Vitamin D levels and their impact on mineral metabolism in HIV infected patients: an exploratory study

Low bone mass and vitamin D in Brazilian people living with HIV under antiretroviral therapy

We performed a cross-sectional study in 212 PLHIV under antiretroviral therapy. Bone mass was compromised in 36.5% of relatively young sample and associated with hypogonadism, older age, higher PTH levels, and metabolic syndrome. Hypovitaminosis D was present in 85%, especially those on NNRTI.

PURPOSE

Previous studies have reported an increased prevalence of bone demineralization among people living with the human immunodeficiency virus (PLHIV). We aimed to assess bone mineral density (BMD), vitamin D levels, and associated risk factors in Brazilian PLHIV.

METHODS

Cross-sectional study with 212 patients in a specialized assistance service. Clinical and demographic information were registered. Laboratory tests were performed, and BMD was measured at the lumbar spine, total hip/femoral neck, and forearm by dual-energy X-ray absorptiometry. Participants were classified into "with low bone mass (wLBM)" and "without low bone mass (woLBM)." Those wLBM encompasses osteoporosis, osteopenia, and below the expected range for age as recommended by the World Health Organization.

RESULTS

One hundred and eighty-seven patients were included. Median age was 46.3 years (interquartile range (IQR) 40-52) and duration of HAART exposure was 11.2 years (IQR 7-15). Plasma viral load was undetectable in 79%. Hypovitaminosis D (< 30 ng/mL) was present in 85% and LBM in 36.5%. Men wLBM were more likely to have testosterone deficiency and had higher PTH levels than those woLBM. LBM in women was associated with older age, menopause, and metabolic syndrome.

CONCLUSION

This study showed a high frequency of LBM in a relatively young sample, and suggests a detrimental effect of hypogonadism, older age, higher PTH levels, and metabolic syndrome. Hypovitaminosis D was frequent, especially those on non-nucleoside reverse transcriptase inhibitor, higher body mass index, and abdominal circumference.

Gut Microbiota and Fecal Metabolites Associated With Neurocognitive Impairment in HIV-Infected Population

Gut microbiota dysbiosis has been associated with many neurological diseases. However, how microbiota composition and metabolism relate to neurocognitive impairment (NCI) in HIV-infected individuals is largely unknown. In this study, a total of 102 HIV infected participants were classified into two groups—those with NCI and those without—using the global deficit score (GDS). Fecal samples were collected from the participants for 16S rRNA gene sequencing and untargeted metabolomics. The plasma level of 25 hydroxy-vitamin D (25(OH)D) was also evaluated. Although α-diversity and β-diversity were comparable, the HIV patients with NCI were significantly different from those without NCI in terms of abundance of several gut microbiota. The decreased abundance of butyrate-producing bacteria (BPB) and increased abundance of Klebsiella were related with NCI and carotid intima-media thickness (CIMT). Significant differences in fecal metabolites were also found between individuals with versus without NCI, including increased bile acids and bioactive lipids, decreased vitamin D, terpenoids, and resolvin D1 in the NCI group. Furthermore, the perturbed metabolic profile was closely related to BPB and Klebsiella. In addition, a low level of vitamin D was associated with NCI and CIMT. Both fecal and plasma vitamin D were positively correlated with BPB. Our results show that BPB and Klebsiella and the associated metabolites are associated with NCI in people with HIV. In addition, vitamin D, both in feces and blood, was associated with NCI and BPB, suggesting a protective effect of vitamin D on NCI.

In vitro anti-inflammatory effects of vitamin D supplementation may be blurred in hemodialysis patients

OBJECTIVES

This study aimed to evaluate the potential anti-inflammatory effects of vitamin D supplementation under uremic conditions, both in vivo and in vitro, and its effects on the parameters of mineral metabolism.

METHODS

Thirty-two hemodialysis patients were randomly assigned to receive placebo (N=14) or cholecalciferol (N=18) for six months. Serum levels of calcium, phosphate, total alkaline phosphatase, intact parathyroid hormone (iPTH), and vitamin D were measured at baseline and after three and six months. The levels of fibroblast growth factor-23 (FGF-23), interleukin-1β (IL-1β), and high-sensitivity C-reactive protein (hs-CRP) were also measured at baseline and at six months. Human monocytes were used for in vitro experiments and treated with cholecalciferol (150 nM) and uremic serum. Cell viability, reactive oxygen species (ROS) production, and cathelicidin (CAMP) expression were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, dichloro-dihydro-fluorescein diacetate assay, and real time-quantitative polymerase chain reaction, respectively.

RESULTS

Both patient groups were clinically and biochemically similar at baseline. After six months, the levels of vitamin D and iPTH were higher and lower, respectively, in the cholecalciferol group than in the placebo group (p<0.05). There was no significant difference between the parameters of mineral metabolism, such as IL-1β and hs-CRP levels, in both groups. Treatment with uremic serum lowered the monocyte viability (p<0.0001) and increased ROS production (p<0.01) and CAMP expression (p<0.05); these effects were counterbalanced by cholecalciferol treatment (p<0.05).

CONCLUSIONS

Thus, cholecalciferol supplementation is an efficient strategy to ameliorate hypovitaminosis D in hemodialysis patients, but its beneficial effects on the control of secondary hyperparathyroidism are relatively unclear. Even though cholecalciferol exhibited anti-inflammatory effects in vitro, its short-term supplementation was not effective in improving the inflammatory profile of patients on hemodialysis, as indicated by the IL-1β and hs-CRP levels.

Continued Interest and Controversy: Vitamin D in HIV

PURPOSE OF REVIEW

Vitamin D (VitD) deficiency is highly prevalent among HIV-infected individuals. Given the overlapping risk for several chronic disease and immunomodulatory outcomes from both long-standing HIV and VitD deficiency, there is great interest in clarifying the clinical role of VitD for this population.

RECENT FINDINGS

Recent studies have expanded our knowledge regarding the epidemiology and mechanisms of VitD deficiency-associated outcomes in the setting of HIV. Clinical trials focusing on VitD supplementation have demonstrated a positive impact on bone mineral density in subgroups of HIV-infected individuals initiating ART or on suppressive ART regimens; however, significant heterogeneity exists between studies and data are less consistent with other clinical outcomes. Further research is needed to clarify uncertainly in several domains, including identifying patients at greatest risk for poor outcomes from VitD deficiency, standardizing definitions and measurement techniques, and better quantifying the benefits and risks of VitD supplementation across different demographic strata for skeletal and extra-skeletal outcomes.

Osteoporosis complicating some inborn or acquired diseases

Osteoporosis in chronic diseases is very frequent and pathogenetically varied. It complicates the course of the underlying disease by the occurrence of fractures, which aggravate the quality of life and increase the mortality of patients from the underlying disease. The secondary deterioration of bone quality in chronic diseases, such as diabetes of type 1 and type 2 and/or other endocrine and metabolic disorders, as well as inflammatory diseases, including rheumatoid arthritis - are mostly associated with structural changes to collagen, altered bone turnover, increased cortical porosity and damage to the trabecular and cortical microarchitecture. Mechanisms of development of osteoporosis in some inborn or acquired disorders are discussed.

A preliminary investigation of metal element profiles in the serum of patients with bloodstream infections using inductively-coupled plasma mass spectrometry (ICP-MS)

BACKGROUND

We determined metal element profiles (MEPs) by inductively-coupled plasma mass spectrometry (ICP-MS) in the serum of patients with blood stream infection (BSI) and find out very important (VIP) metal elements in specific infections.

METHODS

Sixty-eight metal elements were identified in both serum and the bacteria isolated from 14 BSI patients with Staphylococcus infection, 39 with Enterobacteriaceae infection, 5 with Enterococcus infection and 58 healthy subjects without infection by ICP-MS methods. Statistical analysis, Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA) were performed to process data among different groups, select differential metal elements and operate correlation analysis.

RESULTS

The MEPs in the serum of BSI patients with 4 types of bacteria (Staphylococcus aureus, Escherichia coli, Enterococcus faecium, and Klebsiella pneumonia), and the corresponding MEPs of the bacteria were established. VIP metal elements were screened out in different BSI patients. Correlation analysis showed that there were some correlations between serum concentrations of metal elements and bacterial infection.

CONCLUSION

We found differential metal elements in the serum of BSI patients compared with controls, thus providing a basis for the diagnosis, prevention and treatment of BSI from the perspective of metallomics.