No link between vitamin D and metabolic syndrome among female SLE patients

Higher serum 25‐hydroxyvitamin D (25(OH)D) concentrations confer no protective benefit in terms of metabolic syndrome in nondiabetic women with systemic lupus erythematosus (SLE), a study suggests.

The study included 160 nondiabetic SLE women (mean age, 43.3 years), most of whom had mild disease activity (median SLEDAI‐2K score, 2; median disease duration, 11 years). The proportion of patients with an SDI ≥1 was 33.1 percent. Eighty-eight percent of the participants were taking prednisone, while 65 percent were on antimalarial therapy. Nearly half of the patients (49 percent) used concurrent immunosuppressive therapy.

Vitamin D deficiency (<20 ng/mL) was found in 40.6 percent of participants, while vitamin D insufficiency (20–29 ng/mL) was 49.4 percent. Mean serum 25(OH)D concentrations did not differ significantly in patients with neuropsychiatric (23.2 ng/mL), haematological (22.0 ng/mL) and nephritis lupus (21.7 ng/mL) manifestations.

About half of the participants (49.3 percent) had metabolic syndrome. The likelihood of having metabolic syndrome decreased with increasing quartiles of 25(OH)D concentrations (p-trend=0.03). Compared with the lowest 25(OH)D quartile, the highest quartile was associated with 60-percent reduced odds of having metabolic syndrome (odds ratio [OR], 0.4, 95 percent confidence interval, 0.2–0.9; p=0.04). Similarly, the odds of having elevated hypertriglyceridemia decreased according to increasing quartiles of 25(OH)D concentrations (p-trend=0.036).

However, this association between 25(OH)D concentrations and MetS and its individual components disappeared after controlling for body mass index and smoking.

Researchers underscored a need for large prospective studies to establish the roles of 25(OH)D in the incidence of metabolic syndrome in SLE patients.