Nutritional Status of Vegetarian Patients Before and After Bariatric Surgery: a Monocentric Retrospective Observational Case-Control Study.

The obesity pandemic is associated with an increasing number of bariatric surgeries which allow improvement in obesity-related comorbidities and life expectancy but potentially induce nutritional deficiencies. Vegetarianism becomes more and more popular and exposes as well to vitamin and micronutrient deficiencies. Only one study has explored the impact of vegetarianism on the preoperative nutritional status of eligible patients for bariatric surgery, but none in postoperative care. MATERIALS AND METHODS: We conducted a retrospective case-control study in our cohort of bariatric patients, matching 5 omnivores for each vegetarian. We compared their biological profile regarding vitamin and micronutrient blood levels before and 3, 6, 12, and 30 months after surgery. RESULTS: We included 7 vegetarians including 4 lacto-ovo-vegetarians (57%), 2 lacto-vegetarians (29%), and one lacto-ovo-pesco-vegetarian (14%). Three years after surgery with equivalent daily standard vitamin supplementation, the two groups showed a similar biological profile including blood levels of ferritin (p = 0.6), vitamin B1 (p = 0.1), and B12 (p = 0.7), while the total median weight loss at 3 years was comparable (39.1% [27.0-46.6] in vegetarians vs 35.7% [10.5-46.5] in omnivores, p = 0.8). We observed no significant difference between vegetarians and omnivores before surgery regarding comorbidities and nutritional status. CONCLUSION: It seems that, after bariatric surgery, vegetarian patients taking a standard vitamin supplementation do not show an increased risk of nutritional deficiencies compared to omnivores. However, a larger study with a longer follow-up is needed to confirm these data, including an evaluation of different types of vegetarianism such as veganism.

Functional Characterization of Glucocorticoid Receptor Variants Is Required to Avoid Misinterpretation of NGS Data.

Recent advances in genetic analysis technologies such as next-generation sequencing (NGS) have considerably increased the incidental discovery of genetic abnormalities. Six heterozygous missense mutations of the human glucocorticoid receptor (GR; encoded by the NR3C1 gene) have been identified in the context of genetic screening of endocrine pathologies. GR, a nuclear receptor, hormone-induced transcription factor, is involved in many physiological processes. Nevertheless, the pathogenic significance of incidentally discovered mutations remains obscure. The aim of this work was to characterize these variants by evaluating their functional impact on GR signaling. Six original GR variants, located in exon 2, led to amino acid substitutions of the N-terminal domain of GR (F65V, M86V, A229T, A304E, N374S, and R386Q), excluding mainly the activation function tau core 1 domain, the potential site of functional interaction with transcriptional coregulators. Transient cotransfection in HEK293T cells of mutated GR-expressing vectors and a luciferase reporter established dose-response curves for dexamethasone. This excluded any major transactivation abnormality of the mutated GRs (ligand concentration leading to 50% maximal transactivation capacity ≈ 0.2 nM), with maximal transactivation capacity identical to that of the wild-type (WT) GR and without modification of the potentiation of transcriptional coactivator steroid receptor coactivator 2 except in N374S. Moreover, protein expression of mutated GRs and their cytonuclear translocation studied by immunocytochemistry were almost unchanged compared with WT GR. These results underline the silent nature of these missense GR variants and call for cautious interpretation of the discovery of genetic incidentalomas by NGS in the absence of detailed characterization in order to appropriately assess their functional impact on a particular signaling pathway.