Study: Vitamin D Deficiency in Patients With Lupus Linked to Metabolic Disorders

Patients with lupus who have lower vitamin D levels are more likely to have metabolic syndrome and insulin resistance, both of which are linked to heart disease, according to a new study published in Rheumatology. The study suggests boosting vitamin D levels may improve control of these cardiovascular risk factors as well as long-term outcomes for patients with systemic lupus erythematosus (SLE), according to the authors.

An international research team, led by experts at the University of Birmingham and University of Manchester, studied vitamin D levels in 1163 patients with SLE across 33 centers in 11 countries. As photosensitivity is a key feature of SLE, the researchers said that a combination of avoiding the sun, using high-factor sunblock, and living in more northern countries may contribute to lower levels of vitamin D in patients with lupus. Patients with more severe disease had lower vitamin D levels.

“We found a link between lower levels of vitamin D and metabolic syndrome and insulin resistance,” said John A Reynolds, PhD, clinical senior lecturer in rheumatology at the University of Birmingham and the study’s co-author, in a press release. “Further studies could confirm whether restoring vitamin D levels helps to reduce these cardiovascular risk factors and improve quality of life for patients with lupus.”

Lupus is an uncommon and incurable immune system illness in which the immune system is overactive, causing inflammation anywhere in the body. If left untreated, the condition can cause irreversible damage to major organs, including the kidneys, heart, lungs, and brain.

The researchers note that patients with SLE have cardiovascular risk up to 50 times higher than people without the condition, which cannot be attributed exclusively to traditional cardiovascular risk factors, such as high blood pressure or smoking. The mechanisms behind the association between high blood pressure and low vitamin D in SLE are not clear, but researchers believe they may be linked to the impact of vitamin D deficiency on the renin-angiotensin hormone system, which regulates blood pressure, fluid and electrolyte balance, as well as systemic vascular resistance.

“This is the largest-ever study examining associations between vitamin D levels and metabolic syndrome in SLE; it also has the advantage of being an international cohort with diverse racial and ethnic backgrounds—generating results that will be applicable across many settings,” Reynolds said in the press release.

REFERENCE

Vitamin D deficiency linked to metabolic changes in patients with lupus – study [news release]. EurekAlert; March 26, 2021. Accessed April 2, 2021. https://www.eurekalert.org/pub_releases/2021-03/uob-vdd032621.php