Obesity and a higher body mass index (BMI) are associated with both increased multiple sclerosis (MS) risk and harmful autoimmune activity that is induced by leptin, a hormone secreted by fat cells, a study finds.
These results indicate that leptin, which helps regulate body weight, may act as a functional link between obesity and MS.
The study, “Obesity and the risk of Multiple Sclerosis. The role of Leptin,” was published in the Annals of Clinical and Translational Neurology.
The worldwide prevalence of MS has increased over the past years, and previous studies have found a potential association between BMI and the risk of developing the disease — raising the possibility that increasing global obesity and MS cases may be related.
Obesity is known to promote chronic systemic inflammation, partially mediated by fat cells that secrete immune signaling proteins called cytokines, and can worsen immune disorders like MS. The hormone leptin plays a key role in regulating energy balance by inhibiting hunger and functions by binding to leptin receptors.
Read more about obesity and multiple sclerosis
Leptin also is involved in the regulation of inflammatory and autoimmune responses, in which the body’s immune system mistakenly attacks its own cells. Because MS is considered an autoimmune disease, researchers now investigated if leptin is involved in regulating the autoimmune response in MS patients, thereby linking the disorder to BMI and obesity.
Between July 2013 and October 2019, a total of 631 people participated in the study: 309 relapsing-remitting MS (RRMS) patients and 322 age- and sex-matched healthy individuals (controls).
Based on the World Health Organization BMI definition, 162 MS patients (52.4%) and 145 healthy controls (45%) were normal weight or underweight. Meanwhile, 90 patients (29.1%) and 108 controls (33.5%) were overweight, and 57 patients (18.4%) and 69 controls (21.4%) were obese.