In South Africa, HIV-infected men who are receiving treatment with anti-HIV drugs (antiretroviral therapy) are almost a third more likely to die than HIV-positive women who are receiving similar treatment: however, these differences are likely to be due to gender differences in death rates in the general population rather than related to HIV, according to a study by a team of international researchers published in this week's PLOS Medicine.
An international research collaboration, led by Morna Cornell from the University of Cape Town, analyzed data collected from 46,201 adults who started taking antiretroviral therapy between 2002 and 2009 in eight HIV treatment programs in South Africa.
They found that at the start of treatment, men generally had a lower CD4 count (a biomarker of HIV activity—a lower count indicates increased infection) and were more likely to have advanced HIV disease than women. But even after allowing for these factors, the researchers found that HIV-positive men on antiretroviral therapy were almost a third (31%) more likely to die than HIV-positive women on similar treatment.
The researchers also found that men were more likely to be lost to follow up than women, but men and women who were lost to follow-up were equally likely to die. Furthermore, women had a slightly better immunological response to antiretroviral therapy than men but suppression of the HIV virus was similar in both genders.
However, importantly, the researchers found that, the gender differences in the deaths rates they observed in this study were smaller than the gender differences in death rates (standardized by age) in the general (HIV-negative) South African population—a situation that may explain their results
The researchers say: "HIV-infected men have higher mortality on antiretroviral therapy than women in South African programmes, but these differences are only partly explained by more advanced HIV disease at the time of antiretroviral therapy initiation, differential loss-to-follow-up and subsequent mortality, and differences in responses to treatment."
They conclude: "The observed differences in mortality on antiretroviral therapy may be best explained by background differences in mortality between men and women in the South African population unrelated to the HIV/AIDS epidemic."
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Cornell M, Schomaker M, Garone DB, Giddy J, Hoffmann CJ, et al. (2012) Gender Differences in Survival among Adult Patients Starting Antiretroviral Therapy in South Africa: A Multicentre Cohort Study. PLoS Med 9(9): e1001304. doi:10.1371/journal.pmed.1001304