After people with HIV switch their antiretrovirals (ARVs) to include an integrase inhibitor, what factors are linked to a rise in body weight?

Integrase inhibitors include Isentress (raltegravir); elvitegravir, which is a component of the Genvoya and Stribild combination pills; bictegravir, which is included in Biktarvy; and Tivicay (dolutegravir), which is included in Triumeq, Juluca and Dovato. The long-acting injectable regimen Cabenuva, which was awaiting Food and Drug Administration approval at press time, includes the new integrase inhibitor cabotegravir. (For a complete listing of the components of ARV coformulations, please visit POZ.com/basics/hiv-basics/hiv-medications.)

Researchers at George Washington University analyzed data on 260 people living with HIV in Washington, DC, who switched to an integrase inhibitor regimen from a non-nucleoside reverse transcriptase inhibitor regimen (107 people) or a protease inhibitor regimen (97 people).

After 18 months, those who switched regimens, compared with the 56 people who remained on their existing regimen, gained more weight (6 pounds versus 1 pound) and gained a greater percentage of their body weight (3.6% versus 0.7%). In addition, when comparing weight gain during the 18 months before the medication switch versus the following 18 months, those who changed regimens gained more weight during the latter period.

Gaining weight following a switch to an integrase inhibitor was associated with initially weighing less than 150 pounds. Such individuals gained 6.6% of their body weight, compared with a 3.0% gain among those weighing 150 to 200 pounds and a 2.3% gain among those weighing more than 200 pounds.

Those who had a normal body weight, those who were overweight and those who were obese gained 4.9%, 2.8% and 2.4% of their body weight, respectively.

Lastly, older individuals gained less weight after switching medications than younger people.

The investigators called for research to assess changes in metabolic factors, such as cholesterol and triglycerides, among those switching to integrase inhibitors in hopes of identifying mechanisms by which the drug class promotes weight gain.