Lupus Independently Increases Insulin Resistance

Keypoints
• Insulin resistance is increased in patients with systemic lupus erythematosus (SLE) compared with control subjects.

• Insulin resistance is related to the damage caused by SLE and may accelerate subclinical atherosclerosis.

• C-peptide levels are up-regulated in patients with lupus.

• There did not appear to be any beneficial effects conferred by anti-rheumatic drugs on insulin resistance.

• Glucocorticoids appear to exert a negative effect on insulin resistance.

Background
SLE is associated with atherosclerosis: patients with lupus have more than twice the risk of cardiovascular events such as stroke and myocardial infarction than the general population.

Sanchez-Perez and colleagues¹ in Spain point out that patients with lupus often have several traditional risk factors for cardiovascular disease; however, this fact does not explain their higher risk of premature atherosclerosis independent of those factors. "This finding supports a role for disease-related factors in SLE patients' atherogenesis," state the researchers.

Insulin resistance is a known contributor to cardiovascular disease and in particular atherosclerosis. While previous studies have looked at the metabolic syndrome in patients with lupus as a factor in insulin resistance, few have sought to determine whether SLE itself has an impact on insulin resistance and how that relationship affects subclinical atherosclerosis. Sanchez-Perez and colleagues recently presented their findings in Clinical and Experimental Rheumatology.

Thestudy
This cross-sectional study included 87 patients with SLE and 82 matched control subjects. C-peptide concentrations were measured, ultrasound was used to assess vascular intimal wall thickening, and comorbidities were recorded.

Theresults
• Patients with SLE had higher serum levels of C-peptide than controls (P = .00).

• Patients with SLE also had higher rates of insulin resistance than control subjects (P = .01).

• Following adjustment for steroid intake and traditional insulin resistance factors, the difference between patients with lupus and controls remained statistically significant.

• Prednisone was independently linked to increased insulin resistance.

Implicationsforphysicians
• Be vigilant with regards to insulin resistance and the development of type 2 diabetes in patients with SLE.

• SLE may cause beta cell dysfunction as a disease effect.

• Increased insulin resistance appears to be related to the damage lupus causes over time independent of other traditional risk factors.

• Increased insulin resistance caused by SLE damage may lead to premature atherosclerosis; however, results were not statistically significant in this study.

References:

Sanchez-Perez H, Tejera-Segura B, de Vera-Gonzalez A, et al. Insulin resistance in systemic lupus erythematosus patients: contributing factors and relationship with subclinical atherosclerosis. ClinExpRheumatol. 2017;35:885-892.