Bsm1 Vitamin D Receptor Polymorphism and Calcium Homeostasis Following Bariatric Surgery

Prevalence and risk factors for secondary hyperparathyroidism (SHPT) in patients undergoing bariatric surgery

INTRODUCTION

Secondary hyperparathyroidism (SHPT) after bariatric surgery has significant adverse implications for bone metabolism, increasing the risk for osteoporosis and fracture. Our aim was to characterize prevalence and identify risk factors for SHPT in bariatric surgery patients.

METHODS

We performed a single-institution, retrospective chart review of patients who underwent bariatric surgery from June 2017 through December 2021. Demographic and clinical data were collected, including serum parathyroid hormone, calcium, and vitamin D3 at enrollment and 3, 6, and 12-months postoperatively. Chi-square or Fisher's exact tests were used to analyze categorical data and Mann-Whitney U test for continuous data. Multivariable analysis using binomial logistic regression assessed risk factors for SHPT. P-values ≤ 0.05 were considered significant.

RESULTS

350 patients were analyzed. SHPT prevalence at any time point was 72.9%. 65.8% had SHPT at enrollment; 45.9% resolved with intensive vitamin supplementation; and 19.7% had recurrent SHPT. New-onset SHPT occurred in 8.6%. Persistent SHPT was present in 42.4% at 1-year. Baseline SHPT correlated with black race and T2DM. SHPT at any time point correlated with T2DM and higher baseline BMI. 1-year SHPT correlated with RYGB, depression, and longer time in program. SHPT was not correlated with %TBWL at any time point. In patients with SHPT, vitamin D3 deficiency prevalence was significantly higher at baseline (77.0%) compared to all post-bariatric time points (16.7%, 17.3%, and 23.1%; P < 0.0001).

CONCLUSIONS

SHPT is highly prevalent in patients with obesity seeking weight loss surgery. 42% had persistent SHPT at 1-year despite appropriate vitamin supplementation. Current vitamin D3 and calcium supplementation protocols may not effectively prevent SHPT in many post-bariatric patients. Low prevalence of concomitant vitamin D3 deficiency with SHPT after bariatric surgery suggests that there may be alternative mechanisms in this population. Further studies are needed to develop effective treatment strategies to mitigate the adverse effects of bariatric surgery on bone metabolism.

Lack of secondary hyperparathyroidism in sub-group of vitamin D deficient postmenopausal women: Is VDR gene polymorphism behind this mystery?

BACKGROUND AND AIMS

We aimed to determine the cause of non-secondary hyperparathyroidism (Non-SHPT) in Indian postmenopausal women.

MATERIALS & METHODS

334 apparently healthy postmenopausal women were assessed for bone mineral homeostaisis including Vitamin D, PTH and VDR polymorphism.

RESULTS

83% of the subjects had vitamin D deficiency further associated with VDR gene polymorphism (P 0.000). A sizable number of subjects (N = 83) did evoke SHPT despite low vitamin D levels. We observe that VDR gene polymorphism was strongly associated in the sub-group of non-SHPT.

CONCLUSION

lack of SHPT warrants researchers to study the pathophysiology of non-SHPT in detail to substantiate our findings.

A Systematic Review of Genetic Correlates of Weight Loss After Bariatric Surgery

This systematic review synthesized research evaluating the relationship between genetic predictors and weight loss after bariatric surgery. Fifty-seven studies were identified that examined single genes or genetic risk scores. Uncoupling protein (UCP) rs660339 was associated with excess weight loss after surgery in 4 of 6 studies. The most commonly assessed genes were fat mass and obesity-associated (FTO) gene (n = 10) and melanocortin-4 receptor (MC4R) (n = 14). Both were inconsistently related to weight loss. Genetic risk scores predicted weight loss in 6 of 7 studies. This evidence suggests the potential of using genetic variants and genetic risk scores to predict the amount of weight loss anticipated after bariatric surgery and identify patients who may be at risk for suboptimal weight reduction.

Iron and Vitamin D/Calcium Deficiency after Gastric Bypass: Mechanisms Involved and Strategies to Improve Oral Supplement Disposition

Background:

Nutritional deficiencies are common following Roux-en-Y Gastric Bypass (RYGB). Aetiology is diverse; including non-compliance, altered diet, unresolved preoperative deficiency and differential degrees of post-operative malabsorption occurring as function of length of bypassed intestine. Iron and calcium/vitamin D deficiency occur in up to 50% of patients following RYGB. Currently, treatment strategies recommend the prescription of oral supplements for those who become deficient. Meanwhile, debate exists regarding the absorption capacity of these post-operatively and their efficacy in treating deficiency.

Objective:

To examine the disposition of oral iron and calcium/vitamin D supplementation following RYGB. Methods: A literature review was carried out using PubMed and Embase. Data from the key interventional studies investigating iron and calcium/vitamin D oral supplement absorption and efficacy following RYGB was summarized.

Results:

Absorption of both iron and vitamin D/calcium is adversely affected following RYGB. Distribution and metabolism may be altered by the predominance of paracellular absorption pathways which promote unregulated influx into the circulatory system. Overall, studies indicate that current supplementation strategies are efficacious to a degree in treating deficiency following RYGB, generally restoration of optimal status is not achieved.

Conclusion:

Oral supplement disposition is altered following RYGB. As a result, patients are required to take regimens of oral supplementation indefinitely. The dosage which confers optimum health benefit while avoiding potential toxicity and tolerability issues remains unknown. Novel preparations with improved disposition could help limit the extent of post-RYGB nutritional deficiencies.

Association of Sun Exposure, Skin Colour and Body Mass Index with Vitamin D Status in Individuals Who Are Morbidly Obese

Vitamin D deficiency is a common issue, particularly in obese populations, and is tested by assessing serum 25(OH)D concentrations. This study aimed to identify factors that contribute to the vitamin D status in fifty morbidly obese individuals recruited prior to bariatric surgery. Data collected included serum 25(OH)D concentrations, dietary and supplement intake of vitamin D, sun exposure measures, skin colour via spectrophotometry, and genotype analysis of several single nucleotide polymorphisms in the vitamin D metabolism pathway. Results showed a significant correlation between serum 25(OH)D concentrations and age, and serum 25(OH)D and ITAC score (natural skin colour). Natural skin colour accounted for 13.5% of variation in serum 25(OH)D, with every 10° increase in ITAC score (i.e., lighter skin) leading to a 9 nmol/L decrease in serum 25(OH)D. Multiple linear regression using age, ITAC score, and average UV index in the three months prior to testing, significantly predicted serum 25(OH)D concentrations (R² = 29.7%). Single nucleotide polymorphisms for all vitamin D genes tested, showed lower serum 25(OH)D for those with the rare genotype compared to the common genotype; this was most pronounced for fok1 and rs4588, where those with the rare genotype were insufficient (<50 nmol/L), and those with the common genotype were sufficient (≥50 nmol/L). Assessing vitamin D status in individuals with morbid obesity requires testing of 25(OH)D, but potential risk factors for this population include natural skin colour and age.

Greek-origin royal jelly improves the lipid profile of postmenopausal women

AIM

Menopause transition is associated with chronic conditions such as osteoporosis and cardiovascular disease. Concerns about the long-term safety of menopausal hormone therapy make alternative natural methods an appealing approach to management. The aim of this study was to examine the effect of royal jelly (RJ) on cardiovascular and bone turnover markers in clinically healthy postmenopausal women.

METHODS

A total of 36 postmenopausal healthy women were studied in a prospective follow-up study. Participants received 150 mg of RJ daily for three months. Circulating cardiovascular risk markers [lipid profile, antithrombin-III (ATIII), Protein C, Protein S, Plasminogen Activator Inhibitor-1 (PAI-1)] and bone turnover parameters [Total calcium, phosphate (P), parathormone (PTH), total type-1 Procollagen N-terminal (P1NP), Osteocalcin and serum collagen type 1 cross-linked C-telopeptide (CTX)] were compared between the baseline and the three-month visit.

RESULTS

The RJ used in this study was particularly rich in medium chain fatty acids, compounds with hypolipidemic properties, which comprised 63% of the dry weight fatty content. RJ treatment resulted in a significant increase in high density lipoprotein - cholesterol (HDL-C 60.2 mg/dL ± 12.3 versus 64.7 mg/dL ± 13.9, 7.7% increase, p = 0.0003), as well as in a significant decrease in low density lipoprotein - cholesterol (LDL-C, 143.9 ± 37.5 versus 136.2 ± 32, 4.1% decrease, p = 0.011) and in total cholesterol (224.4 ± 38.6 to 216.1 ± 36.5, 3.09% decrease, p = 0.018). No statistical significant changes were found in the remaining cardiovascular or the bone turnover parameters.

CONCLUSIONS

The intake of RJ 150 mg for three months is associated with significant improvements of the lipid profile of postmenopausal women. RJ supplementation may offer an alternative method of controlling the menopause - associated dyslipidemia.

Epigenetics and nutrition-related epidemics of metabolic diseases: Current perspectives and challenges

We live in a world fascinated by the relationship between disease and nutritional disequilibrium. The subtle and slow effects of chronic nutrient toxicity are a major public health concern. Since food is potentially important for the development of "metabolic memory", there is a need for more information on the type of nutrients causing adverse or toxic effects. We now know that metabolic alterations produced by excessive intake of some nutrients, drugs and chemicals directly impact epigenetic regulation. We envision that understanding how metabolic pathways are coordinated by environmental and genetic factors will provide novel insights for the treatment of metabolic diseases. New methods will enable the assembly and analysis of large sets of complex molecular and clinical data for understanding how inflammation and mitochondria affect bioenergetics, epigenetics and health. Collectively, the observations we highlight indicate that energy utilization and disease are intimately connected by epigenetics. The challenge is to incorporate metabolo-epigenetic data in better interpretations of disease, to expedite therapeutic targeting of key pathways linking nutritional toxicity and metabolism. An additional concern is that changes in the parental phenotype are detectable in the methylome of subsequent offspring. The effect might create a menace to future generations and preconceptional considerations.