Low bone mass in behaviorally HIV-infected young men on antiretroviral therapy: adolescent trials network (ATN) study 021B

Authors: MULLIGAN, KATHLEEN - University Of California; HARRIS, D. ROBERT - Westat Inc; EMMANUEL, PATRICIA - University Of South Florida; FIELDING, ROGER A. - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; WORRELL, CAROL - National Institute Of Health (INSA); KAPOGIANNIS, BILL G. - National Institute Of Health (INSA); MONTE, DINA - Westat Inc; SLEASMAN, JOHN - University Of Florida; WILSON, CRAIG - University Of Alabama; ALDROVANDI, GRACE M. - Children'S Hospital Los Angeles

Submitted to: Clinical Infectious Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/11/2012
Publication Date: 8/1/2012
Citation: Mulligan, K., Harris, D., Emmanuel, P., Fielding, R., Worrell, C., Kapogiannis, B., Monte, D., Sleasman, J., Wilson, C., Aldrovandi, G. 2012. Low bone mass in behaviorally HIV-infected young men on antiretroviral therapy: adolescent trials network (ATN) study 021B. Clinical Infectious Diseases. 55(3):461-468.

Interpretive Summary: Two hundred fifty teens and young men (14 to 25 years old) participated in the study. About 88 percent of the study participants identified themselves as African-American or Hispanic and all lived in urban areas. All subjects underwent whole body scans to measure their bone density as well as the distribution of fat and lean muscle mass in certain regions of their bodies. We calculated the density of bones in the body as a whole, as well as the spine and hipbones. These bones are more susceptible than other bones to bone loss. We also assessed total body fat and amounts of fat in the arms, legs and trunk. We found that the HIV-positive participants who had not yet begun treatment tended to have less body fat than either their counterparts on medication or the study’s HIV-negative participants. Both bone density and the calcium and other mineral content of bones tended to be lowest in participants taking medication for HIV. Youth with HIV who had not begun treatment had higher bone mass levels than HIV positive youth who were on anti-HIV regimens, but lower bone mass levels than youth who did not have HIV. Participants’ responses to questions about diet indicated that at least half of them did not consume sufficient calcium or vitamin D. The researchers also found that more than 30 percent of all the participants smoked. Half said they did not get regular exercise. Smoking and lack of exercise can contribute to weaker bones. We noted that additional studies are needed to follow HIV-positive young men long term to determine whether bone loss during adolescence increases the risk of fractures later in life. These results suggest both HIV infection and the treatment regimens for HIV both are associated with bone mass and density in these patients.

Technical Abstract: Peak bone mass is achieved in adolescence/early adulthood and is the key determinant of bone mass in adulthood. We evaluated the association of bone mass with HIV infection and antiretroviral therapy (ART) during this critical period among behaviorally HIV infected young men and seronegative controls. HIV-positive men (N=199) and HIV-negative controls (N=53), ages 14-25 years, were studied at 15 ATN sites. HIV-positive participants were recruited on the basis of ART status: ART-naïve (N=105) or on a regimen containing a non-nucleoside reverse transcriptase inhibitor (NNRTI; N=52) or protease inhibitor (PI; N=42). Bone mineral density (BMD) and content (BMC) and body composition were measured by dual-energy X-ray absorptiometry (DXA). Results were compared across groups by linear modeling. Bone results were adjusted for race, BMI, and type of DXA (Hologic/Lunar). The HIV-positive and HIV-negative groups had comparable median age (21 years) and racial/ethnic distribution. Median times since HIV diagnosis were 1.3, 1.9, and 2.2 years in the ART-naïve, NNRTI, and PI groups, respectively (P=0.01). Total and regional fat were significantly lower in the ART-naïve group, compared with seronegative controls. Mean BMD and Z-scores were generally lower among HIV-positive participants on ART, particularly in the PI group. Average Z-scores for the spine were below zero in all four groups, including controls. Young men on ART with a relatively recent diagnosis of HIV infection have lower bone mass than controls. Impaired accrual or actual loss of bone during adolescence may increase fracture risk in adulthood.