Body mass index and early CD 4 T ‐cell recovery among adults initiating antiretroviral therapy in N orth A merica, 1998–2010

Objectives Adipose tissue affects several aspects of the cellular immune system, but prior epidemiological studies have differed on whether a higher body mass index ( BMI ) promotes CD 4 T ‐cell recovery on antiretroviral therapy ( ART ). The objective of this analysis was to assess the relationship between BMI at ART initiation and early changes in CD4 T‐cell count. Methods We used the N orth A merican AIDS C ohort C ollaboration on R esearch and D esign ( NA ‐ ACCORD ) data set to analyse the relationship between pre‐treatment BMI and 12‐month CD 4 T ‐cell recovery among adults who started ART between 1998 and 2010 and maintained HIV‐1 RNA levels < 400 copies/mL for at least 6 months. Multivariable regression models were adjusted for age, race, sex, baseline CD 4 count and HIV RNA level, year of ART initiation, ART regimen and clinical site. Results A total of 8381 participants from 13 cohorts contributed data; 85% were male, 52% were nonwhite, 32% were overweight ( BMI 25–29.9 kg/m 2 ) and 15% were obese ( BMI > 30 kg/m 2 ). Pretreatment BMI was associated with 12‐month CD 4 T ‐cell change ( P  < 0.001), but the relationship was nonlinear ( P  < 0.001). Compared with a reference of 22 kg/m 2 , a BMI of 30 kg/m 2 was associated with a 36 cells/μL [95% confidence interval ( CI ) 14, 59 cells/μL] greater CD 4 T ‐cell count recovery among women and a 19 cells/μL (95% CI 9, 30 cells/μL) greater recovery among men at 12 months. At a BMI  > 30 kg/m 2 , the observed benefit was attenuated among men to a greater degree than among women, although this difference was not statistically significant. Conclusions A BMI of approximately 30 kg/m 2 at ART initiation was associated with greater CD 4 T ‐cell recovery at 12 months compared with higher or lower BMI values, suggesting that body composition may affect peripheral CD 4 T ‐cell recovery.