Iron deficiency and anaemia in bariatric surgical patients: causes, diagnosis and proper management

Obesity-induced chronic inflammation leads to activation of the immune system that causes alterations of iron homeostasis including hypoferraemia, iron-restricted erythropoiesis, and finally mild-to-moderate anaemia. Thus, preoperative anaemia and iron deficiency are common among obese patients scheduled for bariatric surgery (BS). Assessment of patients should include a complete haematological and biochemical laboratory work-up, including measurement of iron stores, vitamin B12 and folate. In addition, gastrointestinal evaluation is recommended for most patients with iron-deficiency anaemia. On the other hand, BS is a long-lasting inflammatory stimulus in itself and entails a reduction of the gastric capacity and/or exclusion from the gastrointestinal tract which impair nutrients absorption, including dietary iron. Chronic gastrointestinal blood loss and iron-losingenteropathy may also contribute to iron deficiency after BS. Perioperative anaemia has been linked to increased postoperative morbidity and mortality and decreased quality of life after major surgery, whereas treatment of perioperative anaemia, and even haematinic deficiency without anaemia, has been shown to improve patient outcomes and quality of life. However, long-term follow-up data in regard to prevalence, severity, and causes of anaemia after BS are mostly absent. Iron supplements should be administered to patients after BS, but compliance with oral iron is no good. In addition, once iron deficiency has developed, it may prove refractory to oral treatment. In these situations, IV iron (which can circumvent the iron blockade at enterocytes and macrophages) has emerged as a safe and effective alternative for perioperative anaemia management. Monitoring should continue indefinitely even after the initial iron repletion and anaemia resolution, and maintenance IV iron treatment should be provided as required. New IV preparations, such ferric carboxymaltose, are safe, easy to use and up to 1000 mg can be given in a single session, thus providing an excellent tool to avoid or treat iron deficiency in this patient population.

Bone turnover markers in HIV-infected patients before starting antiretroviral therapy.

Purpose: Bone turnover markers (BTM) - aminoterminal propeptide of type 1 collagen (P1NP) and C-terminal telopeptide of type 1 collagen (b-CTX) - are related to bone density and fracture risk. A high prevalence of osteopenia/osteoporosis and hypovitaminosis D has been reported in HIV patients, however there are few data about BTM in this population. Our aim was to analyse the prevalence of elevated serum levels of BTM in HIV patients before starting antiretroviral therapy (ART), and related factors. Methods: Cross-sectional study of a series of HIV-patients who started ART during June/11-June/12 in our hospital. Patients with presence of diseases or treatments known to affect bone metabolism were excluded. Epidemiological, clinical, and immunovirological data in addition to serum fasting levels of glucose, lipid profile, calcium, phosphate, alkaline phosphatase, 25-hydroxyvitamin D3 (25OHD), parathyroid hormone (PTH), P1NP, and β-CTX were collected. Definitions: hypovitaminosis D if 25OHD<30 ng/ml, vitamin D deficiency if 25OHD<20 ng/ml; elevated levels of BTM if β-CTX (ng/ml) >0.64 (men<70 years),>0.85 (men>70 years),>0.58 (pre-menopause women), >0.99 (post-menopause women), or P1NP (ng/mL)>69.4 (men<60 years), >71.1 (men>60 years), >55.7 (pre-menopause women), >61.2 (post-menopause women). Results: 47 patients were included, 91.5% men, median age 37.1 years (30.0-44.3), and 93.6% sexual transmission of HIV (34 HMX, 10 HTX). Median time since the diagnosis of HIV was 3.4 months (1.4- 31.7); there were 7 (14.9%) Aids cases, median CD4 count was 277/ mm3 (155-433), and HIV-VL 4.8 log10 (4.1-5.2). Median serum 25OHD was 29 mg/L (21.9-41.1), with a prevalence of hypovitaminosis of 52.2%, and deficiency of 17.4%. PTH was in range in all cases. Median serum P1NP was 33.3 ng/mL (24.5-52.5) and β-CTX 0.25 ng/mL (0.20-0.45); five (11.4%) patients presented high levels of BTM: 4 men, median age 37.1 years, median CD4 count 247/mm3, median HIV-VL 5.18 log10, and one with hypovitaminosis D. Elevated BTM were related with no clinical, analytical, immunovirological parameters nor with serum levels of 25OHD nor PTH. Conclusions: The prevalence of elevated BTM was high in this series of HIV-patients, mostly young men, with short time of HIV infection and with no immunovirologic control. BTM were related with no clinical nor analytical data.