Assessment of the rate of glomerular filtration by a non-invasive method

Background. Existing methods for assessing glomerular filtration rate (GF) are invasive. Therefore, we set ourselves the goal of evaluating the rate of glomerular filtration by a non-invasive method. Materials and Methods. The object of observations were 10 men aged 37-69 years without clinical diagnosis tested twice with 7-days interval. The rate of glomerular filtration was calculated according to endogenous creatinine clearance and the Cockcroft & Gault formula. Systolic and diastolic blood pressure was measured three times in a row. The state of the autonomic nervous system was assessed by the HRV method. Results. We confirmed the significant correlation of GF with age and weight. The screening revealed a significant correlation of GF with a number of blood pressure and HRV parameters. If in the classic formula we replace creatinineemia with systolic blood pressure and HRV-markers of sympathetic tone, we get a formula for estimating the GF with a standard error of 10,9 mL/min vs 2,7 mL/min, but without blood sampling. The regression model, which includes HRV and blood pressure parameters, as well as urinary creatinine concentration, allows estimating GF with a standard error of 12 mL/min. Conclusion. The balneotherapy has a significant effect not only on blood creatinine level, but also on HRV and blood pressure parameters, and even more pronounced. Therefore, the estimation of GF based only on the Cockcroft & Gault formula is at least not much more accurate than the one proposed by us, besides, our method is completely non-invasive.