we obtained a repeated GFR measurement after 2 weeks and within 2 months from a random sample of 86 participants. The mean coefficient of variation for the intraindividual variation in GFR was 4.2% (95% confidence interval, 3.4% to 4.9%) as recently reported (23).…”

Comparability of Plasma Iohexol Clearance Across Population-Based Cohorts

“…In RENIS-FU, the CV of recalculated GFR from the remeasured single samples can be compared to the CV of interindividual day-to-day variation in GFR (2.6% vs 4.2%), established in a previous study of the same cohort. 34 By calculating the corresponding variance from the mean GFR observed in that analysis (94 mL/min), 34 we can estimate that~38% of the total day-to-day variance in GFR can be attributed to measurement error, and the rest, to intraindividual biological variation. This result should nevertheless be interpreted with caution because several authors have reported higher CVs for the total day-to-day variation, in the range of 5% to 10%.…”