Vitamin D, vitamin D binding protein, vitamin D receptor levels and cardiac dysautonomia in patients with multiple sclerosis: a cross-sectional study / Vitamina D, proteína de ligação à vitamina D, níveis de receptores de vitamina D e disautonomia cardíaca em pacientes com esclerose múltipla: um estudo transversal

ABSTRACT Vitamin D is a pleiotropic steroid hormone that modulates the autonomic balance. Its deficiency has been described as an environmental risk factor for multiple sclerosis (MS). The aim of this study was to investigate the serum levels of vitamin D, vitamin D binding protein (VDBP) and vitamin D receptors (VDR) and to evaluate cardiac dysautonomia in MS patients due to bidirectional interaction between vitamin D and the autonomic nervous system. Methods: The current cross-sectional study was conducted on 26 patients with relapsing-remitting MS and on 24 healthy controls. Twenty-four-hour ambulatory blood pressure variability (BPV) was calculated and the participants were evaluated for orthostatic hypotension and supine hypertension. Serum levels of vitamin D, VDBP and VDR were measured. Results: The mean serum vitamin D level was significantly lower in MS patients than in controls (p = 0.044); however there was no significant difference in terms of VDR and VDBP levels between the groups. Supine hypertension and orthostatic hypotension were significant and the 24-hour systolic BPV was significantly decreased in patients with MS (p < 0.05) compared to controls. No correlation was found between vitamin D, VDBP and VDR with supine hypertension, orthostatic hypotension and systolic BPV values (p > 0.05). Also, there was a negative correlation between VDBP and the EDSS (p = 0.039, r = −0.406). Conclusion: There was no correlation between orthostatic hypotension, supine hypertension and systolic BPV values and serum vitamin D, VDBP and VDR in MS patients. Future prospective studies with large number of patients may help us to better understand the relationship between vitamin D and the autonomic nervous system.

RESUMO A vitamina D é um hormônio esteroide pleiotrópico que modula o equilíbrio autonômico. Sua deficiência tem sido descrita como fator de risco ambiental para esclerose múltipla (EM). O objetivo deste estudo foi investigar os níveis séricos de vitamina D, proteína de ligação à vitamina D (VDBP) e receptor de vitamina D (VDR) e avaliar a disautonomia cardíaca em pacientes com EM devida à interação bidirecional entre vitamina D e sistema nervoso autônomo. Métodos: O presente estudo transversal foi realizado em 26 pacientes com EM remitente-recorrente e em 24 controles saudáveis. A variabilidade da pressão arterial ambulatorial (BPV) por 24 horas foi calculada e os participantes foram avaliados quanto à hipotensão ortostática e hipertensão supina. Os níveis séricos de vitamina D, VDBP e VDR foram medidos. Resultados: O nível sérico médio de vitamina D foi significativamente menor nos pacientes com EM do que nos controles (p = 0,044); no entanto, não houve diferença significativa em termos de níveis de VDR e VDBP entre os grupos. Hipertensão supina e hipotensão ortostática foram significativas e a BPV sistólica de 24 horas diminuiu significativamente em pacientes com EM (p < 0,05) em comparação aos controles. Não foi encontrada correlação entre vitamina D, VDBP e VDR com hipertensão supina, hipotensão ortostática e BPV sistólica (p > 0,05). Também houve correlação negativa entre VDBP e EDSS (p = 0,039, r = −0,406). Conclusão: Não houve correlação entre hipotensão ortostática, hipertensão supina e valores de BPV sistólica e vitamina D sérica, VDBP e VDR em pacientes com EM. Futuros estudos prospectivos com grande número de pacientes podem nos ajudar a entender melhor a relação entre vitamina D e sistema nervoso autônomo.

Intravenous Immunoglobulin Therapy in Refractory Autoimmune Dysautonomias: A Retrospective Analysis of 38 Patients.

BACKGROUND: Intravenous immunoglobulin (IVIG) has recognized efficacy in autoimmune peripheral nerve disorders, but there has been limited study of the use of IVIG in autoimmune dysautonomias. STUDY QUESTION: To determine the efficacy and safety of IVIG in patients with disabling, refractory autoimmune dysautonomias, including patients with postural tachycardia syndrome and gastrointestinal dysmotility. STUDY DESIGN: Patients with one or more autonomic disorder(s) and persistent serological evidence for autoimmunity who were unable to work or attend school despite usual treatments for dysautonomia were treated with IVIG for at least 3 months at a dose of at least 1 gm/kg monthly. MEASURES AND OUTCOMES: Outcome measures included the composite autonomic symptom scale 31 survey and a functional ability score. RESULTS: There were 38 patients, 84% female and mean age of 28.4 years. Of patients, 83.5% improved on IVIG as defined by at least 20% improvement in the composite autonomic symptom scale 31 and/or functional ability score. The mean pretreatment functional ability score was 21% (mostly bedridden), which improved to a mean of 74% (nearing able to return to work/school) for responsive patients after at least 1 year of IVIG. The mean time to the first sign of response was 5.3 weeks. There were no serious adverse events. The Mayo autoimmune dysautonomia panel antibodies and traditional Sjögren antibodies were present in only 13% and 8% of patients, respectively, but antiphospholipid antibodies and novel Sjögren antibodies were present in 76% and 42% of patients, respectively. CONCLUSIONS: There is increasing evidence that IVIG is safe and effective in a subset of patients with autonomic disorders and evidence for autoimmunity. A 4-month IVIG trial should be considered in severely affected patients who are refractory to lifestyle and pharmacological therapies. Antiphospholipid antibodies and novel Sjögren antibodies are often present in these patients and correlate with a high response rate to IVIG.

Vitamin D, vitamin D binding protein, vitamin D receptor levels and cardiac dysautonomia in patients with multiple sclerosis: a cross-sectional study.

OBJECTIVES: Vitamin D is a pleiotropic steroid hormone that modulates the autonomic balance. Its deficiency has been described as an environmental risk factor for multiple sclerosis (MS). The aim of this study was to investigate the serum levels of vitamin D, vitamin D binding protein (VDBP) and vitamin D receptors (VDR) and to evaluate cardiac dysautonomia in MS patients due to bidirectional interaction between vitamin D and the autonomic nervous system. METHODS: The current cross-sectional study was conducted on 26 patients with relapsing-remitting MS and on 24 healthy controls. Twenty-four-hour ambulatory blood pressure variability (BPV) was calculated and the participants were evaluated for orthostatic hypotension and supine hypertension. Serum levels of vitamin D, VDBP and VDR were measured. RESULTS: The mean serum vitamin D level was significantly lower in MS patients than in controls (p = 0.044); however there was no significant difference in terms of VDR and VDBP levels between the groups. Supine hypertension and orthostatic hypotension were significant and the 24-hour systolic BPV was significantly decreased in patients with MS (p < 0.05) compared to controls. No correlation was found between vitamin D, VDBP and VDR with supine hypertension, orthostatic hypotension and systolic BPV values (p > 0.05). Also, there was a negative correlation between VDBP and the EDSS (p = 0.039, r = -0.406). CONCLUSION: There was no correlation between orthostatic hypotension, supine hypertension and systolic BPV values and serum vitamin D, VDBP and VDR in MS patients. Future prospective studies with large number of patients may help us to better understand the relationship between vitamin D and the autonomic nervous system.