title: Mild to moderate symptoms do not correlate with lactate levels in HIV-positive patients on nucleoside reverse transcriptase inhibitors.
abstract: OBJECTIVE
  Nucleoside reverse transcriptase inhibitors (NRTIs) are associated with mitochondrial toxicities ranging from asymptomatic hyperlactatemia to fatal lactic acidosis. It is uncertain whether mild clinical symptoms predict hyperlactatemia and the need to consider changes in antiretroviral therapy. This cross-sectional study evaluated whether an association exists between mild symptoms and lactate levels.
  
  
  METHODS
  HIV-positive patients on NRTIs attending routine clinic visits were surveyed about symptoms associated with hyperlactatemia. Symptom severity was quantified using Likert scales, and the sum was converted into a symptom score ranging from 0 to 30. Tourniquet-free blood specimens were collected simultaneously to measure serum lactate. Symptom scores were compared between patients with normal and elevated lactates.
  
  
  RESULTS
  284 individuals were included. The most common NRTIs used included lamivudine (79%), zidovudine (50%), abacavir (39%), and stavudine (24%). Twenty-two patients (8%) had increased lactates (mean = 2.7 mmol/L; range, 2.1-4.5 mmol/L), while 262 patients (92%) had normal lactates (mean = 1.2 mmol/L, range, 0.1-2.0 mmol/L). Median symptom scores were similar between groups (3 vs. 2, p = .23). Spearman's correlation coefficient for lactate and symptom score was 0.07 (p = .22).
  
  
  CONCLUSIONS
  Mild symptoms did not correlate with lactate levels, and symptoms alone should not trigger clinicians to measure serum lactates and stop NRTIs if the levels are elevated.
authors.affiliation: Division of Infectious Diseases, University of Toronto, 200 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4. darrell.tan@gmail.com
authors.forename: Darrell
authors.initials: D
authors.lastname: Tan
authors.forename: Sharon
authors.initials: S
authors.lastname: Walmsley
authors.forename: Sandy
authors.initials: S
authors.lastname: Shen
authors.forename: Janet
authors.initials: J
authors.lastname: Raboud
mesh_terms: D015746:Abdominal Pain / Q000473:pathology; D000140:Acidosis, Lactic / Q000097:blood / Q000139:chemically induced / Q000175:diagnosis / Q000517:prevention & control*; D000704:Analysis of Variance; D002170:Canada; D003430:Cross-Sectional Studies; D005221:Fatigue / Q000473:pathology; D005260:Female; D006679:HIV Seropositivity / Q000150:complications / Q000188:drug therapy*; D006801:Humans; D007565:Jaundice / Q000473:pathology; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018894:Reverse Transcriptase Inhibitors / Q000009:adverse effects* / Q000627:therapeutic use; D014505:Urban Population; D014839:Vomiting / Q000473:pathology
chemical_list: D018894:Reverse Transcriptase Inhibitors; D019344:Lactic Acid