Wasting in HIV-positive drug users linked to food insecurity and viral load

Almost one in five HIV-positive drug users from Miami has HIV-related wasting, according to the results of a study published in the 15^th October edition of Clinical Infectious Diseases. The study found that wasting is linked to food insecurity and higher HIV viral loads, despite most of the participants receiving antiretroviral therapy

Although wasting, or unintentional weight loss, has become less common since the advent of effective antiretroviral therapy regimens, it remains a risk factor for HIV disease progression and death. Drug users may be at an elevated risk of wasting due to poor control of HIV disease, low food intake and social problems.

To assess the prevalence of wasting, investigators asked 119 HIV-positive drug users from Miami about their drug and alcohol use, medical history and eating habits. They also measured their height and weight over a period of six months and took blood samples for viral load and CD4 cell count measurements. Most of the participants were homeless.

Eighteen per cent of the participants were found to have wasting, defined as unintentional weight loss of over 10% over six months, being less than 90% of their ideal weight or having a body mass index (BMI) below 18.5kg/m². BMI is a measure of body weight relative to height, with values below 18.5kg/m² being classified as underweight.

The investigators carried out a multivariate analysis to work out which factors were linked to wasting. Age, sex, alcohol and cocaine use and receipt of antiretroviral therapy were not significantly associated with wasting. However, they found that higher viral loads were linked to wasting (odds ratio [OR]: 1.96; p = 0.01). This was despite a greater proportion of the participants with wasting receiving antiretroviral therapy (86 vs. 67%).

“The prevalence of HIV-associated wasting in our cohort … is in the range observed before the highly active antiretroviral therapy (HAART) era, although most of our participants reported receipt of HAART,” the investigators write. “The independent relationship between HIV-related wasting and viral load suggests lack of adherence”.

Similarly, food insecurity, defined as not eating for at least one day in the previous month was also linked to wasting (OR: 1.64, p = 0.05). Eighty-one per cent of those with wasting reported food insecurity, compared with 57% of those who did not have wasting (p = 0.042).

“Food insecurity and viral load were the only independent predictors of wasting,” the investigators conclude. “The social and economic conditions affecting the lifestyle of HIV-infected drug users constitute a challenge for prevention and treatment of wasting.”

Although not independently linked to wasting, the researchers explain that alcohol and cocaine abuse may be associated with lower food intake. “Our participants frequently reported that a six-pack of beer was their only caloric intake for the day. However, the majority of the participants who reported food insecurity were also heavy drinkers,” they write.

They also point out that cocaine inhibits the appetite, and is “one of the most addictive illicit drugs available, especially when used in its crack form”. This may explain the low food intake in many of the study’s participants.

Wasting was also linked to being unemployed, possibly due to the effects of fatigue, low energy and low mood. The investigators also suggest that unemployment could lead to wasting through poverty and erratic food supply.