Unraveling the Connection: Visceral Adipose Tissue and Vitamin D Levels in Obesity

Association of Obesity on Rates of Multiglandular Disease in Primary Hyperparathyroidism: A Cohort Study

INTRODUCTION

Primary hyperparathyroidism (PHPT) is more prevalent in populations with obesity. Obesity-related vitamin D deficiency may affect rates of multigland parathyroid disease, but this relationship is less clear. We aimed to assess the relationship between obesity and the rate of multigland disease in patients with PHPT.

METHODS

Patients who underwent parathyroidectomy from 2015 to 2021 for sporadic PHPT at a tertiary center were retrospectively analyzed. The primary outcome was rates of single-gland versus four-gland parathyroid hyperplasia in relation to obesity. Secondary outcomes included analysis of serum biochemistries [parathyroid hormone (PTH), calcium, 25(OH) vitamin D (25OHD)] before and 6 mo postoperatively based on obesity classification: no obesity (body mass index [BMI] <30 kg/m2), Class 1 (BMI 30-34.9 kg/m2), Class 2 (BMI 35-39.9 kg/m2), Class 3 (BMI ≥40 kg/m2). Statistical analysis was performed using Chi-square, Mann-Whitney U, and Kruskal-Wallis tests where applicable.

RESULTS

Of 2634 patients who underwent parathyroidectomy, a total of 1173 had obesity. Obesity did not confer any differences in the proportion of four-gland versus single-gland hyperplasia (25 versus 26%, P = 0.79). Compared to patients without obesity, preoperative PTH levels were higher in patients with Class 2 [86 (interquartile range [IQR] 66-118) versus 95 (IQR 70-137) pg/mL, P = 0.001] and Class 3 [86 (IQR 66-118) versus 104 (76-150) pg/mL, P < 0.001] obesity. Conversely, 25OHD before surgery was lower across obesity subclasses [no obesity: 36.0 (25.3-49.3), Class 1: 32.5 (24.0-46.0), Class 2: 32.9 (22.0-44.6), Class 3: 31.7 (20.4-45.0) ng/mL, P < 0.001]. Postoperative PTH and 25OHD improved in all cohorts. No calcium-related differences were found among patients based on obesity classification.

CONCLUSIONS

Obesity is not associated with an increased rate of four-gland hyperplasia in patients with PHPT, and therefore should not alter surgical management. The levels of 25OHD in patients with obesity should be monitored for vitamin deficiency preoperatively and postoperatively.

Vitamin D Deficiency: Insights and Perspectives from a Five-Year Retrospective Analysis of Children from Northeastern Romania

BACKGROUND

Vitamin D plays an important role in maintaining bone health with numerous benefits for extraskeletal health as well.

OBJECTIVES

We aimed to assess the prevalence of vitamin D deficiency in children (0-18 years old) in a tertiary hospital in Romania between August 2019 and January 2024 and to investigate the role of adequate supplementation in this vulnerable population.

METHODS

The serum 25(OH)D levels were measured using a chemiluminescence binding assay.

RESULTS

A total of 744 participants were included in this study: 396 female (53.23%) and 348 male (46.77%). The serum levels of 25(OH)D ranged between 2.2 and 125.4 ng/mL, with a mean value of 27.4 ng/mL and a median value of 23.5 ng/mL. According to the cutoff values for the definition of vitamin D status (severe deficiency: <10 ng/mL, deficiency: <20 ng/mL, insufficiency: 20-29 ng/mL, and sufficiency: ≥30 ng/mL), the sample consisted of 77 (10.34%) cases of severe deficiency, 221 (29.7%) cases of deficiency, 194 (26.07%) cases of insufficiency, and 245 (32.93%) cases of sufficiency. There were seven cases of hypervitaminosis D with values above 100 ng/mL. The mean values (and corresponding 95% confidence intervals, CIs) were as follows: 27.85 ng/mL [25.95-29.76] in the males, 22.45 ng/mL [25.12-28.82] in the females, 24.82 ng/mL [21.86-27.77] in the spring, 28.62 ng/mL [26.42-30.81] in the summer, 32.30 ng/mL [29.16-35.44] in the autumn, and 24.01 ng/mL [21.57-26.44] in the winter. We observed a notable decline in the serum 25(OH)D levels with age, with 82.08% of the children in the age group above 6 years old having serum 25(OH)D levels below 30 ng/mL. In obese subjects, a higher prevalence of hypovitaminosis D was observed compared to non-obese subjects, with a mean value of 19.54 [17.50-21.57] ng/mL in obese children versus 28.89 [27.39-30.40] ng/mL in normal weight children.

CONCLUSIONS

In our sample, the mean serum concentration of 25(OH)D was 27.4 ng/mL. Notably, 66.11% of the cases demonstrated varying degrees of hypovitaminosis D, with a significantly higher prevalence of 86.16% observed in the obese group. Healthcare providers should prioritize routine screening for vitamin D levels in pediatric patients with obesity to facilitate timely intervention and personalized supplementation strategies tailored to individual needs.

An Overview of Different Vitamin D Compounds in the Setting of Adiposity

A large body of research shows an association between higher body weight and low vitamin D status, as assessed using serum 25-hydroxyvitamin D concentrations. Vitamin D can be metabolised in adipose tissue and has been reported to influence gene expression and modulate inflammation and adipose tissue metabolism in vitro. However, the exact metabolism of vitamin D in adipose tissue is currently unknown. White adipose tissue expresses the vitamin D receptor and hydroxylase enzymes, substantially involved in vitamin D metabolism and efficacy. The distribution and concentrations of the generated vitamin D compounds in adipose tissue, however, are largely unknown. Closing this knowledge gap could help to understand whether the different vitamin D compounds have specific health effects in the setting of adiposity. This review summarises the current evidence for a role of vitamin D in adipose tissue and discusses options to accurately measure vitamin D compounds in adipose tissue using liquid chromatography tandem mass spectrometry (LC/MS-MS).

The Physiological Requirements of and Nutritional Recommendations for Equestrian Riders

Equestrian sport is under-researched within the sport science literature, creating a possible knowledge vacuum for athletes and support personnel wishing to train and perform in an evidence-based manner. This review aims to synthesise available evidence from equitation, sport, and veterinary sciences to describe the pertinent rider physiology of equestrian disciplines. Estimates of energy expenditure and the contribution of underpinning energy systems to equestrian performance are used to provide nutrition and hydration recommendations for competition and training in equestrian disciplines. Relative energy deficiency and disordered eating are also considered. The practical challenges of the equestrian environment, including competitive, personal, and professional factors, injury and concussion, and female participation, are discussed to better highlight novelty within equestrian disciplines compared to more commonly studied sports. The evidence and recommendations are supported by example scenarios, and future research directions are outlined.