Risk factors for hypertension in primary Sjögren's syndrome patients: a nomogram was constructed

Cardiovascular disease (CVD) is one of the main causes of death in primary Sjögren' s syndrome (pSS) patients, while hypertension is considered an independent risk factor for CVD in pSS patients and its prevalence is increased compared with the general population. In order to identify risk factors of hypertension in patients with pSS, this study included 293 pSS patients admitted in the Third People's Hospital of Chengdu from April 2011 to August 2020 and 195 pSS patients admitted in Sichuan Provincial People's Hospital from January 2011 to June 2018. The multiple logistic regression was used to screen risk factors and nomogram was drawn based on regression coefficients. Then C-index and calibration plot were used to estimate its discrimination and calibration, respectively. Compared with pSS patients without hypertension, those with hypertension were older, higher in blood pressure, longer in duration of pSS, and had higher rates of smoking, xerophthalmia, xerostomia, previous use of botanicals, NSAIDs, and statins. Moreover, they were more likely to have pulmonary interstitial fibrosis and had higher levels of serum lipids and renal function indicators (all P < 0.05). Finally, a nomogram based on four significant factors (age, duration of pSS, LDL-c, and anti-SSA antibody) was constructed. Its' C-index is 0.812 (95% CI: 0.754-0.870), and it shows a good calibration. C-index value of 0.721 and good calibration still could be reached in external verification. Clinicians can use it in pSS population for early detection of hypertension and if necessary, early preventive measures could be taken to reduce its occurrence.