The interaction between detectable plasma viral load and increased body mass index on hypertension among persons living with HIV.

Increased body mass index (BMI) and HIV are each associated with hypertension. This study tested interactions between BMI and detectable plasma viral load (pVL) on hypertension among 659 persons living with HIV (PLWH). All participants were categorized into four subgroups based on BMI (<25 and ≥25 kg/m2) and pVL (<200 and ≥200 copies/ml). Multiplicative interaction was assessed using logistic regression; addictive interaction was assessed using three measures: Relative Excess Risk due to Interaction (RERI), Attributable Proportion (AP), and Synergy index (S). Compared to the participants with normal BMI and undetectable pVL, those who had increased BMI with an undetectable pVL had an elevated risk of hypertension with OR [95%CI] = 1.80 [1.02, 3.20]; the risk was further increased for those who had increased BMI with detectable pVL with OR [95%CI] = 3.54 [1.71, 7.31]. The multiplicative interaction was significant (p = 0.01). Results from additive interaction indicated RERI [95%CI] =1.89 [0.76, 4.79] and AP [95%CI] = 0.64 [0.32, 0. 95]. The interaction effects of increased BMI and detectable pVL on hypertension on both multiplicative and additive scales suggested that PLWH with increased BMI and detectable pVL should be intensively managed and monitored for hypertension prevention and treatment.