Malnutrition is an independent risk factor for mortality in Mexican patients with systemic sclerosis: a cohort study

Factors for mortality in systemic sclerosis (SSc) vary in different cohorts around the world. Case-control study nested in a cohort. We included patients <= 16 years of age with SSc (ACR/EULAR 2013), from 2005 to 2015. Demographic and clinical variables and causes of mortality were recorded. We calculated Crude Mortality Rate (CMR), Standardized Mortality Ratio (SMR), and Kaplan-Meier survival analysis was performed. A Cox proportional hazard (HR) regression analysis of the potential risk factors associated with mortality was also performed. A total of 220 patients with SSc were included. During follow-up, 28 deaths occurred. The sum of total time contributed by all subjects was 1074 years-person, the CMR was 12.72%, the overall SMR was 4.5, in women 3.7, and in men 4.7. The survival rate at 5 and 10 years was 83 and 70%, respectively. The causes of death were definitively attributed to SSc in 21.4% of the cases, probably in 28.7%, unrelated in 35.6%, and unknown in 14.3%. The direct cause of death of the patients was infection in 25% of cases, cardiovascular disease in 14%, lung involvement in 14%, pulmonary embolism in 11%, and neoplasia in 11%. The Cox regression analysis showed that the factors associated with mortality were: male gender (HR 5.84, CI 95% 1.31-26, p = 0.013), severe Medsger's score for general symptoms (HR 5.12, CI 95% 1.74-14.97, p = 0.021) and severe malnutrition (HR 3.77, CI 95% 1.23-11.06, p = 0.008). Infections, cardiovascular disease, and lung involvement were the leading cause of death. Male gender and severe general affection and malnutrition were associated with a poorer prognosis of SSc.