Insulin resistance is not associated with liver fibrosis progression in HIV/hepatitis C virus-coinfected patients.

Insulin resistance (IR) is a common condition in chronic hepatitis C. Recent studies have reported that IR is associated with liver fibrosis progression in these patients. However, there is no information available on this issue in human immunodeficiency virus (HIV)/hepatitis C virus (HCV)-coinfected patients. For these reasons, we investigate the relationship between IR and liver fibrosis in patients with HIV and HCV infections. This was a cross-sectional study where patients from an Infectious Diseases Unit with HIV/HCV coinfection who underwent a liver biopsy, with available frozen sera samples at the time of biopsy and a known or estimated date of infection were included. IR was determined by the homeostasis model assessment (HOMA-IR) method. The relationship between histological findings and several variables, including HOMA-IR values, was examined. Seventy-nine patients fulfilled the inclusion criteria. Age at HCV infection >21 years was the only variable independently associated with advanced liver fibrosis (stages F3 and F4) [adjusted odds ratio (AOR) 4.15; 95% confidence interval (CI) 1.5-11.3]. The variables associated with a fibrosis progression rate above the median were age at HCV infection >21 years (AOR 6.41; 95% CI 2.16-27.96) and previous exposure to nevirapine (AOR 8.9; 95% CI 2.01-39.36). There was no association between HOMA-IR values and the presence of advanced fibrosis or a faster fibrosis progression. Thus IR is not associated with liver damage or fibrosis progression in HIV/HCV-coinfected individuals.

Relationship between osteopenia, free testosterone, and vitamin D metabolite levels in HIV-infected patients with and without highly active antiretroviral therapy.

The prevalence of osteopenia in HIV-infected patients is high. However, the mechanisms implicated in bone mass loss in HIV infection are unclear. Because of this, we analyzed serum free testosterone and vitamin D3 hydroxylated metabolites in HIV-infected patients, with and without antiretroviral treatment, and the relation between them and osteopenia. Seventy-four HIV-infected patients were selected because they had frozen sera available at a date close to a DEXA evaluation. Free testosterone, 25(OH)D3, and 1,25(OH)2D3 were determined in frozen serum. There were no differences in free testosterone, 25(OH)D3, and 1,25(OH)2D3 levels between patients with and without osteopenia. 25(OH)D3 levels in naive and HAART-treated patients were 26.2 (10.3-32.8) and 33.1 (20.6-46.8) ng/ml, respectively (p = 0.04). 1,25(OH)2D3 levels in naive and HAART treated patients were 60.3 (49.2-80.8) and 85.5 (68-111.6) pmol/liter (p = 0.01). Free testosterone levels in 9 naive men and in 50 HAART-treated men were 42.6 (24.1-67.3) and 69.2 (47.5-112.1) pmol/liter, respectively (p = 0.04). In conclusion, HIV-infected patients with and without osteopenia showed similar levels of vitamin D metabolites and free testosterone. However, antiretroviral drug-naive patients showed lower serum levels of vitamin D metabolites and free testosterone than HAART-treated patients.

Developmental alterations and osmoregulatory physiology of a larval anuran under osmotic stress.

Water salinity represents an environmental stress for many species. Amphibians are particularly sensitive because they are generally poor osmoregulators, and most species are completely absent from brackish and saline environments. We experimentally examined the effect of different salinity levels on larvae of the toad Bufo calamita L., a species that occupies freshwater ponds but can also breed in brackish ponds. Two independent experiments are reported here. In both experiments, tadpoles under saline conditions (ranging between 85 and 200 mOsm) showed a slower developmental rate, metamorphosing between 4 and 9 d later than the controls. Bufo calamita tadpoles reared in brackish water increased their osmolality and solute concentration (mainly sodium and chloride), decreased their levels of glucose, and decreased the total protein content, all measured from whole-animal extracts. Although most larval anurans are strictly ammoniotelic until the completion of metamorphosis, a few species exposed to dehydrating environments have evolved the ability to use urea as an osmolyte during the larval phase. The data presented here reveal that although B. calamita seems to be yet another exception to the rule of larval strict ammoniotelism, the tadpoles are not able to use urea as an osmolyte and rely on sodium-chloride balance instead. Preliminary immunoassays of thyroid hormone content suggest a possible decrease in hormone levels induced in water salinity conditions that correlate with a decreased developmental rate.