HIV-Positive Women With Obesity Benefit From Weight Loss

A clinical trial comparing the effects of weight loss on HIV-infected (HIV+) and HIV-uninfected (HIV−) women with obesity found that both groups derived similar metabolic benefits, according to results published in Obesity.¹

In an email interview with Infectious Disease Advisor, Jeffrey A. Lederman, MD, chief of infectious diseases at Montefiore Medical Center, New Rochelle, New York, noted that due to currently available antiretroviral therapies, patients with HIV are living normal lives, which includes the potential for weight gain. “Many patients who had been wasting away before starting medications are now developing obesity. I’ve had to advise them that previously their weight may have been low due to the infection. However, once the infection is well controlled, the patient may have to carefully diet to keep from becoming overweight.” Dr Lederman was not involved in the clinical trial.

The metabolic risks of obesity are of special clinical concern in the HIV+ population. HIV+ individuals have a risk for type-2 diabetes and cardiovascular disease (CVD) that is 2 to 4 times greater than that in HIV−individuals with the same BMI. Weight loss in the general population is known to improve metabolic function, but few prior studies examined whether weight loss is beneficial in a similar manner in patients living with HIV. Lead investigator Dominic N. Reeds, MD of the Washington University School of Medicine, St Louis, Missouri, and colleagues hypothesized that compared with HIV− women, HIV+ women would experience fewer improvements in insulin sensitivity and markers of inflammation, autophagy, and endoplasmic reticulum (ER) stress with weight loss.

For the study, 8 HIV+ and 20 HIV− women with obesity and confirmed insulin resistance took part in a weight loss regimen involving liquid meal replacements for 2 meals per day and weekly counseling from a research dietitian. The meal plan, designed to result in a 1000 kcal/d energy deficit, was continued until patients individually reached a 6% to 8% weight loss. That goal was achieved in 19 of the 28 participants (13 HIV+ and 6 HIV−).

The researchers assessed the participants’ body composition, blood pressure, and metabolic parameters before and after the weight loss intervention. In order to measure the women’s plasma glucose concentration, plasma palmitate, glucose tracer-to-tracee ratios, and plasma hormone concentrations, patients underwent a hyperinsulinemic-euglycemic clamp procedure, a technique that represents the gold standard for quantifying the impact of experimental interventions on insulin sensitivity.² Body fat and fat-free mass were quantified with dual-energy X-ray absorptiometry, and magnetic resonance imaging (MRI) was used to determine visceral and abdominal subcutaneous adipose tissue volumes.

Results showed a weight loss of approximately 7.5% in both groups. HIV+ patients had a greater decrease in fat-free mass after weight loss (-4.4±0.7% difference, P <.05) than HIV- patients (-1.7±1.0% difference, P <.05). Both HIV+ and HIV− women saw similar improvements in insulin sensitivity in adipose tissue (suppression of palmitate rate of appearance [Ra]), liver (suppression of glucose Ra), and muscle (glucose disposal). Systolic and diastolic blood pressure improved in both HIV+ and HIV− patients. Adipose tissue expression of markers of inflammation, autophagy, and ER stress remained unchanged in both groups.

“These results demonstrate that moderate diet-induced weight loss has important therapeutic cardiometabolic effects in HIV-1 women with obesity,” the investigators wrote. “In summary, moderate weight loss improved multiorgan insulin sensitivity and several other key risk factors for CVD in women with obesity and HIV infection to the same degree that weight loss improved these outcome measures in women with obesity but without HIV infection.”

References

1. Reeds DN, Pietka TA, Yarasheski KE, et al. HIV infection does not prevent the metabolic benefits of diet-induced weight loss in women with obesity [published online February 28, 2017]. Obesity. doi:10.1002/oby.21793
2. Tam CS, Xie W, Johnson WD,  Cefalu WT, Redman LM, Ravussin E. Defining Insulin Resistance From Hyperinsulinemic-Euglycemic Clamps. Diabetes Care. 2012;35:1605-1610. doi:10.2337/dc11-2339