Allostatic load index in patients with multiple sclerosis: A case-control study

Elevated allostatic load (AL) index is a cumulative measure of biological dysregulations associated with stress exposure. It has been reported that stress plays an important role in the pathophysiology of multiple sclerosis (MS). However, the AL index has not been investigated in this population so far. Therefore, we aimed to investigate the AL index in patients with MS compared to healthy controls. A total of 90 patients with relapsing-remitting MS (76.7% females) and 47 healthy controls (76.6% females) were included in the study. The AL index was computed based on percentile distributions of 18 biomarkers. The AL index was significantly higher in patients with MS compared to healthy controls (2.74 ± 0.99 vs. 1.96 ± 0.71, p < 0.001), even after adjustment for age and education. With respect to specific AL biomarkers, individuals with MS had significantly lower resting heart rate, the levels of high-density lipoproteins and dehydroepiandrosterone sulfate as well as significantly higher level of hsCRP and albumin compared to healthy controls. There were no significant correlations of the AL index with depressive and anxiety symptoms, perceived stress, type D personality traits, insomnia, the odds of using specific coping strategies as well as MS-related clinical characteristics. These findings indicate that the AL index is increased in patients with MS. However, the exact mechanisms underlying this observation remain unknown and require additional studies.