Сhanges in the functional state of the epithelium of the proximal renal tubules in patients with the initial stage of chronic heart failure during simvastatin therapy

Abstract

To assess the change in the functional state of the proximal renal tubule epithelium in patients with dyslipidemia on the background of obesity, by determining the concentration in the urine of the examined level of cystatin C and the degree of activity of the renal organ-specific enzymes neutral α-glucosidase (NAG) and L-alaninaminopeptidase (laap) during simvastatin therapy at a daily dose of 20 mg for 6 months. The study involved 88 people who were divided into three groups: control, comparison and main. The control group is a group of practically healthy individuals: 30 people, average age 20.67 ± 0.18 years, body mass index (BMI) 21.36 ± 0.4 kg/m2. Comparison group (obese): 27 people, average age 22.38 ± 0.76 years, BMI 31.48 ± 0.56 kg / m2. Patients of the main group were divided into 2 subgroups. The first main subgroup of persons with chronic heart failure stage I (CHF I) without type 2 diabetes mellitus (DM 2)) - 15 observed: average age 56.8 ± 1.8 years, BMI 30.28 ± 1.11 kg / m2. The second main subgroup (CHF I with DM 2) - 16 observed: average age 48.25 ± 2.45 years, BMI 30.37 ± 1.11 kg/m2. The study found that simvastatin therapy does not affect glomerular filtration rate in patients with asymptomatic heart dysfunction. There was an increased level of cystatin C in the urine of the comparison group compared to the control group, the concentration of cystatin C in the main subgroups was statistically significantly higher than the control group. On the background of simvastatin therapy for 6 months, the level of this analyte is statistically significantly increased. The activity of LAAP and NAG during simvastatin therapy during the follow-up period in the CHF I subgroup without DM2 significantly decreased. In the subgroup of CHF I + DM2, a decrease in the concentration of LAAP and an increase in the activity of NAG was revealed, which may indicate that the brush border epithelium dystrophy occurred during simvastatin therapy. Simvastatin therapy for 6 months in patients with the initial stage of heart failure at a daily dosage of 20 mg does not impair glomerular function in the form of reduced glomerular filtration rate (GFR). Cystatin C levels are higher in obese individuals without heart failure and significantly higher in those with asymptomatic heart failure. When treating dyslipidemia with simvastatin at a dose of 20 mg / day, there is a decrease in the activity of NAG and laap in patients with CHF I without DM2. In the result of lipid-lowering therapy with simvastatin in a daily dosage of 20 mg in patients with CHF I+D2M there is increased activity of NAG while reducing the concentration of the LAAP, which may be due to degeneration of the proximal tubular epithelium, amid additional load on a partially renal route of metabolism of simvastatin.