Impact of Sex on Systemic Lupus Erythematosus-Related Causes of Premature Mortality in the United States

Background: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that is a source of significantly decreased life expectancy in the United States. This study investigated causes of deaths among males and females with SLE. Materials and Methods: This cross-sectional study used the national death certificate database of approximate to 2.7 million death records in the United States, 2014. SLE was defined using Tenth Revision of the International Classification of Diseases codes: M32.1, M32.9, and M32.8. We compared sex-stratified demographic characteristics and the most commonly listed comorbidities in decedents with and without SLE. Relative risks (RRs) quantified the risk of dying with the most commonly listed comorbidities among decedents with SLE aged 50 years compared with non-SLE decedents. Results: There were 2,036 decedents with SLE in the United States (86.2% female). Female SLE decedents were 22 years younger than non-SLE females (median: 59 years vs. 81 years). This difference was 12 years among male decedents (median: 61 years vs. 73 years). The most frequently listed causes of death among female SLE decedents were septicemia (4.32%) and hypertension (3.04%). In contrast, heart disease (3.70%) and diabetes mellitus with complications (3.61%) were the most common among male SLE decedents. Among younger male decedents, SLE had higher co-occurrence of coagulation/hemorrhagic disorders and chronic renal failure compared with non-SLE (RR=16.69 [95% confidence interval {CI}=10.50-27.44] and RR=5.76 [95% CI=2.76-12.00], respectively). These also contributed to premature mortality among women (RR=4.98 [95% CI=3.69-6.70] and 8.55 [95% CI=6.89-10.61], respectively). Conclusions: Our findings identify clinically relevant comorbidities that may warrant careful consideration in patients' clinical management and the natural history of SLE.