Lower vitamin D in SLE increases susceptibility to MetS, insulin resistance

In patients with systemic lupus erythematosus (SLE), lower vitamin D levels contribute to an increased risk of metabolic syndrome (MetS) and insulin resistance, as shown in a study.

The study included patients recently diagnosed with SLE (<15 months) from 33 centres across 11 countries from 2000. There were 1,847 SLE patients included in the analysis. Their clinical, laboratory, and therapeutic data were collected.

Vitamin D level was defined according to tertiles based on distribution across the study population, as follows: first (10–36 nmol/l), second (37–60 nmol/l), and third (61–174 nmol/l). A total of 1,163 (63 percent) patients had vitamin D data, of whom 398 (34.2 percent) were in the lowest 25(OH)D tertile (first tertile).

MetS was detected in 286 of 860 (33 percent) patients whose status could be determined. According to linear and logistic regressions, lower 25(OH)D concentrations were associated with a greater likelihood of having MetS and elevated HOMA-IR.

Furthermore, all the MetS components, along with hypertension, hypertriglyceridaemia, and reduced high-density lipoprotein cholesterol, were all significantly related to lower 25(OH)D levels. Greater average glucocorticoid exposure, on the other hand, was linked to higher insulin resistance.

More studies are needed to establish whether vitamin D repletion confers better control of these cardiovascular risk factors and improve long-term outcomes in SLE.