Results
In our study, the renal biopsy samples of 70 patients with DM type 2 were evaluated. The mean age was 55.7 ± 9.4 of patients 43 (61.4) was male. The pathologic diagnosis of kidney biopsy was 38 (54.3%) DN and 32 (45.7%) PGN. The average time of DM diagnosis at the time of kidney biopsy was 9.15 ± 7.5 years. During the biopsy, two patients were diagnosed with new DM. In PGN group, membranous GN (20, 62.5%), focal segmental glomerulosclerosis (FSGS) (8, 25%) IgA nephropathy (IgAN) (2, 6.3%) and minimal change disease (MDH) (2, 6.3%) were detected (Table 1).
According to PGN in DN patients; the duration of DM was longer (p<0.001), the frequencies of retinopathy (p<0.001), neuropathy(p<0.001), hypertension (p=0.0025), coronary artery disease (p=0.008), heart failure (p=0.013) were higher. In DN group hemoglobin level was lower and the number of patients with eGFR <30, <60 and <90 ml/min /1.73 m2 were higher (for all p <0.001) (Table 2).
At the time of renal biopsy, fasting blood sugar, HbA1C, blood pressure, serum albumin, and proteinuria values were similar in 2 groups. DN patients had lower eGFR values at baseline, sixth and 12th months, and higher proteinuria at sixth and 12th months than PGN patients. In the first year after kidney biopsy decrease in eGFR was higher in DN patients, whereas eGFR did not change in PGN patients. At the time of biopsy, daily proteinuria was not different between the two groups, but in the 6th and 12th months, the daily proteinuria was lower in the PGN group.
The pathological damage findings of kidney biopsy (percentage of interstitial fibrosis, presence of tubular atrophy, sclerosis glomeruli number) in DN patients were more severe.
There were differences for eGFR change between the DN group and PGN group at 0, 6, and 12th months. (F(1,56)=46.336, p<0.001)(Table 3 ve Figure 1). There were differences between for eGFR values each other baseline, 6th, and 12th months in DN patients (F(1.2, 32.392)=16.727, p<0.001). In PGN patients, there was no difference between eGFR changes at 0, 6, and 12th months. (F(1.247, 7.480)=0.887, p=0.401). There was no difference between eGFR changes at 0, 6, and 12 months in all patients (DN + PGN). (F(1.304, 74.356)=2.388, p=0.118)