Absence of sustained hyperlactatemia in HIV-infected patients with risk factors for mitochondrial toxicity

Background: The prevalence of asymptomatic hyperlactatemia among HIV-infected individuals has been reported to be 4% to 36%. This variability may reflect differences in the definition of and risk factors for hyperlactatemia and/or techniques for venous lactate collection. Methods: We examined the prevalence of elevated venous lactate collected in accordance with Adult AIDS Clinical Trials Group (AACTG) guidelines among HIV-infected and nucleoside analogue-treated subjects with risk factors associated with hyperlactatemia. Sustained hyperlactaternia was defined as 2 consecutive levels greater than or equal to1.5 but less than or equal to4 times the upper limit of normal (ULN) within 30 days. Results: Eighty-three subjects were enrolled. Two thirds had greater than or equal to2 risk factors, with 11% having >4 risk factors. The median entry venous lactate level was 1.2 mmol/L (range: 0.7-5.1 mmol/L). Two subjects had a lactate level >1.5 times the ULN: 1 with a value of 2.1 times the ULN at entry and a week 2 level of 1.2 times the ULN and a second subject with a week 2 value of 1.9 times the ULN but an entry level of 1.4 times the ULN. The latter subject developed symptomatic lactic acidosis 3 weeks following study discontinuation. Conclusions: Sustained asymptomatic hyperlactatemia among subjects with risk factors associated with hyperlactaternia was not observed when venous lactate was measured in a standardized fashion. One case of hyperlactaternia that evolved into symptomatic lactic acidosis was diagnosed soon after the completion of the study, however. Our findings indicate that asymptomatic hyperlactaternia is either very rare or an artifact of collection technique.