Within subject variability of HDL-cholesterol in HIV-infected patients.

: Within-subject variability of cardiovascular risk factors may influence the development of cardiovascular disease. We aimed to improve knowledge on HDL-cholesterol variability and its clinical significance in HIV-infected patients, a population at high risk of cardiovascular disease.: This was a cohort study to quantify the variability of HDL-cholesterol between two consecutive visits and to determine factors associated with such variability, in a group of HIV-infected patients.: A total of 307 patients were included, mean ± standard deviation of their age was 45.1 ± 8.5 years, and 225 of them (73.3%) were male. The absolute difference (after squaring and root squaring) of serum HDL-cholesterol level between the first and the second visit was 12.1 ± 9.2 mg/dL. In 65 patients (21.2%) the absolute value of the difference between both serum HDL-cholesterol level results were 20 mg/dL or higher. In a multivariable analysis the number of cigarettes smoked per day showed a significant, negative, correlation with the absolute difference in serum HDL-cholesterol level between the two visits (P = 0,009).: Within-subject variability of HDL-cholesterol was substantial among our HIV-infected patients. Smoking was inversely correlated with such variability.