The use of antioxidants alongside a pre-existing HAART regimen by patients with lipoatrophy was associated with a trend to lower LDL cholesterol and a slight improvement in waist-to-hip ratio , but may also have led to increased insulin resistance, according to a small US study published in the August 15th edition of the Journal of Acquired Immune Deficiency Syndromes.
Oxidative stress is thought to contribute to lipoatrophy. Accordingly, investigators in Ohio recruited eight HAART-treated patients with lipoatrophy to a 24 week study to see if antioxidants improved body shape and lipids.
The patients all had a HIV viral load below 400 copies/mL, an average age of 42 years and a median CD4 cell count of over 600 cells/mm3. They remained on their existing HAART regimen and were prescribed 800/IU of vitamin E a day, with 1000mg of vitamin C and 600mg of N-acetyl cysteine twice daily.
Viral load remained undetectable and average CD4 cell counts were unchanged at the end of the study. However, neither the study doctors, study dietitian, not patients noticed any improvement in peripheral fat loss. Nor did fasting triglycerides or HDL cholesterol change significantly. There was however a trend to lower LDL cholesterol, down from 124mg/dL at baseline to 102mg/dL at week 24 (p=0.006).
Hip-to-waist ratio also decreased from 0.94 to 0.92 by week 24 (p=0.05), however, fasting glucose increased significantly from a median of 84mg/dL at baseline to 110mg/dL at the end of the study (p=0.017), and fasting insulin trended upwards (14.2IU/mL at baseline to 54IU/mL at week 24, p=0.1). A homoestatic model for insulin resistance suggested that insulin sensitivity increased significantly, from 2.75 at entry to 7.20 at week 24 (p=0.03).
The investigators comment, “these findings are of concern, and suggest increased insulin resistance.” However, the trend towards lower LDL cholesterol and waist to hip ratio are described as “encouraging.” The investigators acknowledge limitations in their study, not least that they did not use CT or MRI scans to measure body fat, and could therefore have failed to notice small improvements in body shape. They conclude “controlled studies are required to evaluate directly the effects of [antioxidant] agents on lipid and glucose metabolism.”
Further information on this website
Body fat and metabolic changes whilst on treatment - menu of information
Lipodystrophy - factsheets
Lipodystrophy - booklet in the information for HIV-positive people series (pdf)
McComsey G et al. Effects of antioxidants on glucose metabolism and plasma lipids in HIV-infected subjects with lipoatrophy. JAIDS 33: 605 – 07, 2003.