title: Vitamin D Levels Are Associated with Expression of SLE, but Not Flare Frequency.
abstract: This study explores links between vitamin D deficiency (25(OH)D = 50 nmol/L) and serological autoimmunity (ANA > 1 : 80) and frequency of self-reported flares (SRF) in participants with clinical autoimmunity (SLE). 25(OH)D levels of 121 females were quantified and compared. The cohort consisted of 80 ACR defined SLE patients and 41 age and sex matched controls. Association analysis of log2 (25(OH)D) levels and ANA 80 positivity was undertaken via two-sample t-tests and regression models. Significant differences were found for 25(OH)D levels (mean: control 74 nmol/L (29.5 ng/ml); SLE 58 nmol/L (23.1 ng/ml), P = 0.04), 25(OH)D deficiency (P = 0.02). Regression models indicate that, for a twofold rise in 25(OH)D level, the odds ratio (OR) for ANA-positivity drops to 36% of the baseline OR. No link was found between SRF-days and 25(OH)D levels. Our results support links between vitamin D deficiency and expression of serological autoimmunity and clinical autoimmunity (SLE). However, no demonstrable association between 25(OH)D and SRF was confirmed, suggesting independent influences of other flare-inducing factors. Results indicate that SLE patients have high risk of 25(OH)D deficiency and therefore supplementation with regular monitoring should be considered as part of patient management.
authors.affiliation: Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia ; Faculty of Science and Information Technology, University of Newcastle, Callaghan, NSW 2308, Australia ; Autoimmune Resource and Research Centre, 2nd Floor HAPS Building, John Hunter Hospital, New Lambton, NSW 2305, Australia ; Pathology North, Hunter New England, New Lambton, NSW 2305, Australia ; Hunter Medical Research Institute, New Lambton, NSW 2305, Australia.
authors.forename: Marline L
authors.initials: ML
authors.lastname: Squance
authors.affiliation: Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia ; Autoimmune Resource and Research Centre, 2nd Floor HAPS Building, John Hunter Hospital, New Lambton, NSW 2305, Australia ; Pathology North, Hunter New England, New Lambton, NSW 2305, Australia ; Hunter Medical Research Institute, New Lambton, NSW 2305, Australia.
authors.forename: Glenn E M
authors.initials: GE
authors.lastname: Reeves
authors.affiliation: Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia ; Pathology North, Hunter New England, New Lambton, NSW 2305, Australia.
authors.forename: Huy A
authors.initials: HA
authors.lastname: Tran