Arterial Hypertension and Kidney Function Decline in Systemic Sclerosis and Sjögren’s Disease: A Longitudinal Comparative Study

Renal involvement is increasingly recognized in Systemic Sclerosis (SSc) and Sjögren’s Disease (SjD). However, the association between hypertension and renal function decline in these conditions remains poorly understood. to compare renal function changes over time in patients with SSc and SjD; identify factors associated with clinically relevant renal function decline; and to evaluate whether the association between hypertension and renal function differs between the two diseases. We retrospectively analyzed patients with SSc and SjD, followed for up to 3 years. Renal function was assessed using estimated glomerular filtration rate (eGFR). Clinically relevant renal decline was defined as a reduction in eGFR ≥10 ml/min Multivariable logistic regression identified factors associated with renal function decline, including the interaction between diagnosis and hypertension. A total of 238 patients were included (114 with SSc and 124 with SjD), with a median age of 55 years (IQR 45–65) in SSc and 57 years (IQR 48–66) in SjD. At baseline, SSc patients showed higher eGFR compared to SjD, but experienced a greater decline over time (median −6 vs −2.1 ml/min, p < 0.05). Overall, 33.8% of patients developed clinically significant renal decline. In multivariable analysis, hypertension was independently associated with renal function decline (OR 10.01, 95% CI 3.51–28.56, p < 0.001), whereas diagnosis was not. A significant interaction between diagnosis and hypertension was observed (OR 6.56, 95% CI 1.03–41.69, p = 0.046), indicating a stronger association between hypertension and renal function decline in SSc than in SjD. In subgroup analyses, hypertension was significantly associated with renal decline in SSc but not in SjD. Hypertension was independently associated with renal function decline, with a stronger association in SSc than in SjD. These findings warrant confirmation in prospective studies. Systemic Sclerosis, Sjögren's disease, Estimated Glomerular Filtration Rate; arterial hypertension