Long-term use of tumor necrosis factor (TNF) α inhibitors in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) is associated with both gains in fat mass and a shift in fat mass to the visceral region.
Eric Toussirot, MD, PhD, and colleagues of the University Hospital Besançon in France reported the results of their prospective study in the European Journal of Nutrition.1 The study was designed to investigate the body composition and changes in fat distribution in patients with inflammatory rheumatic diseases who receive treatment with anti-TNFα. It included eight consecutive outpatients with RA and twelve patients with AS.
“The major message is that biologics may influence body composition, modify fat distribution, and this could influence the cardiovascular risk. Indeed, in our study we clearly demonstrated a shift of fat mass to the android region, and also to the visceral abdominal region in patients receiving TNFα blockers. Both of these fat depositions are associated with the development of cardiovascular events,” said Dr. Toussirot.
The authors used dual-energy X-ray absorptiometry (DEXA) to evaluate body composition parameters and measure fat in the abdominal/visceral region. They found that patients with RA who received anti-TNFα therapy had a significant gain in body mass index, and a tendency for weight, android fat, and visceral fat increase. There was no significant change in other body composition measurements.
Patients with AS who received anti-TNFα experienced an increase in total mass and weight gain.
The total population of 20 patients experienced, over two years, a significant increase in body weight, body mass index, total fat mass, and fat in the android region. The authors also documented a substantial, but insignificant, gain in visceral fat. There was no change in lean mass and gynoid fat.
“Our results confirm what the clinicians observed in their patients and clarify that this weight gain is composed of fat and where fat is localized,” wrote Dr. Toussirot.
The investigators also analyzed changes in serum adipokines and total ghrelin in patients who received anti-TNFα. Repeated measures did not show changes in serum adipokine and ghrelin levels over time.
The authors report no significant changes in serum leptin, total adiponectin, ghrelin, insulin, or homeostasis model assessment for insulin resistance in patients treated with anti-TNFα. Serum leptin levels were inversely correlated with changes in android fat. Fasting glucose was not affected by treatment with anti-TNFα.
At baseline, resistin was significantly correlated with levels of C-reactive protein, but weakly correlated with erythrocyte sedimentation rate. The investigators saw a significant decrease in resistin and a slight decrease in high–molecular weight adiponectin.
