Background:  Lipid and glucose metabolism disturbances and reduced bone mineral density are prevalent among HIV-infected patients, but data concerning this relationship are negligible.

Methods:  In 55 HIV⁺ patients (39 male, 16 female, aged 21 to 53 years; 37 on HAART) and 15 HIV^– bone mineral density of lumbar spine (L2-L4) was assessed by DEXA. Serum osteocalcin concentrations as well as osteoprotegerin were measured by ELISA (Biosource and BioVendor, respectively);\. H1 MR spectra of the lumbar vertebral bodies were recorded at 1.5 T, using the PRES pulse sequence. In statistical analyses U Mann-Whitney and Spearman correlation tests were used.

Results:  Osteopenia was observed in 18 (35%) of patients, osteoporosis in 10 (19%), while no bone density alterations were observed in 23 (46%) of HIV⁺ patients. There was negative correlation between serum cholesterol and L3 lumbar spine bone mineral density (r = –0.78, p = 0.02), T-score (r = –0.79, p = 0.02), and Z-score (r = –0.85, p = 0.01). HIV infection resulted in the increase of serum osteocalcin (6.7 ± 0.8 vs 3.3 ± 0.54 ng/mL, p < 0.001). Further increase was observed in HAART patients (7.5 ± 1.1 ng/mL) with highest values in lipodystrophy patients (12.5 ± 2.4 ng/mL). A positive correlation between serum osteocalcin and total cholesterol (r = 0.43, p = 0.01), LDL cholesterol (r = 0.48, p < 0.01), triglycerides (r = 0.4, p = 0.02), and fasting glucose levels (r = 0.38, p < 0.05) were observed in HAART patients. Such correlations were absent in individuals without ARV treatement. H1 MR spectra of lumbar vertebral body revealed the decrease in intravertebral marrow fat in HIV⁺ HAART patients compared to HIV^– (197.9 ± 19.5 vs 265.7 ± 27.4 relative units). It was negatively correlated with total cholesterol concentrations (r = –0.6, p < 0.05) in HIV⁺. The increase in serum ostoprotegerin in HIV⁺ patients toward control group was observed (9.2 ± 1.6 vs 6.29 ± 1.1 units/L, p < 0.05). However, there were no significant differences in serum osteoprotegerin regarding to HAART (9.3 ± 0.9 U/L), as well HAART-induced lipodystrophy (9.38 ± 2.0 U/L).

Conclusions:  Serum cholesterol concentration is associated with decreased bone mass and high osteoblastic activity in HIV⁺ patients. Therefore hipercholesterolaemia may increase the risk of osteopenia and osteoporosis in this population.

Keywords: osteoprotegerin; interleukin 6; tissue inhibitor of metalloproteinase 1