This is the first reported evaluation of RP, potential VEDOSS, and SSc in this relatively young cohort of Post-9/11 Veterans. This provides a unique population of SSc patients that can allow a better understanding of the natural history of this connective tissue disease characterized by vasculopathy and progressive fibrosis in several respects. It allows study in a primarily male population, provides insight into possible military exposures associated with RP, describes associated comorbidities, and possible treatment gaps. Our study suggests an under-diagnosis of these conditions in Veterans and the need for better screening and treatment of vasculopathy.
This study found that in a this health system, RP, VEDOSS and SSc occur possibly at a higher rate in men in the VA than the general population. The increased likelihood of RP, potential VEDOSS and SSc in Veteran females is consistent with estimates from other population-based studies of SSc and RP [12,13,14]. The study of a predominately-male cohort is important since there are more severe internal organ-based complications and higher mortality in men with SSc [15]. Our previous work using Veteran’s electronic health records highlights that ICD-9 code may not capture all cases of SSc in Veterans [9].
The younger age of those with RP than with VEDOSS or SSc supports the concept of reporting both RP and non-RP disease duration in analyses of SSc is important for understanding pathogenesis [16]. In this present study, we identified individuals with VEDOSS, patients with puffy hands and RP who are at higher risk for SSc, but who do not yet meet full criteria for SSc. An increase prevalence of autoimmune disorders and musculoskeletal pain is reported among Veterans serving in Afghanistan and Iraq [17,18,19]. While our study does not adequately characterize the source of pain, our data suggest that there is a need for further surveillance of Veterans with RP and VEDOSS to understand disease features and potentially that SSc is under-diagnosed in male Veterans.
There was no difference in the likelihood RP, potential VEDOSS or SSc across branch of military service. This result should be verified in future studies due to the rare nature of VEDOSS and SSc. However, RP patients were more likely to be craft-workers, health care workers, or in engineering /maintenance. Perhaps RP symptoms are more commonly reported in Veterans using their fingers for fine motor activities.
Alternatively, this may highlight the value of understanding occupational exposures that are unique to this patient population. As an example, polyvinyl chloride is used largely as coatings for computer cables and wires and is reported as a potential occupational risk factor for SSc [20,21,22,23]. Exposure to cleaning products, solvents and adhesives is associated with increased risk of SSc [24]. Exposures to these products could be greater among craft-workers, health care workers, and those in engineering/maintenance. Our work highlights the importance of further exposure assessments in all service branches. There is evidence in other military cohorts that exposures are important for autoantibody formation in autoimmune disease [25]. Our study emphasizes that increased awareness and improved protective professional measures are indicated. Differences in SSc risk between males and females may exist [26], and this cohort may allow future research to further examine those differences.
Use of vasodilators is standard of care for management of secondary RP, VEDOSS and SSc. We were unable to differentiate between primary and secondary RP in this cohort but our data suggests that vasodilators are potentially being under-utilized in VEDOSS and SSc Veteran population. Vasodilators treat both RP and hypertension. The importance of blood pressure monitoring and identification of hypertension is important in SSc patients [27]. This is a potentially unmet management need in the Veteran population. Our data demonstrates high prevalence of depression consistent with other reports that highlight mood and pain management is an important aspect of SSc [28]. Our data suggests this is also true for RP and potential VEDOSS patients. This cohort provides the possible opportunity for improved management of Veterans with RP, VEDOSS, and SSc.
The use of a national cohort of Veterans is a strength; however, there are also some limitations. In this cohort, the low prevalence of RP suggests that perhaps this billing code is underutilized. The prevalence of SSc in this cohort is also low compared to the prevalence reported in the literature, which could be a result of missed cases through the ICD-9 code identification that could have led to selection bias. As such, the small number of patients included in the potential VEDOSS and SSc sub-cohorts limit robust conclusions. The predominance of young males in the examined cohorts limits the extraction of any general conclusions for SSc and certain disease features such as esophageal involvement and pulmonary fibrosis. We did not have information on primary versus secondary RP. We did not have information on exposures associated with RP, such as use of vibration tools or amphetamines. In order to reduce errors associated with “rule out” diagnoses, identification of RP, potential VEDOSS and SSc cases required two diagnoses at least 7 days apart, which is likely a conservative estimate, especially for SSc cases where we did not have access to many clinical signs or biomarkers for SSc, such as ANA or autoantibody data, and subtype characterization of limited versus diffuse cutaneous disease. Our characterization of potential VEDOSS would be strengthened by serology data and capillaroscopy reports. The severity of RP and etiology of pain may introduce bias and explain the low use of vasodilators. Further classification of pain as a diagnostic code is needed to best interpret this symptom. Moreover, data from care in non-VA health care systems, including specialty care for SSc, is not represented in our database.
