Background Apart from scleroderma renal crisis, which is a rare but life-threatening condition in systemic sclerosis (SSc), many patients demonstrate less severe renal complications, probably associated with reduced renal blood flow and the consequent reduction in glomerular filtration rate (GFR).
Objectives To identify risk factors associated with reduced GFR in patients with SSc.
Methods 73 consecutive patients with SSc (67 women and 6 men), mean age 56.2 years, mean disease duration 6.7 years, were included in this study. Fifty (68.5%) of patients had limited SSc, and 23 (31.5%) had diffuse form of the disease. ACA were positive in 27 (37%) and ATA in 34 (46.6%) of patients. GFR was assessed by calculating creatinine clearance (CCr) in all patients. CCr values ≥90ml/min were considered normal. There are four stages of renal insufficiency depending on the calculated CCr value: mild (60-89ml/min), moderate (40-59ml/min), severe (15-39ml/min) and terminal (end-stage) renal failure (less then 15ml/min). We assessed the prevalence and severity of renal insufficiency in our patients with SSc, and estimated the relationship with age, disease duration, earlier diagnosed arterial hypertension and the use of medications which may have impact on renal function (cytostatics, NSAIDs, corticosteroids, ACE inhibitors, diuretics and calcium channel blockers). The univariate General Linear Model (GLM), ANOVA, Mann-Whitney and Student's T-test from SPSS 14.0 software were used for statistical analyses.
Results Decreased GFR was noticed in 56/73 (76.7%) of patients with SSc. Mild renal insufficiency was present in 28/73 (38.4%), moderate in 21/73 (28.8%), severe in 5/43 (6.8%) and terminal in 2/73 (2.7%) of patients. Age, disease duration, cytostatics or NSAIDs were found not to be risk factors associated with low GFR. On the other hand, we have noticed a statistically significant association between corticosteroid use and reduced GFR (F=11.89, p=0.001), as well as previously diagnosed arterial hypertension and reduced GFR (F=4.77, p=0.03). Moreover, mean GFR was significantly lower (F=4.88, p=0.008) in SSc patients and arterial hypertension treated with ACE-inhibitors (41.7ml/min) or diuretics (53.5ml/min), than in patients treated with calcium channel blockers (90.4ml/min).
Conclusions Corticosteroid use and arterial hypertension are independent risk factors associated with reduced GFR in SSc. Compared to calcium channel blockers, ACE-inhibitors and diuretics, used to treat arterial hypertension in our patients, are associated with lower GFR.
Disclosure of Interest None declared