Epidemiology and Trends in Survival of Systemic Sclerosis in Olmsted County (1980-2018): A Population-based Study

A scoping review of the epidemiology of systemic sclerosis and its organ manifestations: 2018-2024

PURPOSE OF REVIEW

Updates from large, observational cohorts and new statistical techniques have resulted in new data on the epidemiology of systemic sclerosis (SSc). This scoping review uses data from 2018 to 2024 to describe the current understanding of the epidemiology of SSc and several of its organ- manifestations.

RECENT FINDINGS

Our review identified new estimates for the global incidence and prevalence of SSc (1.4-8.6 per 100 000 person-years and 17.6-18.9 per 100 000 individuals, respectively). Mortality rates remain high, though mortality at younger ages has decreased. interstitial lung disease and pulmonary arterial hypertension remain the most common causes of death for patients with SSc. Literature on gastrointestinal (GI) manifestations of SSc was scarce, and we identified significant heterogeneity in results. Furthermore, data on the epidemiology of racial, ethnic and sex-based disparities was lacking.

SUMMARY

New techniques for the evaluation of the epidemiology of SSc highlight the high morbidity and mortality of SSc, and a growing prevalence rate compared with prior eras. Further research is needed to address notable heterogeneity in the reporting of epidemiological data and understudied disease manifestations, including GI disease and health disparities in disease outcomes.

Pathogenesis of interstitial lung disease in systemic sclerosis

Interstitial lung disease (ILD) is a frequent important complication of systemic sclerosis (SSc). Factors relevant to aetiopathogenesis of SSc are also central to SSc-ILD. Severity of SSc-ILD is variable but it has a major impact on morbidity and mortality. Factors determining SSc-ILD susceptibility reflect the genetic architecture of SSc and are increasingly being defined. There are aspects linked to immunogenomics and non-immunological genetic factors that may be less conserved and underlie some of the geographical and racial diversity of SSc. These associations may also underlie important links between autoantibody subgroups and patient level risk of SSc-ILD. Examination of blood and tissue samples and observational clinical research together with integrated analysis of in vitro and in vivo preclinical models have elucidated pathogenic mechanisms of SSc-ILD. These have confirmed the potential importance of immune mechanisms in the innate and adaptive immune systemic as well as a significant role for profibrotic pathways especially transforming growth factor beta (TGFbeta) and its regulators and downstream mediators. Recent analysis of clinical trial cohorts as well as integrated and multilevel high dimensional analysis of bio-samples has shed further light on SSc-ILD. This is likely to underpin future advances in stratified and precision medicine for treatment of SSc.

Association between sinusitis and incident rheumatic diseases: a population-based study

OBJECTIVES

To determine whether antecedent sinusitis is associated with incident rheumatic disease.

METHODS

This population-based case-control study included all individuals meeting classification criteria for rheumatic diseases between 1995 and 2014. We matched three controls to each case on age, sex and length of prior electronic health record history. The primary exposure was presence of sinusitis, ascertained by diagnosis codes (positive predictive value 96%). We fit logistic regression models to estimate ORs for incident rheumatic diseases and disease groups, adjusted for confounders.

RESULTS

We identified 1729 incident rheumatic disease cases and 5187 matched controls (mean age 63, 67% women, median 14 years electronic health record history). After adjustment, preceding sinusitis was associated with increased risk of several rheumatic diseases, including antiphospholipid syndrome (OR 7.0, 95% CI 1.8 to 27), Sjögren's disease (OR 2.4, 95% CI 1.1 to 5.3), vasculitis (OR 1.4, 95% CI 1.1 to 1.9) and polymyalgia rheumatica (OR 1.4, 95% CI 1.0 to 2.0). Acute sinusitis was also associated with increased risk of seronegative rheumatoid arthritis (OR 1.8, 95% CI 1.1 to 3.1). Sinusitis was most associated with any rheumatic disease in the 5-10 years before disease onset (OR 1.7, 95% CI 1.3 to 2.3). Individuals with seven or more codes for sinusitis had the highest risk for rheumatic disease (OR 1.7, 95% CI 1.3 to 2.4). In addition, the association between sinusitis and incident rheumatic diseases showed the highest point estimates for never smokers (OR 1.7, 95% CI 1.3 to 2.2).

CONCLUSIONS

Preceding sinusitis is associated with increased incidence of rheumatic diseases, suggesting a possible role for sinus inflammation in their pathogenesis.

Standardized mortality ratios in systemic sclerosis: a meta-analysis assessing overall and sex- and disease subtype-specific differences

OBJECTIVE

This study aims to evaluate the overall and sex- and illness subtype-specific standardized mortality ratios (SMRs) in patients with systemic sclerosis (SSc).

METHODS

We searched and examined studies that compared the overall and sex- and illness subtype-specific SMRs in patients with SSc to those in the general population using MEDLINE, EMBASE, and Cochrane databases (until May 2023). We then conducted a meta-analysis of the overall and sex- and illness subtype-specific SMRs in patients with SSc.

RESULTS

Overall, 29 studies including 30,673 patients with SSc and 5582 deaths met the inclusion criteria. Patients with SSc had a higher overall SMR than that in the general population (SMR: 2.742, 95% confidence interval [CI]: 2.224-3.38091, p < 0.001). The SMR significantly increased in populations from Europe, North America, Asia, and Oceania according to regional stratification. A sex-specific meta-analysis revealed a substantial increase in the SMR in both men and women (SMR: 3.598, 95% CI: 3.097-4.180, p < 0.001; SMR: 2.833, 95% CI: 2.4384-3.292, p < 0.001, respectively) and the mortality rate was higher in men compared to women. A substantial increase in the SMR in diffuse cutaneous SSc (dcSSc) and limited cutaneous SSc (lcSSc) was observed in a disease subtype-specific meta-analysis. In addition, the SMR in the dcSSc group was higher than that in the lcSSc group (SMR: 4.726, 95% CI: 3.795-5.885, p < 0.001; SMR: 1.987, 95% CI: 1.586-2.489, p < 0.001, respectively).

CONCLUSION

Our findings demonstrated that the mortality rate in patients with SSc was 2.74-times greater than that in the general population. The mortality rate was higher in men compared to women. Additionally, compared to patients with lcSSc, those with dcSSc showed much higher fatality rates.

Secular Trends in Systemic Sclerosis Mortality in the United States from 1981 to 2020

BACKGROUND

Systemic sclerosis (SSc) has the highest mortality rate among autoimmune disorders. Individuals with SSc frequently die from complications or infections related to SSc. Nonetheless, the sex-age-period interaction of SSc is complex and remains unclear. The study aims to analyze the secular trend of SSc mortality based on data regarding underlying cause of death (UCD) and multiple causes of death (MCD) and clarify the sex-age interaction with time.

METHODS

The multiple-cause mortality statistics provided by the National Center for Health Statistics were used to identify all deaths in the United States from 1981 to 2020 in which SSc was indicated anywhere on the death certificates. The age-standardized mortality rate (ASMR) was determined for both sexes, as well as the variations in these rates. Joinpoint regression analysis was utilized to determine the annual percentage change (APC) of ASMR.

RESULTS

A total of 44,672 and 66,259 individuals who died between 1981 and 2020 were identified based on the UCD and MCD data, respectively. According to the UCD data, SSc-related AMSR (SSc-ASMR) of the male and female decedents, respectively, declined from 5.01 and 1.94 in 1981-1990 to 4.77 and 1.32 in 2011-2020, respectively (mortality rate ratio 0.95, 95% confidence interval 0.92-0.98). From 1986 to 1999, the APC of SSc-ASMR in female decedents decreased except for those aged 45-64 years (APC 2.1%, p = 0.002). For MCD analysis, in trend 1, only APC of SSc-ASMR in male decedents aged 45-64 years decreased. The SSc-ASMR of both male and female decedents fell on trend 2 arm. In 2011-2020, the ratio of UCD to MCD increased across all age groups for both sexes compared to 1981-1990. Overall, compared to the male decedents, the SSc-ASMR in female decedents increased significantly before 1999, peaked in 1999, followed by continuous decrease until 2020 according to UCD and MCD statistics.

CONCLUSIONS

Over the past four decades, the SSc deaths based on the MCD data were 1.48 times more than the UCD data, and the proportion of UCD over MCD increased over time. The SSc-ASMRs in all the sex-age groups significantly decreased over the past two decades. Notably, the mortality rate ratio of women to men with SSc increased in the past four decades.