HIV and Obesity: Where Did the Wasting Go?

A study recently published online in theJournal of Acquired Immune Deficiency Syndromehighlights a growing problem in HIV/AIDS patients: A substantial proportion are now overweight or obese, mirroring the US population at large.

“This is a very big problem for us,” said senior author Amanda Willig, PhD, RD, of the Center for AIDS Research at the University of Alabama at Birmingham. Their study found that 65% of the 1,844 HIV-infected patients they followed were overweight 2 years after diagnosis, and 29% of them obese. The more participants weighed, the higher the likelihood that they would have comorbid conditions such as hypertension, diabetes, and chronic kidney disease. “This means our patients take other medications on top of the antiretrovirals and experience additional side effects from the medications, as well as symptoms from the other diseases,” she said. It also makes medication adherence more challenging.

Overall, the researchers found that 65% of patients had at least one chronic medical condition other than HIV/AIDS, but that nearly 80% of those who were obese did. That translated into a 52% increased risk of a comorbid condition, such as hypertension, gout, diabetes mellitus, chronic kidney disease,  mood disorders, dyslipidemia, chronic obstructive pulmonary disease, osteoarthritis, obstructive sleep apnea, and cardiac disorders.

An earlier study on overweight and AIDS, also from Dr. Willig’s group, found that 20% of the same cohort moved from normal to overweight/obese, or from overweight to the obese category, within 2 years of starting ART, an “alarming” increase and one that should be targeted for intervention. The culprit wasn’t the antiretroviral therapy, which only accounted for 20% of the weight gain.

“Our team calls that the ‘normalizing of the HIV population’ in catching up to the Western world in general in terms of obesity,” she said. Yet such a high rate of weight gain would be unusual even in the general population, she said. Perhaps, she suggested, the virus itself contributes to increased weight gain, magnifying the effects of the current obesogenic environment.

Other studies find that obesity slows immune recovering, resulting in a poorer response to ART therapies.¹ Why? “That’s the $20 million question,” Dr. Willig said. “(The drugs) are working, but not as well.” One theory is that obesity impacts the leptin pathway, conferring increased viral resistance to the drugs, or that the increased chronic inflammation of obesity reduces their effectiveness. That inflammation and the increased mitochondrial dysfunction seen with HIV may also increase patients’ risk of metabolic disorders like diabetes and hypertension.

Indeed, a 2010 longitudinal study that evaluated data from the US Military HIV Natural History Study consisting of patients diagnosed between 1985 and 2004 found that 62% of patients gained weight during their infection, with those diagnosed later in the cohort having the greatest increase in BMI. The only class of drugs associated with the weight gain was nucleoside agents.

As the authors noted, “Although encouraging in terms of the ability of antiretroviral therapy to reduce the occurrence of end-stage disease and wasting, HIV clinicians now need to be cognizant of weight excess among their patients.”

Primary care physicians need to proactive about the issue of obesity and HIV, Dr. Willig said. “That means increased screening for high blood pressure and cholesterol management that may not be done until later age” in non-infected patients, she said. Clinicians also need to be aware of non-AIDS-related cancers that are higher in obese populations, such as colorectal cancer. “So those screenings might need to occur earlier in this population compared to the general population,” she said, an area that needs more research.

Her studies also point to the importance of helping newly diagnosed patients attain and maintain a healthy weight after diagnosis.

Clinicians are on their own, however. For despite the “alarming” trends being reported, the most current guidelines for the management of HIV/AIDS make no mention of obesity in the entire 240-page document.²






 

References:

REFERENCES 1. Crum-Cianflone NF, Roediger M, Eberly LE, et al. Obesity among HIV-infected persons: impact of weight on CD4 cell count. AIDS. 2010;24(7):1069-1072. 2. Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. 2012; http://aidsinfo.nih.gov/guidelines.