Investigating the Relationship of Anthropometric Indices with Kidney Function and Serum Levels of Fibroblast Growth Factor-23 and Matrix Gamma Carboxyglutamate Protein in Kidney Transplant Patients

Considering that overweight and obesity in transplant patients are considered as a risk factor for the occurrence of metabolic disorders, heart diseases and reduced kidney function, therefore, the purpose of the present study was to determine and investigate the relationship between anthropometric indicators and kidney function. In addition, the serum levels of fibroblast growth factor-23 and matrix gamma carboxyglutamate protein were markers of cardiovascular disease risk in kidney transplant patients.

The present study was conducted as a cross-sectional study in 2016-2019. Ninety kidney transplant patients referred to Tabriz Imam Reza (AS) hospital clinic, between 18 and 70 years of age and had normal kidney function and were within 6-12 months after transplant, were selected. Weight, height, waist circumference, body mass index and ratio of waist circumference to height were measured. Serum levels of fibroblast growth factor-23 and dephosphorylated and non-carboxylated protein matrix gamma carboxyglutamate were measured and glomerular filtration rate was calculated as an index of kidney function. Collected data were analyzed using Kolmogorov-Smirnov, Pearson and Spearman statistical tests.

The mean and standard deviation of the age of the subjects was 44.10±13.05 years and 59% of the patients were male. Mean ± standard deviation of weight, body mass index, waist circumference and ratio of waist circumference to height of the patients were 69.61±11.59 kg, 25.77±4.42 kg/m2, 94.07±15.48 cm and respectively. It was 0.58±0.11. The prevalence of overweight and obesity based on body mass index was 38% and 17%, respectively. The mean ± standard deviation of the glomerular filtration rate is 57.45±12.61 ml/min per 1.73 square meter and the serum level of fibroblast growth factor-23 is 73.63±20.9 units/ml and the median (25th percentile) and the 75th percentile) the dephosphorylated and non-carboxylated protein gamma carboxy glutamate matrix of serum was also (1.3, 60.20) 2.40 micrograms/liter. Significant correlation between anthropometric indices with glomerular filtration rate and serum levels of fibroblast growth factor-23 and matrix gamma carboxy glutamate dephosphorylated and non-carboxylated protein, as well as between glomerular filtration rate and serum levels of fibroblast growth factor-23 and matrix gamma carboxy glutamate dephosphorylated protein and Non-carboxylated was not observed (p>0.05). A significant inverse correlation was observed between serum levels of fibroblast growth factor-23 and dephosphorylated and non-carboxylated protein gamma-carboxyglutamate matrix (p=0.036).

Considering that in the present study, the average weight, body mass index and also the performance of all patients were almost within the normal range, therefore, there is a significant relationship between anthropometric indices with glomerular filtration rate and serum levels of fibroblast growth factor-23 and gamma carboxy matrix. Dephosphorylated and non-carboxylated protein glutamate was not observed.