Epidemiological features of primary glomerular disease in Turkey: a multicenter study by the Turkish Society of Nephrology Glomerular Diseases Working Group.

BACKGROUND: The largest data on the epidemiology of primary glomerular diseases (PGDs) are obtained from the databases of countries or centers. Here, we present the extended results of the Primary Glomerular Diseases Study of the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) Working Group. METHODS: Data of patients who underwent renal biopsy and received the diagnosis of PGD were recorded in the database prepared for the study. A total of 4399 patients from 47 centers were evaluated between May 2009 and May 2019. The data obtained at the time of kidney biopsy were analyzed. After the exclusion of patients without light microscopy and immunofluorescence microscopy findings, a total of 3875 patients were included in the study. RESULTS: The mean age was 41.5 ± 14.9 years. 1690 patients were female (43.6%) and 2185 (56.3%) were male. Nephrotic syndrome was the most common biopsy indication (51.7%). This was followed by asymptomatic urinary abnormalities (18.3%) and nephritic syndrome (17.8%). The most common PGD was IgA nephropathy (25.7%) followed by membranous nephropathy (25.6%) and focal segmental glomerulosclerosis (21.9%). The mean total number of glomeruli per biopsy was 17 ± 10. The mean baseline systolic blood pressure was 130 ± 20 mmHg and diastolic blood pressure was 81 ± 12 mmHg. The median proteinuria, serum creatinine, estimated GFR, and mean albumin values were 3300 (IQR: 1467-6307) mg/day, 1.0 (IQR: 0.7-1.6) mg/dL, 82.9 (IQR: 47.0-113.0) mL/min and 3.2 ± 0.9 g/dL, respectively. CONCLUSIONS: The distribution of PGDs in Turkey has become similar to that in other European countries. IgA nephropathy diagnosed via renal biopsy has become more prevalent compared to membranous nephropathy.

Fibroblast growth factor-23 but not sKlotho levels are related to diastolic dysfunction in type 1 diabetic patients with early diabetic nephropathy.

PURPOSE: To investigate the soluble Klotho (sKlotho) and fibroblast growth factor-23 (FGF-23) levels and echocardiographic findings in type 1 diabetic patients with no or early diabetic nephropathy. METHODS: A total of 147 subjects (mean age 34.1 ± 9.2 years, 55.8 % were females) including type 1 diabetic patients with glomerular filtration rate (GFR) >60 ml/min (n = 71, mean age 34.3 ± 9.5 years, 54.9 % were females) and healthy controls (n = 76, mean age 33.9 ± 9.1 years, 56.6 % were females) were included in this study. Data on demographic characteristics, blood biochemistry, urinalysis, diabetes-related complications and echocardiography were recorded. Serum levels for sKlotho and FGF-23 were determined by ELISA method. RESULTS: Patient and control groups were similar in terms of mean sKlotho (509.2 ± 183.5 and 547.6 ± 424.0 pg/ml, respectively) and FGF-23 (76.2 ± 15.6 and 77.2 ± 15.1 pg/ml, respectively) levels as well as echocardiographic findings. No significant correlation of sKlotho (pg/ml) and FGF-23 (pg/ml) levels with cardiac parameters was noted among diabetic patients. In subgroup analysis, the correlations between FGF-23 levels and isovolumic relaxation time (ms) and early diastolic velocity at medial/septal annulus (E'med) (m/s) were significant only in patients with early diabetic nephropathy (DN) but not in non-DN patients. No significant association of sKlotho levels with echocardiographic findings was noted. CONCLUSIONS: Our findings in young adult type 1 diabetic patients with GFR >60 ml/min versus healthy controls revealed no difference between groups in terms of sKlotho and FGF-23 levels and echocardiographic findings, while a significant correlation of FGF-23 (pg/ml) levels and diastolic dysfunction was noted only in patients with DN.