Seasonal Variation in Estimated Glomerular Filtration Rate Based on Serum Creatinine Levels in Hypertensive Patients

Abstract

Seasonal variations in blood pressures should be kept in mind when controlling blood pressure in hypertensive patients. Seasonal variations in glomerular filtration rate (GFR) also may have a clinical significance. However, it is time-consuming to measure GFR directly. We therefore examined the seasonal variation in estimated glomerular filtration rate (eGFR) based on serum creatinine levels in hypertensive patients without CKD (eGFR ≥ 60 mL/min/1.73 m 2 ) and those with chronic kidney disease (CKD) (eGFR < 60 mL/min/1.73 m 2 ). This study included 47 hypertensive patients without CKD (69 ± 11 yrs) and 55 hypertensive patients with CKD (76 ± 8 yrs). The eGFR was determined from the equation: eGFR = 194 × age −0.287 × (serum creatinine) −1.094 (× 0.739 if female). Overall, both groups of hypertensive patients demonstrated similar seasonal variations in eGFR. Importantly, hypertensive patients without CKD and those with CKD showed the lower eGFR in summer (June-August) (71.8 ± 13.2 and 37.2 ± 13.0 mL/min/1.73 m 2 , respectively) compared with the eGFR in spring (March-May) (77.9 ± 13.0 and 43.0 ± 14.0 mL/min/1.73 m 2 , respectively) ( p < 0.05). The decrease in eGFR from spring to summer was similar for both types of hypertensive patients (without CKD, −6.1 ± 7.0; with CKD, −5.8 ± 5.2 mL/min/1.73 m 2 ). However, the percent change in eGFR from spring to summer was greater in hypertensive patients with CKD (−13.8 ± 9.4 %) than in those without CKD (−7.7 ± 8.3 %) ( p = 0.001). In conclusion, careful observation regarding renal function is needed for hypertensive patients with CKD during summer.

Vitamin D status is seasonally stable in northern European dogs

“…Albumin and creatinine are biomarkers of kidney function and are routinely included in the diagnosis of chronic kidney disease. In humans, seasonal variation of kidney biomarkers has been identified, with albumin concentrations tending to be highest in winter months 47‐49 and creatinine concentrations highest in summer months 50,51 . In this study, cosinor analysis revealed statistically significant seasonal variation in both albumin and creatinine, with albumin concentrations peaking in autumn months (October and November) and creatinine concentrations peaking in late spring/early summer (May and June) in dogs.…”

Influence of Renal Function on the 52-Week Efficacy and Safety of the Sodium Glucose Cotransporter 2 Inhibitor Luseogliflozin in Japanese Patients with Type 2 Diabetes Mellitus

“…Although the reasons for the variations observed with luseogliflozin after Week 4 (eGFR was increased above the baseline level and decreased thereafter) remain unclear, 1 reason could be the involvement of seasonal variations, given that many patients included in this analysis tended to start and finish treatment during the summer when eGFR levels have a tendency to be decreased. 36 Furthermore, although our analysis showed that eGFR was significantly decreased at Week 52 in those with normal renal function, a subanalysis showed that eGFR tended to be decreased particularly in those with baseline eGFR Z120 mL/min/1.73 m 2 . Because elevated GFR is caused by intraglomerular hypertension, which, in turn, may lead to nephron loss, 37 our findings could suggest a favorable effect of luseogliflozin in those presenting with hyperfiltration by decreasing eGFR.…”

Protective effects of Eucommia lignans against hypertensive renal injury by inhibiting expression of aldose reductase

“…Aldose reductase (AR) can be activated by all of the above-mentioned pathways. AR is involved in proliferation of mesangial cells, deposition of extracellular matrix, inflammation, apoptosis, tubular injury and decrease of glomerular filtration rate (Kuo et al, 2006;Efrati et al, 2007;Ding et al, 2010;Zhang et al, 2010;Chang et al, 2011;Masugata et al, 2011), and ultimately result in renal dysfunction (Krzesinski and Cohen, 2007;Barri, 2008;Bidani et al, 2009).…”