Changes in body composition and micronutrient status during lactation in HIV-infected and HIV-uninfected South African women

Background. The nutritional consequences of HIV infection in lactating women are unknown.; Objectives. In HIV-infected and HIV-uninfected South African mothers, to validate the ability of bioimpedance spectroscopy (BIS) and anthropometry to measure fat free mass (FFM) and fat mass (FM) compared with isotope dilution (2H2O); and to measure FFM and FM, serum protein and micronutrients during the first 6 months of lactation in relation to HIV status.; Methods. In a cross sectional study, total body water content of 68 lactating mothers (20 HIV-infected, 48 HIV-uninfected) was measured at 10 wks post-partum using BIS and 2H2O for determination of FFM and FM and was compared with anthropometric measurements. In the longitudinal study, 92 HIV-infected and 52 HIV-uninfected lactating mothers had the following measurements taken at 6-, 14-, and 24-weeks post partum: Height, weight (WT), skinfold thicknesses, and FFM and FM using BIS; serum albumin, prealbumin, folate, vitamin B12, retinol, alpha-tocopherol, ferritin, zinc, selenium, copper concentrations.; Results. FFM and FM determined by BIS were well correlated with 2H2O in both groups of women. TBW measured by BIS was greater than by 2H2O method in both HIVpos (1.8 L) and HIVneg women (1.5L), with no difference between methods for FM or FFM. Between 8 and 24 weeks, HIV-infected mothers had a mean WT loss of 1.4 kg in contrast to a 0.4 kg WT gain in HIV-uninfected mothers (p < 0.01). There were no significant group differences with regard to change in FFM (0.3 vs 0.1 kg, p = 0.9) and FM (-1.5 vs. -0.3 kg, p = 0.2) though most of the weight change in HIVpos mothers was due to FM loss. Deficiencies of folate, vitamins B12 and E, and ferritin, and zinc were common in all breastfeeding mothers between 6 and 24 weeks post partum. At 24 weeks postpartum, HIV-infected mothers had lower mean serum concentrations of albumin, prealbumin, folate and vitamins A and B12 than HIVpos mothers, even though the HIVpos mothers were not severely immune suppressed.