Frontiers in Endocrinology (Nov 2020)

Improvement in Cardiovascular Autonomic Neuropathy After High-Dose Vitamin D Supplementation in Patients With Type 1 Diabetes

  • Lilian de Souza D’Albuquerque Silva,
  • Natércia Neves Marques de Queiroz,
  • Franciane Trindade Cunha de Melo,
  • João Felício Abrahão Neto,
  • Luísa Corrêa Janaú,
  • Norberto Jorge Kzan de Souza Neto,
  • Manuela Nascimento de Lemos,
  • Maria Clara Neres Iunes de Oliveira,
  • Angélica Leite de Alcântara,
  • Lorena Vilhena de Moraes,
  • Wanderson Maia da Silva,
  • Ícaro José Araújo de Souza,
  • Nivin Mazen Said,
  • Gabriela Nascimento de Lemos,
  • Karem Miléo Felício,
  • Márcia Costa dos Santos,
  • Ana Regina Bastos Motta,
  • Melissa de Sá Oliveira dos Reis,
  • Isabel Jane Campos Lobato,
  • Priscila Boaventura Barbosa de Figueiredo,
  • Ana Carolina Contente Braga de Souza,
  • Pedro Paulo Freire Piani,
  • João Soares Felício

DOI
https://doi.org/10.3389/fendo.2020.605681
Journal volume & issue
Vol. 11

Abstract

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BackgroundCardiovascular autonomic neuropathy (CAN) is associated with diabetes mellitus, increasing morbidity and mortality. Some cross-sectional studies associated CAN with low 25-hydroxyvitamin D levels. The aim of our study was to evaluate the effect of high-dose vitamin D (VD) supplementation on CAN in Type 1 Diabetes Mellitus (T1DM) patients.MethodsWe performed a prospective study with 23 patients diagnosed with T1DM and CAN. Subjects with VD levels <30 ng/ml received 10,000 IU/day; the ones with VD levels between 30–60 ng/ml were given 4,000 IU/day for 12 weeks.ResultsThere was an improvement in CAN parameters related to resting heart rate variability, such as time domain parameters [Maximum RR interval (0.77 ± 0.11 vs 0.94 ± 0.51 s, p <0.05), Mean length of regular RR intervals (0.71 ± 0.10 vs 0.76 ± 0.09 s, p <0.05) and Standard deviation of all NN intervals (0.02 ± 0.01 vs 0.03 ± 0.02 s; p <0.01)] and frequency domain parameters [Low Frequency (1.9 ± 0.5 vs 2.5 ± 0.9 s, p < 0.001), Total Power (2.5 ± 0.4 vs 2.8 ± 0.6 s, p <0.05)]. In addition, there was a correlation between absolute VD level variation and posttreatment High Frequency (%), as well as among percent variation in VD level and end-of-study Low Frequency/High Frequency ratio (r=0.6, p<0.01; r= -0.5, p<0.05, respectively).ConclusionOur pilot study is the first to suggest a strong association between high-dose vitamin D supplementation and improved cardiovascular autonomic neuropathy in T1DM patients. It occurred without any variation in HbA1C, blood pressure levels, lipids, and insulin dose.Clinical Trial Registrationhttp://www.isrctn.com/ISRCTN32601947, identifier ISRCTN32601947.

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