Hyperlactataemia and lactic acidosis during antiretroviral therapy: relevance, reproducibility and possible risk factors.

Abstract

To evaluate the prevalence, outcome and possible risk factors for hyperlactataemia and lactic acidosis in HIV-positive persons receiving antiretroviral therapy. Cross-sectional and longitudinal data from a prospectively collected clinical database. Associations with antiretroviral regimen, clinical and laboratory parameters were assessed using univariate and multivariate Cox's proportional hazards model. Patients naive to therapy and patients on current therapy for a minimum of 4 months were assessed. Median lactate was 1.1 mol/l in 253 untreated individuals and 1.4 mmol/l in 1239 patients stable on therapy for at least 4 months. At least two on-therapy samples were available for 750 of the 1239 individuals, taken a median 92 days apart. Lactate measurement showed a low positive predictive value of 38.9% but a high negative predictive value (98%) for normal values. Lactate was elevated > or = 2.4 mmol/l in 102 individuals on at least one occasion. In the multivariate Cox's proportional hazards model, no demographic characteristics were associated with hyperlactataemia. Didanosine-containing regimens doubled the relative hazard of hyperlactataemia compared with those sparing didanosine. Abacavir-containing regimens reduced the hazard of hyperlactataemia. Choice of thymidine analogue did not influence risk. Hyperlactataemia was associated with acid-base disturbance. Use of didanosine and female sex were over-represented amongst nine patients with severe hyperlactataemia (> 5 mmol/l) or lactic acidosis. Screening of lactate is of limited use in asymptomatic individuals on antiretroviral therapy. Raised lactate represents part of a spectrum of lactate and acid-base disturbance that infrequently includes lactic acidosis. Didanosine appears associated with an increased risk of hyperlactataemia.