1.
Vitamin D Daily versus Monthly Administration: Bone Turnover and Adipose Tissue Influences.
Dalle Carbonare, L, Valenti, MT, Del Forno, F, Piacentini, G, Pietrobelli, A
Nutrients. 2018;(12)
Abstract
Vitamin D is involved in bone metabolism and in many various extra-skeletal diseases such as malabsorption syndromes, cardiovascular and metabolic diseases, cancer, and autoimmune and neurological diseases. However, data on the optimal route of administration are not consistent. The aims of our study were to analyze not only the influence of daily vs. monthly administration of vitamin D on bone metabolism and bone turnover, but also the effects of different routes of administration on fat mass in a cohort of adults with low levels of 25(OH) vitamin D3 at baseline. We analyzed 44 patients with hypovitaminosis at baseline and after six months of two different regimens of administration: seven drops (1750 IU)/day vs. 50,000 IU/month. We found that the two regimens were equivalent; 36 out of 44 patients reached the normal range of vitamin D after six months of treatment. Interestingly, the main determinant of vitamin D at baseline was the waist circumference. In addition, 22 patients treated by monthly regimen were evaluated after 18 months of treatment. At the end of follow-up, patients showed normal levels of vitamin D, with increased calcium levels and decreased bone turnover. Waist circumference also decreased. Our results support the efficacy of vitamin D3 given monthly both for correcting hypovitaminosis and for maintaining vitamin D levels. The relationship between serum 25(OH)vitamin D3 concentration and waist circumference supports vitamin D having a protective role in the current setting, since waist size is directly associated with the risk of cardiovascular and metabolic diseases.
2.
Prolyl carboxypeptidase activity in the circulation and its correlation with body weight and adipose tissue in lean and obese subjects.
Kehoe, K, Noels, H, Theelen, W, De Hert, E, Xu, S, Verrijken, A, Arnould, T, Fransen, E, Hermans, N, Lambeir, AM, et al
PloS one. 2018;(5):e0197603
Abstract
BACKGROUND Prolyl carboxypeptidase (PRCP) is involved in the regulation of body weight, likely by hydrolysing alpha-melanocyte-stimulating hormone and apelin in the hypothalamus and in the periphery. A link between PRCP protein concentrations in plasma and metabolic disorders has been reported. In this study, we investigated the distribution of circulating PRCP activity and assessed its relation with body weight and adipose tissue in obese patients and patients who significantly lost weight. METHODS PRCP activity was measured using reversed-phase high-performance liquid chromatography in different isolated blood fractions and primary human cells to investigate the distribution of circulating PRCP. PRCP activity was measured in serum of individuals (n = 75) categorized based on their body mass index (BMI < 25.0; 25.0-29.9; 30.0-39.9; ≥ 40.0 kg/m2) and the diagnosis of metabolic syndrome. Differences in serum PRCP activity were determined before and six months after weight loss, either by diet (n = 45) or by bariatric surgery (n = 24). Potential correlations between serum PRCP activity and several metabolic and biochemical parameters were assessed. Additionally, plasma PRCP concentrations were quantified using a sensitive ELISA in the bariatric surgery group. RESULTS White blood cells and plasma contributed the most to circulating PRCP activity. Serum PRCP activity in lean subjects was 0.83 ± 0.04 U/L and increased significantly with a rising BMI (p<0.001) and decreased upon weight loss (diet, p<0.05; bariatric surgery, p<0.001). The serum PRCP activity alteration reflected body weight changes and was found to be positively correlated with several metabolic parameters, including: total, abdominal and visceral adipose tissue. Plasma PRCP concentration was found to be significantly correlated to serum PRCP activity (0.865; p<0.001). Additionally, a significant decrease (p<0.001) in plasma PRCP protein concentration (mean ± SD) before (18.2 ± 3.7 ng/mL) and 6 months after bariatric surgery (15.7 ± 2.7 ng/mL) was found. CONCLUSION Our novel findings demonstrate that white blood cells and plasma contributed the most to circulating PRCP activity. Additionally, we have shown that there were significant correlations between serum PRCP activity and various metabolic parameters, and that plasma PRCP concentration was significantly correlated to serum PRCP activity. These novel findings on PRCP activity in serum support further investigation of its in vivo role and involvement in several metabolic diseases.
3.
Visceral fat as a determinant of fibrinolysis and hemostasis.
Mertens, I, Van Gaal, LF
Seminars in vascular medicine. 2005;(1):48-55
Abstract
An increased amount of deep abdominal visceral fat has generally been accepted as an important cardiovascular risk factor, and disturbances in hemostasis and fibrinolysis have been suggested to play a role. Fibrinogen and von Willebrand factor, representatives of the hemostatic system, and plasminogen activator inhibitor 1 (PAI-1), as the most important inhibitor of the fibrinolytic system, have been associated with visceral obesity, with the most convincing evidence found for the involvement of PAI-1. The association with fibrinogen and von Willebrand factor has been suggested to be merely a reflection of the association with inflammation and endothelial dysfunction. The fact that PAI-1 is secreted by adipose tissue has attracted much attention. The increase of PAI-1 in visceral obesity could be because visceral adipose tissue produces more PAI-1 compared with subcutaneous abdominal adipose tissue. The contribution of other cell types such as hepatocytes or endothelial cells is probably more important, with stimulation of PAI-1 production by different components of the metabolic syndrome. PAI-1 secretion by adipose tissue has been suggested to have a more local effect, playing a role in tissue remodeling during the development of obesity.