Abstract
Background
The significance of asymptomatic hyperlactataemia is unknown.
Methods
We measured serial lactate levels in a group of HIV-infected subjects. Objectives were to identify covariates associated with hyperlactataemia, and to explore the natural history of hyperlactataemia.
Results
Overall, 1487 lactate measurements were performed on 396 subjects; 299 subjects had serial lactate testing, with a median of four performed per patient (range: 2–16). At study entry, lactate was >2.4 mmol/l in 6% of subjects and >3.6 mmol/l in 1%. A multiple logistic regression analysis revealed that cholesterol and current stavudine were the only predictors of hyperlactataemia. Lactate levels were highly reproducible both for short-term (within 3 months) and long-term (>1 year) follow-up. During the study period, 16 subjects were identified with sustained hyperlactataemia; 12/16 remained asymptomatic after a median of 210 days (30–585), and four developed symptoms suggestive of lactic acidosis syndrome. In three of the four, asymptomatic hyperlactataemia had preceded the onset of symptoms by 18–122 days. A longitudinal model showed a rapid rise of lactate levels from 0 to 12 months on nucleoside reverse transcriptase inhibitor (NRTI) and then stabilization. Lactate levels did not correlate with baseline or on-study development of lipoatrophy.
Conclusions
Even when optimal methods of collection are used, asymptomatic hyperlactataemia does exist and could be sustained in a subset of NRTI-treated subjects for as long as 585 days. A subset of these subjects became symptomatic, after as long as 122 days of asymptomatic hyperlactataemia. Asymptomatic hyperlactataemia is not predictive of lipoatrophy.
This work was partly presented at the 9th Conference on Retroviruses & Opportunistic Infections. Seattle, Wash., USA, February 2002.